const path = require("path");
const exec = require("child_process").exec;
const fs = require("fs");
const argv = require("yargs-parser")(process.argv.slice(2));
const inquirer = require("inquirer");
const chalk = require("chalk");

const grammarsPath = path.resolve(__dirname, "../src/grammar");
const outputPath = path.resolve(__dirname, "../src/lib");

const languageEntries = fs
    .readdirSync(grammarsPath)
    .filter((item) => item !== "impala"); // impala is not support yet.

const baseCmd = 'antlr4ts -visitor -listener -Xexact-output-dir -o';

function compile(language) {
    const cmd = `${baseCmd} ${outputPath}/${language} ${grammarsPath}/${language}/*.g4`;

    console.info(chalk.green(`\nRemoving:`, chalk.gray(`${outputPath}/${language}/*`)));
    fs.rmdirSync(`${outputPath}/${language}`, { recursive: true })

    console.info(chalk.green("Executing:"), chalk.gray(cmd));
    exec(cmd, (err) => {
        if (err) {
            console.error(
                chalk.redBright(`\n[Antlr4 compile error]:`),
                chalk.cyan(language),
                chalk.gray(err)
            );
        } else {
            console.log(chalk.greenBright(`\nCompile ${language} succeeded!`));
        }
    });
}

function prompt() {
    inquirer
        .prompt([
            {
                type: "list",
                name: "language",
                message: "Which language you want compile (or all languages)",
                choices: ["All Languages", ...languageEntries],
                loop: true,
            },
        ])
        .then((result) => {
            const language = result.language;
            if(language === 'All Languages') {
                languageEntries.forEach((language) => {
                    compile(language);
                });
            } else {
                compile(result.language);
            }
        });
}

function main() {
    if (argv.all) {
        // compile all: yarn antlr4 --all
        languageEntries.forEach((language) => {
            compile(language);
        });
    } else if (argv.lang) {
        // compile single: yarn antlr4 --lang=generic
        const supportedLanguage = languageEntries.some(
            (language) => language === argv.lang
        );
        if (supportedLanguage) {
            compile(argv.lang);
        } else {
            console.error(
                chalk.bold.red("\n[Invalid language]:"),
                chalk.white.underline(`${argv.lang}\n`)
            );
            prompt();
        }
    } else {
        prompt();
    }
}

main();