[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8,"_9":10},"actionData","errors","root",{"_154":155,"_156":157},"routes/_app.x.$handle.$name",{"_96":95,"_32":45,"_104":86,"_27":99,"_13":14,"_105":-5,"_11":106,"_107":108,"_109":110,"_111":112,"_113":114,"_20":-5,"_115":-5,"_116":-5,"_117":25,"_118":119,"_120":58,"_121":-5,"_122":-5,"_123":124},"routes/_app.x.$handle.$name.branch.$branch.version.$version.diff",{"_11":12,"_13":14,"_15":16,"_17":-5,"_18":-5},"project",{"_43":44,"_32":45,"_38":46,"_47":-5,"_48":25,"_49":50,"_51":50,"_52":53,"_54":-5,"_18":55,"_56":31,"_57":58,"_59":-5,"_60":-5,"_61":62,"_63":64,"_65":-5,"_66":-5,"_67":-5,"_68":-5,"_69":70,"_71":70,"_72":73,"_74":73,"_75":73,"_76":70,"_77":70,"_78":79,"_80":81,"_82":83,"_84":25},"version",31,"changes",[19],"aiChatInfo","userId",{"_20":21,"_22":23,"_24":25,"_26":25,"_27":28,"_29":28},"file",{"_30":31,"_32":28,"_33":34,"_35":37,"_38":39,"_40":14,"_41":42,"_24":25},"previous",{"_30":31,"_32":28,"_33":34,"_35":36},"deleted",false,"deletedHere","path","main.ts","latestPath","fileId","f41ee43c-3800-11f1-9187-42b51c65c3df","name","fileType","http","content","/**\n * Lyric Analysis API — Val.town HTTP handler\n * ==========================================\n * POST /parse-lyrics detect format and return structured lyric JSON\n * POST /rhyme-map phonetic rhyme analysis (+ optional HTML visualisation)\n * GET /health liveness check (no auth)\n *\n * Auth: X-API-Key header required on all non-health endpoints.\n * Set API_KEY in Val.town Environment (Settings → Environment Variables).\n *\n * Deploy: paste this file into a new Val.town HTTP val.\n */\n\nimport { dictionary as cmuDict } from \"npm:cmu-pronouncing-dictionary\";\nimport { blob } from \"https://esm.town/v/std/blob\";\n\n// ─── Auth ─────────────────────────────────────────────────────────────────────\n\nconst API_KEY = Deno.env.get(\"API_KEY\") ?? \"\";\n\nfunction checkAuth(req: Request): Response | null {\n if (!API_KEY) return json({ error: \"API_KEY not configured\" }, 500);\n const url = new URL(req.url);\n const key = req.headers.get(\"X-API-Key\") ?? url.searchParams.get(\"key\") ?? \"\";\n if (key !== API_KEY) {\n return json({ error: \"Invalid or missing API key\" }, 403);\n }\n return null;\n}\n\n// ─── Constants ────────────────────────────────────────────────────────────────\n\nconst VOWELS = new Set([\n \"AA\",\n \"AE\",\n \"AH\",\n \"AO\",\n \"AW\",\n \"AY\",\n \"EH\",\n \"ER\",\n \"EY\",\n \"IH\",\n \"IY\",\n \"OW\",\n \"OY\",\n \"UH\",\n \"UW\",\n]);\n\n// ─── Types ────────────────────────────────────────────────────────────────────\n\ninterface SyllableData {\n chars: [number, number]; // [start, end] char positions in the word\n vowel: string | null; // ARPAbet vowel nucleus (no stress digit)\n stress: 0 | 1 | 2; // 0 = unstressed, 1 = primary, 2 = secondary\n}\n\ninterface WordData {\n vowel: string | null; // primary stressed vowel (for rhyme grouping)\n tail: string[] | null;\n tail_type: string | null;\n span: [number, number] | null; // kept for compat; use syllables where possible\n syllables: SyllableData[] | null;\n}\n\ntype WordIndex = Record;\n\ninterface LyricEntry {\n type: \"section\" | \"line\" | \"blank\";\n text: string;\n}\n\ninterface SectionLine {\n text: string;\n end_word: string | null;\n rhyme_tail: string[] | null;\n rhyme_vowel: string | null;\n rhyme_type: string | null;\n rhyme_label: string;\n}\n\ninterface AnalysisSection {\n label: string | null;\n rhyme_scheme: string;\n lines: SectionLine[];\n}\n\ninterface RhymeGroup {\n tail: string[];\n vowel: string | null;\n rhyme_type: string;\n members: Array<{ word: string; section: string | null; line_index: number }>;\n}\n\n// ─── CMU Dict helpers ─────────────────────────────────────────────────────────\n\nconst _dict = cmuDict as Record;\n\nfunction getPhones(word: string): string[] | null {\n const w = word.toLowerCase();\n const candidates = [w];\n if (w.endsWith(\"'s\")) candidates.push(w.slice(0, -2));\n if (w.endsWith(\"s\")) candidates.push(w.slice(0, -1));\n if (w.endsWith(\"'\")) candidates.push(w.slice(0, -1));\n if (w.endsWith(\"in'\")) candidates.push(w.slice(0, -1) + \"g\");\n for (const c of candidates) {\n if (c in _dict) return _dict[c].split(\" \");\n }\n return null;\n}\n\nfunction primaryStressedVowel(phones: string[]): string | null {\n for (const p of phones) {\n if (p.endsWith(\"1\") && VOWELS.has(p.slice(0, -1))) return p.slice(0, -1);\n }\n for (const p of phones) {\n if (p.endsWith(\"2\") && VOWELS.has(p.slice(0, -1))) return p.slice(0, -1);\n }\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n if (VOWELS.has(base)) return base;\n }\n return null;\n}\n\nfunction rhymeTail(phones: string[]): string[] | null {\n const tail: string[] = [];\n let found = false;\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n const stress = /[012]$/.test(p) ? p[p.length - 1] : null;\n if (!found && VOWELS.has(base) && stress === \"1\") found = true;\n if (found) tail.push(base);\n }\n if (!found) {\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n if (!found && VOWELS.has(base)) found = true;\n if (found) tail.push(base);\n }\n }\n return tail.length > 0 ? tail : null;\n}\n\nfunction rhymeTypeFn(tail: string[] | null): string | null {\n if (!tail) return null;\n return tail.length > 1 ? \"perfect\" : \"slant\";\n}\n\nfunction tailKey(tail: string[] | null): string | null {\n return tail ? tail.join(\",\") : null;\n}\n\n// ─── Core analysis ────────────────────────────────────────────────────────────\n\nfunction analyseWord(word: string): WordData | null {\n const phones = getPhones(word);\n if (!phones) return null;\n const vowel = primaryStressedVowel(phones);\n const tail = rhymeTail(phones);\n return {\n vowel,\n tail,\n tail_type: rhymeTypeFn(tail),\n span: syllableSpanPosition(word, phones),\n syllables: syllableBreakdown(word, phones),\n };\n}\n\nfunction lineWords(text: string): string[] {\n return (text.match(/[A-Za-z']+/g) ?? []).map((w) =>\n w.toLowerCase().replace(/^'|'$/g, \"\")\n );\n}\n\nfunction buildWordIndex(parsed: LyricEntry[]): WordIndex {\n const index: WordIndex = {};\n for (const entry of parsed) {\n if (entry.type !== \"line\") continue;\n for (const w of lineWords(entry.text)) {\n if (w && !(w in index)) index[w] = analyseWord(w);\n }\n }\n return index;\n}\n\nfunction assignRhymeLabels(\n lines: LyricEntry[],\n wordIndex: WordIndex,\n): [string[], string] {\n const labelMap: Record = {};\n const labels: string[] = [];\n let code = 65; // \"A\"\n for (const line of lines) {\n const words = lineWords(line.text);\n const endWord = words.length > 0 ? words[words.length - 1] : null;\n const data = endWord ? wordIndex[endWord] : null;\n const tk = data?.tail ? tailKey(data.tail) : null;\n if (!tk) {\n labels.push(\"?\");\n } else {\n if (!(tk in labelMap)) labelMap[tk] = String.fromCharCode(code++);\n labels.push(labelMap[tk]);\n }\n }\n return [labels, labels.join(\"\")];\n}\n\nfunction buildSections(\n parsed: LyricEntry[],\n wordIndex: WordIndex,\n): AnalysisSection[] {\n const sections: AnalysisSection[] = [];\n let currentLabel: string | null = null;\n let currentLines: LyricEntry[] = [];\n\n function flush() {\n if (currentLines.length === 0) return;\n const [rhymeLabels, scheme] = assignRhymeLabels(currentLines, wordIndex);\n const linesOut: SectionLine[] = currentLines.map((line, i) => {\n const words = lineWords(line.text);\n const endWord = words.length > 0 ? words[words.length - 1] : null;\n const data = endWord ? wordIndex[endWord] : null;\n return {\n text: line.text,\n end_word: endWord,\n rhyme_tail: data?.tail ?? null,\n rhyme_vowel: data?.vowel ?? null,\n rhyme_type: data?.tail_type ?? null,\n rhyme_label: rhymeLabels[i],\n };\n });\n sections.push({\n label: currentLabel,\n rhyme_scheme: scheme,\n lines: linesOut,\n });\n currentLabel = null;\n currentLines = [];\n }\n\n for (const entry of parsed) {\n if (entry.type === \"section\") {\n flush();\n currentLabel = entry.text;\n } else if (entry.type === \"line\") currentLines.push(entry);\n // blank: don't flush — sections can contain blank lines between stanzas\n }\n flush();\n return sections;\n}\n\nfunction buildRhymeGroups(\n sections: AnalysisSection[],\n _wordIndex: WordIndex,\n): RhymeGroup[] {\n const tailMap: Record<\n string,\n Array<{ word: string; section: string | null; line_index: number }>\n > = {};\n for (const section of sections) {\n section.lines.forEach((line, i) => {\n if (line.rhyme_tail && line.end_word) {\n const tk = tailKey(line.rhyme_tail) ?? \"\";\n if (!tailMap[tk]) tailMap[tk] = [];\n tailMap[tk].push({\n word: line.end_word,\n section: section.label,\n line_index: i,\n });\n }\n });\n }\n const groups: RhymeGroup[] = [];\n for (const [tk, members] of Object.entries(tailMap)) {\n if (members.length < 2) continue;\n const tailList = tk.split(\",\");\n const vowel = tailList[0] && VOWELS.has(tailList[0]) ? tailList[0] : null;\n groups.push({\n tail: tailList,\n vowel,\n rhyme_type: tailList.length > 1 ? \"perfect\" : \"slant\",\n members,\n });\n }\n return groups.sort((a, b) => b.members.length - a.members.length);\n}\n\nfunction buildAnalysis(\n title: string,\n parsed: LyricEntry[],\n wordIndex: WordIndex,\n) {\n const unresolved = Object.entries(wordIndex)\n .filter(([, d]) => d === null).map(([w]) => w).sort();\n const sections = buildSections(parsed, wordIndex);\n const rhymeGroups = buildRhymeGroups(sections, wordIndex);\n const wordMap = Object.fromEntries(\n Object.entries(wordIndex).filter(([, d]) => d !== null),\n ) as Record;\n return {\n title,\n meta: {\n cmudict_version: \"0.7b\",\n dialect: \"North American English\",\n unresolved_words: unresolved,\n },\n sections,\n rhyme_groups: rhymeGroups,\n word_map: wordMap,\n };\n}\n\nfunction splitIntoSyllables(phones: string[]): [string[][], number] {\n const syllables: string[][] = [];\n let current: string[] = [];\n let stressedIdx = -1;\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n const stress = /[012]$/.test(p) ? p[p.length - 1] : null;\n if (VOWELS.has(base)) {\n current.push(p);\n if (stress === \"1\") stressedIdx = syllables.length;\n syllables.push(current);\n current = [];\n } else current.push(p);\n }\n if (current.length > 0 && syllables.length > 0) {\n syllables[syllables.length - 1].push(...current);\n } else if (current.length > 0) syllables.push(current);\n return [syllables, stressedIdx < 0 ? 0 : stressedIdx];\n}\n\nfunction syllableBreakdown(word: string, phones: string[]): SyllableData[] {\n const [syllables] = splitIntoSyllables(phones);\n const w = word.toLowerCase();\n\n const sylMeta = syllables.map((syl) => {\n const vowelPhone = syl.find((p) => VOWELS.has(p.replace(/[012]$/, \"\")));\n const vowel = vowelPhone ? vowelPhone.replace(/[012]$/, \"\") : null;\n const stress = (vowelPhone && /[012]$/.test(vowelPhone)\n ? Number(vowelPhone[vowelPhone.length - 1])\n : 0) as 0 | 1 | 2;\n return { vowel, stress };\n });\n\n if (syllables.length <= 1) {\n return [{\n chars: [0, word.length] as [number, number],\n ...(sylMeta[0] ?? { vowel: null, stress: 0 as const }),\n }];\n }\n\n // Find orthographic vowel runs to approximate syllable character boundaries\n const orthoVowels = \"aeiouy\";\n const vowelRuns: [number, number][] = [];\n let i = 0;\n while (i < w.length) {\n if (orthoVowels.includes(w[i])) {\n let j = i;\n while (j < w.length && orthoVowels.includes(w[j])) j++;\n vowelRuns.push([i, j]);\n i = j;\n } else i++;\n }\n\n // Onset-preference: put all consonants except the onset cluster with the\n // following syllable. Default: 1 character at onset (nextVStart - 1).\n // Exception: English onset digraphs (th, wh, ch, sh, ph) stay together —\n // if the last 2 chars before the next vowel run form a digraph, keep both.\n const ONSET_DIGRAPHS = new Set([\n \"th\",\n \"wh\",\n \"ch\",\n \"sh\",\n \"ph\",\n \"gh\",\n \"wr\",\n \"kn\",\n \"qu\",\n ]);\n const boundaries: number[] = [0];\n for (let si = 0; si < syllables.length - 1; si++) {\n if (si < vowelRuns.length - 1) {\n const vEnd = vowelRuns[si][1];\n const nextVStart = vowelRuns[si + 1][0];\n const clusterLen = nextVStart - vEnd;\n const useTwo = clusterLen >= 2 &&\n ONSET_DIGRAPHS.has(w.slice(nextVStart - 2, nextVStart));\n boundaries.push(Math.max(vEnd, nextVStart - (useTwo ? 2 : 1)));\n } else {\n boundaries.push(Math.round((si + 1) * w.length / syllables.length));\n }\n }\n boundaries.push(word.length);\n\n return sylMeta.map((meta, si) => ({\n chars: [boundaries[si], boundaries[si + 1]] as [number, number],\n ...meta,\n }));\n}\n\nfunction syllableSpanPosition(\n word: string,\n phones: string[],\n): [number, number] {\n const [syllables, stressedIdx] = splitIntoSyllables(phones);\n const w = word.toLowerCase();\n if (syllables.length <= 1) return [0, word.length];\n const orthoVowels = \"aeiouy\";\n const vowelRuns: [number, number][] = [];\n let i = 0;\n while (i < w.length) {\n if (orthoVowels.includes(w[i])) {\n let j = i;\n while (j < w.length && orthoVowels.includes(w[j])) j++;\n vowelRuns.push([i, j]);\n i = j;\n } else i++;\n }\n if (vowelRuns.length === 0 || stressedIdx >= vowelRuns.length) {\n return [0, w.length];\n }\n const [vStart, vEnd] = vowelRuns[stressedIdx];\n const sylStart = vStart;\n let sylEnd: number;\n if (stressedIdx + 1 < vowelRuns.length) {\n const nextVStart = vowelRuns[stressedIdx + 1][0];\n sylEnd = vEnd + Math.min(nextVStart - vEnd, 2);\n } else sylEnd = w.length;\n return [sylStart, sylEnd];\n}\n\n// ─── Rhyme map HTML template (injected server-side on format=html) ────────────\n\nconst RHYME_MAP_TEMPLATE = `\n\n\n\n\nRhyme Map\n\n\n\n\n

\n\n

\n Stress syllable\n

\n End-of-line only\n

\n Scheme labels\n

\n Compact legend\n

\n\n

\n\n\n\n`;\n\nfunction injectRhymeData(analysis: ReturnType): string {\n return RHYME_MAP_TEMPLATE.replace(\n \"const RHYME_DATA = null; // <<>>\",\n `const RHYME_DATA = ${JSON.stringify({ analysis })};`,\n );\n}\n\n// ─── Parse lyrics ─────────────────────────────────────────────────────────────\n\nconst _CHORD_PAT =\n \"[A-G][b#]?(?:maj|min|m|dim|aug|sus|add)?(?:\\\\d+)?(?:/[A-G][b#]?)?\";\nconst INLINE_CHORD_RE = new RegExp(`\\\\[(${_CHORD_PAT})\\\\]`, \"g\");\nconst CHORD_LINE_RE = new RegExp(\n `^\\\\s*(${_CHORD_PAT})(\\\\s+(${_CHORD_PAT}))*\\\\s*$`,\n);\nconst SECTION_BRACKET_RE = /^\\[([^\\]]{2,})\\]$/;\n\nfunction detectFormat(raw: string): string {\n const lines = raw.trim().split(\"\\n\").filter((l) => l.trim());\n if (lines.some((l) => /^\\{[a-z_]+/.test(l.trim()))) return \"chordpro\";\n const bracketLines = lines.map((l) => l.trim()).filter((l) =>\n l.startsWith(\"[\")\n );\n const sectionBrackets = bracketLines.filter((l) =>\n !new RegExp(`^\\\\[(${_CHORD_PAT})\\\\]$`).test(l)\n );\n if (sectionBrackets.length > 0) return \"bracketed\";\n const allcaps = lines.filter((l) => /^[A-Z][A-Z\\s\\-\\d]{2,}$/.test(l.trim()));\n if (allcaps.length > 0) return \"allcaps\";\n const chordLines = lines.filter((l) => CHORD_LINE_RE.test(l));\n if (chordLines.length >= 2) return \"ultimate_guitar\";\n return \"plain\";\n}\n\nfunction extractMetadata(\n lines: string[],\n): [Record, string[], string | null] {\n const metadata: Record = {};\n let title: string | null = null;\n let i = 0;\n while (i < lines.length) {\n const m = lines[i].trim().match(/^([A-Za-z][A-Za-z /]*?):\\s*(.+)/);\n if (m) {\n const key = m[1].trim().toLowerCase();\n const value = m[2].trim();\n if (key === \"title\") title = value;\n else metadata[key] = value;\n i++;\n } else break;\n }\n return [metadata, lines.slice(i), title];\n}\n\nfunction inferTitle(\n lines: string[],\n parseNotes: string[],\n): [string | null, string[]] {\n if (lines.length === 0) return [null, lines];\n const first = lines[0].trim();\n const words = first.split(/\\s+/);\n if (\n first && words.length >= 1 && words.length <= 8 &&\n first[0] === first[0].toUpperCase() &&\n !first.startsWith(\"[\") &&\n !/^[A-Z][A-Z\\s\\-]{2,}$/.test(first) &&\n !first.endsWith(\",\")\n ) {\n parseNotes.push(`Title inferred from first line: \"${first}\"`);\n return [first, lines.slice(1)];\n }\n return [null, lines];\n}\n\nfunction stripInlineChords(line: string): string {\n return line.replace(INLINE_CHORD_RE, \"\").trim();\n}\n\nfunction stanzaHint(\n lines: string[],\n priorSections: Array<{ label?: string }>,\n): string {\n const count = lines.length;\n const hasChorus = priorSections.some((s) =>\n (s.label ?? \"\").toLowerCase().includes(\"chorus\")\n );\n if (count <= 2) return \"possible_outro_or_hook\";\n if (count === 4) {\n return hasChorus\n ? \"possible_verse\"\n : \"possible_verse_or_chorus\";\n }\n if (count >= 6) return \"possible_verse\";\n return \"unknown\";\n}\n\nfunction makeResult(\n title: string | null,\n fmt: string,\n metadata: Record,\n sections: object[],\n unparsedBlocks: object[],\n parseNotes: string[],\n) {\n return {\n title,\n format_detected: fmt,\n metadata,\n sections,\n unparsed_blocks: unparsedBlocks,\n requires_llm: unparsedBlocks.length > 0,\n parse_notes: parseNotes,\n };\n}\n\nfunction parseChordpro(raw: string) {\n const lines = raw.trim().split(\"\\n\");\n let title: string | null = null;\n const metadata: Record = {};\n const sections: object[] = [];\n const parseNotes: string[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n let inSection = false;\n let verseN = 0, chorusN = 0, partN = 0;\n\n const SECTION_START: Record = {\n start_of_verse: \"Verse\",\n start_of_chorus: \"Chorus\",\n start_of_bridge: \"Bridge\",\n start_of_part: \"Part\",\n };\n const SKIP_START = new Set([\"start_of_tab\", \"start_of_grid\"]);\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l);\n if (lyricLines.length > 0 && currentLabel !== null) {\n sections.push({\n label: `[${currentLabel}]`,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else if (lyricLines.length > 0) {\n sections.push({\n label: \"[Unlabelled]\",\n confidence: \"low\",\n alternatives: [\"[Verse]\", \"[Chorus]\"],\n reason: \"Lyric lines appeared outside a {start_of_*} directive.\",\n lines: lyricLines,\n });\n }\n currentLabel = null;\n currentLines = [];\n inSection = false;\n }\n\n for (const rawLine of lines) {\n const stripped = rawLine.trim();\n const d = stripped.match(/^\\{([a-z_]+)(?::\\s*(.*?))?\\}$/);\n if (d) {\n const directive = d[1], value = (d[2] ?? \"\").trim();\n if (directive === \"title\") title = value;\n else if (\n [\n \"artist\",\n \"composer\",\n \"lyricist\",\n \"album\",\n \"year\",\n \"key\",\n \"tempo\",\n \"time\",\n \"copyright\",\n \"capo\",\n \"meta\",\n ].includes(directive)\n ) {\n metadata[directive] = value;\n } else if (directive in SECTION_START) {\n flush();\n const kind = SECTION_START[directive];\n if (value) currentLabel = value;\n else if (kind === \"Verse\") {\n verseN++;\n currentLabel = `Verse ${verseN}`;\n } else if (kind === \"Chorus\") {\n chorusN++;\n currentLabel = chorusN === 1 ? \"Chorus\" : `Chorus ${chorusN}`;\n } else if (kind === \"Bridge\") currentLabel = \"Bridge\";\n else {\n partN++;\n currentLabel = `Part ${partN}`;\n }\n inSection = true;\n } else if (SKIP_START.has(directive)) {\n flush();\n inSection = false;\n } else if (directive.startsWith(\"end_of_\")) { /* flush on next start */ }\n else if (directive === \"comment\") {\n parseNotes.push(`Source comment: \"${value}\"`);\n }\n continue;\n }\n const clean = stripInlineChords(stripped);\n if (inSection && clean) currentLines.push(clean);\n else if (clean && !stripped.startsWith(\"#\")) currentLines.push(clean);\n }\n flush();\n if (!title) parseNotes.push(\"No {title} directive found — title unknown.\");\n return makeResult(title, \"chordpro\", metadata, sections, [], parseNotes);\n}\n\nfunction parseBracketed(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const sections: object[] = [];\n const unparsedBlocks: object[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l.trim());\n if (lyricLines.length === 0) {\n currentLabel = null;\n currentLines = [];\n return;\n }\n if (currentLabel !== null) {\n sections.push({\n label: currentLabel,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else {\n unparsedBlocks.push({\n raw: lyricLines.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(lyricLines, sections as Array<{ label?: string }>),\n });\n }\n currentLabel = null;\n currentLines = [];\n }\n\n for (const line of lines) {\n const stripped = line.trim();\n if (!stripped) flush();\n else if (\n SECTION_BRACKET_RE.test(stripped) &&\n !new RegExp(`^\\\\[(${_CHORD_PAT})\\\\]$`).test(stripped)\n ) {\n flush();\n currentLabel = stripped;\n } else currentLines.push(stripped);\n }\n flush();\n\n if (unparsedBlocks.length > 0) {\n parseNotes.push(\n `${unparsedBlocks.length} block(s) have no section header — LLM labelling needed.`,\n );\n }\n return makeResult(\n title,\n \"bracketed\",\n metadata,\n sections,\n unparsedBlocks,\n parseNotes,\n );\n}\n\nfunction parseAllcaps(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const sections: object[] = [];\n const unparsedBlocks: object[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l.trim());\n if (lyricLines.length === 0) {\n currentLabel = null;\n currentLines = [];\n return;\n }\n if (currentLabel !== null) {\n const label = currentLabel.charAt(0) +\n currentLabel.slice(1).toLowerCase();\n sections.push({\n label: `[${label}]`,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else {\n unparsedBlocks.push({\n raw: lyricLines.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(lyricLines, sections as Array<{ label?: string }>),\n });\n }\n currentLabel = null;\n currentLines = [];\n }\n\n for (const line of lines) {\n const stripped = line.trim();\n if (!stripped) flush();\n else if (/^[A-Z][A-Z\\s\\-\\d]{2,}$/.test(stripped)) {\n flush();\n currentLabel = stripped;\n } else currentLines.push(stripped);\n }\n flush();\n\n if (unparsedBlocks.length > 0) {\n parseNotes.push(\n `${unparsedBlocks.length} block(s) have no section header — LLM labelling needed.`,\n );\n }\n return makeResult(\n title,\n \"allcaps\",\n metadata,\n sections,\n unparsedBlocks,\n parseNotes,\n );\n}\n\nfunction parsePlain(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const stanzas: string[][] = [];\n let current: string[] = [];\n for (const line of lines) {\n if (line.trim()) current.push(line.trim());\n else if (current.length > 0) {\n stanzas.push(current);\n current = [];\n }\n }\n if (current.length > 0) stanzas.push(current);\n\n const unparsedBlocks = stanzas.map((stanza, i) => ({\n raw: stanza.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(stanza, []),\n stanza_index: i,\n }));\n parseNotes.push(\n `No section headers detected. ${stanzas.length} stanza(s) require LLM labelling.`,\n );\n return makeResult(title, \"plain\", metadata, [], unparsedBlocks, parseNotes);\n}\n\nfunction parseUltimateGuitar(raw: string) {\n const lines = raw.trim().split(\"\\n\");\n const lyricLines = lines.filter((l) => !CHORD_LINE_RE.test(l));\n const cleaned = lyricLines.join(\"\\n\");\n const fmt = detectFormat(cleaned);\n const result = fmt === \"bracketed\"\n ? parseBracketed(cleaned)\n : fmt === \"allcaps\"\n ? parseAllcaps(cleaned)\n : parsePlain(cleaned);\n result.format_detected = \"ultimate_guitar\";\n (result.parse_notes as string[]).unshift(\n \"Chord-above-lines stripped before section detection.\",\n );\n return result;\n}\n\nfunction parseLyrics(raw: string) {\n const fmt = detectFormat(raw);\n return fmt === \"chordpro\"\n ? parseChordpro(raw)\n : fmt === \"bracketed\"\n ? parseBracketed(raw)\n : fmt === \"allcaps\"\n ? parseAllcaps(raw)\n : fmt === \"ultimate_guitar\"\n ? parseUltimateGuitar(raw)\n : parsePlain(raw);\n}\n\n// Convert parse result sections → flat LyricEntry list for rhyme analysis\nfunction toFlatEntries(\n parseResult: ReturnType,\n): LyricEntry[] {\n const entries: LyricEntry[] = [];\n for (\n const section of parseResult.sections as Array<\n { label: string; lines: string[] }\n >\n ) {\n entries.push({ type: \"section\", text: section.label });\n for (const line of section.lines) {\n entries.push({ type: \"line\", text: line });\n }\n }\n // Include unparsed block lines so rhyme analysis still runs on them\n for (\n const block of (parseResult.unparsed_blocks as Array<{ raw: string }>) ?? []\n ) {\n for (const line of block.raw.split(\"\\n\")) {\n if (line.trim()) entries.push({ type: \"line\", text: line.trim() });\n }\n }\n return entries;\n}\n\n// ─── OAuth + MCP ──────────────────────────────────────────────────────────────\n\nconst CODE_TTL_MS = 5 * 60 * 1000; // 5 minutes\n\nconst MCP_TOOLS = [\n {\n name: \"parse_lyrics\",\n description:\n \"Detect the format of raw lyric text and return structured JSON with sections and lines. Supports ChordPro, bracketed, ALLCAPS, Ultimate Guitar, and plain formats.\",\n inputSchema: {\n type: \"object\",\n properties: {\n lyrics: { type: \"string\", description: \"Raw lyric text\" },\n },\n required: [\"lyrics\"],\n },\n },\n {\n name: \"rhyme_map\",\n description:\n \"Phonetic rhyme analysis using the CMU Pronouncing Dictionary. Returns rhyme schemes, cross-song rhyme groups, per-line end-word analysis, and a word_map with per-syllable vowel and stress data for every word. The response includes an html field containing a complete interactive HTML page. Create an HTML artifact from it — copy the html field content verbatim as a rendered artifact. Do not modify or regenerate the HTML.\",\n inputSchema: {\n type: \"object\",\n properties: {\n lyrics: { type: \"string\", description: \"Raw lyric text\" },\n html: {\n type: \"boolean\",\n description: \"Include interactive HTML visualisation (default true)\",\n },\n },\n required: [\"lyrics\"],\n },\n },\n];\n\nasync function sha256Base64url(input: string): Promise {\n const data = new TextEncoder().encode(input);\n const digest = await crypto.subtle.digest(\"SHA-256\", data);\n return btoa(String.fromCharCode(...new Uint8Array(digest)))\n .replace(/\\+/g, \"-\").replace(/\\//g, \"_\").replace(/=/g, \"\");\n}\n\nfunction checkBearerAuth(req: Request, baseUrl: string): Response | null {\n if (!API_KEY) return json({ error: \"API_KEY not configured\" }, 500);\n const auth = req.headers.get(\"Authorization\") ?? \"\";\n if (!auth.startsWith(\"Bearer \") || auth.slice(7) !== API_KEY) {\n return new Response(JSON.stringify({ error: \"Unauthorized\" }), {\n status: 401,\n headers: {\n \"Content-Type\": \"application/json\",\n \"WWW-Authenticate\":\n `Bearer resource_metadata=\"${baseUrl}/.well-known/oauth-protected-resource\"`,\n \"Access-Control-Allow-Origin\": \"*\",\n },\n });\n }\n return null;\n}\n\nfunction oauthMeta(baseUrl: string) {\n return {\n issuer: baseUrl,\n authorization_endpoint: `${baseUrl}/oauth/authorize`,\n token_endpoint: `${baseUrl}/oauth/token`,\n registration_endpoint: `${baseUrl}/oauth/register`,\n code_challenge_methods_supported: [\"S256\"],\n grant_types_supported: [\"authorization_code\"],\n response_types_supported: [\"code\"],\n token_endpoint_auth_methods_supported: [\"none\"],\n scopes_supported: [\"mcp\"],\n };\n}\n\nasync function handleRegister(req: Request): Promise {\n let body: Record = {};\n try {\n body = await req.json();\n } catch { /* ignore — body is optional */ }\n const redirectUris = (body.redirect_uris as string[]) ?? [];\n return new Response(\n JSON.stringify({\n client_id: crypto.randomUUID(),\n client_id_issued_at: Math.floor(Date.now() / 1000),\n redirect_uris: redirectUris,\n grant_types: [\"authorization_code\"],\n response_types: [\"code\"],\n token_endpoint_auth_method: \"none\",\n }),\n {\n status: 201,\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n },\n },\n );\n}\n\nfunction resourceMeta(baseUrl: string) {\n return {\n resource: `${baseUrl}/mcp`,\n authorization_servers: [baseUrl],\n };\n}\n\nasync function handleAuthorize(req: Request, url: URL): Promise {\n if (req.method === \"GET\") {\n const challenge = url.searchParams.get(\"code_challenge\") ?? \"\";\n const redirectUri = url.searchParams.get(\"redirect_uri\") ?? \"\";\n const state = url.searchParams.get(\"state\") ?? \"\";\n const clientId = url.searchParams.get(\"client_id\") ?? \"\";\n const esc = (s: string) => s.replace(/&/g, \"&\").replace(/\"/g, \""\");\n return new Response(\n `\n\n\nLyric Analysis — Authorize\n\n

Lyric Analysis

Claude is requesting access to the phonetic rhyme analysis tools.

\n \n

`,\n { headers: { \"Content-Type\": \"text/html\" } },\n );\n }\n\n if (req.method === \"POST\") {\n const form = new URLSearchParams(await req.text());\n const challenge = form.get(\"code_challenge\") ?? \"\";\n const redirectUri = form.get(\"redirect_uri\") ?? \"\";\n const state = form.get(\"state\") ?? \"\";\n if (!challenge || !redirectUri) {\n return new Response(\"Missing parameters\", { status: 400 });\n }\n const code = crypto.randomUUID();\n await blob.setJSON(`oauth_code_${code}`, {\n challenge,\n expires: Date.now() + CODE_TTL_MS,\n });\n const dest = new URL(redirectUri);\n dest.searchParams.set(\"code\", code);\n if (state) dest.searchParams.set(\"state\", state);\n return Response.redirect(dest.toString(), 302);\n }\n\n return new Response(\"Method not allowed\", { status: 405 });\n}\n\nasync function handleToken(req: Request): Promise {\n const form = new URLSearchParams(await req.text());\n const grantType = form.get(\"grant_type\");\n const code = form.get(\"code\") ?? \"\";\n const verifier = form.get(\"code_verifier\") ?? \"\";\n\n if (grantType !== \"authorization_code\") {\n return Response.json({ error: \"unsupported_grant_type\" }, { status: 400 });\n }\n if (!code || !verifier) {\n return Response.json({\n error: \"invalid_request\",\n error_description: \"code and code_verifier required\",\n }, { status: 400 });\n }\n\n const stored = await blob.getJSON(`oauth_code_${code}`) as {\n challenge: string;\n expires: number;\n } | null;\n if (!stored) {\n return Response.json({\n error: \"invalid_grant\",\n error_description: \"Unknown or expired code\",\n }, { status: 400 });\n }\n if (Date.now() > stored.expires) {\n await blob.delete(`oauth_code_${code}`);\n return Response.json({\n error: \"invalid_grant\",\n error_description: \"Code expired\",\n }, { status: 400 });\n }\n\n const computed = await sha256Base64url(verifier);\n if (computed !== stored.challenge) {\n return Response.json({\n error: \"invalid_grant\",\n error_description: \"PKCE verification failed\",\n }, { status: 400 });\n }\n\n await blob.delete(`oauth_code_${code}`);\n return Response.json({\n access_token: API_KEY,\n token_type: \"Bearer\",\n expires_in: 86400,\n });\n}\n\nfunction mcpResponse(id: unknown, result: unknown): Response {\n return new Response(JSON.stringify({ jsonrpc: \"2.0\", id, result }), {\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n },\n });\n}\n\nfunction mcpError(id: unknown, code: number, message: string): Response {\n return new Response(\n JSON.stringify({ jsonrpc: \"2.0\", id, error: { code, message } }),\n {\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n },\n },\n );\n}\n\nfunction handleMcp(body: Record, _baseUrl: string): Response {\n const method = body.method as string;\n const id = body.id ?? null;\n const params = (body.params ?? {}) as Record;\n\n if (method?.startsWith(\"notifications/\")) {\n return new Response(null, { status: 202 });\n }\n\n if (method === \"initialize\") {\n return mcpResponse(id, {\n protocolVersion: \"2024-11-05\",\n capabilities: { tools: {} },\n serverInfo: { name: \"lyric-analysis\", version: \"1.0\" },\n });\n }\n\n if (method === \"tools/list\") return mcpResponse(id, { tools: MCP_TOOLS });\n\n if (method === \"tools/call\") {\n const name = params.name as string;\n const args = (params.arguments ?? {}) as Record;\n const lyrics = args.lyrics as string;\n if (!lyrics) return mcpError(id, -32602, \"lyrics argument required\");\n\n if (name === \"parse_lyrics\") {\n return mcpResponse(id, {\n content: [{ type: \"text\", text: JSON.stringify(parseLyrics(lyrics)) }],\n });\n }\n\n if (name === \"rhyme_map\") {\n const parseResult = parseLyrics(lyrics);\n const title = parseResult.title ?? \"Untitled\";\n const parsed = toFlatEntries(parseResult);\n const wordIndex = buildWordIndex(parsed);\n const analysis = buildAnalysis(title, parsed, wordIndex);\n const html = injectRhymeData(analysis);\n return mcpResponse(id, {\n content: [{ type: \"text\", text: JSON.stringify({ analysis, html }) }],\n });\n }\n\n return mcpError(id, -32601, `Unknown tool: ${name}`);\n }\n\n return mcpError(id, -32601, `Method not found: ${method}`);\n}\n\n// ─── HTTP handler ─────────────────────────────────────────────────────────────\n\nfunction json(body: unknown, status = 200): Response {\n return new Response(JSON.stringify(body), {\n status,\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n \"Access-Control-Allow-Headers\": \"Content-Type, X-API-Key\",\n \"Access-Control-Allow-Methods\": \"GET, POST, OPTIONS\",\n },\n });\n}\n\nexport default async function handler(req: Request): Promise {\n const url = new URL(req.url);\n const baseUrl = `${url.protocol}//${url.host}`;\n\n // CORS preflight\n if (req.method === \"OPTIONS\") {\n return new Response(null, {\n status: 204,\n headers: {\n \"Access-Control-Allow-Origin\": \"*\",\n \"Access-Control-Allow-Headers\":\n \"Content-Type, X-API-Key, Authorization\",\n \"Access-Control-Allow-Methods\": \"GET, POST, OPTIONS\",\n },\n });\n }\n\n // Health / root (no auth)\n if (\n req.method === \"GET\" && (url.pathname === \"/health\" || url.pathname === \"/\")\n ) {\n return json({\n status: \"ok\",\n name: \"lyric-analysis-api\",\n mcp: `${baseUrl}/mcp`,\n });\n }\n\n // OAuth metadata (no auth)\n if (url.pathname === \"/.well-known/oauth-authorization-server\") {\n return json(oauthMeta(baseUrl));\n }\n if (url.pathname === \"/.well-known/oauth-protected-resource\") {\n return json(resourceMeta(baseUrl));\n }\n\n // OAuth endpoints\n if (url.pathname === \"/oauth/authorize\") return handleAuthorize(req, url);\n if (req.method === \"POST\" && url.pathname === \"/oauth/token\") {\n return handleToken(req);\n }\n if (req.method === \"POST\" && url.pathname === \"/oauth/register\") {\n return handleRegister(req);\n }\n\n // MCP endpoint (Bearer auth)\n if (url.pathname === \"/mcp\") {\n const bearerError = checkBearerAuth(req, baseUrl);\n if (bearerError) return bearerError;\n if (req.method !== \"POST\") {\n return new Response(JSON.stringify({ error: \"Method not allowed\" }), {\n status: 405,\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n },\n });\n }\n let mcpBody: Record;\n try {\n mcpBody = await req.json();\n } catch {\n return json({ error: \"Invalid JSON\" }, 400);\n }\n return handleMcp(mcpBody, baseUrl);\n }\n\n // All other routes require auth\n const authError = checkAuth(req);\n if (authError) return authError;\n\n // GET /parse-lyrics?lyrics=\n if (req.method === \"GET\" && url.pathname === \"/parse-lyrics\") {\n const lyrics = url.searchParams.get(\"lyrics\");\n if (!lyrics) return json({ error: \"lyrics query param required\" }, 400);\n return json(parseLyrics(lyrics));\n }\n\n // GET /rhyme-map?lyrics=[&format=html]\n if (req.method === \"GET\" && url.pathname === \"/rhyme-map\") {\n const lyrics = url.searchParams.get(\"lyrics\");\n if (!lyrics) return json({ error: \"lyrics query param required\" }, 400);\n\n const parseResult = parseLyrics(lyrics);\n const title = parseResult.title ?? \"Untitled\";\n const parsed = toFlatEntries(parseResult);\n const wordIndex = buildWordIndex(parsed);\n const analysis = buildAnalysis(title, parsed, wordIndex);\n\n if (url.searchParams.get(\"format\") === \"html\") {\n const slug = title.toLowerCase().replace(/[^a-z0-9]+/g, \"-\").replace(\n /^-|-$/g,\n \"\",\n );\n return new Response(injectRhymeData(analysis), {\n headers: {\n \"Content-Type\": \"text/html; charset=utf-8\",\n \"Content-Disposition\":\n `attachment; filename=\"${slug}-rhyme-map.html\"`,\n \"Access-Control-Allow-Origin\": \"*\",\n },\n });\n }\n\n return json({ analysis });\n }\n\n if (req.method !== \"POST\") return json({ error: \"Method not allowed\" }, 405);\n\n let body: Record;\n try {\n body = await req.json();\n } catch {\n return json({ error: \"Invalid JSON body\" }, 400);\n }\n\n // POST /parse-lyrics\n if (url.pathname === \"/parse-lyrics\") {\n const lyrics = body.lyrics as string;\n if (!lyrics) return json({ error: \"lyrics field required\" }, 400);\n return json(parseLyrics(lyrics));\n }\n\n // POST /rhyme-map\n if (url.pathname === \"/rhyme-map\") {\n const lyrics = body.lyrics as string;\n if (!lyrics) return json({ error: \"lyrics field required\" }, 400);\n\n const parseResult = parseLyrics(lyrics);\n let title = (body.title as string) ?? null;\n if (!title) title = parseResult.title ?? \"Untitled\";\n\n const parsed = toFlatEntries(parseResult);\n const wordIndex = buildWordIndex(parsed);\n const analysis = buildAnalysis(title, parsed, wordIndex);\n\n return json({ analysis });\n }\n\n return json({ error: \"Not found\" }, 404);\n}","/**\n * Lyric Analysis API — Val.town HTTP handler\n * ==========================================\n * POST /parse-lyrics detect format and return structured lyric JSON\n * POST /rhyme-map phonetic rhyme analysis (+ optional HTML visualisation)\n * GET /health liveness check (no auth)\n *\n * Auth: X-API-Key header required on all non-health endpoints.\n * Set API_KEY in Val.town Environment (Settings → Environment Variables).\n *\n * Deploy: paste this file into a new Val.town HTTP val.\n */\n\nimport { dictionary as cmuDict } from \"npm:cmu-pronouncing-dictionary\";\nimport { blob } from \"https://esm.town/v/std/blob\";\n\n// ─── Auth ─────────────────────────────────────────────────────────────────────\n\nconst API_KEY = Deno.env.get(\"API_KEY\") ?? \"\";\n\nfunction checkAuth(req: Request): Response | null {\n if (!API_KEY) return json({ error: \"API_KEY not configured\" }, 500);\n const url = new URL(req.url);\n const key = req.headers.get(\"X-API-Key\") ?? url.searchParams.get(\"key\") ?? \"\";\n if (key !== API_KEY) {\n return json({ error: \"Invalid or missing API key\" }, 403);\n }\n return null;\n}\n\n// ─── Constants ────────────────────────────────────────────────────────────────\n\nconst VOWELS = new Set([\n \"AA\",\n \"AE\",\n \"AH\",\n \"AO\",\n \"AW\",\n \"AY\",\n \"EH\",\n \"ER\",\n \"EY\",\n \"IH\",\n \"IY\",\n \"OW\",\n \"OY\",\n \"UH\",\n \"UW\",\n]);\n\n// ─── Types ────────────────────────────────────────────────────────────────────\n\ninterface SyllableData {\n chars: [number, number]; // [start, end] char positions in the word\n vowel: string | null; // ARPAbet vowel nucleus (no stress digit)\n stress: 0 | 1 | 2; // 0 = unstressed, 1 = primary, 2 = secondary\n}\n\ninterface WordData {\n vowel: string | null; // primary stressed vowel (for rhyme grouping)\n tail: string[] | null;\n tail_type: string | null;\n span: [number, number] | null; // kept for compat; use syllables where possible\n syllables: SyllableData[] | null;\n}\n\ntype WordIndex = Record;\n\ninterface LyricEntry {\n type: \"section\" | \"line\" | \"blank\";\n text: string;\n}\n\ninterface SectionLine {\n text: string;\n end_word: string | null;\n rhyme_tail: string[] | null;\n rhyme_vowel: string | null;\n rhyme_type: string | null;\n rhyme_label: string;\n}\n\ninterface AnalysisSection {\n label: string | null;\n rhyme_scheme: string;\n lines: SectionLine[];\n}\n\ninterface RhymeGroup {\n tail: string[];\n vowel: string | null;\n rhyme_type: string;\n members: Array<{ word: string; section: string | null; line_index: number }>;\n}\n\n// ─── CMU Dict helpers ─────────────────────────────────────────────────────────\n\nconst _dict = cmuDict as Record;\n\nfunction getPhones(word: string): string[] | null {\n const w = word.toLowerCase();\n const candidates = [w];\n if (w.endsWith(\"'s\")) candidates.push(w.slice(0, -2));\n if (w.endsWith(\"s\")) candidates.push(w.slice(0, -1));\n if (w.endsWith(\"'\")) candidates.push(w.slice(0, -1));\n if (w.endsWith(\"in'\")) candidates.push(w.slice(0, -1) + \"g\");\n for (const c of candidates) {\n if (c in _dict) return _dict[c].split(\" \");\n }\n return null;\n}\n\nfunction primaryStressedVowel(phones: string[]): string | null {\n for (const p of phones) {\n if (p.endsWith(\"1\") && VOWELS.has(p.slice(0, -1))) return p.slice(0, -1);\n }\n for (const p of phones) {\n if (p.endsWith(\"2\") && VOWELS.has(p.slice(0, -1))) return p.slice(0, -1);\n }\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n if (VOWELS.has(base)) return base;\n }\n return null;\n}\n\nfunction rhymeTail(phones: string[]): string[] | null {\n const tail: string[] = [];\n let found = false;\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n const stress = /[012]$/.test(p) ? p[p.length - 1] : null;\n if (!found && VOWELS.has(base) && stress === \"1\") found = true;\n if (found) tail.push(base);\n }\n if (!found) {\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n if (!found && VOWELS.has(base)) found = true;\n if (found) tail.push(base);\n }\n }\n return tail.length > 0 ? tail : null;\n}\n\nfunction rhymeTypeFn(tail: string[] | null): string | null {\n if (!tail) return null;\n return tail.length > 1 ? \"perfect\" : \"slant\";\n}\n\nfunction tailKey(tail: string[] | null): string | null {\n return tail ? tail.join(\",\") : null;\n}\n\n// ─── Core analysis ────────────────────────────────────────────────────────────\n\nfunction analyseWord(word: string): WordData | null {\n const phones = getPhones(word);\n if (!phones) return null;\n const vowel = primaryStressedVowel(phones);\n const tail = rhymeTail(phones);\n return {\n vowel,\n tail,\n tail_type: rhymeTypeFn(tail),\n span: syllableSpanPosition(word, phones),\n syllables: syllableBreakdown(word, phones),\n };\n}\n\nfunction lineWords(text: string): string[] {\n return (text.match(/[A-Za-z']+/g) ?? []).map((w) =>\n w.toLowerCase().replace(/^'|'$/g, \"\")\n );\n}\n\nfunction buildWordIndex(parsed: LyricEntry[]): WordIndex {\n const index: WordIndex = {};\n for (const entry of parsed) {\n if (entry.type !== \"line\") continue;\n for (const w of lineWords(entry.text)) {\n if (w && !(w in index)) index[w] = analyseWord(w);\n }\n }\n return index;\n}\n\nfunction assignRhymeLabels(\n lines: LyricEntry[],\n wordIndex: WordIndex,\n): [string[], string] {\n const labelMap: Record = {};\n const labels: string[] = [];\n let code = 65; // \"A\"\n for (const line of lines) {\n const words = lineWords(line.text);\n const endWord = words.length > 0 ? words[words.length - 1] : null;\n const data = endWord ? wordIndex[endWord] : null;\n const tk = data?.tail ? tailKey(data.tail) : null;\n if (!tk) {\n labels.push(\"?\");\n } else {\n if (!(tk in labelMap)) labelMap[tk] = String.fromCharCode(code++);\n labels.push(labelMap[tk]);\n }\n }\n return [labels, labels.join(\"\")];\n}\n\nfunction buildSections(\n parsed: LyricEntry[],\n wordIndex: WordIndex,\n): AnalysisSection[] {\n const sections: AnalysisSection[] = [];\n let currentLabel: string | null = null;\n let currentLines: LyricEntry[] = [];\n\n function flush() {\n if (currentLines.length === 0) return;\n const [rhymeLabels, scheme] = assignRhymeLabels(currentLines, wordIndex);\n const linesOut: SectionLine[] = currentLines.map((line, i) => {\n const words = lineWords(line.text);\n const endWord = words.length > 0 ? words[words.length - 1] : null;\n const data = endWord ? wordIndex[endWord] : null;\n return {\n text: line.text,\n end_word: endWord,\n rhyme_tail: data?.tail ?? null,\n rhyme_vowel: data?.vowel ?? null,\n rhyme_type: data?.tail_type ?? null,\n rhyme_label: rhymeLabels[i],\n };\n });\n sections.push({\n label: currentLabel,\n rhyme_scheme: scheme,\n lines: linesOut,\n });\n currentLabel = null;\n currentLines = [];\n }\n\n for (const entry of parsed) {\n if (entry.type === \"section\") {\n flush();\n currentLabel = entry.text;\n } else if (entry.type === \"line\") currentLines.push(entry);\n // blank: don't flush — sections can contain blank lines between stanzas\n }\n flush();\n return sections;\n}\n\nfunction buildRhymeGroups(\n sections: AnalysisSection[],\n _wordIndex: WordIndex,\n): RhymeGroup[] {\n const tailMap: Record<\n string,\n Array<{ word: string; section: string | null; line_index: number }>\n > = {};\n for (const section of sections) {\n section.lines.forEach((line, i) => {\n if (line.rhyme_tail && line.end_word) {\n const tk = tailKey(line.rhyme_tail) ?? \"\";\n if (!tailMap[tk]) tailMap[tk] = [];\n tailMap[tk].push({\n word: line.end_word,\n section: section.label,\n line_index: i,\n });\n }\n });\n }\n const groups: RhymeGroup[] = [];\n for (const [tk, members] of Object.entries(tailMap)) {\n if (members.length < 2) continue;\n const tailList = tk.split(\",\");\n const vowel = tailList[0] && VOWELS.has(tailList[0]) ? tailList[0] : null;\n groups.push({\n tail: tailList,\n vowel,\n rhyme_type: tailList.length > 1 ? \"perfect\" : \"slant\",\n members,\n });\n }\n return groups.sort((a, b) => b.members.length - a.members.length);\n}\n\nfunction buildAnalysis(\n title: string,\n parsed: LyricEntry[],\n wordIndex: WordIndex,\n) {\n const unresolved = Object.entries(wordIndex)\n .filter(([, d]) => d === null).map(([w]) => w).sort();\n const sections = buildSections(parsed, wordIndex);\n const rhymeGroups = buildRhymeGroups(sections, wordIndex);\n const wordMap = Object.fromEntries(\n Object.entries(wordIndex).filter(([, d]) => d !== null),\n ) as Record;\n return {\n title,\n meta: {\n cmudict_version: \"0.7b\",\n dialect: \"North American English\",\n unresolved_words: unresolved,\n },\n sections,\n rhyme_groups: rhymeGroups,\n word_map: wordMap,\n };\n}\n\nfunction splitIntoSyllables(phones: string[]): [string[][], number] {\n const syllables: string[][] = [];\n let current: string[] = [];\n let stressedIdx = -1;\n for (const p of phones) {\n const base = p.replace(/[012]$/, \"\");\n const stress = /[012]$/.test(p) ? p[p.length - 1] : null;\n if (VOWELS.has(base)) {\n current.push(p);\n if (stress === \"1\") stressedIdx = syllables.length;\n syllables.push(current);\n current = [];\n } else current.push(p);\n }\n if (current.length > 0 && syllables.length > 0) {\n syllables[syllables.length - 1].push(...current);\n } else if (current.length > 0) syllables.push(current);\n return [syllables, stressedIdx < 0 ? 0 : stressedIdx];\n}\n\nfunction syllableBreakdown(word: string, phones: string[]): SyllableData[] {\n const [syllables] = splitIntoSyllables(phones);\n const w = word.toLowerCase();\n\n const sylMeta = syllables.map((syl) => {\n const vowelPhone = syl.find((p) => VOWELS.has(p.replace(/[012]$/, \"\")));\n const vowel = vowelPhone ? vowelPhone.replace(/[012]$/, \"\") : null;\n const stress = (vowelPhone && /[012]$/.test(vowelPhone)\n ? Number(vowelPhone[vowelPhone.length - 1])\n : 0) as 0 | 1 | 2;\n return { vowel, stress };\n });\n\n if (syllables.length <= 1) {\n return [{\n chars: [0, word.length] as [number, number],\n ...(sylMeta[0] ?? { vowel: null, stress: 0 as const }),\n }];\n }\n\n // Find orthographic vowel runs to approximate syllable character boundaries\n const orthoVowels = \"aeiouy\";\n const vowelRuns: [number, number][] = [];\n let i = 0;\n while (i < w.length) {\n if (orthoVowels.includes(w[i])) {\n let j = i;\n while (j < w.length && orthoVowels.includes(w[j])) j++;\n vowelRuns.push([i, j]);\n i = j;\n } else i++;\n }\n\n // Onset-preference: put all consonants except the onset cluster with the\n // following syllable. Default: 1 character at onset (nextVStart - 1).\n // Exception: English onset digraphs (th, wh, ch, sh, ph) stay together —\n // if the last 2 chars before the next vowel run form a digraph, keep both.\n const ONSET_DIGRAPHS = new Set([\n \"th\",\n \"wh\",\n \"ch\",\n \"sh\",\n \"ph\",\n \"gh\",\n \"wr\",\n \"kn\",\n \"qu\",\n ]);\n const boundaries: number[] = [0];\n for (let si = 0; si < syllables.length - 1; si++) {\n if (si < vowelRuns.length - 1) {\n const vEnd = vowelRuns[si][1];\n const nextVStart = vowelRuns[si + 1][0];\n const clusterLen = nextVStart - vEnd;\n const useTwo = clusterLen >= 2 &&\n ONSET_DIGRAPHS.has(w.slice(nextVStart - 2, nextVStart));\n boundaries.push(Math.max(vEnd, nextVStart - (useTwo ? 2 : 1)));\n } else {\n boundaries.push(Math.round((si + 1) * w.length / syllables.length));\n }\n }\n boundaries.push(word.length);\n\n return sylMeta.map((meta, si) => ({\n chars: [boundaries[si], boundaries[si + 1]] as [number, number],\n ...meta,\n }));\n}\n\nfunction syllableSpanPosition(\n word: string,\n phones: string[],\n): [number, number] {\n const [syllables, stressedIdx] = splitIntoSyllables(phones);\n const w = word.toLowerCase();\n if (syllables.length <= 1) return [0, word.length];\n const orthoVowels = \"aeiouy\";\n const vowelRuns: [number, number][] = [];\n let i = 0;\n while (i < w.length) {\n if (orthoVowels.includes(w[i])) {\n let j = i;\n while (j < w.length && orthoVowels.includes(w[j])) j++;\n vowelRuns.push([i, j]);\n i = j;\n } else i++;\n }\n if (vowelRuns.length === 0 || stressedIdx >= vowelRuns.length) {\n return [0, w.length];\n }\n const [vStart, vEnd] = vowelRuns[stressedIdx];\n const sylStart = vStart;\n let sylEnd: number;\n if (stressedIdx + 1 < vowelRuns.length) {\n const nextVStart = vowelRuns[stressedIdx + 1][0];\n sylEnd = vEnd + Math.min(nextVStart - vEnd, 2);\n } else sylEnd = w.length;\n return [sylStart, sylEnd];\n}\n\n// ─── Rhyme map HTML template (injected server-side on format=html) ────────────\n\nconst RHYME_MAP_TEMPLATE = `\n\n\n\n\nRhyme Map\n\n\n\n\n

\n\n

\n Stress syllable\n

\n End-of-line only\n

\n Scheme labels\n

\n Compact legend\n

\n\n

\n\n\n\n`;\n\nfunction injectRhymeData(analysis: ReturnType): string {\n return RHYME_MAP_TEMPLATE.replace(\n \"const RHYME_DATA = null; // <<>>\",\n `const RHYME_DATA = ${JSON.stringify({ analysis })};`,\n );\n}\n\n// ─── Parse lyrics ─────────────────────────────────────────────────────────────\n\nconst _CHORD_PAT =\n \"[A-G][b#]?(?:maj|min|m|dim|aug|sus|add)?(?:\\\\d+)?(?:/[A-G][b#]?)?\";\nconst INLINE_CHORD_RE = new RegExp(`\\\\[(${_CHORD_PAT})\\\\]`, \"g\");\nconst CHORD_LINE_RE = new RegExp(\n `^\\\\s*(${_CHORD_PAT})(\\\\s+(${_CHORD_PAT}))*\\\\s*$`,\n);\nconst SECTION_BRACKET_RE = /^\\[([^\\]]{2,})\\]$/;\n\nfunction detectFormat(raw: string): string {\n const lines = raw.trim().split(\"\\n\").filter((l) => l.trim());\n if (lines.some((l) => /^\\{[a-z_]+/.test(l.trim()))) return \"chordpro\";\n const bracketLines = lines.map((l) => l.trim()).filter((l) =>\n l.startsWith(\"[\")\n );\n const sectionBrackets = bracketLines.filter((l) =>\n !new RegExp(`^\\\\[(${_CHORD_PAT})\\\\]$`).test(l)\n );\n if (sectionBrackets.length > 0) return \"bracketed\";\n const allcaps = lines.filter((l) => /^[A-Z][A-Z\\s\\-\\d]{2,}$/.test(l.trim()));\n if (allcaps.length > 0) return \"allcaps\";\n const chordLines = lines.filter((l) => CHORD_LINE_RE.test(l));\n if (chordLines.length >= 2) return \"ultimate_guitar\";\n return \"plain\";\n}\n\nfunction extractMetadata(\n lines: string[],\n): [Record, string[], string | null] {\n const metadata: Record = {};\n let title: string | null = null;\n let i = 0;\n while (i < lines.length) {\n const m = lines[i].trim().match(/^([A-Za-z][A-Za-z /]*?):\\s*(.+)/);\n if (m) {\n const key = m[1].trim().toLowerCase();\n const value = m[2].trim();\n if (key === \"title\") title = value;\n else metadata[key] = value;\n i++;\n } else break;\n }\n return [metadata, lines.slice(i), title];\n}\n\nfunction inferTitle(\n lines: string[],\n parseNotes: string[],\n): [string | null, string[]] {\n if (lines.length === 0) return [null, lines];\n const first = lines[0].trim();\n const words = first.split(/\\s+/);\n if (\n first && words.length >= 1 && words.length <= 8 &&\n first[0] === first[0].toUpperCase() &&\n !first.startsWith(\"[\") &&\n !/^[A-Z][A-Z\\s\\-]{2,}$/.test(first) &&\n !first.endsWith(\",\")\n ) {\n parseNotes.push(`Title inferred from first line: \"${first}\"`);\n return [first, lines.slice(1)];\n }\n return [null, lines];\n}\n\nfunction stripInlineChords(line: string): string {\n return line.replace(INLINE_CHORD_RE, \"\").trim();\n}\n\nfunction stanzaHint(\n lines: string[],\n priorSections: Array<{ label?: string }>,\n): string {\n const count = lines.length;\n const hasChorus = priorSections.some((s) =>\n (s.label ?? \"\").toLowerCase().includes(\"chorus\")\n );\n if (count <= 2) return \"possible_outro_or_hook\";\n if (count === 4) {\n return hasChorus\n ? \"possible_verse\"\n : \"possible_verse_or_chorus\";\n }\n if (count >= 6) return \"possible_verse\";\n return \"unknown\";\n}\n\nfunction makeResult(\n title: string | null,\n fmt: string,\n metadata: Record,\n sections: object[],\n unparsedBlocks: object[],\n parseNotes: string[],\n) {\n return {\n title,\n format_detected: fmt,\n metadata,\n sections,\n unparsed_blocks: unparsedBlocks,\n requires_llm: unparsedBlocks.length > 0,\n parse_notes: parseNotes,\n };\n}\n\nfunction parseChordpro(raw: string) {\n const lines = raw.trim().split(\"\\n\");\n let title: string | null = null;\n const metadata: Record = {};\n const sections: object[] = [];\n const parseNotes: string[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n let inSection = false;\n let verseN = 0, chorusN = 0, partN = 0;\n\n const SECTION_START: Record = {\n start_of_verse: \"Verse\",\n start_of_chorus: \"Chorus\",\n start_of_bridge: \"Bridge\",\n start_of_part: \"Part\",\n };\n const SKIP_START = new Set([\"start_of_tab\", \"start_of_grid\"]);\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l);\n if (lyricLines.length > 0 && currentLabel !== null) {\n sections.push({\n label: `[${currentLabel}]`,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else if (lyricLines.length > 0) {\n sections.push({\n label: \"[Unlabelled]\",\n confidence: \"low\",\n alternatives: [\"[Verse]\", \"[Chorus]\"],\n reason: \"Lyric lines appeared outside a {start_of_*} directive.\",\n lines: lyricLines,\n });\n }\n currentLabel = null;\n currentLines = [];\n inSection = false;\n }\n\n for (const rawLine of lines) {\n const stripped = rawLine.trim();\n const d = stripped.match(/^\\{([a-z_]+)(?::\\s*(.*?))?\\}$/);\n if (d) {\n const directive = d[1], value = (d[2] ?? \"\").trim();\n if (directive === \"title\") title = value;\n else if (\n [\n \"artist\",\n \"composer\",\n \"lyricist\",\n \"album\",\n \"year\",\n \"key\",\n \"tempo\",\n \"time\",\n \"copyright\",\n \"capo\",\n \"meta\",\n ].includes(directive)\n ) {\n metadata[directive] = value;\n } else if (directive in SECTION_START) {\n flush();\n const kind = SECTION_START[directive];\n if (value) currentLabel = value;\n else if (kind === \"Verse\") {\n verseN++;\n currentLabel = `Verse ${verseN}`;\n } else if (kind === \"Chorus\") {\n chorusN++;\n currentLabel = chorusN === 1 ? \"Chorus\" : `Chorus ${chorusN}`;\n } else if (kind === \"Bridge\") currentLabel = \"Bridge\";\n else {\n partN++;\n currentLabel = `Part ${partN}`;\n }\n inSection = true;\n } else if (SKIP_START.has(directive)) {\n flush();\n inSection = false;\n } else if (directive.startsWith(\"end_of_\")) { /* flush on next start */ }\n else if (directive === \"comment\") {\n parseNotes.push(`Source comment: \"${value}\"`);\n }\n continue;\n }\n const clean = stripInlineChords(stripped);\n if (inSection && clean) currentLines.push(clean);\n else if (clean && !stripped.startsWith(\"#\")) currentLines.push(clean);\n }\n flush();\n if (!title) parseNotes.push(\"No {title} directive found — title unknown.\");\n return makeResult(title, \"chordpro\", metadata, sections, [], parseNotes);\n}\n\nfunction parseBracketed(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const sections: object[] = [];\n const unparsedBlocks: object[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l.trim());\n if (lyricLines.length === 0) {\n currentLabel = null;\n currentLines = [];\n return;\n }\n if (currentLabel !== null) {\n sections.push({\n label: currentLabel,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else {\n unparsedBlocks.push({\n raw: lyricLines.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(lyricLines, sections as Array<{ label?: string }>),\n });\n }\n currentLabel = null;\n currentLines = [];\n }\n\n for (const line of lines) {\n const stripped = line.trim();\n if (!stripped) flush();\n else if (\n SECTION_BRACKET_RE.test(stripped) &&\n !new RegExp(`^\\\\[(${_CHORD_PAT})\\\\]$`).test(stripped)\n ) {\n flush();\n currentLabel = stripped;\n } else currentLines.push(stripped);\n }\n flush();\n\n if (unparsedBlocks.length > 0) {\n parseNotes.push(\n `${unparsedBlocks.length} block(s) have no section header — LLM labelling needed.`,\n );\n }\n return makeResult(\n title,\n \"bracketed\",\n metadata,\n sections,\n unparsedBlocks,\n parseNotes,\n );\n}\n\nfunction parseAllcaps(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const sections: object[] = [];\n const unparsedBlocks: object[] = [];\n let currentLabel: string | null = null;\n let currentLines: string[] = [];\n\n function flush() {\n const lyricLines = currentLines.filter((l) => l.trim());\n if (lyricLines.length === 0) {\n currentLabel = null;\n currentLines = [];\n return;\n }\n if (currentLabel !== null) {\n const label = currentLabel.charAt(0) +\n currentLabel.slice(1).toLowerCase();\n sections.push({\n label: `[${label}]`,\n confidence: \"high\",\n lines: lyricLines,\n });\n } else {\n unparsedBlocks.push({\n raw: lyricLines.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(lyricLines, sections as Array<{ label?: string }>),\n });\n }\n currentLabel = null;\n currentLines = [];\n }\n\n for (const line of lines) {\n const stripped = line.trim();\n if (!stripped) flush();\n else if (/^[A-Z][A-Z\\s\\-\\d]{2,}$/.test(stripped)) {\n flush();\n currentLabel = stripped;\n } else currentLines.push(stripped);\n }\n flush();\n\n if (unparsedBlocks.length > 0) {\n parseNotes.push(\n `${unparsedBlocks.length} block(s) have no section header — LLM labelling needed.`,\n );\n }\n return makeResult(\n title,\n \"allcaps\",\n metadata,\n sections,\n unparsedBlocks,\n parseNotes,\n );\n}\n\nfunction parsePlain(raw: string) {\n const allLines = raw.trim().split(\"\\n\");\n const [metadata, remaining, extractedTitle] = extractMetadata(allLines);\n const parseNotes: string[] = [];\n let lines = remaining;\n let title = extractedTitle;\n if (!title) [title, lines] = inferTitle(lines, parseNotes);\n\n const stanzas: string[][] = [];\n let current: string[] = [];\n for (const line of lines) {\n if (line.trim()) current.push(line.trim());\n else if (current.length > 0) {\n stanzas.push(current);\n current = [];\n }\n }\n if (current.length > 0) stanzas.push(current);\n\n const unparsedBlocks = stanzas.map((stanza, i) => ({\n raw: stanza.join(\"\\n\"),\n issue: \"no_header\",\n hint: stanzaHint(stanza, []),\n stanza_index: i,\n }));\n parseNotes.push(\n `No section headers detected. ${stanzas.length} stanza(s) require LLM labelling.`,\n );\n return makeResult(title, \"plain\", metadata, [], unparsedBlocks, parseNotes);\n}\n\nfunction parseUltimateGuitar(raw: string) {\n const lines = raw.trim().split(\"\\n\");\n const lyricLines = lines.filter((l) => !CHORD_LINE_RE.test(l));\n const cleaned = lyricLines.join(\"\\n\");\n const fmt = detectFormat(cleaned);\n const result = fmt === \"bracketed\"\n ? parseBracketed(cleaned)\n : fmt === \"allcaps\"\n ? parseAllcaps(cleaned)\n : parsePlain(cleaned);\n result.format_detected = \"ultimate_guitar\";\n (result.parse_notes as string[]).unshift(\n \"Chord-above-lines stripped before section detection.\",\n );\n return result;\n}\n\nfunction parseLyrics(raw: string) {\n const fmt = detectFormat(raw);\n return fmt === \"chordpro\"\n ? parseChordpro(raw)\n : fmt === \"bracketed\"\n ? parseBracketed(raw)\n : fmt === \"allcaps\"\n ? parseAllcaps(raw)\n : fmt === \"ultimate_guitar\"\n ? parseUltimateGuitar(raw)\n : parsePlain(raw);\n}\n\n// Convert parse result sections → flat LyricEntry list for rhyme analysis\nfunction toFlatEntries(\n parseResult: ReturnType,\n): LyricEntry[] {\n const entries: LyricEntry[] = [];\n for (\n const section of parseResult.sections as Array<\n { label: string; lines: string[] }\n >\n ) {\n entries.push({ type: \"section\", text: section.label });\n for (const line of section.lines) {\n entries.push({ type: \"line\", text: line });\n }\n }\n // Include unparsed block lines so rhyme analysis still runs on them\n for (\n const block of (parseResult.unparsed_blocks as Array<{ raw: string }>) ?? []\n ) {\n for (const line of block.raw.split(\"\\n\")) {\n if (line.trim()) entries.push({ type: \"line\", text: line.trim() });\n }\n }\n return entries;\n}\n\n// ─── OAuth + MCP ──────────────────────────────────────────────────────────────\n\nconst CODE_TTL_MS = 5 * 60 * 1000; // 5 minutes\n\nconst MCP_TOOLS = [\n {\n name: \"parse_lyrics\",\n description:\n \"Detect the format of raw lyric text and return structured JSON with sections and lines. Supports ChordPro, bracketed, ALLCAPS, Ultimate Guitar, and plain formats.\",\n inputSchema: {\n type: \"object\",\n properties: {\n lyrics: { type: \"string\", description: \"Raw lyric text\" },\n },\n required: [\"lyrics\"],\n },\n },\n {\n name: \"rhyme_map\",\n description:\n \"Phonetic rhyme analysis using the CMU Pronouncing Dictionary. Returns rhyme schemes, cross-song rhyme groups, per-line end-word analysis, and a word_map with per-syllable vowel and stress data for every word. The response includes a download_url field. Create a minimal HTML artifact: an iframe filling the full panel that loads the download_url. Do not fetch or reproduce the HTML yourself.\",\n inputSchema: {\n type: \"object\",\n properties: {\n lyrics: { type: \"string\", description: \"Raw lyric text\" },\n html: {\n type: \"boolean\",\n description: \"Include interactive HTML visualisation (default true)\",\n },\n },\n required: [\"lyrics\"],\n },\n },\n];\n\nasync function sha256Base64url(input: string): Promise {\n const data = new TextEncoder().encode(input);\n const digest = await crypto.subtle.digest(\"SHA-256\", data);\n return btoa(String.fromCharCode(...new Uint8Array(digest)))\n .replace(/\\+/g, \"-\").replace(/\\//g, \"_\").replace(/=/g, \"\");\n}\n\nfunction checkBearerAuth(req: Request, baseUrl: string): Response | null {\n if (!API_KEY) return json({ error: \"API_KEY not configured\" }, 500);\n const auth = req.headers.get(\"Authorization\") ?? \"\";\n if (!auth.startsWith(\"Bearer \") || auth.slice(7) !== API_KEY) {\n return new Response(JSON.stringify({ error: \"Unauthorized\" }), {\n status: 401,\n headers: {\n \"Content-Type\": \"application/json\",\n \"WWW-Authenticate\":\n `Bearer resource_metadata=\"${baseUrl}/.well-known/oauth-protected-resource\"`,\n \"Access-Control-Allow-Origin\": \"*\",\n },\n });\n }\n return null;\n}\n\nfunction oauthMeta(baseUrl: string) {\n return {\n issuer: baseUrl,\n authorization_endpoint: `${baseUrl}/oauth/authorize`,\n token_endpoint: `${baseUrl}/oauth/token`,\n registration_endpoint: `${baseUrl}/oauth/register`,\n code_challenge_methods_supported: [\"S256\"],\n grant_types_supported: [\"authorization_code\"],\n response_types_supported: [\"code\"],\n token_endpoint_auth_methods_supported: [\"none\"],\n scopes_supported: [\"mcp\"],\n };\n}\n\nasync function handleRegister(req: Request): Promise {\n let body: Record = {};\n try {\n body = await req.json();\n } catch { /* ignore — body is optional */ }\n const redirectUris = (body.redirect_uris as string[]) ?? [];\n return new Response(\n JSON.stringify({\n client_id: crypto.randomUUID(),\n client_id_issued_at: Math.floor(Date.now() / 1000),\n redirect_uris: redirectUris,\n grant_types: [\"authorization_code\"],\n response_types: [\"code\"],\n token_endpoint_auth_method: \"none\",\n }),\n {\n status: 201,\n headers: {\n \"Content-Type\": \"application/json\",\n \"Access-Control-Allow-Origin\": \"*\",\n },\n },\n );\n}\n\nfunction resourceMeta(baseUrl: string) {\n return {\n resource: `${baseUrl}/mcp`,\n authorization_servers: [baseUrl],\n };\n}\n\nasync function handleAuthorize(req: Request, url: URL): Promise {\n if (req.method === \"GET\") {\n const challenge = url.searchParams.get(\"code_challenge\") ?? \"\";\n const redirectUri = url.searchParams.get(\"redirect_uri\") ?? \"\";\n const state = url.searchParams.get(\"state\") ?? \"\";\n const clientId = url.searchParams.get(\"client_id\") ?? \"\";\n const esc = (s: string) => s.replace(/&/g, \"&\").replace(/\"/g, \""\");\n return new Response(\n `\n\n\nLyric Analysis — Authorize\n\n

Lyric Analysis

Claude is requesting access to the phonetic rhyme analysis tools.

\n \n

Diff · v31