const readline = require('readline');

function createQuestion(item, result) {
    let question = item.question || item.name;
    if(item.default) {
        question += ` (${item.default(result)})`
    }
    question += ': '
    return question
}

function promptQuestion(question, results) {
    process.stdout.write(createQuestion(question, results))
}

module.exports.start = function(schema, cb) {

    let rl = readline.createInterface({
      input: process.stdin,
      output: process.stdout,
      terminal: true
    });
    
    let results = {};
    let idx = 0;
    let currentQuestion = schema[idx];
    
    promptQuestion(currentQuestion, results);    

    rl.on('line', function(line){
        if(currentQuestion.validator && !line.match(currentQuestion.validator)) {
            console.error('Error:', currentQuestion.error || 'Invalid input!')
        } else {
            if(!line && currentQuestion.default) {
                line = currentQuestion.default(results)
            }
            line = line.length && line || undefined
            results[currentQuestion.name] = line;
            idx++;
            if(idx >= schema.length) {
                rl.close();
                cb(results);
                return;
            }
            currentQuestion = schema[idx];
        }
        promptQuestion(currentQuestion, results);
    })
}