/* eslint-env node */
import fs from 'fs';
import path from 'path';

const root = process.cwd();
const includeExts = new Set(['.js', '.html', '.css']);
const ignoreDirs = new Set(['node_modules', '.git']);

const patterns = [
    { name: 'question-marks', regex: /\?\?\?/g },
    { name: 'replacement-char', regex: /\uFFFD/g },
];

function isIgnoredDir(dirName) {
    return ignoreDirs.has(dirName);
}

function walk(dir, files = []) {
    const entries = fs.readdirSync(dir, { withFileTypes: true });
    for (const entry of entries) {
        if (entry.isDirectory()) {
            if (isIgnoredDir(entry.name)) continue;
            walk(path.join(dir, entry.name), files);
        } else if (entry.isFile()) {
            const ext = path.extname(entry.name);
            if (includeExts.has(ext)) {
                files.push(path.join(dir, entry.name));
            }
        }
    }
    return files;
}

function scanFile(filePath) {
    let content = '';
    try {
        content = fs.readFileSync(filePath, 'utf8');
    } catch {
        return [];
    }

    const lines = content.split(/\r?\n/);
    const hits = [];

    for (let i = 0; i < lines.length; i++) {
        const line = lines[i];
        for (const { name, regex } of patterns) {
            regex.lastIndex = 0;
            if (regex.test(line)) {
                const preview = line.replace(/\t/g, '\\t').slice(0, 200);
                hits.push({ line: i + 1, name, preview });
            }
        }
    }

    return hits;
}

const files = walk(root);
const issues = [];

for (const file of files) {
    const hits = scanFile(file);
    if (hits.length) {
        issues.push({ file, hits });
    }
}

if (issues.length) {
    console.error('Garbled text check failed:');
    for (const issue of issues) {
        const rel = path.relative(root, issue.file);
        for (const hit of issue.hits) {
            console.error(`- ${rel}:${hit.line} [${hit.name}] ${hit.preview}`);
        }
    }
    process.exit(1);
} else {
    console.log('Garbled text check passed.');
}