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

import { AfterViewInit, ChangeDetectionStrategy, ChangeDetectorRef, Component, ElementRef, forwardRef, Input, OnChanges, Renderer2, SimpleChanges, ViewChild } from '@angular/core';
import { NG_VALUE_ACCESSOR } from '@angular/forms';

import { StatefulControlComponent, Types } from '@app/framework/internal';

export const SQX_IFRAME_EDITOR_CONTROL_VALUE_ACCESSOR: any = {
    provide: NG_VALUE_ACCESSOR, useExisting: forwardRef(() => IFrameEditorComponent), multi: true
};

@Component({
    selector: 'sqx-iframe-editor',
    styleUrls: ['./iframe-editor.component.scss'],
    templateUrl: './iframe-editor.component.html',
    providers: [SQX_IFRAME_EDITOR_CONTROL_VALUE_ACCESSOR],
    changeDetection: ChangeDetectionStrategy.OnPush
})
export class IFrameEditorComponent extends StatefulControlComponent<any, any> implements OnChanges, AfterViewInit {
    private value: any;
    private isDisabled = false;
    private isInitialized = false;

    @ViewChild('iframe', { static: false })
    public iframe: ElementRef<HTMLIFrameElement>;

    @Input()
    public context: any = {};

    @Input()
    public formValue: any;

    @Input()
    public url: string;

    constructor(changeDetector: ChangeDetectorRef,
        private readonly renderer: Renderer2
    ) {
        super(changeDetector, {});
    }

    public ngOnChanges(changes: SimpleChanges) {
        if (this.iframe) {
            if (changes['url']) {
                this.setupUrl();
            }

            if (changes['formValue'] && this.formValue) {
                this.sendFormValue();
            }
        }
    }

    private setupUrl() {
        this.iframe.nativeElement.src = this.url;
    }

    public ngAfterViewInit() {
        this.setupUrl();

        this.own(
            this.renderer.listen('window', 'message', (event: MessageEvent) => {
                if (event.source === this.iframe.nativeElement.contentWindow) {
                    const { type } = event.data;

                    if (type === 'started') {
                        this.isInitialized = true;

                        this.sendMessage('init', { context: this.context || {} });
                        this.sendFormValue();
                        this.sendDisabled();
                        this.sendValue();
                    } else if (type === 'resize') {
                        const { height } = event.data;

                        this.iframe.nativeElement.height = height + 'px';
                    } else if (type === 'valueChanged') {
                        const { value } = event.data;

                        if (!Types.jsJsonEquals(this.value, value)) {
                            this.value = value;

                            this.callChange(value);
                        }
                    } else if (type === 'touched') {
                        this.callTouched();
                    }
                }
            }));
    }

    public writeValue(obj: any) {
        this.value = obj;

        this.sendValue();
    }

    public setDisabledState(isDisabled: boolean): void {
        this.isDisabled = isDisabled;

        this.sendDisabled();
    }

    private sendValue() {
        this.sendMessage('valueChanged', { value: this.value });
    }

    private sendDisabled() {
        this.sendMessage('disabled', { isDisabled: this.isDisabled });
    }

    private sendFormValue() {
        this.sendMessage('formValueChanged', { formValue: this.formValue });
    }

    private sendMessage(type: string, payload: any) {
        if (!this.iframe) {
            return;
        }

        const iframe = this.iframe.nativeElement;

        if (this.isInitialized && iframe.contentWindow && Types.isFunction(iframe.contentWindow.postMessage)) {
            const message = { type, ...payload };

            iframe.contentWindow.postMessage(message, '*');
        }
    }
}