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

function toEssentialIcon(icon = {}) {
    const name = typeof icon.name === 'string' ? icon.name : '';
    const prefix = typeof icon.prefix === 'string' ? icon.prefix : '';

    if (!name || !prefix) return null;

    const minimal = { name, prefix };
    if (typeof icon.tags === 'string' && icon.tags.trim()) {
        minimal.tags = icon.tags;
    }

    return minimal;
}

function buildIconsJs({
    inputPath = path.join(__dirname, 'data', 'all_icons.json'),
    outputPath = path.join(__dirname, 'data', 'all_icons.js')
} = {}) {
    if (!fs.existsSync(inputPath)) {
        throw new Error(`Missing ${inputPath}`);
    }

    const raw = fs.readFileSync(inputPath, 'utf8');
    const icons = JSON.parse(raw).map(toEssentialIcon).filter(Boolean);

    const payload = `window.FICONS_DATA = ${JSON.stringify(icons)};\n`;
    fs.writeFileSync(outputPath, payload, 'utf8');

    const sizeMb = (payload.length / (1024 * 1024)).toFixed(1);
    console.log(`Wrote ${outputPath} (${sizeMb} MB)`);
}

if (require.main === module) {
    try {
        buildIconsJs();
    } catch (error) {
        console.error(error.message || error);
        process.exit(1);
    }
}

module.exports = buildIconsJs;