import IframeReference from './IframeReference';
import EventBus from './EventBus';
import UserStore from './UserStrore';
import { isProfileData, type ProfileCreated, type ProfileData } from './models/ProfileData';
import { isFolderData, type FolderCreated, type FolderData } from './models/FolderData';
import { v4 as uuidv4 } from 'uuid';
import type { RoleDefinition } from './models/Roles';

export default class MessageBus {
  private static instance: MessageBus;
  private readonly origin: string;
  private messageListener: ((event: MessageEvent) => void) | null = null;
  private errors: { [key: string]: string } = {};
  private readyPromise: Promise<void> | null = null;
  private isReadyFlag = false;

  private constructor(origin: string) {
    this.origin = origin;
  }

  public static getInstance(origin: string): MessageBus {
    if (!MessageBus.instance) {
      MessageBus.instance = new MessageBus(origin);
    }
    return MessageBus.instance;
  }

  public isReady(): Promise<void> {
    if (this.isReadyFlag) {
      return Promise.resolve();
    }

    if (this.readyPromise) {
      return this.readyPromise;
    }

    this.readyPromise = new Promise<void>((resolve) => {
      const correlationId = uuidv4();
      this.initMessageListener(correlationId);

      const unsubscribe = EventBus.getInstance().on('IS_READY', (responseId: string) => {
        if (responseId !== correlationId) return;
        unsubscribe();
        this.destroyMessageListener();
        this.isReadyFlag = true;
        resolve();
      });
    });

    return this.readyPromise;
  }

  public requestLink(): Promise<void> {
    return new Promise<void>((resolve: () => void, reject: (error: string) => void) => {
      const correlationId = uuidv4();
      this.initMessageListener(correlationId);

      const unsubscribe = EventBus.getInstance().on('LINK_ACCEPTED', (responseId: string, accessToken: string, refreshToken: string) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribe();
        this.destroyMessageListener();
        UserStore.getInstance().connect(accessToken, refreshToken);
        resolve();
      });

      const unsubscribeError = EventBus.getInstance().on('ERROR_LINK_ACCEPTED', (responseId: string, error: string) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribeError();
        this.destroyMessageListener();
        reject(error);
      });

      this.sendMessage({
        type: 'REQUEST_LINK'
      });
    });
  }

  public getUserPairingId(): Promise<string> {
    return new Promise<string>((resolve: (userPairingId: string) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('PAIRING_ID', (responseId: string, userPairingId: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve(userPairingId);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_PAIRING_ID', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'GET_PAIRING_ID',
          accessToken,
        });
      }).catch(console.error);
    });
  }

  public validateToken(): Promise<boolean> {
    return new Promise<boolean>((resolve: (isValid: boolean) => void, reject: (error: string) => void) => {
      const userStore = UserStore.getInstance();
      if (!userStore.isConnected()) {
        reject('User is not connected');
        return;
      }
      const accessToken = userStore.getAccessToken()!;
      const refreshToken = userStore.getRefreshToken()!;

      const correlationId = uuidv4();
      this.initMessageListener(correlationId);

      const unsubscribe = EventBus.getInstance().on('TOKEN_VALIDATED', (responseId: string, isValid: boolean) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribe();
        this.destroyMessageListener();
        resolve(isValid);
      });

      const unsubscribeError = EventBus.getInstance().on('ERROR_TOKEN_VALIDATED', (responseId: string, error: string) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribeError();
        this.destroyMessageListener();
        reject(error);
      });

      this.sendMessage({
        type: 'VALIDATE_TOKEN',
        accessToken,
        refreshToken
      });
    });
  }

  public renewToken(): Promise<void> {
    return new Promise<void>((resolve: () => void, reject: (error: string) => void) => {
      const userStore = UserStore.getInstance();
      if (!userStore.isConnected()) {
        reject('User is not connected');
        return;
      }
      const refreshToken = userStore.getRefreshToken()!;

      const correlationId = uuidv4();
      this.initMessageListener(correlationId);

      const unsubscribe = EventBus.getInstance().on('TOKEN_RENEWED', (responseId: string, accessToken: string, refreshToken: string) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribe();
        this.destroyMessageListener();
        UserStore.getInstance().connect(accessToken, refreshToken);
        resolve();
      });

      const unsubscribeError = EventBus.getInstance().on('ERROR_TOKEN_RENEWED', (responseId: string, error: string) => {
        if (responseId !== correlationId) {
          return;
        }
        unsubscribeError();
        this.destroyMessageListener();
        reject(error);
      });

      this.sendMessage({
        type: 'RENEW_TOKEN',
        refreshToken
      });
    });
  }

  public getProcesses(): Promise<any> {
    return new Promise<any>((resolve: (processes: any) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        console.log(correlationId);
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('PROCESSES_RETRIEVED', (responseId: string, processes: any) => {
          console.log(responseId);
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve(processes);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_PROCESSES_RETRIEVED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'GET_PROCESSES',
          accessToken,
        });
      }).catch(console.error);
    });
  }

  public getMyProcesses(): Promise<string[]> {
    return new Promise<string[]>((resolve: (myProcesses: string[]) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('GET_MY_PROCESSES', (responseId: string, myProcesses: string[]) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve(myProcesses);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_GET_MY_PROCESSES', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'GET_MY_PROCESSES',
          accessToken,
        });
      }).catch(console.error);
    });
  }

  public getData(processId: string, stateId: string): Promise<any> {
    return new Promise<any>((resolve: (data: any) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('DATA_RETRIEVED', (responseId: string, data: any) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve(data);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_DATA_RETRIEVED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'RETRIEVE_DATA',
          processId,
          stateId,
          token: accessToken
        });
      }).catch(console.error);
    });
  }

  public createProfile(profileData: ProfileData, profilePrivateData: string[], roles: Record<string, RoleDefinition>): Promise<ProfileCreated> {
    return new Promise<ProfileCreated>((resolve: (profileCreated: ProfileCreated) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('PROCESS_CREATED', (responseId: string, processCreated: any) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          // Return value must contain the data commited in the new process
          const profileData = processCreated.processData;
          if (!profileData || !isProfileData(profileData)) {
            reject('Returned invalid profile data');
          }
          if (!processCreated.processId || typeof processCreated.processId !== 'string') {
            console.error('Returned invalid process id');
            reject('Returned invalid process id');
          }
          // TODO check that process is of type Process

          const profileCreated: ProfileCreated = {
            processId: processCreated.processId,
            process: processCreated.process,
            profileData
          };

          resolve(profileCreated);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_PROCESS_CREATED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'CREATE_PROCESS',
          processData: profileData,
          privateFields: profilePrivateData,
          roles,
          accessToken
        });
      }).catch(console.error);
    });
  }

  public createFolder(folderData: FolderData, folderPrivateData: string[], roles: Record<string, RoleDefinition>): Promise<FolderCreated> {
    return new Promise<FolderCreated>((resolve: (folderData: FolderCreated) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('PROCESS_CREATED', (responseId: string, processCreated: any) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          // Return value must contain the data commited in the new process
          const folderData = processCreated.processData;
          if (!folderData || !isFolderData(folderData)) reject('Returned invalid process data');
          if (!processCreated.processId || typeof processCreated.processId !== 'string') reject('Returned invalid process id');
          // TODO check that process is of type Process

          const folderCreated: FolderCreated = {
            processId: processCreated.processId,
            process: processCreated.process,
            folderData
          };

          resolve(folderCreated);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_PROCESS_CREATED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'CREATE_PROCESS',
          processData: folderData,
          privateFields: folderPrivateData,
          roles,
          accessToken
        });
      }).catch(console.error);
    });
  }

  public notifyProcessUpdate(processId: string, stateId: string): Promise<void> {
    return new Promise<void>((resolve: () => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('UPDATE_NOTIFIED', (responseId: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve();
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_UPDATE_NOTIFIED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'NOTIFY_UPDATE',
          processId,
          stateId,
          accessToken
        });
      }).catch(console.error);
    });
  }

  public validateState(processId: string, stateId: string): Promise<any> {
    return new Promise<any>((resolve: (updatedProcess: any) => void, reject: (error: string) => void) => {
      this.checkToken().then(() => {
        const userStore = UserStore.getInstance();
        const accessToken = userStore.getAccessToken()!;

        const correlationId = uuidv4();
        this.initMessageListener(correlationId);

        const unsubscribe = EventBus.getInstance().on('STATE_VALIDATED', (responseId: string, updatedProcess: any) => {
          console.log(updatedProcess);
          if (responseId !== correlationId) {
            return;
          }
          unsubscribe();
          this.destroyMessageListener();
          resolve(updatedProcess);
        });

        const unsubscribeError = EventBus.getInstance().on('ERROR_STATE_VALIDATED', (responseId: string, error: string) => {
          if (responseId !== correlationId) {
            return;
          }
          unsubscribeError();
          this.destroyMessageListener();
          reject(error);
        });

        this.sendMessage({
          type: 'VALIDATE_STATE',
          processId,
          stateId,
          accessToken
        });
      }).catch(console.error);
    });
  }

  private checkToken(): Promise<void> {
    return new Promise<void>((resolve: () => void, reject: (error: string) => void) => {
      this.validateToken().then((isValid: boolean) => {
        if (!isValid) {
          this.renewToken().then(resolve).catch(reject);
        } else {
          resolve();
        }
      }).catch(reject);
    });
  }

  private sendMessage(message: any): void {
    const iframe = IframeReference.getIframe();
    if (!iframe) {
      console.error('[MessageBus] sendMessage: iframe not found');
      return;
    }
    console.log('[MessageBus] sendMessage:', message);
    iframe.contentWindow?.postMessage(message, this.origin);
  }

  private initMessageListener(correlationId: string): void {
    this.destroyMessageListener();

    this.messageListener = this.handleMessage.bind(this, correlationId);
    window.addEventListener('message', this.messageListener);
  }

  private destroyMessageListener(): void {
    if (this.messageListener) {
      window.removeEventListener('message', this.messageListener);
      this.messageListener = null;
    }
  }

  private handleMessage(correlationId: string, event: MessageEvent): void {
    if (event.origin !== this.origin) {
      return;
    }

    if (!event.data || typeof event.data !== 'object') {
      return;
    }

    const message = event.data;
    switch (message.type) {
      case 'LISTENING':
        EventBus.getInstance().emit('IS_READY', correlationId);
        break;

      case 'LINK_ACCEPTED':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_LINK_ACCEPTED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('LINK_ACCEPTED', correlationId, message.accessToken, message.refreshToken);
        break;

      case 'VALIDATE_TOKEN':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_TOKEN_VALIDATED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('TOKEN_VALIDATED', correlationId, message.isValid);
        break;

      case 'RENEW_TOKEN':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_TOKEN_RENEWED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('TOKEN_RENEWED', correlationId, message.accessToken, message.refreshToken);
        break;

      case 'GET_PAIRING_ID':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_PAIRING_ID', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('PAIRING_ID', correlationId, message.userPairingId);
        break;

      case 'PROCESSES_RETRIEVED': // GET_PROCESSES
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_PROCESSES_RETRIEVED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('PROCESSES_RETRIEVED', correlationId, message.processes);
        break;

      case 'GET_MY_PROCESSES': 
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_GET_MY_PROCESSES', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('GET_MY_PROCESSES', correlationId, message.myProcesses);
        break;

      case 'PROFILE_CREATED': // CREATE_PROFILE
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_PROFILE_CREATED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('PROFILE_CREATED', correlationId, message.profileCreated);
        break;

      case 'FOLDER_CREATED': // CREATE_FOLDER
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_FOLDER_CREATED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('FOLDER_CREATED', message.folderCreated);
        break;

      case 'DATA_RETRIEVED': // RETRIEVE_DATA
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_DATA_RETRIEVED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('DATA_RETRIEVED', correlationId, message.data);
        break;

      case 'PROCESS_CREATED':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_PROCESS_CREATED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('PROCESS_CREATED', correlationId, message.processCreated);
        break;

      case 'UPDATE_NOTIFIED':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_UPDATE_NOTIFIED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('UPDATE_NOTIFIED', correlationId);
        break;
        
      case 'STATE_VALIDATED':
        if (this.errors[correlationId]) {
          const error = this.errors[correlationId];
          delete this.errors[correlationId];
          EventBus.getInstance().emit('ERROR_STATE_VALIDATED', correlationId, error);
          return;
        }
        EventBus.getInstance().emit('MESSAGE_RECEIVED', message);
        EventBus.getInstance().emit('STATE_VALIDATED', correlationId, message.validatedProcess);
        break;

      case 'ERROR':
        console.error('Error:', message);
        this.errors[correlationId] = message.error;
        break;
    }
  }
}