${valIdentifier ? `${valIdentifier} - The Book` : \"The Book\"}

[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8,"_9":10},"actionData","errors","root",{"_158":159,"_160":161},"routes/_app.x.$handle.$name",{"_99":98,"_32":45,"_107":89,"_27":55,"_13":14,"_108":-5,"_11":109,"_110":111,"_112":113,"_114":115,"_116":117,"_20":-5,"_118":-5,"_119":-5,"_120":25,"_121":122,"_123":124,"_125":-5,"_126":-5,"_127":128},"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":55,"_18":56,"_57":-5,"_58":25,"_59":-5,"_60":-5,"_61":62,"_63":64,"_65":66,"_67":68,"_69":70,"_71":-5,"_72":73,"_74":73,"_75":76,"_77":76,"_78":76,"_79":73,"_80":73,"_81":82,"_83":84,"_85":86,"_87":25},"version",47,"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","f3c6aeba-05ed-11f1-8ba5-42dde27851f2","name","fileType","http","content","import Cerebras from \"npm:@cerebras/cerebras_cloud_sdk\";\n\ninterface ValFile {\n name: string;\n path: string;\n type: \"file\" | \"directory\" | \"interval\" | \"http\" | \"email\" | \"script\";\n}\n\ninterface FileContent {\n name: string;\n path: string;\n code: string;\n chapterTitle?: string;\n explanation?: string;\n}\n\ninterface ValInfo {\n id: string;\n name: string;\n description?: string;\n}\n\nasync function fetchValByAlias(\n handle: string,\n valName: string,\n): Promise {\n const res = await fetch(\n `https://api.val.town/v2/alias/vals/${handle}/${valName}`,\n );\n if (!res.ok) {\n throw new Error(`Failed to fetch val: ${res.status} ${res.statusText}`);\n }\n return res.json();\n}\n\nasync function fetchValFiles(valId: string): Promise {\n const res = await fetch(`https://api.val.town/v2/vals/${valId}/files?path`);\n if (!res.ok) {\n throw new Error(\n `Failed to fetch files: ${res.status} ${res.statusText} ${await res\n .text()}`,\n );\n }\n const data = await res.json();\n return data.data || [];\n}\n\nasync function fetchFileContent(valId: string, path: string): Promise {\n const res = await fetch(\n `https://api.val.town/v2/vals/${valId}/files/content?path=${\n encodeURIComponent(path)\n }`,\n );\n if (!res.ok) {\n return `// Failed to load content: ${res.status}`;\n }\n const data = await res.text();\n return data || \"\";\n}\n\nasync function generateChapterTitles(files: FileContent[]): Promise {\n const apiKey = Deno.env.get(\"CEREBRAS_API_KEY\");\n if (!apiKey) {\n return files.map((f) => f.path);\n }\n\n const client = new Cerebras({ apiKey });\n\n const codeSnippets = files\n .map(\n (f, i) =>\n `File ${i + 1} (${f.path}):\\n\\`\\`\\`\\n${f.code.slice(0, 1500)}\\n\\`\\`\\``,\n )\n .join(\"\\n\\n\");\n\n const prompt = `You are creating chapter titles for a programming book..\n\nHere are the code files:\n\n${codeSnippets}\n\nGenerate one title per file, in the same order. Keep titles concise (2-6 words). They should be technical but readable.`;\n\n const schema = {\n type: \"object\",\n properties: {\n titles: {\n type: \"array\",\n items: { type: \"string\" },\n },\n },\n required: [\"titles\"],\n additionalProperties: false,\n };\n\n try {\n const completion = await client.chat.completions.create({\n model: \"llama3.3-70b\",\n messages: [{ role: \"user\", content: prompt }],\n temperature: 0.7,\n response_format: {\n type: \"json_schema\",\n json_schema: {\n name: \"chapter_titles\",\n strict: true,\n schema: schema,\n },\n },\n });\n\n const content = completion.choices?.[0]?.message?.content || \"\";\n\n if (content) {\n const result = JSON.parse(content);\n if (\n result.titles && Array.isArray(result.titles) &&\n result.titles.length === files.length\n ) {\n return result.titles;\n }\n }\n\n return files.map((f) => f.path);\n } catch (e) {\n console.error(\"Error generating chapter titles:\", e);\n return files.map((f) => f.path);\n }\n}\n\nasync function generateExplanation(file: FileContent): Promise {\n const apiKey = Deno.env.get(\"CEREBRAS_API_KEY\");\n if (!apiKey) {\n return \"\";\n }\n\n const client = new Cerebras({ apiKey });\n\n const prompt =\n `You are writing prose explanations for a programming book. Explain what this code does in 2-4 paragraphs of engaging, literary prose.\n\nIMPORTANT: Reference specific parts of the code using markdown links in this format: [description](/${file.path}:START-END) where START and END are line numbers (1-indexed).\n\nFor example:\n- [the main function](/${file.path}:15-20) - references lines 15-20\n- [database initialization](/${file.path}:5-8) - references lines 5-8\n- [error handling](/${file.path}:42-42) - references a single line\n\nUse these links frequently to connect your prose to specific code sections. Make the prose literary and engaging, like you're telling a story about what the code accomplishes.\n\nHere is the code for ${file.path}:\n\n\\`\\`\\`\n${file.code}\n\\`\\`\\`\n\nWrite 2-4 paragraphs explaining this code with markdown links to specific line ranges:`;\n\n const schema = {\n type: \"object\",\n properties: {\n explanation: {\n type: \"string\",\n },\n },\n required: [\"explanation\"],\n additionalProperties: false,\n };\n\n try {\n const completion = await client.chat.completions.create({\n model: \"llama3.3-70b\",\n messages: [{ role: \"user\", content: prompt }],\n temperature: 0.7,\n response_format: {\n type: \"json_schema\",\n json_schema: {\n name: \"code_explanation\",\n strict: true,\n schema: schema,\n },\n },\n });\n\n const content = completion.choices?.[0]?.message?.content || \"\";\n\n if (content) {\n const result = JSON.parse(content);\n return result.explanation || \"\";\n }\n\n return \"\";\n } catch (e) {\n console.error(\"Error generating explanation:\", e);\n return \"\";\n }\n}\n\nfunction filterCodeFiles(files: ValFile[]): ValFile[] {\n return files.filter(\n (f) => f.type !== \"directory\" && /\\.(ts|tsx|js|jsx)$/.test(f.name),\n );\n}\n\nfunction escapeHtml(str: string): string {\n return str\n .replace(/&/g, \"&\")\n .replace(//g, \">\")\n .replace(/\"/g, \""\");\n}\n\nfunction parseMarkdownLinks(text: string): string {\n // Convert markdown links [text](/path:start-end) to clickable spans\n return text.replace(\n /\\[([^\\]]+)\\]\$\\/[^:]+:(\\d+)-(\\d+)\$/g,\n (match, linkText, start, end) => {\n return `${\n escapeHtml(linkText)\n }`;\n },\n );\n}\n\nfunction renderPage(\n valIdentifier: string,\n chapters: FileContent[],\n selectedIndex: number = 0,\n error?: string,\n): string {\n const selected = chapters[selectedIndex];\n\n const chapterItems = chapters\n .map(\n (ch, i) => `\n \n ${String(i + 1).padStart(2, \"0\")}\n ${\n escapeHtml(ch.chapterTitle || ch.path)\n }\n \n `,\n )\n .join(\"\");\n\n const middleContent = selected?.explanation\n ? `

${\n selected.explanation.split(\"\\n\\n\").map((para) =>\n `

${parseMarkdownLinks(para)}

`\n ).join(\"\")\n }

`\n : selected\n ? `

Loading explanation...

`\n : error\n ? `

${escapeHtml(error)}

`\n : `

Select a chapter to read

`;\n\n const codeContent = selected\n ? `

${\n      escapeHtml(selected.code)\n    }

`\n : `

Select a file to view its code

`;\n\n return `\n\n\n \n \n ${valIdentifier ? `${valIdentifier} - The Book` : \"The Book\"}\n \n \n \n \n \n \n \n\n\n

Chapters

\n ${\n chapters.length > 0\n ? chapterItems\n : '

No files to display

'\n }\n

\n\n

\n ${middleContent}\n

\n\n

\n ${codeContent}\n

\n \n \n\n`;\n}\n\nexport default async function (req: Request): Promise {\n const url = new URL(req.url);\n const valParam = url.searchParams.get(\"val\") || \"\";\n const chapterParam = url.searchParams.get(\"chapter\");\n const selectedIndex = chapterParam ? parseInt(chapterParam, 10) : 0;\n\n let chapters: FileContent[] = [];\n let error: string | undefined;\n\n if (valParam) {\n const parts = valParam.split(\"/\");\n if (parts.length === 2) {\n const [handle, valName] = parts;\n try {\n const valInfo = await fetchValByAlias(handle, valName);\n const files = await fetchValFiles(valInfo.id);\n const codeFiles = filterCodeFiles(files);\n\n chapters = await Promise.all(\n codeFiles.map(async (f) => ({\n name: f.name,\n path: f.path,\n code: await fetchFileContent(valInfo.id, f.path),\n })),\n );\n\n const titles = await generateChapterTitles(chapters);\n chapters = chapters.map((ch, i) => ({\n ...ch,\n chapterTitle: titles[i],\n }));\n\n // Generate explanation for selected chapter\n if (chapters[selectedIndex]) {\n const explanation = await generateExplanation(\n chapters[selectedIndex],\n );\n chapters[selectedIndex].explanation = explanation;\n }\n } catch (e) {\n error = e instanceof Error ? e.message : \"Failed to fetch val\";\n }\n } else {\n error = \"Invalid val identifier. Use format: handle/valName\";\n }\n }\n\n const validIndex = Math.max(0, Math.min(selectedIndex, chapters.length - 1));\n\n return new Response(renderPage(valParam, chapters, validIndex, error), {\n headers: { \"Content-Type\": \"text/html\" },\n });\n}","import Cerebras from \"npm:@cerebras/cerebras_cloud_sdk\";\nimport { sqlite } from \"https://esm.town/v/std/sqlite@14-main/main.ts\";\n\ninterface ValFile {\n name: string;\n path: string;\n type: \"file\" | \"directory\" | \"interval\" | \"http\" | \"email\" | \"script\";\n}\n\ninterface FileContent {\n name: string;\n path: string;\n code: string;\n chapterTitle?: string;\n explanation?: string;\n}\n\ninterface ValInfo {\n id: string;\n name: string;\n description?: string;\n}\n\n// Initialize database\nawait sqlite.execute(`\n CREATE TABLE IF NOT EXISTS file_cache (\n val_identifier TEXT NOT NULL,\n file_path TEXT NOT NULL,\n code_hash TEXT NOT NULL,\n chapter_title TEXT,\n explanation TEXT,\n created_at INTEGER DEFAULT (strftime('%s', 'now')),\n PRIMARY KEY (val_identifier, file_path)\n )\n`);\n\n// Create index for faster lookups\nawait sqlite.execute(`\n CREATE INDEX IF NOT EXISTS idx_val_file ON file_cache(val_identifier, file_path)\n`);\n\nfunction hashCode(str: string): string {\n let hash = 0;\n for (let i = 0; i < str.length; i++) {\n const char = str.charCodeAt(i);\n hash = ((hash << 5) - hash) + char;\n hash = hash & hash;\n }\n return hash.toString(36);\n}\n\nasync function getCachedData(\n valIdentifier: string,\n filePath: string,\n codeHash: string,\n): Promise<{ chapterTitle?: string; explanation?: string } | null> {\n const result = await sqlite.execute({\n sql: `SELECT chapter_title, explanation FROM file_cache \n WHERE val_identifier = ? AND file_path = ? AND code_hash = ?`,\n args: [valIdentifier, filePath, codeHash],\n });\n\n if (result.rows.length > 0) {\n const row = result.rows[0] as { chapter_title: string; explanation: string };\n return {\n chapterTitle: row.chapter_title,\n explanation: row.explanation,\n };\n }\n return null;\n}\n\nasync function setCachedData(\n valIdentifier: string,\n filePath: string,\n codeHash: string,\n chapterTitle?: string,\n explanation?: string,\n): Promise {\n await sqlite.execute({\n sql: `INSERT OR REPLACE INTO file_cache \n (val_identifier, file_path, code_hash, chapter_title, explanation)\n VALUES (?, ?, ?, ?, ?)`,\n args: [valIdentifier, filePath, codeHash, chapterTitle || null, explanation || null],\n });\n}\n\nasync function fetchValByAlias(\n handle: string,\n valName: string,\n): Promise {\n const res = await fetch(\n `https://api.val.town/v2/alias/vals/${handle}/${valName}`,\n );\n if (!res.ok) {\n throw new Error(`Failed to fetch val: ${res.status} ${res.statusText}`);\n }\n return res.json();\n}\n\nasync function fetchValFiles(valId: string): Promise {\n const res = await fetch(`https://api.val.town/v2/vals/${valId}/files?path`);\n if (!res.ok) {\n throw new Error(\n `Failed to fetch files: ${res.status} ${res.statusText} ${await res\n .text()}`,\n );\n }\n const data = await res.json();\n return data.data || [];\n}\n\nasync function fetchFileContent(valId: string, path: string): Promise {\n const res = await fetch(\n `https://api.val.town/v2/vals/${valId}/files/content?path=${\n encodeURIComponent(path)\n }`,\n );\n if (!res.ok) {\n return `// Failed to load content: ${res.status}`;\n }\n const data = await res.text();\n return data || \"\";\n}\n\nasync function generateChapterTitles(\n valIdentifier: string,\n files: FileContent[],\n): Promise {\n const apiKey = Deno.env.get(\"CEREBRAS_API_KEY\");\n if (!apiKey) {\n return files.map((f) => f.path);\n }\n\n // Check cache for all files\n const cachedTitles: (string | null)[] = await Promise.all(\n files.map(async (f) => {\n const hash = hashCode(f.code);\n const cached = await getCachedData(valIdentifier, f.path, hash);\n return cached?.chapterTitle || null;\n }),\n );\n\n // If all are cached, return them\n if (cachedTitles.every((t) => t !== null)) {\n return cachedTitles as string[];\n }\n\n const client = new Cerebras({ apiKey });\n\n const codeSnippets = files\n .map(\n (f, i) =>\n `File ${i + 1} (${f.path}):\\n\\`\\`\\`\\n${f.code.slice(0, 1500)}\\n\\`\\`\\``,\n )\n .join(\"\\n\\n\");\n\n const prompt =\n `You are creating chapter titles for a programming book. Each chapter corresponds to a code file. Generate creative, evocative chapter titles that capture the essence of what each file does - like chapters in a novel about code.\n\nHere are the code files:\n\n${codeSnippets}\n\nGenerate one title per file, in the same order. Keep titles concise (2-6 words). Be creative and literary, not just technical descriptions. Examples of good titles: \"The Guardian at the Gate\", \"Where Data Flows\", \"A Promise Kept\", \"The Shape of Things\".`;\n\n const schema = {\n type: \"object\",\n properties: {\n titles: {\n type: \"array\",\n items: { type: \"string\" },\n },\n },\n required: [\"titles\"],\n additionalProperties: false,\n };\n\n try {\n const completion = await client.chat.completions.create({\n model: \"llama3.3-70b\",\n messages: [{ role: \"user\", content: prompt }],\n temperature: 0.7,\n response_format: {\n type: \"json_schema\",\n json_schema: {\n name: \"chapter_titles\",\n strict: true,\n schema: schema,\n },\n },\n });\n\n const content = completion.choices?.[0]?.message?.content || \"\";\n\n if (content) {\n const result = JSON.parse(content);\n if (\n result.titles && Array.isArray(result.titles) &&\n result.titles.length === files.length\n ) {\n // Cache the generated titles\n await Promise.all(\n files.map(async (f, i) => {\n const hash = hashCode(f.code);\n await setCachedData(\n valIdentifier,\n f.path,\n hash,\n result.titles[i],\n undefined,\n );\n }),\n );\n return result.titles;\n }\n }\n\n return files.map((f) => f.path);\n } catch (e) {\n console.error(\"Error generating chapter titles:\", e);\n return files.map((f) => f.path);\n }\n}\n\nasync function generateExplanation(\n valIdentifier: string,\n file: FileContent,\n): Promise {\n const apiKey = Deno.env.get(\"CEREBRAS_API_KEY\");\n if (!apiKey) {\n return \"\";\n }\n\n // Check cache first\n const hash = hashCode(file.code);\n const cached = await getCachedData(valIdentifier, file.path, hash);\n if (cached?.explanation) {\n return cached.explanation;\n }\n\n const client = new Cerebras({ apiKey });\n\n const prompt = `You are writing prose explanations for a programming book. Explain what this code does in 2-4 paragraphs of engaging, literary prose.\n\nIMPORTANT: Reference specific parts of the code using markdown links in this format: [description](/${file.path}:START-END) where START and END are line numbers (1-indexed).\n\nFor example:\n- [the main function](/${file.path}:15-20) - references lines 15-20\n- [database initialization](/${file.path}:5-8) - references lines 5-8\n- [error handling](/${file.path}:42-42) - references a single line\n\nUse these links frequently to connect your prose to specific code sections. Make the prose literary and engaging, like you're telling a story about what the code accomplishes.\n\nHere is the code for ${file.path}:\n\n\\`\\`\\`\n${file.code}\n\\`\\`\\`\n\nWrite 2-4 paragraphs explaining this code with markdown links to specific line ranges:`;\n\n const schema = {\n type: \"object\",\n properties: {\n explanation: {\n type: \"string\",\n },\n },\n required: [\"explanation\"],\n additionalProperties: false,\n };\n\n try {\n const completion = await client.chat.completions.create({\n model: \"llama3.3-70b\",\n messages: [{ role: \"user\", content: prompt }],\n temperature: 0.7,\n response_format: {\n type: \"json_schema\",\n json_schema: {\n name: \"code_explanation\",\n strict: true,\n schema: schema,\n },\n },\n });\n\n const content = completion.choices?.[0]?.message?.content || \"\";\n\n if (content) {\n const result = JSON.parse(content);\n if (result.explanation) {\n // Cache the explanation\n await setCachedData(\n valIdentifier,\n file.path,\n hash,\n file.chapterTitle,\n result.explanation,\n );\n return result.explanation;\n }\n }\n\n return \"\";\n } catch (e) {\n console.error(\"Error generating explanation:\", e);\n return \"\";\n }\n}\n\nfunction filterCodeFiles(files: ValFile[]): ValFile[] {\n return files.filter(\n (f) => f.type !== \"directory\" && /\\.(ts|tsx|js|jsx)$/.test(f.name),\n );\n}\n\nfunction escapeHtml(str: string): string {\n return str\n .replace(/&/g, \"&\")\n .replace(//g, \">\")\n .replace(/\"/g, \""\");\n}\n\nfunction parseMarkdownLinks(text: string): string {\n // Convert markdown links [text](/path:start-end) to clickable spans\n return text.replace(\n /\\[([^\\]]+)\\]\$\\/[^:]+:(\\d+)-(\\d+)\$/g,\n (match, linkText, start, end) => {\n return `${\n escapeHtml(linkText)\n }`;\n },\n );\n}\n\nfunction renderPage(\n valIdentifier: string,\n chapters: FileContent[],\n selectedIndex: number = 0,\n error?: string,\n): string {\n const selected = chapters[selectedIndex];\n\n const chapterItems = chapters\n .map(\n (ch, i) => `\n \n ${String(i + 1).padStart(2, \"0\")}\n ${\n escapeHtml(ch.chapterTitle || ch.path)\n }\n \n `,\n )\n .join(\"\");\n\n const middleContent = selected?.explanation\n ? `

${\n selected.explanation.split(\"\\n\\n\").map((para) =>\n `

${parseMarkdownLinks(para)}

`\n ).join(\"\")\n }

`\n : selected\n ? `

Loading explanation...

`\n : error\n ? `

${escapeHtml(error)}

`\n : `

Select a chapter to read

`;\n\n const codeContent = selected\n ? `

${escapeHtml(selected.code)}

`\n : `

Select a file to view its code

`;\n\n return `\n\n\n \n \n ${valIdentifier ? `${valIdentifier} - The Book` : \"The Book\"}\n \n \n \n \n \n \n \n\n\n

Chapters

\n ${\n chapters.length > 0\n ? chapterItems\n : '

No files to display

'\n }\n

\n\n

\n ${middleContent}\n

\n\n

\n ${codeContent}\n

Diff · v47