const path = require("path");
const fs = require("fs");
const socket = require("./socket.js");
const db = require("./db.js");
const {
  bot,
  getDisplayName,
  getGroupMsgSpeaker,
  getGroupMsgContent,
  getNickName,
} = require("./bot.js");
const {
  composeMessageID,
  composeMediaFilePath,
  composeFilename,
  composeCacheFilePath,
  fileMD5,
  ensureMediaDir,
} = require("./util");

async function processMessage(msg) {
  if ([50, 51, 52, 53, 9999].includes(msg.MsgType)) {
    return;
  }
  const peerContact = bot.contacts[msg.getPeerUserName()];
  const fromContact = bot.contacts[msg["FromUserName"]];
  const toContact = bot.contacts[msg["ToUserName"]];
  if (!peerContact || !fromContact || !toContact) {
    // TODO: notify self
    return;
  }
  if (
    bot.Contact.isPublicContact(peerContact) ||
    (bot.Contact.isSpContact(peerContact) &&
      peerContact.UserName !== "filehelper")
  ) {
    return;
  }

  ensureMediaDir(msg);

  const msgID = msg["MsgId"];
  const msgType = msg["MsgType"];

  const m = {
    messageID: msgID,
    composedID: composeMessageID(msg),
    createTimestamp: msg["CreateTime"],
    messageType: msgType,
    fromID: msg["FromUserName"],
    toID: msg["ToUserName"],
    fromName: getDisplayName(fromContact),
    fromNickName: getNickName(fromContact),
    toName: getDisplayName(toContact),
    toNickName: getNickName(toContact),
    type: "unknown",
    content: null,
    group: bot.Contact.isRoomContact(peerContact) ? peerContact : null,
    speakingGroupMember: null,
    filename: null,
    displayFilename: msg["FileName"] || "",
    fileSize: msg.FileSize | 0,
    isGroupMessage: bot.Contact.isRoomContact(peerContact),
    isSentBySelf: msg.isSendBySelf,
  };

  if (m.isGroupMessage) {
    if (!msg.isSendBySelf) {
      m.speakingGroupMember = getGroupMsgSpeaker(msg);
    }
  }

  switch (msgType) {
    case bot.CONF.MSGTYPE_TEXT:
      // 文本消息
      m.type = "text";
      m.content = m.isGroupMessage ? getGroupMsgContent(msg) : msg["Content"];
      break;
    case bot.CONF.MSGTYPE_EMOTICON:
    case bot.CONF.MSGTYPE_IMAGE: {
      const suffix = msgType === bot.CONF.MSGTYPE_IMAGE ? ".jpg" : ".gif";
      m.type = "img";
      m.content =
        `[${msgType === bot.CONF.MSGTYPE_IMAGE ? "图片" : "表情"}]` +
        (msg["FileName"] || "");
      if (msg["HasProductId"]) {
        m.type = "unknown";
        m.content = "[表情贴图]请在手机上查看";
        break;
      }
      const cachePath = composeCacheFilePath(msg, suffix);
      // ENHANCE: 提前判断表情是否存在，节约带宽
      const res = await bot.getMsgImg(msg.MsgId);
      fs.writeFileSync(cachePath, res.data);
      const md5 = await fileMD5(cachePath);
      m.filename = md5 + suffix;
      const filename = composeMediaFilePath(msg, m.filename);
      if (fs.existsSync(filename)) {
        fs.rmSync(cachePath);
      } else {
        fs.renameSync(cachePath, filename);
      }
      break;
    }
    case bot.CONF.MSGTYPE_VOICE: {
      m.type = "voice";
      m.content = "[语音消息]";
      m.filename = composeFilename(msg, ".mp3");
      const { data } = await bot.getVoice(msg.MsgId);
      fs.writeFileSync(composeMediaFilePath(msg, m.filename), data);
      break;
    }
    case bot.CONF.MSGTYPE_VIDEO:
    case bot.CONF.MSGTYPE_MICROVIDEO: {
      m.type = "video";
      m.content = "[视频]";
      const suffix = ".mp4";
      const cachePath = composeCacheFilePath(msg, suffix);
      const res = await bot.getVideo(msg.MsgId);
      fs.writeFileSync(cachePath, res.data);
      const md5 = await fileMD5(cachePath);
      m.filename = md5 + suffix;
      const filename = composeMediaFilePath(msg, m.filename);
      if (fs.existsSync(filename)) {
        fs.rmSync(cachePath);
      } else {
        fs.renameSync(cachePath, filename);
      }
      break;
    }
    case bot.CONF.MSGTYPE_APP:
      if (msg.AppMsgType === 5) {
        m.type = "text";
        m.content = "[链接]" + msg["FileName"] + ": " + msg["Url"];
        break;
      } else if (msg.AppMsgType == 6) {
        m.type = "file";
        m.content = "[文件]" + m.displayFilename;
        if (!(msg.FileSize < 10 * 1024 * 1024)) {
          // 忽略10M以上的大文件
          m.type = "unknown";
          m.filename = null;
          break;
        }
        const suffix = path.extname(m.displayFilename);
        const cachePath = composeCacheFilePath(msg, suffix);
        const res = await bot.getDoc(
          msg.FromUserName,
          msg.MediaId,
          msg.FileName
        );
        fs.writeFileSync(cachePath, res.data);
        const md5 = await fileMD5(cachePath);
        m.filename = md5 + suffix;
        const filename = composeMediaFilePath(msg, m.filename);
        if (fs.existsSync(filename)) {
          fs.rmSync(cachePath);
        } else {
          fs.renameSync(cachePath, filename);
        }
        break;
      }
      break;
    default:
      break;
  }
  if (m.type === "unknown") {
    m.content ||= "未知类型的消息，请在手机上查看";
  }

  const dbMsg = {
    messageID: m.composedID,
    createTimestamp: m.createTimestamp,
    type: m.type,
    messageType: m.messageType,
    fromName: m.fromName,
    fromNickName: m.fromNickName,
    toName: m.toName,
    toNickName: m.toNickName,
    isGroupMessage: m.isGroupMessage,
    speakingGroupMemberName:
      (m.speakingGroupMember && getDisplayName(m.speakingGroupMember)) || null,
    content: m.content,
    filename: m.filename,
    fileSize: m.fileSize,
    displayFilename: m.displayFilename,
    isSentBySelf: m.isSentBySelf,
  };
  const clientMsg = {
    messageID: m.composedID,
    createTimestamp: m.createTimestamp,
    type: m.type,
    fromID: m.fromID,
    fromName: m.fromName,
    fromNickName: m.fromNickName,
    toID: m.toID,
    toName: m.toName,
    toNickName: m.toNickName,
    isGroupMessage: m.isGroupMessage,
    isSentBySelf: m.isSentBySelf,
    speakingGroupMemberID:
      m.speakingGroupMember && m.speakingGroupMember.UserName,
    speakingGroupMemberName:
      (m.speakingGroupMember && getDisplayName(m.speakingGroupMember)) || null,
    content: m.content,
    filename: m.filename,
    fileSize: m.fileSize,
    displayFilename: m.displayFilename,
  };
  if (!bot.Contact.isSpContact(peerContact)) {
    await db.pushMessage(dbMsg);
  }
  socket.pushMessage(clientMsg);
}

module.exports = {
  processMessage,
};