export class DocumentFormatter {
    static MONTHS_ID = ['Jan', 'Feb', 'Mar', 'Apr', 'Mei', 'Jun', 'Jul', 'Agu', 'Sep', 'Okt', 'Nov', 'Des'];

    static CATEGORY_RULES = [
        { key: 'skripsi', match: ['skripsi', 'tugas akhir', 'ta'] },
        { key: 'akademik', match: ['akademik', 'kalender', 'kaldik'] },
        { key: 'praktik', match: ['praktik', 'praktek', 'kerja praktik', 'kp'] },
    ];

    static formatDate(iso) {
        if (!iso) return '';
        const date = new Date(iso);
        if (Number.isNaN(date.getTime())) return '';
        const day = String(date.getDate()).padStart(2, '0');
        const month = this.MONTHS_ID[date.getMonth()];
        return `${day} ${month} ${date.getFullYear()}`;
    }

    static categoryFromTags(tags) {
        if (!tags || tags.length === 0) return 'umum';
        const lower = tags.map(tag => tag.toLowerCase());
        for (const rule of this.CATEGORY_RULES) {
            if (rule.match.some(match => lower.includes(match))) return rule.key;
        }
        return 'umum';
    }

    static fileTypeFromName(name) {
        const lower = (name || '').toLowerCase();
        if (lower.endsWith('.docx') || lower.endsWith('.doc')) return 'docx';
        return 'pdf';
    }

    static downloadFilename(name, type) {
        const ext = `.${type}`;
        return name.toLowerCase().endsWith(ext) ? name : `${name}${ext}`;
    }

    static escapeHtml(str) {
        if (str == null) return '';
        return String(str)
            .replace(/&/g, '&')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;')
            .replace(/"/g, '&quot;')
            .replace(/'/g, '&#39;');
    }

    static escapeAttr(str) {
        return this.escapeHtml(str);
    }

    static parseTags(raw) {
        if (!raw) return [];
        const str = String(raw).trim();
        if (!str) return [];

        if (str.startsWith('[')) {
            try {
                const arr = JSON.parse(str);
                if (Array.isArray(arr)) {
                    return arr.map(tag => String(tag).trim()).filter(Boolean);
                }
            } catch {
                // Fall through to comma-separated parsing.
            }
        }

        return str.split(',').map(tag => tag.trim()).filter(Boolean);
    }
}