import "dotenv/config";
import express from "express";
import path from "path";
import { fileURLToPath } from "url";
import { client, all, get, run, initDb } from "./db.js";
import {
  noteToMarkdown,
  notesToHtml,
  htmlToPdf,
  categoryPath,
  safeName,
  makeZip,
} from "./export.js";
import { requireApiAuth, isAuthed, loginHandler, logoutHandler } from "./auth.js";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const PUBLIC = path.join(__dirname, "public");
const app = express();
const PORT = process.env.PORT || 3000;

app.set("trust proxy", 1);
app.use(express.json());

// ---------- Auth (single admin) ----------
app.post("/api/login", loginHandler);
app.post("/api/logout", logoutHandler);
app.get("/api/me", (req, res) => res.json({ authed: isAuthed(req) }));

// Static assets (css/js/login page) are public; index=false so "/" hits our gate
app.use(express.static(PUBLIC, { index: false }));

// Everything under /api (besides the auth routes above) requires login
app.use("/api", requireApiAuth);

// ---------- Helpers ----------
const bool = (v) => (v ? 1 : 0);
// Wrap async route handlers so rejections become a 500 instead of crashing
const h = (fn) => (req, res) =>
  fn(req, res).catch((e) => {
    console.error(e);
    if (!res.headersSent) res.status(500).json({ error: e.message });
  });

function buildCategoryTree(rows) {
  const map = new Map();
  rows.forEach((r) => map.set(r.id, { ...r, children: [] }));
  const roots = [];
  for (const cat of map.values()) {
    if (cat.parent_id && map.has(cat.parent_id)) {
      map.get(cat.parent_id).children.push(cat);
    } else {
      roots.push(cat);
    }
  }
  return roots;
}

// ===================================================================
//  CATEGORIES
// ===================================================================
app.get("/api/categories", h(async (req, res) => {
  const { kind } = req.query;
  const rows = kind
    ? await all("SELECT * FROM categories WHERE kind = ? ORDER BY id", [kind])
    : await all("SELECT * FROM categories ORDER BY id");
  res.json({ flat: rows, tree: buildCategoryTree(rows) });
}));

app.post("/api/categories", h(async (req, res) => {
  const { name, parent_id = null, kind = "task", color = null } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: "İsim gerekli" });
  const info = await run(
    "INSERT INTO categories (name, parent_id, kind, color) VALUES (?, ?, ?, ?)",
    [name.trim(), parent_id || null, kind, color]
  );
  res.json(await get("SELECT * FROM categories WHERE id = ?", [info.lastInsertRowid]));
}));

app.put("/api/categories/:id", h(async (req, res) => {
  const { name, color, parent_id } = req.body;
  const cur = await get("SELECT * FROM categories WHERE id = ?", [req.params.id]);
  if (!cur) return res.status(404).json({ error: "Bulunamadı" });
  await run("UPDATE categories SET name = ?, color = ?, parent_id = ? WHERE id = ?", [
    name ?? cur.name,
    color ?? cur.color,
    parent_id === undefined ? cur.parent_id : parent_id,
    req.params.id,
  ]);
  res.json(await get("SELECT * FROM categories WHERE id = ?", [req.params.id]));
}));

app.delete("/api/categories/:id", h(async (req, res) => {
  await run("DELETE FROM categories WHERE id = ?", [req.params.id]);
  res.json({ ok: true });
}));

// ===================================================================
//  TODOS
// ===================================================================
app.get("/api/todos", h(async (req, res) => {
  const { category_id, priority, status, due_from, due_to, search } = req.query;
  const where = [];
  const params = [];

  if (category_id) {
    // include subcategories of a parent
    const subIds = (
      await all("SELECT id FROM categories WHERE id = ? OR parent_id = ?", [category_id, category_id])
    ).map((r) => r.id);
    where.push(`t.category_id IN (${subIds.map(() => "?").join(",")})`);
    params.push(...subIds);
  }
  if (priority) {
    where.push("t.priority = ?");
    params.push(priority);
  }
  if (status === "active") where.push("t.completed = 0");
  if (status === "done") where.push("t.completed = 1");
  if (due_from) {
    where.push("t.due_date >= ?");
    params.push(due_from);
  }
  if (due_to) {
    where.push("t.due_date <= ?");
    params.push(due_to);
  }
  if (search) {
    where.push("(t.title LIKE ? OR t.description LIKE ?)");
    params.push(`%${search}%`, `%${search}%`);
  }

  const sql = `
    SELECT t.*, c.name AS category_name, c.color AS category_color
      FROM todos t LEFT JOIN categories c ON c.id = t.category_id
    ${where.length ? "WHERE " + where.join(" AND ") : ""}
    ORDER BY t.completed ASC, t.sort_order ASC, t.created_at DESC`;
  res.json(await all(sql, params));
}));

// Manual reorder (drag & drop): body { ids: [orderedTodoIds] }
app.put("/api/todos/reorder", h(async (req, res) => {
  const { ids } = req.body;
  if (!Array.isArray(ids)) return res.status(400).json({ error: "ids dizisi gerekli" });
  await client.batch(
    ids.map((id, i) => ({ sql: "UPDATE todos SET sort_order = ? WHERE id = ?", args: [i, id] })),
    "write"
  );
  res.json({ ok: true });
}));

app.post("/api/todos", h(async (req, res) => {
  const { title, description = "", category_id = null, priority = "P3", due_date = null } = req.body;
  if (!title?.trim()) return res.status(400).json({ error: "Başlık gerekli" });
  // New tasks go to the top of the manual order
  const minOrder = (await get("SELECT MIN(sort_order) AS m FROM todos")).m;
  const sortOrder = (minOrder ?? 0) - 1;
  const info = await run(
    `INSERT INTO todos (title, description, category_id, priority, due_date, sort_order)
     VALUES (?, ?, ?, ?, ?, ?)`,
    [title.trim(), description, category_id || null, priority, due_date || null, sortOrder]
  );
  res.json(await get("SELECT * FROM todos WHERE id = ?", [info.lastInsertRowid]));
}));

app.put("/api/todos/:id", h(async (req, res) => {
  const cur = await get("SELECT * FROM todos WHERE id = ?", [req.params.id]);
  if (!cur) return res.status(404).json({ error: "Bulunamadı" });
  const b = req.body;
  await run(
    `UPDATE todos SET
       title = ?, description = ?, category_id = ?, priority = ?,
       due_date = ?, completed = ?, updated_at = datetime('now')
     WHERE id = ?`,
    [
      b.title ?? cur.title,
      b.description ?? cur.description,
      b.category_id === undefined ? cur.category_id : b.category_id || null,
      b.priority ?? cur.priority,
      b.due_date === undefined ? cur.due_date : b.due_date || null,
      b.completed === undefined ? cur.completed : bool(b.completed),
      req.params.id,
    ]
  );
  res.json(await get("SELECT * FROM todos WHERE id = ?", [req.params.id]));
}));

app.delete("/api/todos/:id", h(async (req, res) => {
  await run("DELETE FROM todos WHERE id = ?", [req.params.id]);
  res.json({ ok: true });
}));

// ===================================================================
//  NOTES (Knowledge Center)
// ===================================================================
// Collect a folder id plus all of its (recursive) subfolder ids
async function descendantCategoryIds(rootId) {
  const cats = await all("SELECT id, parent_id FROM categories");
  const ids = [Number(rootId)];
  let added = true;
  while (added) {
    added = false;
    for (const c of cats) {
      if (c.parent_id && ids.includes(c.parent_id) && !ids.includes(c.id)) {
        ids.push(c.id);
        added = true;
      }
    }
  }
  return ids;
}

async function queryNotes({ category_id, search } = {}) {
  const where = [];
  const params = [];
  if (category_id) {
    const ids = await descendantCategoryIds(category_id);
    where.push(`n.category_id IN (${ids.map(() => "?").join(",")})`);
    params.push(...ids);
  }
  if (search) {
    where.push("(n.title LIKE ? OR n.content LIKE ?)");
    params.push(`%${search}%`, `%${search}%`);
  }
  return all(
    `SELECT n.*, c.name AS category_name, c.color AS category_color
       FROM notes n LEFT JOIN categories c ON c.id = n.category_id
     ${where.length ? "WHERE " + where.join(" AND ") : ""}
     ORDER BY n.pinned DESC, n.updated_at DESC`,
    params
  );
}

app.get("/api/notes", h(async (req, res) => {
  res.json(await queryNotes(req.query));
}));

app.post("/api/notes", h(async (req, res) => {
  const { title, content = "", category_id = null, pinned = false } = req.body;
  if (!title?.trim()) return res.status(400).json({ error: "Başlık gerekli" });
  const info = await run(
    "INSERT INTO notes (title, content, category_id, pinned) VALUES (?, ?, ?, ?)",
    [title.trim(), content, category_id || null, bool(pinned)]
  );
  res.json(await get("SELECT * FROM notes WHERE id = ?", [info.lastInsertRowid]));
}));

app.put("/api/notes/:id", h(async (req, res) => {
  const cur = await get("SELECT * FROM notes WHERE id = ?", [req.params.id]);
  if (!cur) return res.status(404).json({ error: "Bulunamadı" });
  const b = req.body;
  await run(
    `UPDATE notes SET title = ?, content = ?, category_id = ?, pinned = ?, updated_at = datetime('now') WHERE id = ?`,
    [
      b.title ?? cur.title,
      b.content ?? cur.content,
      b.category_id === undefined ? cur.category_id : b.category_id || null,
      b.pinned === undefined ? cur.pinned : bool(b.pinned),
      req.params.id,
    ]
  );
  res.json(await get("SELECT * FROM notes WHERE id = ?", [req.params.id]));
}));

app.delete("/api/notes/:id", h(async (req, res) => {
  await run("DELETE FROM notes WHERE id = ?", [req.params.id]);
  res.json({ ok: true });
}));

// ===================================================================
//  EXPORT (Markdown / PDF)  —  bulk routes BEFORE :id routes
// ===================================================================
function noteById(id) {
  return get(
    `SELECT n.*, c.name AS category_name FROM notes n
       LEFT JOIN categories c ON c.id = n.category_id WHERE n.id = ?`,
    [id]
  );
}

const dl = (res, name) => {
  // ASCII fallback + RFC 5987 UTF-8 filename for Turkish/non-ASCII names
  const ascii = name.replace(/[^\x20-\x7E]/g, "_").replace(/"/g, "'");
  res.setHeader(
    "Content-Disposition",
    `attachment; filename="${ascii}"; filename*=UTF-8''${encodeURIComponent(name)}`
  );
};
const stamp = () => new Date().toISOString().slice(0, 10);

// --- Bulk: all filtered notes as a ZIP of .md files (folder structure preserved) ---
app.get("/api/notes/export/md", h(async (req, res) => {
  const notes = await queryNotes(req.query);
  const cats = await all("SELECT * FROM categories");
  const files = [];
  const used = new Set();
  for (const n of notes) {
    const folder = n.category_id ? categoryPath(n.category_id, cats) : "Kategorisiz";
    let entry = `${folder}/${safeName(n.title)}.md`;
    let i = 2;
    while (used.has(entry)) entry = `${folder}/${safeName(n.title)} (${i++}).md`;
    used.add(entry);
    files.push({ name: entry, data: noteToMarkdown(n, folder) });
  }
  if (!files.length) files.push({ name: "BOS.md", data: "Not bulunamadı.\n" });
  const zip = makeZip(files);
  res.setHeader("Content-Type", "application/zip");
  dl(res, `notlar-${stamp()}.zip`);
  res.end(zip);
}));

// --- Bulk: all filtered notes as a single PDF ---
app.get("/api/notes/export/pdf", h(async (req, res) => {
  const notes = await queryNotes(req.query);
  const cats = await all("SELECT * FROM categories");
  const pathFn = (id) => (id ? categoryPath(id, cats) : "");
  const html = notesToHtml(notes, pathFn, "Bilgi Merkezi");
  const pdf = await htmlToPdf(html);
  res.setHeader("Content-Type", "application/pdf");
  dl(res, `notlar-${stamp()}.pdf`);
  res.end(pdf);
}));

// --- Single note as .md ---
app.get("/api/notes/:id/export/md", h(async (req, res) => {
  const note = await noteById(req.params.id);
  if (!note) return res.status(404).json({ error: "Bulunamadı" });
  const cats = await all("SELECT * FROM categories");
  const folder = note.category_id ? categoryPath(note.category_id, cats) : "";
  res.setHeader("Content-Type", "text/markdown; charset=utf-8");
  dl(res, `${safeName(note.title)}.md`);
  res.end(noteToMarkdown(note, folder));
}));

// --- Single note as PDF ---
app.get("/api/notes/:id/export/pdf", h(async (req, res) => {
  const note = await noteById(req.params.id);
  if (!note) return res.status(404).json({ error: "Bulunamadı" });
  const cats = await all("SELECT * FROM categories");
  const pathFn = (id) => (id ? categoryPath(id, cats) : "");
  const html = notesToHtml([note], pathFn, note.title);
  const pdf = await htmlToPdf(html);
  res.setHeader("Content-Type", "application/pdf");
  dl(res, `${safeName(note.title)}.pdf`);
  res.end(pdf);
}));

// SPA fallback — gate behind login, otherwise show the login page
app.get("*", (req, res) => {
  if (!isAuthed(req)) return res.sendFile(path.join(PUBLIC, "login.html"));
  res.sendFile(path.join(PUBLIC, "index.html"));
});

// ---------- Boot ----------
await initDb();
app.listen(PORT, () => {
  console.log(`\n🚀 Uygulama çalışıyor:  http://localhost:${PORT}\n`);
});