/*
 * Squidex Headless CMS
 *
 * @license
 * Copyright (c) Squidex UG (haftungsbeschränkt). All rights reserved.
 */

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable, of } from 'rxjs';
import { map } from 'rxjs/operators';

import { UsersProviderService } from './users-provider.service';

import {
    ApiUrlConfig,
    DateTime,
    pretifyError
} from '@app/framework';

export class HistoryEventDto {
    constructor(
        public readonly eventId: string,
        public readonly actor: string,
        public readonly message: string,
        public readonly version: number,
        public readonly created: DateTime
    ) {
    }
}

const REPLACEMENT_TEMP = '$TEMP$';

export function formatHistoryMessage(message: string, users: UsersProviderService): Observable<string> {
    const userName = (userId: string) => {
        const parts = userId.split(':');

        if (parts.length === 1) {
            return users.getUser(parts[0], null).pipe(map(u => u.displayName));
        } else if (parts[0] === 'subject') {
            return users.getUser(parts[1], null).pipe(map(u => u.displayName));
        } else {
            if (parts[1].endsWith('client')) {
                return of(parts[1]);
            } else {
                return of(`${parts[1]}-client`);
            }
        }
    };

    let foundUserId: string | null = null;

    message = message.replace(/{([^\s:]*):([^}]*)}/, (match: string, type: string, id: string) => {
        if (type === 'user') {
            foundUserId = id;
            return REPLACEMENT_TEMP;
        } else {
            return id;
        }
    });

    message = message.replace(/{([^}]*)}/g, (match: string, marker: string) => {
        return `<span class="marker-ref">${marker}</span>`;
    });

    if (foundUserId) {
        return userName(foundUserId).pipe(map(t => message.replace(REPLACEMENT_TEMP, `<span class="user-ref">${t}</span>`)));
    }

    return of(message);
}

@Injectable()
export class HistoryService {
    constructor(
        private readonly http: HttpClient,
        private readonly apiUrl: ApiUrlConfig
    ) {
    }

    public getHistory(appName: string, channel: string): Observable<ReadonlyArray<HistoryEventDto>> {
        const url = this.apiUrl.buildUrl(`api/apps/${appName}/history?channel=${channel}`);

        return this.http.get<any[]>(url).pipe(
            map(body => {
                const history = body.map(item =>
                    new HistoryEventDto(
                        item.eventId,
                        item.actor,
                        item.message,
                        item.version,
                        DateTime.parseISO_UTC(item.created)));

                return history;
            }),
            pretifyError('Failed to load history. Please reload.'));
    }
}