/* ===== Panel Resizer (Universal) ===== */
window.NAIResizer = {
    instances: [],

    create(containerId, leftSel, rightSel, opts = {}) {
        const container = document.querySelector(containerId);
        if (!container) return null;

        const left = container.querySelector(leftSel);
        const right = container.querySelector(rightSel);
        if (!left || !right) return null;

        left.style.minHeight = '0';
        right.style.minHeight = '0';
        const minLeft = opts.minLeft ?? 200;
        const minRight = opts.minRight ?? 200;
        const storeKey = opts.storeKey || containerId;

        // Create resizer element
        const resizer = document.createElement('div');
        resizer.className = 'panel-resizer';
        resizer.style.flexShrink = '0';

        // Insert between left and right
        right.parentNode.insertBefore(resizer, right);

        const state = {
            container, left, right, resizer,
            minLeft, minRight, storeKey,
            savedSize: null,
            dragging: false,
        };

        // Detect orientation
        const isVertical = () => {
            const style = getComputedStyle(container);
            return style.flexDirection === 'column' || style.flexDirection === 'column-reverse';
        };

        // Apply orientation class
        const updateOrientation = () => {
            const vert = isVertical();
            resizer.classList.toggle('vertical', vert);
        };

        // Observe container for flex-direction changes (responsive breakpoints)
        let prevVertical = isVertical();
        let resizeTimer;
        const resizeObserver = new ResizeObserver(() => {
            clearTimeout(resizeTimer);
            resizeTimer = setTimeout(() => {
                const nowVertical = isVertical();
                if (nowVertical !== prevVertical) {
                    prevVertical = nowVertical;
                    this._resetSizes(state);
                    updateOrientation();
                }
            }, 100);
            const nowVertical = isVertical();
            if (nowVertical !== prevVertical) {
                prevVertical = nowVertical;
                this._resetSizes(state);
                updateOrientation();
            }
        });
        resizeObserver.observe(container);

        updateOrientation();

        // ── Drag logic ──
        let startPos, startSize;

        const onDown = (e) => {
            e.preventDefault();
            state.dragging = true;
            const vert = isVertical();
            startPos = vert
                ? (e.touches ? e.touches[0].clientY : e.clientY)
                : (e.touches ? e.touches[0].clientX : e.clientX);
            startSize = vert
                ? left.getBoundingClientRect().height
                : left.getBoundingClientRect().width;
            resizer.classList.add('active');
            document.body.style.cursor = vert ? 'row-resize' : 'col-resize';
            document.body.style.userSelect = 'none';
        };

        const onMove = (e) => {
            if (!state.dragging) return;
            const vert = isVertical();
            const clientPos = vert
                ? (e.touches ? e.touches[0].clientY : e.clientY)
                : (e.touches ? e.touches[0].clientX : e.clientX);
            const delta = clientPos - startPos;
            const resizerSize = vert ? resizer.getBoundingClientRect().height : resizer.getBoundingClientRect().width;
            const containerSize = vert
                ? container.getBoundingClientRect().height - resizerSize
                : container.getBoundingClientRect().width - resizerSize;
            const newSize = Math.max(minLeft, Math.min(containerSize - minRight, startSize + delta));

            const prop = vert ? 'height' : 'width';
            const minProp = vert ? 'minHeight' : 'minWidth';
            const maxProp = vert ? 'maxHeight' : 'maxWidth';

            left.style[prop] = newSize + 'px';
            left.style[minProp] = newSize + 'px';
            left.style[maxProp] = newSize + 'px';
            left.style.flex = 'none';
            right.style.flex = '1';
        };

        const onUp = () => {
            if (!state.dragging) return;
            state.dragging = false;
            resizer.classList.remove('active');
            document.body.style.cursor = '';
            document.body.style.userSelect = '';
        };

        resizer.addEventListener('mousedown', onDown);
        document.addEventListener('mousemove', onMove);
        document.addEventListener('mouseup', onUp);
        resizer.addEventListener('touchstart', onDown, { passive: false });
        document.addEventListener('touchmove', onMove, { passive: false });
        document.addEventListener('touchend', onUp);

        // Double click to reset
        resizer.addEventListener('dblclick', () => {
            this._resetSizes(state);
        });

        updateOrientation();

        this.instances.push(state);
        return state;
    },

    _resetSizes(state) {
        const props = ['width', 'minWidth', 'maxWidth', 'height', 'minHeight', 'maxHeight',
                       'flex', 'overflow', 'padding', 'border'];
        for (const p of props) {
            state.left.style[p] = '';
            state.right.style[p] = '';
        }
    },

    init() {
        this.create('.gen-layout', '.gen-params', '.gen-result', {
            minLeft: 280, minRight: 200, storeKey: 'gen',
        });
        this.create('.dt-layout', '.dt-left', '.dt-right', {
            minLeft: 250, minRight: 200, storeKey: 'dt',
        });
        this.create('.pi-layout', '.pi-left', '.pi-right', {
            minLeft: 200, minRight: 200, storeKey: 'pi',
        });
        this.create('.tagger-layout', '.tagger-left', '.tagger-right', {
            minLeft: 250, minRight: 200, storeKey: 'tagger',
        });
        this.create('.history-layout', '.history-left', '.history-right', {
            minLeft: 200, minRight: 250, storeKey: 'history',
        });
        // Cloud: between main and detail panel
        this.create('.cloud-layout', '.cloud-main', '.cloud-detail-panel', {
            minLeft: 200, minRight: 250, storeKey: 'cloud',
        });
    },
};