const semver = require('semver');
const chalk = require('chalk');
const packageConfig = require('./package.json');
const exec = function (cmd) {
    return require('child_process')
        .execSync(cmd).toString().trim();
};

const versionRequirements = [
    {
        name: 'node',
        currentVersion: semver.clean(process.version),
        versionRequirement: packageConfig.engines.node
    },
    {
        name: 'npm',
        currentVersion: exec('npm --version'),
        versionRequirement: packageConfig.engines.npm
    }
];

const warnings = [];
for (var i = 0; i < versionRequirements.length; i++) {
    const mod = versionRequirements[i];
    if (!semver.satisfies(mod.currentVersion, mod.versionRequirement)) {
        warnings.push(`${mod.name}: ${
            chalk.red(mod.currentVersion)} should be ${
            chalk.green(mod.versionRequirement)}`
        );
    }
}

if (warnings.length) {
    console.log(chalk.white.bgRed.bold('******************************************************************'));
    console.log(chalk.white.bgRed.bold('To use this template, you must update the following modules:      '));
    console.log();
    for (var i = 0; i < warnings.length; i++) {
        const warning = warnings[i];
        console.log(`  ${warning}`);
    }
    console.log(chalk.white.bgRed.bold('******************************************************************'));
    console.log();
    process.exit(1);
}
else {
    console.log('');
    console.log(chalk.green('NPM and Node versions are all good!'));
    console.log();
}