#!/usr/bin/env node
/**
 * Remove duplicate MindSpace pages for one user, keeping one page per workspace path/title.
 *
 * Usage:
 *   node scripts/dedupe-user-pages.mjs --username=john --dry-run
 *   node scripts/dedupe-user-pages.mjs --username=john --yes
 */
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import fs from 'node:fs';
import { createDbPool } from '../db.mjs';
import { createPageService } from '../mindspace-pages.mjs';
import { loadH5Environment } from './load-env.mjs';

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const root = path.join(scriptDir, '..');
loadH5Environment(scriptDir);

function readArg(name) {
  const prefix = `--${name}=`;
  const hit = process.argv.find((arg) => arg.startsWith(prefix));
  return hit ? hit.slice(prefix.length).trim() : null;
}

function loadEnvFromFile(filePath) {
  if (!fs.existsSync(filePath)) return;
  for (const line of fs.readFileSync(filePath, 'utf8').split('\n')) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) continue;
    const eq = trimmed.indexOf('=');
    if (eq < 0) continue;
    const key = trimmed.slice(0, eq).trim();
    const value = trimmed.slice(eq + 1).trim();
    if (!process.env[key]) process.env[key] = value;
  }
}

const prodEnv = '/Users/john/Project/Memind/.env';
if (fs.existsSync(prodEnv)) loadEnvFromFile(prodEnv);

const dryRun = process.argv.includes('--dry-run');
const confirmed = process.argv.includes('--yes');
const removeFromPlaza = process.argv.includes('--remove-from-plaza');
const username = readArg('username');
const userIdArg = readArg('user-id');

const storageRoot = process.env.MINDSPACE_STORAGE_ROOT
  ? path.resolve(process.env.MINDSPACE_STORAGE_ROOT)
  : path.join(root, 'data', 'mindspace');
const h5Root = process.env.MINDSPACE_H5_ROOT
  ? path.resolve(process.env.MINDSPACE_H5_ROOT)
  : root;

async function resolveUserId(pool) {
  if (userIdArg) return userIdArg;
  if (!username) throw new Error('请指定 --username=... 或 --user-id=...');
  const [rows] = await pool.query(
    `SELECT id, username, email FROM h5_users WHERE username = ? LIMIT 1`,
    [username],
  );
  const row = rows[0];
  if (!row) throw new Error(`用户不存在: ${username}`);
  return row.id;
}

function groupKey(row) {
  const relativePath = String(row.relative_path ?? '').trim();
  if (relativePath) return `path:${relativePath}`;
  const title = String(row.title ?? '').trim().toLowerCase();
  return `title:${title || row.id}`;
}

function mergeGroupsByTitle(groups) {
  const titleToPathKey = new Map();
  for (const [key, items] of groups.entries()) {
    if (!key.startsWith('path:')) continue;
    const title = String(items[0]?.title ?? '').trim().toLowerCase();
    if (title) titleToPathKey.set(title, key);
  }
  for (const [key, items] of [...groups.entries()]) {
    if (!key.startsWith('title:')) continue;
    const title = key.slice('title:'.length);
    const pathKey = titleToPathKey.get(title);
    if (!pathKey) continue;
    groups.get(pathKey).push(...items);
    groups.delete(key);
  }
  return groups;
}

function pickKeeper(rows) {
  return [...rows].sort((left, right) => {
    const leftHasPath = Boolean(String(left.relative_path ?? '').trim());
    const rightHasPath = Boolean(String(right.relative_path ?? '').trim());
    if (leftHasPath !== rightHasPath) return rightHasPath ? 1 : -1;
    const pubDiff = Number(right.has_online_pub ?? 0) - Number(left.has_online_pub ?? 0);
    if (pubDiff !== 0) return pubDiff;
    const sessionDiff = Number(Boolean(right.source_session_id)) - Number(Boolean(left.source_session_id));
    if (sessionDiff !== 0) return sessionDiff;
    const updatedDiff = Number(right.updated_at ?? 0) - Number(left.updated_at ?? 0);
    if (updatedDiff !== 0) return updatedDiff;
    return String(left.id).localeCompare(String(right.id));
  })[0];
}

const pool = createDbPool();
const pageService = createPageService(pool, { h5Root, storageRoot });

try {
  const userId = await resolveUserId(pool);
  const [userRows] = await pool.query(
    `SELECT username, email FROM h5_users WHERE id = ? LIMIT 1`,
    [userId],
  );
  const user = userRows[0];

  const [rows] = await pool.query(
    `SELECT p.id, p.title, p.source_session_id, p.created_at, p.updated_at,
            JSON_UNQUOTE(JSON_EXTRACT(pv.source_snapshot_json, '$.relative_path')) AS relative_path,
            EXISTS(
              SELECT 1 FROM h5_publish_records pr
              WHERE pr.page_id = p.id AND pr.user_id = p.user_id AND pr.status = 'online'
            ) AS has_online_pub
     FROM h5_page_records p
     JOIN h5_page_versions pv ON pv.id = p.current_version_id
     WHERE p.user_id = ? AND p.status <> 'deleted'
     ORDER BY p.updated_at DESC, p.id DESC`,
    [userId],
  );

  const groups = new Map();
  for (const row of rows) {
    const key = groupKey(row);
    if (!groups.has(key)) groups.set(key, []);
    groups.get(key).push(row);
  }
  mergeGroupsByTitle(groups);

  const duplicateGroups = [...groups.entries()].filter(([, items]) => items.length > 1);
  const toDelete = [];
  for (const [key, items] of duplicateGroups) {
    const keeper = pickKeeper(items);
    for (const item of items) {
      if (item.id !== keeper.id) {
        toDelete.push({ key, keeperId: keeper.id, page: item });
      }
    }
  }

  console.log(`用户: ${user?.username ?? userId} (${user?.email ?? 'unknown'})`);
  console.log(`总页面: ${rows.length}`);
  console.log(`重复组: ${duplicateGroups.length}`);
  console.log(`待删除重复页: ${toDelete.length}`);

  for (const [key, items] of duplicateGroups.sort((a, b) => b[1].length - a[1].length).slice(0, 20)) {
    const keeper = pickKeeper(items);
    console.log(`- ${key}: ${items.length} 份，保留 ${keeper.id}，删除 ${items.length - 1} 份`);
  }
  if (duplicateGroups.length > 20) {
    console.log(`... 另有 ${duplicateGroups.length - 20} 组未展开`);
  }

  if (toDelete.length === 0) {
    console.log('没有需要清理的重复页面。');
    process.exit(0);
  }

  if (dryRun) {
    console.log('[dry-run] 未执行删除。');
    process.exit(0);
  }

  if (!confirmed) {
    console.error('请加 --yes 确认删除，或先用 --dry-run 查看。');
    process.exit(1);
  }

  let deleted = 0;
  let failed = 0;
  for (const entry of toDelete) {
    try {
      await pageService.deletePage(userId, entry.page.id, { removeFromPlaza });
      deleted += 1;
      if (deleted % 25 === 0) {
        console.log(`已删除 ${deleted}/${toDelete.length} ...`);
      }
    } catch (error) {
      failed += 1;
      const message = error instanceof Error ? error.message : String(error);
      console.error(`删除失败 ${entry.page.id} (${entry.page.title}): ${message}`);
    }
  }

  const [remainingRows] = await pool.query(
    `SELECT COUNT(*) AS count FROM h5_page_records WHERE user_id = ? AND status <> 'deleted'`,
    [userId],
  );
  console.log('---');
  console.log(`完成：删除 ${deleted}，失败 ${failed}，剩余 ${Number(remainingRows[0]?.count ?? 0)} 页`);
  process.exit(failed > 0 ? 1 : 0);
} finally {
  await pool.end();
}