/**
 * android-wechat-tracker-sqlcipher.js — 通过 sqlcipher 轮询 WeChat DB 检测新消息
 *
 * 不依赖 LSPosed HOOK，直接查询 EnMicroMsg.db 的 message 表。
 * 需要 root 权限（su -c）。
 */

const { spawn } = require('child_process');
const EventEmitter = require('events');
const fs = require('fs');

const DB_PATH = '/data/data/com.tencent.mm/MicroMsg/653cdc2320abb089e149a3f7a7683fcf/EnMicroMsg.db';
const SQLCIPHER_KEY = 'e03ce81';
const SQLCIPHER_BIN = '/data/data/com.termux/files/usr/bin/sqlcipher';

function hasRoot() {
  return process.getuid && process.getuid() === 0;
}

function wrapCmd(cmd) {
  if (hasRoot()) return cmd;
  return `su -c "${cmd.replace(/"/g, '\\"')}"`;
}

function shell(cmd, timeoutMs = 15000) {
  const fullCmd = wrapCmd(cmd);
  const args = ['-c', fullCmd];
  const shellBin = process.env.SHELL || '/system/bin/sh';

  return new Promise((resolve, reject) => {
    const proc = spawn(shellBin, args, { timeout: timeoutMs });
    let stdout = '';
    let stderr = '';
    proc.stdout.on('data', d => stdout += d.toString());
    proc.stderr.on('data', d => stderr += d.toString());
    proc.on('close', code => {
      if (code !== 0) {
        reject(new Error(`exit ${code}: ${stderr.trim() || stdout.trim()}`));
      } else {
        resolve(stdout.trim());
      }
    });
    proc.on('error', reject);
  });
}

class AndroidWechatTrackerSQLCipher extends EventEmitter {
  constructor() {
    super();
    this.polling = false;
    this.lastMsgId = 0;
    this.dbPath = DB_PATH;
  }

  async init() {
    const out = await this._query(`SELECT MAX(msgId) AS max_id FROM message;`, 5000);
    const val = this._extractValue(out, 'max_id');
    this.lastMsgId = parseInt(val, 10) || 0;
    console.log(`[TrackerSQLCipher] DB: ${this.dbPath}, lastMsgId: ${this.lastMsgId}`);
  }

  async _query(sql, timeoutMs = 10000) {
    // 使用 .mode line 和 .headers off 获取干净输出
    const script = `.headers off\n.mode line\nPRAGMA key="${SQLCIPHER_KEY}";\nPRAGMA cipher_compatibility=1;\nPRAGMA cipher_page_size=1024;\n${sql}\n`;
    // 写入临时文件避免命令行转义问题
    const tmpFile = `/data/data/com.termux/files/usr/tmp/sqlcipher_query_${Date.now()}.sql`;
    fs.writeFileSync(tmpFile, script);
    const cmd = `${SQLCIPHER_BIN} "${this.dbPath}" < ${tmpFile}`;
    const out = await shell(cmd, timeoutMs);
    // 清理临时文件
    try { fs.unlinkSync(tmpFile); } catch (_) {}
    return out;
  }

  _extractValue(out, columnName) {
    if (!out) return '';
    const lines = out.trim().split('\n');
    // .mode line 输出格式: columnName = value 或 columnName: value
    for (const line of lines) {
      const trimmed = line.trim();
      const eqPrefix = `${columnName} = `;
      const colonPrefix = `${columnName}: `;
      if (trimmed.startsWith(eqPrefix)) {
        return trimmed.substring(eqPrefix.length);
      }
      if (trimmed.startsWith(colonPrefix)) {
        return trimmed.substring(colonPrefix.length);
      }
    }
    return '';
  }

  /**
   * 获取新消息（msgId > lastMsgId）
   */
  async fetchNew() {
    // 只查询文本消息 (type=1) 和撤回通知 (type=10002)，排除自己发送的
    const sql = `SELECT msgId, type, isSend, talker, content, createTime FROM message WHERE msgId > ${this.lastMsgId} AND isSend = 0 AND type IN (1, 10002) ORDER BY msgId ASC;`;
    const out = await this._query(sql, 10000);
    const msgs = this._parseRows(out);
    if (msgs.length > 0) {
      this.lastMsgId = Math.max(...msgs.map(m => m.msgId));
    }
    return msgs;
  }

  /**
   * 查询 talker 最近 limit 条文本消息（按时间正序），用于喂给 hermes 做上下文。
   * 返回 [{ msgId, isSend, content, createTime }, ...]
   */
  async fetchHistory(talker, limit = 10) {
    const safeTalker = String(talker).replace(/'/g, "''");
    const sql = `SELECT msgId, isSend, content, createTime FROM message `
      + `WHERE talker='${safeTalker}' AND type=1 `
      + `ORDER BY msgId DESC LIMIT ${parseInt(limit, 10) || 10};`;
    const out = await this._query(sql, 10000);
    const rows = this._parseRows(out);
    // _parseRows 期望 msgId/talker/content 等字段，这里 talker 没查所以补一下
    return rows
      .map(r => ({
        msgId: r.msgId,
        isSend: r.isSend,
        content: r.content,
        createTime: r.createTime,
      }))
      .reverse(); // 正序：旧 → 新
  }

  /**
   * 根据 wxid 查询联系人的显示名（用于 A11y 搜索框输入）。
   * 优先级：conRemark（备注名）→ nickname → 内置 helper 映射 → wxid 本身
   *
   * @param {string} wxid
   * @returns {Promise<string>}
   */
  async getContactNickname(wxid) {
    if (!wxid) return '';

    // 微信内置 helper 没有 rcontact 记录，直接硬编码
    const builtin = {
      filehelper: '文件传输助手',
      weixin: '微信团队',
      newsapp: '腾讯新闻',
    };
    if (builtin[wxid]) return builtin[wxid];

    // 群聊 ID 走另一个表（chatroom），先简单返回 wxid 让上层处理
    if (wxid.endsWith('@chatroom')) {
      return wxid;
    }

    const safeWxid = String(wxid).replace(/'/g, "''");
    const sql = `SELECT conRemark, nickname FROM rcontact WHERE username='${safeWxid}' LIMIT 1;`;
    try {
      const out = await this._query(sql, 5000);
      const conRemark = this._extractValue(out, 'conRemark');
      const nickname = this._extractValue(out, 'nickname');
      return conRemark || nickname || wxid;
    } catch (_) {
      return wxid;
    }
  }

  startPolling(intervalMs = 3000) {
    if (this.polling) return;
    this.polling = true;

    const tick = async () => {
      if (!this.polling) return;
      try {
        const msgs = await this.fetchNew();
        for (const msg of msgs) {
          this.emit('message', msg);
        }
      } catch (e) {
        // 静默失败，防止日志刷屏
        if (!e.message.includes('database is locked')) {
          this.emit('error', e);
        }
      }
      setTimeout(tick, intervalMs);
    };

    tick();
  }

  stopPolling() {
    this.polling = false;
  }

  _parseRows(text) {
    const messages = [];
    if (!text) return messages;

    // .mode line 输出格式：每行一个 "column = value"，记录之间用空行分隔
    const records = [];
    let current = {};
    for (const line of text.split('\n')) {
      const trimmed = line.trim();
      if (!trimmed) {
        if (Object.keys(current).length > 0) {
          records.push(current);
          current = {};
        }
        continue;
      }
      // sqlcipher .mode line 输出格式: "key: value" 或 "key = value"
      let sepIdx = trimmed.indexOf(': ');
      if (sepIdx < 0) sepIdx = trimmed.indexOf(' = ');
      if (sepIdx > 0) {
        const key = trimmed.substring(0, sepIdx).trim();
        const val = trimmed.substring(sepIdx + 2).trim();
        current[key] = val;
      }
    }
    if (Object.keys(current).length > 0) {
      records.push(current);
    }

    for (const rec of records) {
      if (!rec.msgId) continue;
      const isSendVal = parseInt(rec.isSend, 10);
      messages.push({
        msgId: parseInt(rec.msgId, 10),
        msgType: parseInt(rec.type, 10),
        isSend: isSendVal,
        talker: rec.talker || '',
        content: rec.content || '',
        createTime: parseInt(rec.createTime, 10),
        type: isSendVal === 1 ? 'send' : 'recv',
        timestamp: Date.now(),
        raw: JSON.stringify(rec),
      });
    }
    return messages;
  }
}

module.exports = { AndroidWechatTrackerSQLCipher, shell };