'use strict';

import * as path from 'path';
import { spawn, execFile, ChildProcess } from 'child_process';
import * as vscode from 'vscode';
import { LanguageClient, LanguageClientOptions, StreamInfo } from 'vscode-languageclient';
import * as semver from 'semver';

export function activate(context: vscode.ExtensionContext) {

    // Check if PHP is available and version is ^7.0.0
    execFile('php', ['--version'], (err: NodeJS.ErrnoException, stdout: Buffer, stderr: Buffer) => {

        if (err) {
            if (err.code === 'ENOENT') {
                vscode.window.showErrorMessage('PHP executable not found. You need PHP 7 installed and in your PATH');
            } else {
                vscode.window.showErrorMessage('Error spawning PHP: ' + err.message);
                console.error(err);
            }
            return;
        }

        let version = stdout.toString().match(/^PHP ([^\s]+)/)[1];
        // Convert PHP prerelease format like 7.0.0rc1 to 7.0.0-rc1
        if (!/^\d+.\d+.\d+$/.test(version)) {
            version = version.replace(/(\d+.\d+.\d+)/, '$1-');
        }
        if (!semver.satisfies(version, '^7.0.0')) {
            vscode.window.showErrorMessage('The language server needs at least PHP 7 installed and in your PATH. Version found: ' + version);
            return;
        }

        const serverOptions = (): Promise<ChildProcess | StreamInfo> => {
            // The server is implemented in PHP
            const serverPath = context.asAbsolutePath(path.join('vendor', 'felixfbecker', 'language-server', 'bin', 'php-language-server.php'));
            const childProcess = spawn('php', [serverPath]);
            childProcess.stderr.on('data', (chunk: Buffer) => {
                console.error(chunk + '');
            });
            childProcess.stdout.on('data', (chunk: Buffer) => {
                console.log(chunk + '');
            });
            return Promise.resolve(childProcess);
        };

        // Options to control the language client
        let clientOptions: LanguageClientOptions = {
            // Register the server for php documents
            documentSelector: ['php']
            // synchronize: {
            //     // Synchronize the setting section 'php' to the server
            //     configurationSection: 'php',
            //     // Notify the server about file changes to composer.json files contain in the workspace
            //     fileEvents: workspace.createFileSystemWatcher('**/composer.json')
            // }
        };

        // Create the language client and start the client.
        const disposable = new LanguageClient('PHP Language Client', serverOptions, clientOptions).start();

        // Push the disposable to the context's subscriptions so that the
        // client can be deactivated on extension deactivation
        context.subscriptions.push(disposable);
    });
}