"use client";

import AgoraRTC, {
  IAgoraRTCClient,
  IMicrophoneAudioTrack,
  IRemoteAudioTrack,
  UID,
} from "agora-rtc-sdk-ng";
import { EMessageDataType, EMessageType, IChatItem, ITextItem } from "@/types";
import { AGEventEmitter } from "../events";
import { RtcEvents, IUserTracks } from "./types";
import { apiGenAgoraData, VideoSourceType } from "@/common";

const TIMEOUT_MS = 5000; // Timeout for incomplete messages

interface TextDataChunk {
  message_id: string;
  part_index: number;
  total_parts: number;
  content: string;
}

export class RtcManager extends AGEventEmitter<RtcEvents> {
  private _joined;
  client: IAgoraRTCClient;
  localTracks: IUserTracks;
  appId: string | null = null;
  token: string | null = null;
  userId: number | null = null;

  constructor() {
    super();
    this._joined = false;
    this.localTracks = {};
    this.client = AgoraRTC.createClient({ mode: "rtc", codec: "vp8" });
    this._listenRtcEvents();
  }

  async join({ channel, userId }: { channel: string; userId: number }) {
    if (!this._joined) {
      const res = await apiGenAgoraData({ channel, userId });
      const { code, data } = res;
      if (code != 0) {
        throw new Error("Failed to get Agora token");
      }
      const { appId, token } = data;
      this.appId = appId;
      this.token = token;
      this.userId = userId;
      await this.client?.join(appId, channel, token, userId);
      this._joined = true;
    }
  }

  async createCameraTracks() {
    try {
      const videoTrack = await AgoraRTC.createCameraVideoTrack();
      this.localTracks.videoTrack = videoTrack;
    } catch (err) {
      console.error("Failed to create video track", err);
    }
    this.emit("localTracksChanged", this.localTracks);
  }

  async createMicrophoneAudioTrack() {
    try {
      const audioTrack = await AgoraRTC.createMicrophoneAudioTrack();
      this.localTracks.audioTrack = audioTrack;
    } catch (err) {
      console.error("Failed to create audio track", err);
    }
    this.emit("localTracksChanged", this.localTracks);
  }

  async createScreenShareTrack() {
    try {
      const screenTrack = await AgoraRTC.createScreenVideoTrack({
        encoderConfig: {
          width: 1200,
          height: 800,
          frameRate: 5
        }
      }, "disable");
      this.localTracks.screenTrack = screenTrack;
    } catch (err) {
      console.error("Failed to create screen track", err);
    }
    this.emit("localTracksChanged", this.localTracks);
  }

  async switchVideoSource(type: VideoSourceType) {
    if (type === VideoSourceType.SCREEN) {
      await this.createScreenShareTrack();
      if (this.localTracks.screenTrack) {
        this.client.unpublish(this.localTracks.videoTrack);
        this.localTracks.videoTrack?.close();
        this.localTracks.videoTrack = undefined;
        this.client.publish(this.localTracks.screenTrack);
        this.emit("localTracksChanged", this.localTracks);
      }
    } else if (type === VideoSourceType.CAMERA) {
      await this.createCameraTracks();
      if (this.localTracks.videoTrack) {
        this.client.unpublish(this.localTracks.screenTrack);
        this.localTracks.screenTrack?.close();
        this.localTracks.screenTrack = undefined;
        this.client.publish(this.localTracks.videoTrack);
        this.emit("localTracksChanged", this.localTracks);
      }
    }
  }

  async publish() {
    const tracks = [];
    if (this.localTracks.videoTrack) {
      tracks.push(this.localTracks.videoTrack);
    }
    if (this.localTracks.audioTrack) {
      tracks.push(this.localTracks.audioTrack);
    }
    if (tracks.length) {
      await this.client.publish(tracks);
    }
  }

  async destroy() {
    this.localTracks?.audioTrack?.close();
    this.localTracks?.videoTrack?.close();
    if (this._joined) {
      await this.client?.leave();
    }
    this._resetData();
  }

  // ----------- public methods ------------

  // -------------- private methods --------------
  private _listenRtcEvents() {
    this.client.on("network-quality", (quality) => {
      this.emit("networkQuality", quality);
    });
    this.client.on("user-published", async (user, mediaType) => {
      await this.client.subscribe(user, mediaType);
      if (mediaType === "audio") {
        this._playAudio(user.audioTrack);
      }
      this.emit("remoteUserChanged", {
        userId: user.uid,
        audioTrack: user.audioTrack,
        videoTrack: user.videoTrack,
      });
    });
    this.client.on("user-unpublished", async (user, mediaType) => {
      await this.client.unsubscribe(user, mediaType);
      this.emit("remoteUserChanged", {
        userId: user.uid,
        audioTrack: user.audioTrack,
        videoTrack: user.videoTrack,
      });
    });
    this.client.on("stream-message", (uid: UID, stream: any) => {
      this._parseData(stream);
    });
  }

  private _parseData(data: any): ITextItem | void {
    let decoder = new TextDecoder("utf-8");
    let decodedMessage = decoder.decode(data);

    console.log("[test] textstream raw data", decodedMessage);

    // const { stream_id, is_final, text, text_ts, data_type, message_id, part_number, total_parts } = textstream;

    // if (total_parts > 0) {
    //   // If message is split, handle it accordingly
    //   this._handleSplitMessage(message_id, part_number, total_parts, stream_id, is_final, text, text_ts);
    // } else {
    //   // If there is no message_id, treat it as a complete message
    //   this._handleCompleteMessage(stream_id, is_final, text, text_ts);
    // }

    this.handleChunk(decodedMessage);
  }

  private messageCache: { [key: string]: TextDataChunk[] } = {};

  // Function to process received chunk via event emitter
  handleChunk(formattedChunk: string) {
    try {
      // Split the chunk by the delimiter "|"
      const [message_id, partIndexStr, totalPartsStr, content] =
        formattedChunk.split("|");

      const part_index = parseInt(partIndexStr, 10);
      const total_parts =
        totalPartsStr === "???" ? -1 : parseInt(totalPartsStr, 10); // -1 means total parts unknown

      // Ensure total_parts is known before processing further
      if (total_parts === -1) {
        console.warn(
          `Total parts for message ${message_id} unknown, waiting for further parts.`
        );
        return;
      }

      const chunkData: TextDataChunk = {
        message_id,
        part_index,
        total_parts,
        content,
      };

      // Check if we already have an entry for this message
      if (!this.messageCache[message_id]) {
        this.messageCache[message_id] = [];
        // Set a timeout to discard incomplete messages
        setTimeout(() => {
          if (this.messageCache[message_id]?.length !== total_parts) {
            console.warn(`Incomplete message with ID ${message_id} discarded`);
            delete this.messageCache[message_id]; // Discard incomplete message
          }
        }, TIMEOUT_MS);
      }

      // Cache this chunk by message_id
      this.messageCache[message_id].push(chunkData);

      // If all parts are received, reconstruct the message
      if (this.messageCache[message_id].length === total_parts) {
        const completeMessage = this.reconstructMessage(
          this.messageCache[message_id]
        );
        const { stream_id, is_final, text, text_ts, data_type } = JSON.parse(
          atob(completeMessage)
        );
        console.log(`[test] message_id: ${message_id} stream_id: ${stream_id}, text: ${text}, data_type: ${data_type}`);
        const isAgent = Number(stream_id) != Number(this.userId)
        let textItem: IChatItem = {
          type: isAgent ? EMessageType.AGENT : EMessageType.USER,
          time: text_ts,
          text: text,
          data_type: EMessageDataType.TEXT,
          userId: stream_id,
          isFinal: is_final,
        };;

        if (data_type === "raw") {
          let { data, type } = JSON.parse(text);
          if (type === "image_url") {
            textItem = {
              ...textItem,
              data_type: EMessageDataType.IMAGE,
              text: data.image_url,
            };
          } else if (type === "reasoning") {
            textItem = {
              ...textItem,
              data_type: EMessageDataType.REASON,
              text: data.text,
            };
          } else if (type === "action") {
            const { action, data: actionData } = data
            if (action === "browse_website") {
              console.log("Opening website", actionData.url)
              window.open(actionData.url, "_blank")
              return
            }
          }
        }

        if (text.trim().length > 0) {
          this.emit("textChanged", textItem);
        }

        // Clean up the cache
        delete this.messageCache[message_id];
      }
    } catch (error) {
      console.error("Error processing chunk:", error);
    }
  }

  // Function to reconstruct the full message from chunks
  reconstructMessage(chunks: TextDataChunk[]): string {
    // Sort chunks by their part index
    chunks.sort((a, b) => a.part_index - b.part_index);

    // Concatenate all chunks to form the full message
    return chunks.map((chunk) => chunk.content).join("");
  }

  _playAudio(
    audioTrack: IMicrophoneAudioTrack | IRemoteAudioTrack | undefined
  ) {
    if (audioTrack && !audioTrack.isPlaying) {
      audioTrack.play();
    }
  }

  private _resetData() {
    this.localTracks = {};
    this._joined = false;
  }
}

export const rtcManager = new RtcManager();