/*
Copyright 2019-2021 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 React from 'react';
import {_t, _td} from "../../../../../languageHandler";
import {MatrixClientPeg} from "../../../../../MatrixClientPeg";
import * as sdk from "../../../../..";
import AccessibleButton from "../../../elements/AccessibleButton";
import Modal from "../../../../../Modal";
import {replaceableComponent} from "../../../../../utils/replaceableComponent";
import {EventType} from "matrix-js-sdk/src/@types/event";
import { RoomMember } from "matrix-js-sdk/src/models/room-member";
import { MatrixEvent } from "matrix-js-sdk/src/models/event";
import { RoomState } from "matrix-js-sdk/src/models/room-state";
import { compare } from "../../../../../utils/strings";

const plEventsToLabels = {
    // These will be translated for us later.
    [EventType.RoomAvatar]: _td("Change room avatar"),
    [EventType.RoomName]: _td("Change room name"),
    [EventType.RoomCanonicalAlias]: _td("Change main address for the room"),
    [EventType.RoomHistoryVisibility]: _td("Change history visibility"),
    [EventType.RoomPowerLevels]: _td("Change permissions"),
    [EventType.RoomTopic]: _td("Change topic"),
    [EventType.RoomTombstone]: _td("Upgrade the room"),
    [EventType.RoomEncryption]: _td("Enable room encryption"),
    [EventType.RoomServerAcl]: _td("Change server ACLs"),

    // TODO: Enable support for m.widget event type (https://github.com/vector-im/element-web/issues/13111)
    "im.vector.modular.widgets": _td("Modify widgets"),
};

const plEventsToShow = {
    // If an event is listed here, it will be shown in the PL settings. Defaults will be calculated.
    [EventType.RoomAvatar]: {isState: true},
    [EventType.RoomName]: {isState: true},
    [EventType.RoomCanonicalAlias]: {isState: true},
    [EventType.RoomHistoryVisibility]: {isState: true},
    [EventType.RoomPowerLevels]: {isState: true},
    [EventType.RoomTopic]: {isState: true},
    [EventType.RoomTombstone]: {isState: true},
    [EventType.RoomEncryption]: {isState: true},
    [EventType.RoomServerAcl]: {isState: true},

    // TODO: Enable support for m.widget event type (https://github.com/vector-im/element-web/issues/13111)
    "im.vector.modular.widgets": {isState: true},
};

// parse a string as an integer; if the input is undefined, or cannot be parsed
// as an integer, return a default.
function parseIntWithDefault(val, def) {
    const res = parseInt(val);
    return isNaN(res) ? def : res;
}

interface IBannedUserProps {
    canUnban?: boolean;
    member: RoomMember;
    by: string;
    reason?: string;
}

export class BannedUser extends React.Component<IBannedUserProps> {
    private onUnbanClick = (e) => {
        MatrixClientPeg.get().unban(this.props.member.roomId, this.props.member.userId).catch((err) => {
            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            console.error("Failed to unban: " + err);
            Modal.createTrackedDialog('Failed to unban', '', ErrorDialog, {
                title: _t('Error'),
                description: _t('Failed to unban'),
            });
        });
    };

    render() {
        let unbanButton;

        if (this.props.canUnban) {
            unbanButton = (
                <AccessibleButton className='mx_RolesRoomSettingsTab_unbanBtn'
                    kind='danger_sm'
                    onClick={this.onUnbanClick}
                >
                    { _t('Unban') }
                </AccessibleButton>
            );
        }

        const userId = this.props.member.name === this.props.member.userId ? null : this.props.member.userId;
        return (
            <li>
                {unbanButton}
                <span title={_t("Banned by %(displayName)s", {displayName: this.props.by})}>
                    <strong>{ this.props.member.name }</strong> {userId}
                    {this.props.reason ? " " + _t('Reason') + ": " + this.props.reason : ""}
                </span>
            </li>
        );
    }
}

interface IProps {
    roomId: string;
}

@replaceableComponent("views.settings.tabs.room.RolesRoomSettingsTab")
export default class RolesRoomSettingsTab extends React.Component<IProps> {
    componentDidMount() {
        MatrixClientPeg.get().on("RoomState.members", this.onRoomMembership);
    }

    componentWillUnmount() {
        const client = MatrixClientPeg.get();
        if (client) {
            client.removeListener("RoomState.members", this.onRoomMembership);
        }
    }

    private onRoomMembership = (event: MatrixEvent, state: RoomState, member: RoomMember) => {
        if (state.roomId !== this.props.roomId) return;
        this.forceUpdate();
    };

    private populateDefaultPlEvents(eventsSection: Record<string, number>, stateLevel: number, eventsLevel: number) {
        for (const desiredEvent of Object.keys(plEventsToShow)) {
            if (!(desiredEvent in eventsSection)) {
                eventsSection[desiredEvent] = (plEventsToShow[desiredEvent].isState ? stateLevel : eventsLevel);
            }
        }
    }

    private onPowerLevelsChanged = (inputValue: string, powerLevelKey: string) => {
        const client = MatrixClientPeg.get();
        const room = client.getRoom(this.props.roomId);
        const plEvent = room.currentState.getStateEvents('m.room.power_levels', '');
        let plContent = plEvent ? (plEvent.getContent() || {}) : {};

        // Clone the power levels just in case
        plContent = Object.assign({}, plContent);

        const eventsLevelPrefix = "event_levels_";

        const value = parseInt(inputValue);

        if (powerLevelKey.startsWith(eventsLevelPrefix)) {
            // deep copy "events" object, Object.assign itself won't deep copy
            plContent["events"] = Object.assign({}, plContent["events"] || {});
            plContent["events"][powerLevelKey.slice(eventsLevelPrefix.length)] = value;
        } else {
            const keyPath = powerLevelKey.split('.');
            let parentObj;
            let currentObj = plContent;
            for (const key of keyPath) {
                if (!currentObj[key]) {
                    currentObj[key] = {};
                }
                parentObj = currentObj;
                currentObj = currentObj[key];
            }
            parentObj[keyPath[keyPath.length - 1]] = value;
        }

        client.sendStateEvent(this.props.roomId, "m.room.power_levels", plContent).catch(e => {
            console.error(e);

            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createTrackedDialog('Power level requirement change failed', '', ErrorDialog, {
                title: _t('Error changing power level requirement'),
                description: _t(
                    "An error occurred changing the room's power level requirements. Ensure you have sufficient " +
                    "permissions and try again.",
                ),
            });
        });
    };

    private onUserPowerLevelChanged = (value: string, powerLevelKey: string) => {
        const client = MatrixClientPeg.get();
        const room = client.getRoom(this.props.roomId);
        const plEvent = room.currentState.getStateEvents('m.room.power_levels', '');
        let plContent = plEvent ? (plEvent.getContent() || {}) : {};

        // Clone the power levels just in case
        plContent = Object.assign({}, plContent);

        // powerLevelKey should be a user ID
        if (!plContent['users']) plContent['users'] = {};
        plContent['users'][powerLevelKey] = value;

        client.sendStateEvent(this.props.roomId, "m.room.power_levels", plContent).catch(e => {
            console.error(e);

            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createTrackedDialog('Power level change failed', '', ErrorDialog, {
                title: _t('Error changing power level'),
                description: _t(
                    "An error occurred changing the user's power level. Ensure you have sufficient " +
                    "permissions and try again.",
                ),
            });
        });
    };

    render() {
        const PowerSelector = sdk.getComponent('elements.PowerSelector');

        const client = MatrixClientPeg.get();
        const room = client.getRoom(this.props.roomId);
        const plEvent = room.currentState.getStateEvents('m.room.power_levels', '');
        const plContent = plEvent ? (plEvent.getContent() || {}) : {};
        const canChangeLevels = room.currentState.mayClientSendStateEvent('m.room.power_levels', client);

        const powerLevelDescriptors = {
            "users_default": {
                desc: _t('Default role'),
                defaultValue: 0,
            },
            "events_default": {
                desc: _t('Send messages'),
                defaultValue: 0,
            },
            "invite": {
                desc: _t('Invite users'),
                defaultValue: 50,
            },
            "state_default": {
                desc: _t('Change settings'),
                defaultValue: 50,
            },
            "kick": {
                desc: _t('Kick users'),
                defaultValue: 50,
            },
            "ban": {
                desc: _t('Ban users'),
                defaultValue: 50,
            },
            "redact": {
                desc: _t('Remove messages sent by others'),
                defaultValue: 50,
            },
            "notifications.room": {
                desc: _t('Notify everyone'),
                defaultValue: 50,
            },
        };

        const eventsLevels = plContent.events || {};
        const userLevels = plContent.users || {};
        const banLevel = parseIntWithDefault(plContent.ban, powerLevelDescriptors.ban.defaultValue);
        const defaultUserLevel = parseIntWithDefault(
            plContent.users_default,
            powerLevelDescriptors.users_default.defaultValue,
        );

        let currentUserLevel = userLevels[client.getUserId()];
        if (currentUserLevel === undefined) {
            currentUserLevel = defaultUserLevel;
        }

        this.populateDefaultPlEvents(
            eventsLevels,
            parseIntWithDefault(plContent.state_default, powerLevelDescriptors.state_default.defaultValue),
            parseIntWithDefault(plContent.events_default, powerLevelDescriptors.events_default.defaultValue),
        );

        let privilegedUsersSection = <div>{_t('No users have specific privileges in this room')}</div>;
        let mutedUsersSection;
        if (Object.keys(userLevels).length) {
            const privilegedUsers = [];
            const mutedUsers = [];

            Object.keys(userLevels).forEach((user) => {
                const canChange = userLevels[user] < currentUserLevel && canChangeLevels;
                if (userLevels[user] > defaultUserLevel) { // privileged
                    privilegedUsers.push(
                        <PowerSelector
                            value={userLevels[user]}
                            disabled={!canChange}
                            label={user}
                            key={user}
                            powerLevelKey={user} // Will be sent as the second parameter to `onChange`
                            onChange={this.onUserPowerLevelChanged}
                        />,
                    );
                } else if (userLevels[user] < defaultUserLevel) { // muted
                    mutedUsers.push(
                        <PowerSelector
                            value={userLevels[user]}
                            disabled={!canChange}
                            label={user}
                            key={user}
                            powerLevelKey={user} // Will be sent as the second parameter to `onChange`
                            onChange={this.onUserPowerLevelChanged}
                        />,
                    );
                }
            });

            // comparator for sorting PL users lexicographically on PL descending, MXID ascending. (case-insensitive)
            const comparator = (a, b) => {
                const plDiff = userLevels[b.key] - userLevels[a.key];
                return plDiff !== 0 ? plDiff : compare(a.key.toLocaleLowerCase(), b.key.toLocaleLowerCase());
            };

            privilegedUsers.sort(comparator);
            mutedUsers.sort(comparator);

            if (privilegedUsers.length) {
                privilegedUsersSection =
                    <div className='mx_SettingsTab_section mx_SettingsTab_subsectionText'>
                        <div className='mx_SettingsTab_subheading'>{ _t('Privileged Users') }</div>
                        {privilegedUsers}
                    </div>;
            }
            if (mutedUsers.length) {
                mutedUsersSection =
                    <div className='mx_SettingsTab_section mx_SettingsTab_subsectionText'>
                        <div className='mx_SettingsTab_subheading'>{ _t('Muted Users') }</div>
                        {mutedUsers}
                    </div>;
            }
        }

        const banned = room.getMembersWithMembership("ban");
        let bannedUsersSection;
        if (banned.length) {
            const canBanUsers = currentUserLevel >= banLevel;
            bannedUsersSection =
                <div className='mx_SettingsTab_section mx_SettingsTab_subsectionText'>
                    <div className='mx_SettingsTab_subheading'>{ _t('Banned users') }</div>
                    <ul>
                        {banned.map((member) => {
                            const banEvent = member.events.member.getContent();
                            const sender = room.getMember(member.events.member.getSender());
                            let bannedBy = member.events.member.getSender(); // start by falling back to mxid
                            if (sender) bannedBy = sender.name;
                            return (
                                <BannedUser key={member.userId} canUnban={canBanUsers}
                                    member={member} reason={banEvent.reason}
                                    by={bannedBy}
                                />
                            );
                        })}
                    </ul>
                </div>;
        }

        const powerSelectors = Object.keys(powerLevelDescriptors).map((key, index) => {
            const descriptor = powerLevelDescriptors[key];

            const keyPath = key.split('.');
            let currentObj = plContent;
            for (const prop of keyPath) {
                if (currentObj === undefined) {
                    break;
                }
                currentObj = currentObj[prop];
            }

            const value = parseIntWithDefault(currentObj, descriptor.defaultValue);
            return <div key={index} className="">
                <PowerSelector
                    label={descriptor.desc}
                    value={value}
                    usersDefault={defaultUserLevel}
                    disabled={!canChangeLevels || currentUserLevel < value}
                    powerLevelKey={key} // Will be sent as the second parameter to `onChange`
                    onChange={this.onPowerLevelsChanged}
                />
            </div>;
        });

        // hide the power level selector for enabling E2EE if it the room is already encrypted
        if (client.isRoomEncrypted(this.props.roomId)) {
            delete eventsLevels["m.room.encryption"];
        }

        const eventPowerSelectors = Object.keys(eventsLevels).map((eventType, i) => {
            let label = plEventsToLabels[eventType];
            if (label) {
                label = _t(label);
            } else {
                label = _t("Send %(eventType)s events", {eventType});
            }
            return (
                <div className="" key={eventType}>
                    <PowerSelector
                        label={label}
                        value={eventsLevels[eventType]}
                        usersDefault={defaultUserLevel}
                        disabled={!canChangeLevels || currentUserLevel < eventsLevels[eventType]}
                        powerLevelKey={"event_levels_" + eventType}
                        onChange={this.onPowerLevelsChanged}
                    />
                </div>
            );
        });

        return (
            <div className="mx_SettingsTab mx_RolesRoomSettingsTab">
                <div className="mx_SettingsTab_heading">{_t("Roles & Permissions")}</div>
                {privilegedUsersSection}
                {mutedUsersSection}
                {bannedUsersSection}
                <div className='mx_SettingsTab_section mx_SettingsTab_subsectionText'>
                    <span className='mx_SettingsTab_subheading'>{_t("Permissions")}</span>
                    <p>{_t('Select the roles required to change various parts of the room')}</p>
                    {powerSelectors}
                    {eventPowerSelectors}
                </div>
            </div>
        );
    }
}
