/********************************************************************************
 * Copyright (c) 2021-2026 EclipseSource 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 WITH Classpath-exception-2.01
 ********************************************************************************/
import * as vscode from 'vscode';
import { GlspVscodeConnector } from '../glsp-vscode-connector';
import { GLSPDiagramIdentifier } from '../types';
import { WebviewEndpoint } from './webview-endpoint';
/**
 * An extensible base class to create a CustomEditorProvider that takes care of
 * diagram initialization and custom document events.
 *
 * Webview setup needs to be implemented.
 */
export abstract class GlspEditorProvider implements vscode.CustomEditorProvider {
    /** The diagram type identifier the diagram server is responsible for. */
    abstract diagramType: string;

    /** Used to generate continuous and unique clientIds - TODO: consider replacing this with uuid. */
    private viewCount = 0;

    protected readonly ownedDocuments = new Set<vscode.CustomDocument>();
    protected readonly disposables: vscode.Disposable[] = [];

    protected readonly onDidChangeCustomDocumentEmitter = new vscode.EventEmitter<
        vscode.CustomDocumentEditEvent | vscode.CustomDocumentContentChangeEvent
    >();
    get onDidChangeCustomDocument(): vscode.Event<vscode.CustomDocumentEditEvent> | vscode.Event<vscode.CustomDocumentContentChangeEvent> {
        return this.onDidChangeCustomDocumentEmitter.event;
    }

    constructor(protected readonly glspVscodeConnector: GlspVscodeConnector) {
        this.disposables.push(
            this.onDidChangeCustomDocumentEmitter,
            glspVscodeConnector.onDidChangeCustomDocument(e => {
                if (this.ownedDocuments.has(e.document)) {
                    this.onDidChangeCustomDocumentEmitter.fire(e);
                }
            })
        );
    }

    saveCustomDocument(document: vscode.CustomDocument, _cancellation: vscode.CancellationToken): Thenable<void> {
        return this.glspVscodeConnector.saveDocument(document);
    }

    saveCustomDocumentAs(
        document: vscode.CustomDocument,
        destination: vscode.Uri,
        _cancellation: vscode.CancellationToken
    ): Thenable<void> {
        return this.glspVscodeConnector.saveDocument(document, destination);
    }

    revertCustomDocument(document: vscode.CustomDocument, _cancellation: vscode.CancellationToken): Thenable<void> {
        return this.glspVscodeConnector.revertDocument(document, this.diagramType);
    }

    backupCustomDocument(
        _document: vscode.CustomDocument,
        context: vscode.CustomDocumentBackupContext,
        _cancellation: vscode.CancellationToken
    ): Thenable<vscode.CustomDocumentBackup> {
        // Basically do the bare minimum - which is nothing
        return Promise.resolve({ id: context.destination.toString(), delete: () => undefined });
    }

    openCustomDocument(
        uri: vscode.Uri,
        _openContext: vscode.CustomDocumentOpenContext,
        _token: vscode.CancellationToken
    ): vscode.CustomDocument | Thenable<vscode.CustomDocument> {
        const document: vscode.CustomDocument = {
            uri,
            dispose: () => {
                this.ownedDocuments.delete(document);
            }
        };
        this.ownedDocuments.add(document);
        return document;
    }

    async resolveCustomEditor(
        document: vscode.CustomDocument,
        webviewPanel: vscode.WebviewPanel,
        token: vscode.CancellationToken
    ): Promise<void> {
        // This is used to initialize GLSP for our diagram
        const diagramIdentifier: GLSPDiagramIdentifier = {
            diagramType: this.diagramType,
            uri: serializeUri(document.uri),
            clientId: `${this.diagramType}_${this.viewCount++}`
        };

        const endpoint = new WebviewEndpoint({ diagramIdentifier, messenger: this.glspVscodeConnector.messenger, webviewPanel });

        // Register document/diagram panel/model in vscode connector
        this.glspVscodeConnector.registerClient({
            clientId: diagramIdentifier.clientId,
            diagramType: diagramIdentifier.diagramType,
            document: document,
            webviewEndpoint: endpoint
        });

        this.setUpWebview(document, webviewPanel, token, diagramIdentifier.clientId);
    }

    /**
     * Used to set up the webview within the webview panel.
     */
    abstract setUpWebview(
        document: vscode.CustomDocument,
        webviewPanel: vscode.WebviewPanel,
        token: vscode.CancellationToken,
        clientId: string
    ): void;

    dispose(): void {
        this.disposables.forEach(disposable => disposable.dispose());
    }
}

function serializeUri(uri: vscode.Uri): string {
    let uriString = uri.toString();
    const match = uriString.match(/file:\/\/\/([a-z])%3A/i);
    if (match) {
        uriString = 'file:///' + match[1] + ':' + uriString.substring(match[0].length);
    }
    return uriString;
}