"use strict";

const fs = require("fs");
const path = require("path");
const { obfuscate } = require("./obfuscate");

const C = { reset: "\x1b[0m", dim: "\x1b[2m", green: "\x1b[32m", yellow: "\x1b[33m", red: "\x1b[31m", cyan: "\x1b[36m", white: "\x1b[37m" };

function createLogger({ logDir, retentionDays }) {
  if (!fs.existsSync(logDir)) {
    fs.mkdirSync(logDir, { recursive: true });
  }

  cleanupOldLogs(logDir, retentionDays);
  const cleanupTimer = setInterval(() => cleanupOldLogs(logDir, retentionDays), 3600000);
  cleanupTimer.unref();

  function getLogPath() {
    const date = new Date().toISOString().slice(0, 10);
    return path.join(logDir, `service.${date}.log`);
  }

  function ts() {
    const d = new Date();
    return d.getFullYear() + "-" +
      String(d.getMonth() + 1).padStart(2, "0") + "-" +
      String(d.getDate()).padStart(2, "0") + " " +
      String(d.getHours()).padStart(2, "0") + ":" +
      String(d.getMinutes()).padStart(2, "0") + ":" +
      String(d.getSeconds()).padStart(2, "0") + "." +
      String(d.getMilliseconds()).padStart(3, "0");
  }

  function ipPad(ip) {
    return (ip || "-").padEnd(17);
  }

  // 写文件日志（纯文本格式，异步避免阻塞事件循环）
  function writeFile(line) {
    const filePath = getLogPath();
    const dir = path.dirname(filePath);
    if (!fs.existsSync(dir)) {
      try { fs.mkdirSync(dir, { recursive: true }); } catch (_) {}
    }
    fs.appendFile(filePath, line + "\n", "utf-8", (err) => {
      if (err) console.error(`[logger] 写日志失败: ${filePath} - ${err.message}`);
    });
  }

  // 写控制台 + 文件
  function log(ip, color, icon, msg) {
    const time = ts();
    // 控制台：彩色
    console.log(`${C.dim}${time.slice(-12)}${C.reset} ${color}${icon}${C.reset} ${C.white}${ipPad(ip)}${C.reset} ${msg}`);
    // 文件：纯文本
    writeFile(`${time} ${icon} [${ip || "-"}] ${msg}`);
  }

  return {
    // ── 系统事件 ──
    sys(msg) {
      const time = ts();
      console.log(`${C.dim}${time.slice(-12)}${C.reset} ${C.dim}▸${C.reset} ${C.dim}${msg}${C.reset}`);
      writeFile(`${time} ▸ [system] ${msg}`);
    },

    // ── TCP 握手 ──
    connecting(ip) {
      log(ip, C.cyan, "⏳", `TCP 握手 - 正在连接 ${ip}`);
    },
    connected(ip, port) {
      log(ip, C.green, "✓", `TCP 握手成功 - 已连接 ${ip}:${port}`);
    },
    disconnected(ip, reason) {
      log(ip, C.yellow, "✂", `TCP 连接断开 - ${reason}`);
    },
    reconnecting(ip, delaySec) {
      log(ip, C.cyan, "↻", `计划重连 - ${delaySec.toFixed(1)}s 后重试`);
    },

    // ── 数据收发 ──
    sendK(ip) {
      log(ip, C.yellow, "→", `发送轮询请求`);
    },
    recvK(ip, rawFrame, fieldCount, statusCode) {
      log(ip, C.green, "←", `${obfuscate(rawFrame)}`);
    },

    // ── 异常 ──
    warn(ip, msg) {
      log(ip, C.yellow, "!", msg);
    },
    error(ip, msg, extra) {
      const line = extra ? `${msg} ${JSON.stringify(extra)}` : msg;
      log(ip, C.red, "✗", line);
    },

    // ── 上传事件 ──
    upload(channel, stage, deviceNo, msg) {
      const color = channel === "mqtt" ? C.cyan : channel === "aliyun" ? C.green : C.dim;
      const icon = stage === "publish" || stage === "postProps" ? "↑" :
                   stage === "tuple" ? "⚙" :
                   stage === "connect" ? "✓" :
                   stage === "error" ? "✗" : "·";
      log(deviceNo, color, icon, `[${channel}/${stage}] ${msg}`);
    },

    close() {
      clearInterval(cleanupTimer);
    },
  };
}

function cleanupOldLogs(logDir, retentionDays) {
  const now = Date.now();
  const maxAge = retentionDays * 86400000;

  let files;
  try { files = fs.readdirSync(logDir); } catch (_) { return; }

  for (const file of files) {
    if (!file.endsWith(".log")) continue;
    const filePath = path.join(logDir, file);
    let stat;
    try { stat = fs.statSync(filePath); } catch (_) { continue; }
    if (now - stat.mtimeMs > maxAge) {
      try { fs.unlinkSync(filePath); } catch (_) { /* ignore */ }
    }
  }
}

module.exports = { createLogger };