/**
 * src/static/js/page-dirty.js — v1.5.0 Phase 1
 *
 * Per-page dirty state matrix helpers.
 * state.pageDirty matrix와 sidebar UI (.nav-item.has-dirty) 동기화.
 *
 * v1.4.6.x state.isDirty boolean은 backward-compat로 유지하되 markDirty/clearDirty가
 * matrix 갱신 + 합산 boolean 업데이트.
 */

import { state } from './state.js';

/**
 * v1.7.0 — dirty 변경 옵저버.
 * pending.js 가 onDirtyChange(renderBadge) 로 구독한다.
 * page-dirty 는 pending 을 import 하지 않는다 (순환 import 회피).
 */
const _subs = [];

/** Register a callback invoked after any markDirty/clearDirty/clearAllDirty.
 *  Dedup: a callback already in _subs is not pushed again (guards repeated initPending). */
export function onDirtyChange(cb) {
    if (typeof cb === 'function' && !_subs.includes(cb)) _subs.push(cb);
}

function _notify() {
    _subs.forEach(cb => {
        try { cb(); } catch (e) { /* observer must never break dirty tracking */ }
    });
}

/**
 * Mark a page as having unsaved changes.
 * Sidebar leaf에 dirty dot 표시 + state.isDirty = true.
 *
 * @param {string} pageId — state.pageDirty key (home/ssid/io/network/register/can/opcua/modbus/log/firmware)
 */
export function markDirty(pageId) {
    if (!(pageId in state.pageDirty)) {
        if (typeof console !== 'undefined') console.warn('[page-dirty] unknown pageId:', pageId);
        return;
    }
    state.pageDirty[pageId] = true;
    state.isDirty = true;  // v1.4.6.x compat
    _syncDot(pageId, true);
    _notify();
}

/**
 * Clear dirty state for a page (after successful save).
 *
 * @param {string} pageId
 */
export function clearDirty(pageId) {
    if (!(pageId in state.pageDirty)) return;
    state.pageDirty[pageId] = false;
    _syncDot(pageId, false);
    // 합산 isDirty 갱신
    state.isDirty = Object.values(state.pageDirty).some(v => v === true);
    _notify();
}

/** True if any page has unsaved changes. */
export function hasDirty() {
    return Object.values(state.pageDirty).some(v => v === true);
}

/** Return array of dirty page ids. */
export function getDirtyPages() {
    return Object.entries(state.pageDirty)
        .filter(([, dirty]) => dirty)
        .map(([id]) => id);
}

/** Clear all dirty flags (after Save All). */
export function clearAllDirty() {
    Object.keys(state.pageDirty).forEach(k => { state.pageDirty[k] = false; });
    state.isDirty = false;
    document.querySelectorAll('.nav-item.has-dirty').forEach(el => {
        el.classList.remove('has-dirty');
    });
    _notify();
}

/** Sync sidebar dirty dot for a single page. */
function _syncDot(pageId, dirty) {
    const navEl = document.querySelector(`.nav-item[data-page="${pageId}"]`);
    if (!navEl) return;
    if (dirty) navEl.classList.add('has-dirty');
    else navEl.classList.remove('has-dirty');
}