// *****************************************************************************
// Copyright (C) 2019 Ericsson and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// http://www.eclipse.org/legal/epl-2.0.
//
// This Source Code may also be made available under the following Secondary
// Licenses when the conditions for such availability set forth in the Eclipse
// Public License v. 2.0 are satisfied: GNU General Public License, version 2
// with the GNU Classpath Exception which is available at
// https://www.gnu.org/software/classpath/license.html.
//
// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
// *****************************************************************************

import URI from '@theia/core/lib/common/uri';
import { Emitter, Event } from '@theia/core/lib/common/event';
import { Disposable, DisposableCollection } from '@theia/core/lib/common/disposable';
import { TaskCustomization, TaskConfiguration, TaskConfigurationScope } from '../common/task-protocol';
import { PreferenceProviderDataChanges, PreferenceProviderDataChange, isObject } from '@theia/core/lib/common';
import { PreferenceProvider } from '@theia/core/lib/common/preferences/preference-provider';
import { JSONValue } from '@theia/core/shared/@lumino/coreutils';

/**
 * Holds the task configurations associated with a particular file. Uses an editor model to facilitate
 * non-destructive editing and coordination with editing the file by hand.
 */
export class TaskConfigurationModel implements Disposable {

    protected json: TaskConfigurationModel.JsonContent;

    protected readonly onDidChangeEmitter = new Emitter<void>();
    readonly onDidChange: Event<void> = this.onDidChangeEmitter.event;

    protected readonly toDispose = new DisposableCollection(
        this.onDidChangeEmitter
    );

    constructor(
        protected readonly scope: TaskConfigurationScope,
        readonly preferences: PreferenceProvider | undefined
    ) {
        this.reconcile();
        if (this.preferences) {
            this.toDispose.push(this.preferences.onDidPreferencesChanged((e: PreferenceProviderDataChanges) => {
                const change = e['tasks'];
                if (change && PreferenceProviderDataChange.affects(change, this.getWorkspaceFolder())) {
                    this.reconcile();
                }
            }));
        }
    }

    get uri(): URI | undefined {
        return this.json.uri;
    }

    getWorkspaceFolder(): string | undefined {
        return typeof this.scope === 'string' ? this.scope : undefined;
    }

    dispose(): void {
        this.toDispose.dispose();
    }
    get onDispose(): Event<void> {
        return this.toDispose.onDispose;
    }

    get configurations(): (TaskCustomization | TaskConfiguration)[] {
        return this.json.configurations;
    }

    protected reconcile(): void {
        this.json = this.parseConfigurations();
        this.onDidChangeEmitter.fire(undefined);
    }

    async setConfigurations(value: JSONValue): Promise<boolean> {
        return this.preferences?.setPreference('tasks.tasks', value, this.getWorkspaceFolder()) || false;
    }

    protected parseConfigurations(): TaskConfigurationModel.JsonContent {
        const configurations: (TaskCustomization | TaskConfiguration)[] = [];
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        const res = this.preferences?.resolve<any>('tasks', this.getWorkspaceFolder());
        if (isObject(res?.value) && Array.isArray(res.value.tasks)) {
            for (const taskConfig of res.value.tasks) {
                configurations.push(taskConfig);
            }
        }
        return {
            uri: res?.configUri,
            configurations
        };
    }

}
export namespace TaskConfigurationModel {
    export interface JsonContent {
        uri?: URI;
        configurations: (TaskCustomization | TaskConfiguration)[];
    }
}