/**
 * GraphAnnotation - Ghi Chú Đồ Thị
 * Cho phép thêm/sửa/xóa ghi chú trên node trong đồ thị Cytoscape
 * Lưu/khôi phục annotations từ localStorage
 * Requirements: 33.1, 33.2, 33.3, 33.4, 33.5
 */

class GraphAnnotation {
    /**
     * @param {string} graphContainerSelector - CSS selector cho container đồ thị
     * @param {string} [storagePrefix='onnx_explorer_annotations_'] - Prefix key localStorage
     */
    constructor(graphContainerSelector, storagePrefix) {
        this._containerSelector = graphContainerSelector || '#graphContainer';
        this._storagePrefix = storagePrefix || 'onnx_explorer_annotations_';

        /** @type {Object<string, string>} nodeId → annotation text */
        this._annotations = {};

        /** @type {string|null} current model file name */
        this._modelFileName = null;

        /** @type {HTMLElement|null} popup element */
        this._popup = null;

        /** @type {Function|null} EventBus unsubscribe for model:loaded */
        this._unsubModelLoaded = null;

        /** @type {Function|null} EventBus unsubscribe for graph:rendered */
        this._unsubGraphRendered = null;
    }

    /**
     * Khởi tạo: gắn event listeners cho context menu và model:loaded
     */
    init() {
        this._bindModelLoadedEvent();
        this._bindGraphRenderedEvent();
        console.log('[GraphAnnotation] Initialized');
    }

    /**
     * Hiển thị popup để thêm/sửa ghi chú cho một node
     * @param {string} nodeId - ID của node
     */
    showAnnotationPopup(nodeId) {
        // Remove existing popup
        this._removePopup();

        const existing = this.getAnnotation(nodeId);

        // Create popup element
        const popup = document.createElement('div');
        popup.className = 'annotation-popup';
        popup.setAttribute('role', 'dialog');
        popup.setAttribute('aria-label', 'Ghi chú node');

        const header = document.createElement('div');
        header.className = 'annotation-popup-header';
        header.textContent = 'Ghi chú: ' + nodeId;

        const textarea = document.createElement('textarea');
        textarea.className = 'annotation-popup-textarea';
        textarea.placeholder = 'Nhập ghi chú cho node này...';
        textarea.value = existing || '';
        textarea.rows = 4;

        const btnContainer = document.createElement('div');
        btnContainer.className = 'annotation-popup-buttons';

        const saveBtn = document.createElement('button');
        saveBtn.className = 'annotation-btn annotation-btn-save';
        saveBtn.textContent = 'Lưu';
        saveBtn.addEventListener('click', () => {
            const text = textarea.value.trim();
            if (text) {
                this.saveAnnotation(nodeId, text);
            }
            this._removePopup();
        });

        const deleteBtn = document.createElement('button');
        deleteBtn.className = 'annotation-btn annotation-btn-delete';
        deleteBtn.textContent = 'Xóa';
        deleteBtn.addEventListener('click', () => {
            this.deleteAnnotation(nodeId);
            this._removePopup();
        });

        const closeBtn = document.createElement('button');
        closeBtn.className = 'annotation-btn annotation-btn-close';
        closeBtn.textContent = 'Đóng';
        closeBtn.addEventListener('click', () => {
            this._removePopup();
        });

        btnContainer.appendChild(saveBtn);
        btnContainer.appendChild(deleteBtn);
        btnContainer.appendChild(closeBtn);

        popup.appendChild(header);
        popup.appendChild(textarea);
        popup.appendChild(btnContainer);

        // Position popup in the graph container
        const container = document.querySelector(this._containerSelector);
        if (container) {
            container.style.position = 'relative';
            popup.style.position = 'absolute';
            popup.style.top = '50%';
            popup.style.left = '50%';
            popup.style.transform = 'translate(-50%, -50%)';
            popup.style.zIndex = '1000';
            container.appendChild(popup);
        } else {
            document.body.appendChild(popup);
        }

        this._popup = popup;

        // Focus textarea
        requestAnimationFrame(() => textarea.focus());
    }

    /**
     * Lưu ghi chú cho một node
     * @param {string} nodeId - ID của node
     * @param {string} text - Nội dung ghi chú
     */
    saveAnnotation(nodeId, text) {
        if (!nodeId || !text) return;

        this._annotations[nodeId] = text;
        this._persistToStorage();
        this._addBadgeToNode(nodeId);

        console.log('[GraphAnnotation] Saved annotation for', nodeId);
    }

    /**
     * Xóa ghi chú của một node
     * @param {string} nodeId - ID của node
     */
    deleteAnnotation(nodeId) {
        if (!nodeId || !(nodeId in this._annotations)) return;

        delete this._annotations[nodeId];
        this._persistToStorage();
        this._removeBadgeFromNode(nodeId);

        console.log('[GraphAnnotation] Deleted annotation for', nodeId);
    }

    /**
     * Lấy ghi chú của một node
     * @param {string} nodeId - ID của node
     * @returns {string|null}
     */
    getAnnotation(nodeId) {
        return this._annotations[nodeId] || null;
    }

    /**
     * Lấy tất cả annotations cho model hiện tại
     * @returns {Object} Map nodeId → annotation text
     */
    getAllAnnotations() {
        return Object.assign({}, this._annotations);
    }

    /**
     * Tải annotations từ localStorage cho model hiện tại
     * @param {string} modelFileName - Tên tệp mô hình
     */
    loadAnnotations(modelFileName) {
        if (!modelFileName) {
            this._annotations = {};
            this._modelFileName = null;
            return;
        }

        this._modelFileName = modelFileName;
        const key = this._storagePrefix + modelFileName;

        try {
            const raw = localStorage.getItem(key);
            this._annotations = raw ? JSON.parse(raw) : {};
        } catch (err) {
            console.warn('[GraphAnnotation] Failed to load annotations:', err);
            this._annotations = {};
        }

        console.log('[GraphAnnotation] Loaded annotations for', modelFileName,
            '- count:', Object.keys(this._annotations).length);
    }

    /**
     * Khôi phục badges trên tất cả node có annotation (gọi sau khi graph rendered)
     */
    restoreBadges() {
        const cy = this._getCyInstance();
        if (!cy) return;

        const nodeIds = Object.keys(this._annotations);
        for (var i = 0; i < nodeIds.length; i++) {
            this._addBadgeToNode(nodeIds[i]);
        }
    }

    /**
     * Hủy và dọn dẹp
     */
    destroy() {
        this._removePopup();
        this._removeCxttapListener();

        if (this._unsubModelLoaded) {
            this._unsubModelLoaded();
            this._unsubModelLoaded = null;
        }
        if (this._unsubGraphRendered) {
            this._unsubGraphRendered();
            this._unsubGraphRendered = null;
        }

        this._annotations = {};
        this._modelFileName = null;
        console.log('[GraphAnnotation] Destroyed');
    }

    // ─── Private Helpers ───────────────────────────────────────────────────────

    /**
     * Get the Cytoscape instance
     * @returns {cytoscape.Core|null}
     * @private
     */
    _getCyInstance() {
        try {
            if (window._onnxApp && window._onnxApp.getGraphVisualizer) {
                var gv = window._onnxApp.getGraphVisualizer();
                return gv ? gv._cy : null;
            }
        } catch (e) {
            // ignore
        }
        return null;
    }

    /**
     * Get current model file name from StateManager
     * @returns {string|null}
     * @private
     */
    _getModelFileName() {
        try {
            if (window.StateManager) {
                var model = window.StateManager.getCurrentModel();
                if (model && model.metadata && model.metadata.fileName) {
                    return model.metadata.fileName;
                }
            }
        } catch (e) {
            // ignore
        }
        return null;
    }

    /**
     * Persist annotations to localStorage
     * @private
     */
    _persistToStorage() {
        if (!this._modelFileName) return;

        var key = this._storagePrefix + this._modelFileName;
        try {
            var data = JSON.stringify(this._annotations);
            localStorage.setItem(key, data);
        } catch (err) {
            console.warn('[GraphAnnotation] Failed to persist annotations:', err);
        }
    }

    /**
     * Add 'has-annotation' class to a Cytoscape node
     * @param {string} nodeId
     * @private
     */
    _addBadgeToNode(nodeId) {
        var cy = this._getCyInstance();
        if (!cy) return;

        var node = cy.getElementById(nodeId);
        if (node && node.length > 0) {
            node.addClass('has-annotation');
        }
    }

    /**
     * Remove 'has-annotation' class from a Cytoscape node
     * @param {string} nodeId
     * @private
     */
    _removeBadgeFromNode(nodeId) {
        var cy = this._getCyInstance();
        if (!cy) return;

        var node = cy.getElementById(nodeId);
        if (node && node.length > 0) {
            node.removeClass('has-annotation');
        }
    }

    /**
     * Bind cxttap (right-click) event on Cytoscape nodes
     * @private
     */
    _bindCxttapListener() {
        var cy = this._getCyInstance();
        if (!cy) return;

        // Remove previous listener to avoid duplicates
        this._removeCxttapListener();

        var self = this;
        this._cxttapHandler = function (evt) {
            var node = evt.target;
            var nodeId = node.data('id');
            if (nodeId) {
                self.showAnnotationPopup(nodeId);
            }
        };

        cy.on('cxttap', 'node', this._cxttapHandler);
    }

    /**
     * Remove cxttap listener
     * @private
     */
    _removeCxttapListener() {
        var cy = this._getCyInstance();
        if (cy && this._cxttapHandler) {
            cy.off('cxttap', 'node', this._cxttapHandler);
        }
        this._cxttapHandler = null;
    }

    /**
     * Listen for model:loaded event to auto-load annotations
     * @private
     */
    _bindModelLoadedEvent() {
        if (!window.EventBus) return;

        var self = this;
        var eventName = (typeof CONFIG !== 'undefined' && CONFIG.EVENTS)
            ? CONFIG.EVENTS.MODEL_LOADED
            : 'model:loaded';

        this._unsubModelLoaded = window.EventBus.on(eventName, function (payload) {
            var fileName = self._getModelFileName();
            if (fileName) {
                self.loadAnnotations(fileName);
            }
        });
    }

    /**
     * Listen for graph:rendered event to bind cxttap and restore badges
     * @private
     */
    _bindGraphRenderedEvent() {
        if (!window.EventBus) return;

        var self = this;
        var eventName = (typeof CONFIG !== 'undefined' && CONFIG.EVENTS)
            ? CONFIG.EVENTS.GRAPH_RENDERED
            : 'graph:rendered';

        this._unsubGraphRendered = window.EventBus.on(eventName, function () {
            self._bindCxttapListener();
            self.restoreBadges();
        });
    }

    /**
     * Remove popup from DOM
     * @private
     */
    _removePopup() {
        if (this._popup && this._popup.parentNode) {
            this._popup.parentNode.removeChild(this._popup);
        }
        this._popup = null;
    }
}

// Export as global for browser usage
window.GraphAnnotation = GraphAnnotation;