/**
 * Copyright 2023-present DreamNum Inc.
 *
 * 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 type { DocumentDataModel, EventState, Nullable } from '@univerjs/core';
import { IConfigService,
    IUniverInstanceService,
    LifecycleStages,
    OnLifecycle,
    RxDisposable,
    UniverInstanceType,
} from '@univerjs/core';
import { DOCS_COMPONENT_BACKGROUND_LAYER_INDEX, DOCS_COMPONENT_DEFAULT_Z_INDEX, DOCS_COMPONENT_HEADER_LAYER_INDEX, DOCS_COMPONENT_MAIN_LAYER_INDEX, DOCS_VIEW_KEY, VIEWPORT_KEY } from '@univerjs/docs';
import type { IRender, IWheelEvent, Scene } from '@univerjs/engine-render';
import { DocBackground, Documents, EVENT_TYPE, IRenderManagerService, Layer, ScrollBar, Viewport } from '@univerjs/engine-render';
import { IEditorService } from '@univerjs/ui';
import { BehaviorSubject, takeUntil } from 'rxjs';

@OnLifecycle(LifecycleStages.Starting, DocCanvasView)
export class DocCanvasView extends RxDisposable {
    private _scene!: Scene;

    private _currentDocumentModel!: DocumentDataModel;

    private readonly _fps$ = new BehaviorSubject<string>('');

    readonly fps$ = this._fps$.asObservable();

    constructor(
        @IRenderManagerService private readonly _renderManagerService: IRenderManagerService,
        @IConfigService private readonly _configService: IConfigService,
        @IUniverInstanceService private readonly _univerInstanceService: IUniverInstanceService,
        @IEditorService private readonly _editorService: IEditorService
    ) {
        super();
        this._initialize();
    }

    private _initialize() {
        this._renderManagerService.createRender$.pipe(takeUntil(this.dispose$)).subscribe((unitId) => {
            this._create(unitId);
        });

        this._univerInstanceService.getCurrentTypeOfUnit$(UniverInstanceType.UNIVER_DOC).pipe(takeUntil(this.dispose$)).subscribe((documentModel) => {
            this._create(documentModel?.getUnitId());
        });

        this._univerInstanceService.getAllUnitsForType<DocumentDataModel>(UniverInstanceType.UNIVER_DOC).forEach((documentModel) => {
            this._create(documentModel.getUnitId());
        });
    }

    override dispose(): void {
        this._fps$.complete();
    }

    private _create(unitId: Nullable<string>) {
        if (unitId == null) {
            return;
        }

        const model = this._univerInstanceService.getUniverDocInstance(unitId);

        if (model == null) {
            return;
        }

        this._currentDocumentModel = model;

        if (!this._renderManagerService.has(unitId)) {
            this._addNewRender();
        }
    }

    private _addNewRender() {
        const documentModel = this._currentDocumentModel;

        const unitId = documentModel.getUnitId();
        this._renderManagerService.createRender(unitId);

        const currentRender = this._renderManagerService.getRenderById(unitId);

        if (currentRender == null) {
            return;
        }

        const { scene, engine } = currentRender;

        scene.openTransformer();

        this._scene = scene;

        const viewMain = new Viewport(VIEWPORT_KEY.VIEW_MAIN, scene, {
            left: 0,
            top: 0,
            bottom: 0,
            right: 0,
            isRelativeX: true,
            isRelativeY: true,
            isWheelPreventDefaultX: true,
        });

        scene.attachControl();

        scene.on(EVENT_TYPE.wheel, (evt: unknown, state: EventState) => {
            const e = evt as IWheelEvent;

            if (e.ctrlKey) {
                const deltaFactor = Math.abs(e.deltaX);
                let scrollNum = deltaFactor < 40 ? 0.2 : deltaFactor < 80 ? 0.4 : 0.2;
                scrollNum *= e.deltaY > 0 ? -1 : 1;
                if (scene.scaleX < 1) {
                    scrollNum /= 2;
                }

                if (scene.scaleX + scrollNum > 4) {
                    scene.scale(4, 4);
                } else if (scene.scaleX + scrollNum < 0.1) {
                    scene.scale(0.1, 0.1);
                } else {
                    // const value = e.deltaY > 0 ? 0.1 : -0.1;
                    // scene.scaleBy(scrollNum, scrollNum);
                    e.preventDefault();
                }
            } else {
                viewMain.onMouseWheel(e, state);
            }
        });

        const hasScroll = this._configService.getConfig('hasScroll') as Nullable<boolean>;

        if (hasScroll !== false) {
            new ScrollBar(viewMain);
        }

        scene.addLayer(
            new Layer(scene, [], DOCS_COMPONENT_MAIN_LAYER_INDEX),
            new Layer(scene, [], DOCS_COMPONENT_HEADER_LAYER_INDEX)
        );

        // this._viewLoader(scene);

        this._addComponent(currentRender);

        const should = this._currentDocumentModel.getShouldRenderLoopImmediately();

        if (should) {
            engine.runRenderLoop(() => {
                scene.render();
                this._fps$.next(Math.round(engine.getFps()).toString());
            });
        }

        this._renderManagerService.setCurrent(unitId);
    }

    private _addComponent(currentRender: IRender) {
        const scene = this._scene;
        const documentModel = this._currentDocumentModel;
        const config = {
            pageMarginLeft: documentModel.documentStyle.marginLeft || 0,
            pageMarginTop: documentModel.documentStyle.marginTop || 0,
        };
        const documents = new Documents(DOCS_VIEW_KEY.MAIN, undefined, config);

        const docBackground = new DocBackground(DOCS_VIEW_KEY.BACKGROUND, undefined, config);

        documents.zIndex = DOCS_COMPONENT_DEFAULT_Z_INDEX;

        docBackground.zIndex = DOCS_COMPONENT_DEFAULT_Z_INDEX;

        currentRender.mainComponent = documents;
        currentRender.components.set(DOCS_VIEW_KEY.MAIN, documents);
        currentRender.components.set(DOCS_VIEW_KEY.BACKGROUND, docBackground);

        scene.addObjects([documents], DOCS_COMPONENT_MAIN_LAYER_INDEX);
        scene.addObjects([docBackground], DOCS_COMPONENT_BACKGROUND_LAYER_INDEX);

        if (this._editorService.getEditor(documentModel.getUnitId()) == null) {
            scene.enableLayerCache(DOCS_COMPONENT_MAIN_LAYER_INDEX);
        }
    }
}