/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 * as vscode from 'vscode';
import { homedir } from 'os';

export async function initializeRunConfiguration(): Promise<boolean> {
	const java = await vscode.workspace.findFiles('**/*.java', '**/node_modules/**', 1);
	if (java?.length > 0) {
		const maven = await vscode.workspace.findFiles('pom.xml', '**/node_modules/**', 1);
		if (maven?.length > 0) {
			return true;
		}
		const gradle = await vscode.workspace.findFiles('build.gradle', '**/node_modules/**', 1);
		if (gradle?.length > 0) {
			return true;
		}
	}
	return false;
}

class RunConfigurationProvider implements vscode.DebugConfigurationProvider {

    resolveDebugConfiguration(_folder: vscode.WorkspaceFolder | undefined, config: vscode.DebugConfiguration, _token?: vscode.CancellationToken): vscode.ProviderResult<vscode.DebugConfiguration> {
		return new Promise<vscode.DebugConfiguration>(resolve => {
			resolve(config);
		});
	}

	resolveDebugConfigurationWithSubstitutedVariables?(_folder: vscode.WorkspaceFolder | undefined, config: vscode.DebugConfiguration, _token?: vscode.CancellationToken): vscode.ProviderResult<vscode.DebugConfiguration> {
        return new Promise<vscode.DebugConfiguration>(resolve => {
			const args = argumentsNode.getValue();
			if (args) {
				if (!config.args) {
					config.args = args;
				} else {
					config.args = `${config.args} ${args}`;
				}
			}

			const vmArgs = vmOptionsNode.getValue();
			if (vmArgs) {
				if (!config.vmArgs) {
					config.vmArgs = vmArgs;
				} else {
					config.vmArgs = `${config.vmArgs} ${vmArgs}`;
				}
			}

			const env = environmentVariablesNode.getValue();
			if (env) {
				const envs = env.split(',');
				if (!config.env) {
					config.env = {};
				}
				for (let val of envs) {
					val = val.trim();
					const div = val.indexOf('=');
					if (div > 0) { // div === 0 means bad format (no ENV name)
						config.env[val.substring(0, div)] = val.substring(div + 1, val.length);
					}
				}
			}

			const cwd = workingDirectoryNode.getValue();
			if (cwd) {
				config.cwd = cwd;
			}
			
			resolve(config);
		});
	}

}
export const runConfigurationProvider = new RunConfigurationProvider();

class RunConfigurationNodeProvider implements vscode.TreeDataProvider<vscode.TreeItem> {

	private _onDidChangeTreeData: vscode.EventEmitter<vscode.TreeItem | undefined | null> = new vscode.EventEmitter<vscode.TreeItem | undefined | null>();
	readonly onDidChangeTreeData: vscode.Event<vscode.TreeItem | undefined | null> = this._onDidChangeTreeData.event;

	refresh(): void {
		this._onDidChangeTreeData.fire(undefined);
	}

	getTreeItem(element: vscode.TreeItem): vscode.TreeItem {
		return element;
	}

	getChildren(element?: vscode.TreeItem): vscode.ProviderResult<vscode.TreeItem[]> {
        if (!element) {
            return [ argumentsNode, vmOptionsNode, environmentVariablesNode, workingDirectoryNode ];
        }
        return [];
	}

}
export const runConfigurationNodeProvider = new RunConfigurationNodeProvider();

class RunConfigurationNode extends vscode.TreeItem {

	prompt: string;
	hint: string;
	value: string | undefined;

	settingsKey: string;

    constructor(label: string, prompt: string, hint: string, settingsKey: string) {
        super(label);
        this.contextValue = 'configureRunSettings';
        this.collapsibleState = vscode.TreeItemCollapsibleState.None;

		this.prompt = prompt;
		this.hint = hint;

		this.settingsKey = settingsKey;
		
		this.value = this.getConfig().get(this.settingsKey);
		this.updateNode();
    }

	public configure(_context: vscode.ExtensionContext) {
		vscode.window.showInputBox(
			{
				prompt: this.prompt,
				value: this.value,
				placeHolder: this.hint,
				ignoreFocusOut: true
			}
		).then(async val => {
			if (val !== undefined) {
				const value = val.toString().trim();
				this.setValue(value ? value : undefined);
			}
		});
	}

	public getValue(): string | undefined {
		return this.value;
	}

	setValue(value: string | undefined) {
		this.value = value;
		this.getConfig().update(this.settingsKey, this.value, false);
		this.updateNode();
	}

	updateNode(reload?: boolean) {
            if (reload) {
                this.value  = this.getConfig().get(this.settingsKey) as string;
            }
            this.description = this.value ? this.value : '<default>';
            this.tooltip = `${this.label} ${this.description}`;
            runConfigurationNodeProvider.refresh();
	}

	getConfig(): vscode.WorkspaceConfiguration {
		return vscode.workspace.getConfiguration('java8+.runConfig');
	}

}

class ArgumentsNode extends RunConfigurationNode {

	constructor() {
        super('Arguments:', 'Customize arguments', 'Example: foo bar', 'arguments');
    }

}
const argumentsNode = new ArgumentsNode();

class VMOptionsNode extends RunConfigurationNode {

	constructor() {
        super('VM Options:', 'Customize VM options', 'Example: -Xmx512m -Xms256m', 'vmOptions');
    }

}
const vmOptionsNode = new VMOptionsNode();

class EnvironmentVariablesNode extends RunConfigurationNode {

	constructor() {
        super('Environment:', 'Customize evironment variables', 'Example: var1=one, varTwo=2', 'env');
    }

}
const environmentVariablesNode = new EnvironmentVariablesNode();

class WorkingDirectoryNode extends RunConfigurationNode {

	constructor() {
        super('Working Dir:', 'Customize working directory', WorkingDirectoryNode.getExample(), 'cwd');
    }

	static getExample(): string {
		const dir = homedir();
		return `Example: ${dir}`;
	}

}
const workingDirectoryNode = new WorkingDirectoryNode();

export function configureRunSettings(context: vscode.ExtensionContext, ...params: any[]) {
    if (params[0][0]) {
        (params[0][0] as RunConfigurationNode).configure(context);
    }
}
export function runConfigurationUpdateAll() {
    argumentsNode.updateNode(true);
    vmOptionsNode.updateNode(true);
    environmentVariablesNode.updateNode(true);
    workingDirectoryNode.updateNode(true);
}