import {
  PermissionResponse,
  PermissionStatus,
  PermissionHookOptions,
  createPermissionHook,
  EventEmitter,
  Subscription,
  Platform,
} from 'expo-modules-core';

import {
  _DEFAULT_PROGRESS_UPDATE_INTERVAL_MILLIS,
  AVPlaybackStatus,
  AVPlaybackStatusToSet,
} from '../AV';
import ExponentAV from '../ExponentAV';
import { isAudioEnabled, throwIfAudioIsDisabled } from './AudioAvailability';
import { RecordingOptions, RecordingStatus } from './Recording.types';
import { RECORDING_OPTIONS_PRESET_LOW_QUALITY } from './RecordingConstants';
import { Sound } from './Sound';

let _recorderExists: boolean = false;
const eventEmitter = Platform.OS === 'android' ? new EventEmitter(ExponentAV) : null;

export async function getPermissionsAsync(): Promise<PermissionResponse> {
  return ExponentAV.getPermissionsAsync();
}

export async function requestPermissionsAsync(): Promise<PermissionResponse> {
  return ExponentAV.requestPermissionsAsync();
}

/**
 * Check or request permissions to record audio.
 * This uses both `requestPermissionAsync` and `getPermissionsAsync` to interact with the permissions.
 *
 * @example
 * ```ts
 * const [status, requestPermission] = Audio.usePermissions();
 * ```
 */
export const usePermissions = createPermissionHook({
  getMethod: getPermissionsAsync,
  requestMethod: requestPermissionsAsync,
});

export class Recording {
  _subscription: Subscription | null = null;
  _canRecord: boolean = false;
  _isDoneRecording: boolean = false;
  _finalDurationMillis: number = 0;
  _uri: string | null = null;
  _onRecordingStatusUpdate: ((status: RecordingStatus) => void) | null = null;
  _progressUpdateTimeoutVariable: number | null = null;
  _progressUpdateIntervalMillis: number = _DEFAULT_PROGRESS_UPDATE_INTERVAL_MILLIS;
  _options: RecordingOptions | null = null;

  // Internal methods

  _cleanupForUnloadedRecorder = async (finalStatus?: RecordingStatus) => {
    this._canRecord = false;
    this._isDoneRecording = true;
    this._finalDurationMillis = finalStatus?.durationMillis ?? 0;
    _recorderExists = false;
    if (this._subscription) {
      this._subscription.remove();
      this._subscription = null;
    }
    this._disablePolling();
    return await this.getStatusAsync(); // Automatically calls onRecordingStatusUpdate for the final state.
  };

  _pollingLoop = async () => {
    if (isAudioEnabled() && this._canRecord && this._onRecordingStatusUpdate != null) {
      this._progressUpdateTimeoutVariable = setTimeout(
        this._pollingLoop,
        this._progressUpdateIntervalMillis
      ) as any;
      try {
        await this.getStatusAsync();
      } catch (error) {
        this._disablePolling();
      }
    }
  };

  _disablePolling() {
    if (this._progressUpdateTimeoutVariable != null) {
      clearTimeout(this._progressUpdateTimeoutVariable);
      this._progressUpdateTimeoutVariable = null;
    }
  }

  _enablePollingIfNecessaryAndPossible() {
    if (isAudioEnabled() && this._canRecord && this._onRecordingStatusUpdate != null) {
      this._disablePolling();
      this._pollingLoop();
    }
  }

  _callOnRecordingStatusUpdateForNewStatus(status: RecordingStatus) {
    if (this._onRecordingStatusUpdate != null) {
      this._onRecordingStatusUpdate(status);
    }
  }

  async _performOperationAndHandleStatusAsync(
    operation: () => Promise<RecordingStatus>
  ): Promise<RecordingStatus> {
    throwIfAudioIsDisabled();
    if (this._canRecord) {
      const status = await operation();
      this._callOnRecordingStatusUpdateForNewStatus(status);
      return status;
    } else {
      throw new Error('Cannot complete operation because this recorder is not ready to record.');
    }
  }

  // Note that all calls automatically call onRecordingStatusUpdate as a side effect.

  static createAsync = async (
    options: RecordingOptions = RECORDING_OPTIONS_PRESET_LOW_QUALITY,
    onRecordingStatusUpdate: ((status: RecordingStatus) => void) | null = null,
    progressUpdateIntervalMillis: number | null = null
  ): Promise<{ recording: Recording; status: RecordingStatus }> => {
    const recording: Recording = new Recording();
    if (progressUpdateIntervalMillis) {
      recording._progressUpdateIntervalMillis = progressUpdateIntervalMillis;
    }
    recording.setOnRecordingStatusUpdate(onRecordingStatusUpdate);
    await recording.prepareToRecordAsync({
      ...options,
      keepAudioActiveHint: true,
    });
    try {
      const status = await recording.startAsync();
      return { recording, status };
    } catch (err) {
      recording.stopAndUnloadAsync();
      throw err;
    }
  };

  // Get status API

  getStatusAsync = async (): Promise<RecordingStatus> => {
    // Automatically calls onRecordingStatusUpdate.
    if (this._canRecord) {
      return this._performOperationAndHandleStatusAsync(() => ExponentAV.getAudioRecordingStatus());
    }
    const status = {
      canRecord: false,
      isRecording: false,
      isDoneRecording: this._isDoneRecording,
      durationMillis: this._finalDurationMillis,
    };
    this._callOnRecordingStatusUpdateForNewStatus(status);
    return status;
  };

  setOnRecordingStatusUpdate(onRecordingStatusUpdate: ((status: RecordingStatus) => void) | null) {
    this._onRecordingStatusUpdate = onRecordingStatusUpdate;
    if (onRecordingStatusUpdate == null) {
      this._disablePolling();
    } else {
      this._enablePollingIfNecessaryAndPossible();
    }
    this.getStatusAsync();
  }

  setProgressUpdateInterval(progressUpdateIntervalMillis: number) {
    this._progressUpdateIntervalMillis = progressUpdateIntervalMillis;
    this.getStatusAsync();
  }

  // Record API

  async prepareToRecordAsync(
    options: RecordingOptions = RECORDING_OPTIONS_PRESET_LOW_QUALITY
  ): Promise<RecordingStatus> {
    throwIfAudioIsDisabled();

    if (_recorderExists) {
      throw new Error('Only one Recording object can be prepared at a given time.');
    }

    if (this._isDoneRecording) {
      throw new Error('This Recording object is done recording; you must make a new one.');
    }

    if (!options || !options.android || !options.ios) {
      throw new Error(
        'You must provide recording options for android and ios in order to prepare to record.'
      );
    }

    const extensionRegex = /^\.\w+$/;
    if (
      !options.android.extension ||
      !options.ios.extension ||
      !extensionRegex.test(options.android.extension) ||
      !extensionRegex.test(options.ios.extension)
    ) {
      throw new Error(`Your file extensions must match ${extensionRegex.toString()}.`);
    }

    if (!this._canRecord) {
      if (eventEmitter) {
        this._subscription = eventEmitter.addListener(
          'Expo.Recording.recorderUnloaded',
          this._cleanupForUnloadedRecorder
        );
      }

      const {
        uri,
        status,
      }: {
        uri: string | null;
        // status is of type RecordingStatus, but without the canRecord field populated
        status: Pick<RecordingStatus, Exclude<keyof RecordingStatus, 'canRecord'>>;
      } = await ExponentAV.prepareAudioRecorder(options);
      _recorderExists = true;
      this._uri = uri;
      this._options = options;
      this._canRecord = true;

      const currentStatus = { ...status, canRecord: true };
      this._callOnRecordingStatusUpdateForNewStatus(currentStatus);
      this._enablePollingIfNecessaryAndPossible();
      return currentStatus;
    } else {
      throw new Error('This Recording object is already prepared to record.');
    }
  }

  async startAsync(): Promise<RecordingStatus> {
    return this._performOperationAndHandleStatusAsync(() => ExponentAV.startAudioRecording());
  }

  async pauseAsync(): Promise<RecordingStatus> {
    return this._performOperationAndHandleStatusAsync(() => ExponentAV.pauseAudioRecording());
  }

  async stopAndUnloadAsync(): Promise<RecordingStatus> {
    if (!this._canRecord) {
      if (this._isDoneRecording) {
        throw new Error('Cannot unload a Recording that has already been unloaded.');
      } else {
        throw new Error('Cannot unload a Recording that has not been prepared.');
      }
    }
    // We perform a separate native API call so that the state of the Recording can be updated with
    // the final duration of the recording. (We cast stopStatus as Object to appease Flow)
    let stopResult: RecordingStatus | undefined;
    let stopError: Error | undefined;
    try {
      stopResult = await ExponentAV.stopAudioRecording();
    } catch (err) {
      stopError = err;
    }

    // Web has to return the URI at the end of recording, so needs a little destructuring
    if (Platform.OS === 'web' && stopResult?.uri !== undefined) {
      this._uri = stopResult.uri;
    }

    // Clean-up and return status
    await ExponentAV.unloadAudioRecorder();
    const status = await this._cleanupForUnloadedRecorder(stopResult);
    return stopError ? Promise.reject(stopError) : status;
  }

  // Read API

  getURI(): string | null {
    return this._uri;
  }

  /** @deprecated Use `createNewLoadedSoundAsync()` instead */
  async createNewLoadedSound(
    initialStatus: AVPlaybackStatusToSet = {},
    onPlaybackStatusUpdate: ((status: AVPlaybackStatus) => void) | null = null
  ): Promise<{ sound: Sound; status: AVPlaybackStatus }> {
    console.warn(
      `createNewLoadedSound is deprecated in favor of createNewLoadedSoundAsync, which has the same API aside from the method name`
    );
    return this.createNewLoadedSoundAsync(initialStatus, onPlaybackStatusUpdate);
  }

  async createNewLoadedSoundAsync(
    initialStatus: AVPlaybackStatusToSet = {},
    onPlaybackStatusUpdate: ((status: AVPlaybackStatus) => void) | null = null
  ): Promise<{ sound: Sound; status: AVPlaybackStatus }> {
    if (this._uri == null || !this._isDoneRecording) {
      throw new Error('Cannot create sound when the Recording has not finished!');
    }
    return Sound.createAsync(
      // $FlowFixMe: Flow can't distinguish between this literal and Asset
      { uri: this._uri },
      initialStatus,
      onPlaybackStatusUpdate,
      false
    );
  }
}

export * from './RecordingConstants';

export {
  PermissionResponse,
  PermissionStatus,
  PermissionHookOptions,
  RecordingOptions,
  RecordingStatus,
};