import { IReduxState } from '../app/types';
import { isLocalParticipantModerator, isParticipantModerator } from '../base/participants/functions';
import { IParticipant } from '../base/participants/types';
import { isInBreakoutRoom } from '../breakout-rooms/functions';

import {
    MEDIA_TYPE,
    MEDIA_TYPE_TO_PENDING_STORE_KEY,
    MEDIA_TYPE_TO_WHITELIST_STORE_KEY,
    MediaType
} from './constants';

/**
 * Returns this feature's root state.
 *
 * @param {IReduxState} state - Global state.
 * @returns {Object} Feature state.
 */
const getState = (state: IReduxState) => state['features/av-moderation'];

/**
 * We use to construct once the empty array so we can keep the same instance between calls
 * of getParticipantsAskingToAudioUnmute.
 *
 * @type {any[]}
 */
const EMPTY_ARRAY: any[] = [];

/**
 * Returns whether moderation is enabled per media type.
 *
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @param {IReduxState} state - Global state.
 * @returns {boolean}
 */
export const isEnabledFromState = (mediaType: MediaType, state: IReduxState) => {
    switch (mediaType) {
    case MEDIA_TYPE.AUDIO:
        return getState(state)?.audioModerationEnabled === true;
    case MEDIA_TYPE.DESKTOP:
        return getState(state)?.desktopModerationEnabled === true;
    case MEDIA_TYPE.VIDEO:
        return getState(state)?.videoModerationEnabled === true;
    default:
        throw new Error(`Unknown media type: ${mediaType}`);
    }
};

/**
 * Returns whether moderation is enabled per media type.
 *
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @returns {boolean}
 */
export const isEnabled = (mediaType: MediaType) => (state: IReduxState) => isEnabledFromState(mediaType, state);

/**
 * Returns whether moderation is supported by the backend.
 *
 * @returns {boolean}
 */
export const isSupported = () => (state: IReduxState) => {
    const { conference } = state['features/base/conference'];

    return Boolean(!isInBreakoutRoom(state) && conference?.isAVModerationSupported());
};

/**
 * Returns whether local participant is approved to unmute a media type.
 *
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @param {IReduxState} state - Global state.
 * @returns {boolean}
 */
export const isLocalParticipantApprovedFromState = (mediaType: MediaType, state: IReduxState) => {
    if (isLocalParticipantModerator(state)) {
        return true;
    }

    switch (mediaType) {
    case MEDIA_TYPE.AUDIO:
        return getState(state).audioUnmuteApproved === true;
    case MEDIA_TYPE.DESKTOP:
        return getState(state).desktopUnmuteApproved === true;
    case MEDIA_TYPE.VIDEO:
        return getState(state).videoUnmuteApproved === true;
    default:
        throw new Error(`Unknown media type: ${mediaType}`);
    }
};

/**
 * Returns whether local participant is approved to unmute a media type.
 *
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @returns {boolean}
 */
export const isLocalParticipantApproved = (mediaType: MediaType) =>
    (state: IReduxState) =>
        isLocalParticipantApprovedFromState(mediaType, state);

/**
 * Returns a selector creator which determines if the participant is approved or not for a media type.
 *
 * @param {string} id - The participant id.
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @returns {boolean}
 */
export const isParticipantApproved = (id: string, mediaType: MediaType) => (state: IReduxState) => {
    const storeKey = MEDIA_TYPE_TO_WHITELIST_STORE_KEY[mediaType];

    const avModerationState = getState(state);
    const stateForMediaType = avModerationState[storeKey as keyof typeof avModerationState];

    return Boolean(stateForMediaType && stateForMediaType[id as keyof typeof stateForMediaType]);
};

/**
 * Returns a selector creator which determines if the participant is pending or not for a media type.
 *
 * @param {IParticipant} participant - The participant.
 * @param {MEDIA_TYPE} mediaType - The media type to check.
 * @returns {boolean}
 */
export const isParticipantPending = (participant: IParticipant, mediaType: MediaType) => (state: IReduxState) => {
    const storeKey = MEDIA_TYPE_TO_PENDING_STORE_KEY[mediaType];
    const arr = getState(state)[storeKey];

    return Boolean(arr.find(pending => pending.id === participant.id));
};

/**
 * Selector which returns a list with all the participants asking to audio unmute.
 * This is visible only for the moderator.
 *
 * @param {Object} state - The global state.
 * @returns {Array<Object>}
 */
export const getParticipantsAskingToAudioUnmute = (state: IReduxState) => {
    if (isLocalParticipantModerator(state)) {
        return getState(state).pendingAudio;
    }

    return EMPTY_ARRAY;
};

/**
 * Returns true if a special notification can be displayed when a participant
 * tries to unmute.
 *
 * @param {MediaType} mediaType - 'audio' or 'video' media type.
 * @param {Object} state - The global state.
 * @returns {boolean}
 */
export const shouldShowModeratedNotification = (mediaType: MediaType, state: IReduxState) =>
    isEnabledFromState(mediaType, state)
    && !isLocalParticipantApprovedFromState(mediaType, state);

/**
 * Checks if a participant is force muted.
 *
 * @param {IParticipant|undefined} participant - The participant.
 * @param {MediaType} mediaType - The media type.
 * @param {IReduxState} state - The redux state.
 * @returns {MediaState}
 */
export function isForceMuted(participant: IParticipant | undefined, mediaType: MediaType, state: IReduxState) {
    if (isEnabledFromState(mediaType, state)) {
        if (participant?.local) {
            return !isLocalParticipantApprovedFromState(mediaType, state);
        }

        // moderators cannot be force muted
        if (isParticipantModerator(participant)) {
            return false;
        }

        return !isParticipantApproved(participant?.id ?? '', mediaType)(state);
    }

    return false;
}