export default class AAutoFill extends window.AObject{
    constructor(root = document) {
        super();
        this.root = root;
    }

    fill(data) {
        const sel = '[data-id],[data-control],[data-controll]';
        this.root.querySelectorAll(sel).forEach(el => {
            const path = el.dataset.id ?? el.dataset.control ?? el.dataset.controll;
            const val = AAutoFill.get(data, path);
            if (val === undefined) return;        // không có dữ liệu -> bỏ qua
            AAutoFill.apply(el, val, this.root);
        });
    }

    // --- helpers ---
    static get(obj, path) {
        if (!obj || !path) return undefined;
        // dot + bracket: user.items[0].name
        const parts = path.split('.').flatMap(p => {
            const m = [...p.matchAll(/([^\[\]]+)|\[(\d+)\]/g)];
            return m.map(g => g[1] ?? Number(g[2]));
        });
        return parts.reduce((acc, k) => (acc == null ? undefined : acc[k]), obj);
    }

    static apply(el, value, root) {
        const tag = el.tagName.toLowerCase();
        const type = (el.type || '').toLowerCase();

        if (tag === 'input') {
            if (type === 'checkbox') {
                if (Array.isArray(value)) { el.checked = value.map(String).includes(el.value); }
                else { el.checked = AAutoFill.truthy(value, el.value); }
                AAutoFill.emit(el, 'change'); return;
            }
            if (type === 'radio') {
                const key = el.name || el.dataset.id || el.dataset.control || el.dataset.controll;
                const q = `input[type=radio][name="${CSS.escape(key)}"],input[type=radio][data-id="${CSS.escape(key)}"],input[type=radio][data-control="${CSS.escape(key)}"],input[type=radio][data-controll="${CSS.escape(key)}"]`;
                root.querySelectorAll(q).forEach(r => r.checked = String(r.value) === String(value));
                AAutoFill.emit(el, 'change'); return;
            }
            if (type === 'date' || type === 'time' || type === 'datetime-local') {
                el.value = AAutoFill.formatForInput(type, value);
                AAutoFill.emit(el); AAutoFill.emit(el, 'change'); return;
            }
            el.value = value ?? '';
            AAutoFill.emit(el); AAutoFill.emit(el, 'change'); return;
        }

        if (tag === 'select') {
            if (el.multiple) {
                const arr = Array.isArray(value) ? value.map(String) : [String(value)];
                [...el.options].forEach(o => o.selected = arr.includes(o.value) || arr.includes(o.text));
            } else {
                el.value = String(value);
                if (el.value !== String(value)) {
                    const opt = [...el.options].find(o => o.text === String(value));
                    if (opt) opt.selected = true;
                }
            }
            AAutoFill.emit(el, 'change'); return;
        }

        if (tag === 'textarea') {
            el.value = value ?? '';
            AAutoFill.emit(el); return;
        }

        if (el.isContentEditable) {
            (el.dataset.html === 'true') ? el.innerHTML = String(value ?? '') : el.textContent = String(value ?? '');
            return;
        }

        // fallback: textContent
        el.textContent = String(value ?? '');
    }

    static truthy(v, compareVal) {
        if (typeof v === 'boolean') return v;
        const s = String(v).toLowerCase();
        return ['1', 'true', 'yes', 'on', String(compareVal).toLowerCase()].includes(s);
    }

    static formatForInput(type, v) {
        const asDate = (x) => {
            if (x instanceof Date) return x;
            const n = Number(x);
            if (!Number.isNaN(n) && n > 0) { // epoch (ms or sec)
                const d = new Date(n > 1e12 ? n : n * 1000);
                if (!isNaN(d)) return d;
            }
            const d = new Date(x); return isNaN(d) ? null : d;
        };
        const pad = (n) => String(n).padStart(2, '0');
        const d = asDate(v);
        if (!d) return String(v ?? '');

        if (type === 'date') return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}`;
        if (type === 'time') return `${pad(d.getHours())}:${pad(d.getMinutes())}`;
        if (type === 'datetime-local') return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}T${pad(d.getHours())}:${pad(d.getMinutes())}`;
        return String(v ?? '');
    }

    static emit(el, name = 'input') { el.dispatchEvent(new Event(name, { bubbles: true })); }
}