#!/usr/bin/env node
"use strict";

const fs = require("node:fs");
const path = require("node:path");

function parseArgs(argv) {
  const args = { fixture: "", out: "" };
  for (let index = 0; index < argv.length; index += 1) {
    const arg = argv[index];
    if (arg === "--fixture") {
      args.fixture = argv[++index] || "";
      continue;
    }
    if (arg === "--out") {
      args.out = argv[++index] || "";
      continue;
    }
    if (arg === "--help" || arg === "-h") {
      console.log("用法：node scripts/export-convex-workspace-to-local.js --fixture <fixture.json> --out <dir>");
      process.exit(0);
    }
    throw new Error(`未知参数：${arg}`);
  }
  if (!args.fixture) throw new Error("缺少 --fixture");
  if (!args.out) throw new Error("缺少 --out");
  return args;
}

function ensureDir(dir) {
  fs.mkdirSync(dir, { recursive: true });
}

function writeUtf8(filePath, content) {
  ensureDir(path.dirname(filePath));
  fs.writeFileSync(filePath, content, "utf8");
}

function sanitizeName(name) {
  return String(name || "untitled")
    .trim()
    .replace(/[<>:"/\\|?*\u0000-\u001f]/g, "_")
    .replace(/\s+/g, " ")
    .replace(/\.+$/g, "")
    .trim() || "untitled";
}

function toMarkdownFilename(title) {
  return `${sanitizeName(title)}.md`;
}

function loadFixture(filePath) {
  return JSON.parse(fs.readFileSync(filePath, "utf8"));
}

function buildDocumentIndex(documents) {
  const byId = new Map();
  documents.forEach((doc) => {
    byId.set(String(doc.id), doc);
  });
  return byId;
}

function buildMarkdownPath(doc, documentsById) {
  const segments = [];
  let current = doc;
  while (current) {
    segments.unshift(sanitizeName(current.title || current.id || "untitled"));
    const parentId = current.parent_id || current.parentId || null;
    current = parentId ? documentsById.get(String(parentId)) : null;
  }
  return path.posix.join("pages", ...segments) + ".md";
}

function buildAssetPath(markdownPath, fileName) {
  const base = markdownPath.replace(/\.md$/i, ".assets");
  return path.posix.join(base, sanitizeName(fileName));
}

function findDocumentForAsset(asset, documents) {
  const directId = String(asset.document_id || asset.documentId || asset.page_id || asset.pageId || "").trim();
  if (directId) return directId;
  const assetId = String(asset.id || "").trim();
  if (!assetId) return "";
  const doc = documents.find((item) => {
    const content = typeof item.content === "string" ? item.content : "";
    const rawText = typeof item.raw_text === "string" ? item.raw_text : "";
    const editorText = typeof item.editor_document === "string" ? item.editor_document : "";
    const tiptapText = typeof item.tiptap_document === "string" ? item.tiptap_document : "";
    return [content, rawText, editorText, tiptapText].some((text) => text.includes(assetId));
  });
  return doc ? String(doc.id) : "";
}

function decodeAssetContent(asset) {
  if (typeof asset.contentBase64 === "string" && asset.contentBase64) {
    return Buffer.from(asset.contentBase64, "base64");
  }
  if (typeof asset.content === "string") {
    return Buffer.from(asset.content, "utf8");
  }
  return Buffer.from("", "utf8");
}

function rewriteAssetUrls(markdown, assetPathById) {
  return String(markdown || "").replace(/\/api\/media\/sign\?assetId=([^)\s"'&#]+)/g, (_, assetId) => {
    return assetPathById.get(String(assetId)) || _;
  });
}

function serializePageOptions(doc) {
  return {
    wideLayout: doc.wide_layout ?? null,
    useSmallText: doc.use_small_text ?? null,
    showHeadingNumbers: doc.show_heading_numbers ?? null,
    showToc: doc.show_toc ?? null,
    showStructure: doc.show_structure ?? null,
    protectEditing: doc.protect_editing ?? null,
    showWordCount: doc.show_word_count ?? null,
    collapseBacklinks: doc.collapse_backlinks ?? null,
    pageFont: doc.page_font ?? null,
    layoutDensity: doc.layout_density ?? null,
    hideChildPages: doc.hide_child_pages ?? null,
    showBlockRefCount: doc.show_block_ref_count ?? null,
    embedDefaultBlockId: doc.embed_default_block_id ?? null,
  };
}

function main() {
  const { fixture: fixturePath, out } = parseArgs(process.argv.slice(2));
  const fixture = loadFixture(fixturePath);
  const documents = Array.isArray(fixture.documents) ? fixture.documents : [];
  const mediaAssets = Array.isArray(fixture.mediaAssets) ? fixture.mediaAssets : [];
  const aiSessions = Array.isArray(fixture.aiSessions) ? fixture.aiSessions : [];

  fs.rmSync(out, { recursive: true, force: true });
  ensureDir(out);

  const docsById = buildDocumentIndex(documents);
  const markdownPathByDocId = new Map();
  const assetPathById = new Map();
  const pageIds = {};
  const pageOptions = {};
  const resourceIndex = { version: 1, assets: {} };

  documents.forEach((doc) => {
    const markdownPath = buildMarkdownPath(doc, docsById);
    markdownPathByDocId.set(String(doc.id), markdownPath);
    pageIds[markdownPath] = `local-mdid:${doc.id}`;
    pageOptions[`local-mdid:${doc.id}`] = serializePageOptions(doc);
  });

  mediaAssets.forEach((asset) => {
    const ownerDocId = findDocumentForAsset(asset, documents) || String(documents[0]?.id || "");
    const ownerMarkdownPath = markdownPathByDocId.get(ownerDocId) || "pages/attachments.md";
    const relativePath = buildAssetPath(ownerMarkdownPath, asset.fileName || asset.name || asset.id);
    assetPathById.set(String(asset.id), relativePath);
    resourceIndex.assets[String(asset.id)] = {
      fileName: sanitizeName(asset.fileName || asset.name || asset.id),
      relativePath,
      documentId: ownerDocId || null,
    };
  });

  documents.forEach((doc) => {
    const markdownPath = markdownPathByDocId.get(String(doc.id));
    const assetRoot = markdownPath.replace(/\.md$/i, ".assets");
    const markdownDir = path.posix.dirname(markdownPath);
    const markdownBody = rewriteAssetUrls(
      typeof doc.content === "string"
        ? doc.content
        : String(doc.raw_text || doc.editor_document || doc.tiptap_document || ""),
      new Map(Array.from(assetPathById.entries()).map(([assetId, absolutePath]) => [
        assetId,
        path.posix.relative(markdownDir, absolutePath),
      ])),
    );
    const frontmatter = [
      "---",
      `title: ${String(doc.title || doc.id || "untitled")}`,
      `mnote_id: ${String(doc.id)}`,
      "---",
      "",
    ].join("\n");
    writeUtf8(path.join(out, markdownPath), `${frontmatter}${markdownBody}`);
    ensureDir(path.join(out, assetRoot));
  });

  mediaAssets.forEach((asset) => {
    const relativePath = assetPathById.get(String(asset.id));
    if (!relativePath) return;
    const target = path.join(out, relativePath);
    writeUtf8(target, decodeAssetContent(asset));
  });

  aiSessions.forEach((session) => {
    const sessionId = sanitizeName(session.sessionId || session.id || "session");
    const shareId = String(session.shareId || session.share_id || "").trim();
    const visibility = String(session.visibility || "").trim();
    const dir = shareId || visibility === "shared"
      ? path.join(out, "ai-sessions", "shared", sanitizeName(shareId || "share"))
      : path.join(out, "ai-sessions", "private");
    ensureDir(dir);
    const filePath = path.join(dir, `${sessionId}.jsonl`);
    const events = Array.isArray(session.events) ? session.events : [];
    const lines = events.map((event) => JSON.stringify(event)).join("\n");
    writeUtf8(filePath, lines ? `${lines}\n` : "");
  });

  writeUtf8(path.join(out, ".mnote", "page-ids.json"), JSON.stringify({ version: 1, pages: pageIds }, null, 2));
  writeUtf8(path.join(out, ".mnote", "page-options.json"), JSON.stringify({ version: 1, pages: pageOptions }, null, 2));
  writeUtf8(path.join(out, ".mnote", "resource-index.json"), JSON.stringify(resourceIndex, null, 2));
  writeUtf8(
    path.join(out, ".mnote", "workspace.json"),
    JSON.stringify(
      {
        workspaceId: fixture.workspace?.id || "exported-workspace",
        ownerId: fixture.workspace?.ownerId || fixture.workspace?.owner_id || "unknown",
        createdAt: new Date().toISOString(),
        capabilities: ["local_files", "ai_sessions", "exported_from_convex"],
      },
      null,
      2,
    ),
  );

  console.log(JSON.stringify({ ok: true, out }, null, 2));
}

if (require.main === module) {
  try {
    main();
  } catch (error) {
    console.error(error instanceof Error ? error.stack || error.message : String(error));
    process.exit(1);
  }
}