/*
Copyright 2022 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import {
    MatrixClient,
    LOCAL_NOTIFICATION_SETTINGS_PREFIX,
    NotificationCountType,
    Room,
    LocalNotificationSettings,
    ReceiptType,
    IMarkedUnreadEvent,
} from "matrix-js-sdk/src/matrix";
import { IndicatorIcon } from "@vector-im/compound-web";

import SettingsStore from "../settings/SettingsStore";
import { NotificationLevel } from "../stores/notifications/NotificationLevel";
import { doesRoomHaveUnreadMessages } from "../Unread";

// MSC2867 is not yet spec at time of writing. We read from both stable
// and unstable prefixes and accept the risk that the format may change,
// since the stable prefix is not actually defined yet.

/**
 * Unstable identifier for the marked_unread event, per MSC2867
 */
export const MARKED_UNREAD_TYPE_UNSTABLE = "com.famedly.marked_unread";
/**
 * Stable identifier for the marked_unread event
 */
export const MARKED_UNREAD_TYPE_STABLE = "m.marked_unread";

export const deviceNotificationSettingsKeys = [
    "notificationsEnabled",
    "notificationBodyEnabled",
    "audioNotificationsEnabled",
];

export function getLocalNotificationAccountDataEventType(deviceId: string | null): string {
    return `${LOCAL_NOTIFICATION_SETTINGS_PREFIX.name}.${deviceId}`;
}

export async function createLocalNotificationSettingsIfNeeded(cli: MatrixClient): Promise<void> {
    if (cli.isGuest()) {
        return;
    }
    const eventType = getLocalNotificationAccountDataEventType(cli.deviceId!);
    const event = cli.getAccountData(eventType);
    // New sessions will create an account data event to signify they support
    // remote toggling of push notifications on this device. Default `is_silenced=true`
    // For backwards compat purposes, older sessions will need to check settings value
    // to determine what the state of `is_silenced`
    if (!event) {
        // If any of the above is true, we fall in the "backwards compat" case,
        // and `is_silenced` will be set to `false`
        const isSilenced = !deviceNotificationSettingsKeys.some((key) => SettingsStore.getValue(key));

        await cli.setAccountData(eventType, {
            is_silenced: isSilenced,
        });
    }
}

export function localNotificationsAreSilenced(cli: MatrixClient): boolean {
    const eventType = getLocalNotificationAccountDataEventType(cli.deviceId!);
    const event = cli.getAccountData(eventType);
    return event?.getContent<LocalNotificationSettings>()?.is_silenced ?? false;
}

/**
 * Mark a room as read
 * @param room
 * @param client
 * @returns a promise that resolves when the room has been marked as read
 */
export async function clearRoomNotification(room: Room, client: MatrixClient): Promise<{} | undefined> {
    const lastEvent = room.getLastLiveEvent();

    await setMarkedUnreadState(room, client, false);

    try {
        if (lastEvent) {
            const receiptType = SettingsStore.getValue("sendReadReceipts", room.roomId)
                ? ReceiptType.Read
                : ReceiptType.ReadPrivate;
            return await client.sendReadReceipt(lastEvent, receiptType, true);
        } else {
            return {};
        }
    } finally {
        // We've had a lot of stuck unread notifications that in e2ee rooms
        // They occur on event decryption when clients try to replicate the logic
        //
        // This resets the notification on a room, even though no read receipt
        // has been sent, particularly useful when the clients has incorrectly
        // notified a user.
        room.setUnreadNotificationCount(NotificationCountType.Highlight, 0);
        room.setUnreadNotificationCount(NotificationCountType.Total, 0);
        for (const thread of room.getThreads()) {
            room.setThreadUnreadNotificationCount(thread.id, NotificationCountType.Highlight, 0);
            room.setThreadUnreadNotificationCount(thread.id, NotificationCountType.Total, 0);
        }
    }
}

/**
 * Marks all rooms with an unread counter as read
 * @param client The matrix client
 * @returns a promise that resolves when all rooms have been marked as read
 */
export function clearAllNotifications(client: MatrixClient): Promise<Array<{} | undefined>> {
    const receiptPromises = client.getRooms().reduce((promises: Array<Promise<{} | undefined>>, room: Room) => {
        if (doesRoomHaveUnreadMessages(room, true)) {
            const promise = clearRoomNotification(room, client);
            promises.push(promise);
        }

        return promises;
    }, []);

    return Promise.all(receiptPromises);
}

/**
 * Gives the marked_unread state of the given room
 * @param room The room to check
 * @returns - The marked_unread state of the room, or undefined if no explicit state is set.
 */
export function getMarkedUnreadState(room: Room): boolean | undefined {
    const currentStateStable = room.getAccountData(MARKED_UNREAD_TYPE_STABLE)?.getContent<IMarkedUnreadEvent>()?.unread;
    const currentStateUnstable = room
        .getAccountData(MARKED_UNREAD_TYPE_UNSTABLE)
        ?.getContent<IMarkedUnreadEvent>()?.unread;
    return currentStateStable ?? currentStateUnstable;
}

/**
 * Sets the marked_unread state of the given room. This sets some room account data that indicates to
 * clients that the user considers this room to be 'unread', but without any actual notifications.
 *
 * @param room The room to set
 * @param client MatrixClient object to use
 * @param unread The new marked_unread state of the room
 */
export async function setMarkedUnreadState(room: Room, client: MatrixClient, unread: boolean): Promise<void> {
    // if there's no event, treat this as false as we don't need to send the flag to clear it if the event isn't there
    const currentState = getMarkedUnreadState(room);

    if (Boolean(currentState) !== unread) {
        // Assuming MSC2867 passes FCP with no changes, we should update to start writing
        // the flag to the stable prefix (or both) and then ultimately use only the
        // stable prefix.
        await client.setRoomAccountData(room.roomId, MARKED_UNREAD_TYPE_UNSTABLE, { unread });
    }
}

/**
 * A helper to transform a notification color to the what the Compound Icon Button
 * expects
 */
export function notificationLevelToIndicator(
    level: NotificationLevel,
): React.ComponentPropsWithRef<typeof IndicatorIcon>["indicator"] {
    if (level <= NotificationLevel.None) {
        return undefined;
    } else if (level <= NotificationLevel.Activity) {
        return "default";
    } else if (level <= NotificationLevel.Notification) {
        return "success";
    } else {
        return "critical";
    }
}

/**
 * Return the thread notification level for a room
 * @param room
 * @returns {NotificationLevel}
 */
export function getThreadNotificationLevel(room: Room): NotificationLevel {
    const notificationCountType = room.threadsAggregateNotificationType;
    switch (notificationCountType) {
        case NotificationCountType.Highlight:
            return NotificationLevel.Highlight;
        case NotificationCountType.Total:
            return NotificationLevel.Notification;
        default:
            return NotificationLevel.Activity;
    }
}