// *****************************************************************************
// Copyright (C) 2023 TypeFox 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 { inject, injectable } from '@theia/core/shared/inversify';
import { PreferenceTreeModel } from '../../preference-tree-model';
import { PreferenceTreeLabelProvider } from '../../util/preference-tree-label-provider';
import * as markdownit from '@theia/core/shared/markdown-it';
import * as markdownitemoji from '@theia/core/shared/markdown-it-emoji';
import { CommandRegistry } from '@theia/core';

@injectable()
export class PreferenceMarkdownRenderer {

    @inject(PreferenceTreeModel)
    protected readonly model: PreferenceTreeModel;
    @inject(PreferenceTreeLabelProvider)
    protected readonly labelProvider: PreferenceTreeLabelProvider;
    @inject(CommandRegistry)
    protected readonly commandRegistry: CommandRegistry;

    protected _renderer?: markdownit;

    render(text: string): string {
        return this.getRenderer().render(text);
    }

    renderInline(text: string): string {
        return this.getRenderer().renderInline(text);
    }

    protected getRenderer(): markdownit {
        this._renderer ??= this.buildMarkdownRenderer();
        return this._renderer;
    }

    protected buildMarkdownRenderer(): markdownit {
        const engine = markdownit().use(markdownitemoji.full);
        const inlineCode = engine.renderer.rules.code_inline;

        engine.renderer.rules.code_inline = (tokens, idx, options, env, self) => {
            const token = tokens[idx];
            const content = token.content;
            if (content.length > 2 && content.startsWith('#') && content.endsWith('#')) {
                const id = content.substring(1, content.length - 1);
                // First check whether there's a preference with the given ID
                const preferenceNode = this.model.getNodeFromPreferenceId(id);
                if (preferenceNode) {
                    let name = this.labelProvider.getName(preferenceNode);
                    const prefix = this.labelProvider.getPrefix(preferenceNode, true);
                    if (prefix) {
                        name = prefix + name;
                    }
                    return `<a title="${id}" href="preference:${id}">${name}</a>`;
                }
                // If no preference was found, check whether there's a command with the given ID
                const command = this.commandRegistry.getCommand(id);
                if (command) {
                    const name = `${command.category ? `${command.category}: ` : ''}${command.label}`;
                    return `<span class="command-link" title="${id}">${name}</span>`;
                }
                // If nothing was found, print a warning
                console.warn(`Linked preference "${id}" not found.`);
            }
            return inlineCode ? inlineCode(tokens, idx, options, env, self) : '';
        };
        return engine;
    }
}