const ejs = require('ejs');
const path = require('path');

const html = '<div><%= user.name %></div>'
const options = {}
const data = {
    user: {
        name: 'io'
    }
}

// 1. 多次复用
const template = ejs.compile(html, options);
const compiled = template(data)
console.log(compiled);

// 2. 只用一次
const rendered = ejs.render(html, data, options);
console.log(rendered);

// 3. 读取html, promise调用
const renderedfile = ejs.renderFile(path.resolve(__dirname, './index.html'), data, options);
renderedfile.then(file => console.log(file))

// 传给ejs的加载器
const options = {
    delimiter: '?'
}

// 注意: fileloader里面添加的字符串模板会在每一次读取文件的时候运行一次
// 例如 下面在读取footer.html的时候再次进行了添加
ejs.fileLoader = function (filePath) {
    console.log('fileLoader', filePath);
    const content = '<div>footer: user is <?= user.name ?> </div>'+fs.readFileSync(filePath, 'utf8').toString();
    return content;
}

ejs.renderFile(path.resolve(__dirname, './index.html'), data, options, (err, file) => {
    console.log(file);
});
// <div>footer: user is john </div><%if(user){ -%>
//     <% for (var i=0; i < 10; i++){ -%>
// <%_ %><div><%= user.name -%></div>
//     <%} -%>
// <%} -%>


// <div>footer: user is john </div><div>footer: user is john </div>

const {isContinue} = nquirer.prompt({
    type: 'confirm',
    name: "isContinue",
    message: "当前文件夹不为空,是否继续创建?",
    default: false
})

const cp = require('child_process')
const path = require('path');

cp.exec('ls -al|grep node_modules', function (err, stdout, stderr) {
    console.log(err);
    console.log(stdout);
    console.log(stderr);
})

cp.execFile('ls', ['-al'], function (err, stdout, stderr) {
    console.log(err);
    console.log(stdout);
    console.log(stderr);
})

// 这里要执行shell文件需要系统提供权限  chmod 777 ./test.shell
cp.execFile(path.resolve(__dirname, 'test.shell'), ['-al'], function (err, stdout, stderr) {
    console.log(err);
    console.log(stdout);
    console.log(stderr);
})

// 第一个参数命令或者文件,会在系统中环境变量找到对应的文件
// spawn是流式执行方式,适用于耗时任务,可不断为用户提供日志反馈
const child = cp.spawn(path.resolve(__dirname, 'test.shell'), ['-al', '-bl'], {
    cwd: path.resolve('./'),
    stdio: 'inherit', //会逐行打印子进程的反馈日志
})

console.log(child.pid);

// 可以逐行显示出执行的结果
child.stdout.on('data', function (chunk) {
    console.log('stdout', chunk.toString());
})

child.stderr.on('data', function (chunk) {
    console.log('stderr', chunk.toString());
})


// exec/execFile: 开销较小的任务,最后一次性打印日志
cp.exec(path.resolve(__dirname, 'test.shell'), {
    cwd: path.resolve('./')
}, function (chunk) {
    console.log(chunk);
})

/** ./main_process.js **/ 
// fork: node(main) -> node(child)
// 两个进程是完全独立的
const child2 = cp.fork(path.resolve(__dirname, 'child.js'))

child2.send('hello child process', function (err) {
    // child2.disconnect();
})

child2.on('message', function (msg) {
    console.log(msg);
})
console.log('main process pid:' + process.pid)


/** ./child_process.js **/ 
console.log('child process')
console.log('child process pid: ' + process.pid)

process.on('message', function (msg) {
    console.log(msg);

})

process.send('hello main process', () => {
    process.disconnect();
})

#!/usr/bin/env node

const commander = require('commander')
const program = new commander.Command()
const pkg = require('../package.json')

program
    .name(Object.keys(pkg.bin)[0])
    .usage('<cmd> [option]')
    .version(pkg.version)
    .option('-d, --debug', 'start debug mode', false)
    .option('-e --envName <envName>', 'fetch the environment', 'development')

const clone = program.command('clone <source> [destination]');
clone
    .description('clone an existing project')
    .option('-f, --force', 'clone force')
    .action((source, dest, cmdObj) => {
        console.log('clone', source, dest, cmdObj.force);
    })

const server = new commander.Command('server')
server.command('start [port]')
    .description('start server at specified port')
    .action((port) => {
        console.log(`start server at ${port} ...`);
    })

server.command('stop')
    .description("stop server")
    .action(() => {
        console.log("stop server");
    })

program.command('install [name] [path]', 'install package at specified path', {
    executableFile: 'npm',  // 当前install命令执行，相当于yarn add执行
    // isDefault: true,        // 这里设置为true，当执行脚手架时，默认就会执行npm
    hidden: true            // 作为一个隐藏的命令
}).alias(i)


program.on('--help', function () {
    console.log('help info');
})

// debug模式实现
program.on('--debug', function () {
    process.env.LOG_LEVEL = program.debug ? 'verbose' : 'info';
    console.log(process.env.LOG_LEVEL);
})

// 对未知命令监听
program.on('command:*', function (obj) {
    console.error('unknown command', obj[0]);
    const availableCommand = program.commands.map(cmd => cmd.name);
    console.log('可用命令：' + availableCommand.join("，"));

})


// 适用于所有命令的监听
program.arguments('<cmd> [options]')
    .description('test command', {
        cmd: 'command',
        options: 'options for command',
    })
    .action((cmd, options) => {
        console.log(cmd, options);
    })

program.addCommand(server)

program.parse(process.argv)