/**
 * Tab Management for HM QC Platform
 *
 * Handles tab state preservation, navigation, and cross-tab communication
 */

const TabManager = {
    /**
     * Save state for a specific tab
     * @param {string} tabId - Tab identifier (e.g., 'hm-qc', 'video-qc')
     * @param {object} state - State object to save
     */
    saveState(tabId, state) {
        try {
            const stateKey = `tab_${tabId}_state`;
            sessionStorage.setItem(stateKey, JSON.stringify({
                ...state,
                timestamp: new Date().toISOString()
            }));
        } catch (error) {
            console.error(`Error saving state for tab ${tabId}:`, error);
        }
    },

    /**
     * Load state for a specific tab
     * @param {string} tabId - Tab identifier
     * @returns {object|null} Saved state or null if not found
     */
    loadState(tabId) {
        try {
            const stateKey = `tab_${tabId}_state`;
            const stateStr = sessionStorage.getItem(stateKey);

            if (!stateStr) {
                return null;
            }

            return JSON.parse(stateStr);
        } catch (error) {
            console.error(`Error loading state for tab ${tabId}:`, error);
            return null;
        }
    },

    /**
     * Clear state for a specific tab
     * @param {string} tabId - Tab identifier
     */
    clearState(tabId) {
        try {
            const stateKey = `tab_${tabId}_state`;
            sessionStorage.removeItem(stateKey);
        } catch (error) {
            console.error(`Error clearing state for tab ${tabId}:`, error);
        }
    },

    /**
     * Clear all tab states
     */
    clearAllStates() {
        try {
            const keys = Object.keys(sessionStorage);
            keys.forEach(key => {
                if (key.startsWith('tab_')) {
                    sessionStorage.removeItem(key);
                }
            });
        } catch (error) {
            console.error('Error clearing all tab states:', error);
        }
    },

    /**
     * Get current active tab
     * @returns {string|null} Active tab ID or null
     */
    getActiveTab() {
        const activeLink = document.querySelector('.hm-tabs .nav-link.active');
        return activeLink ? activeLink.dataset.tab : null;
    },

    /**
     * Set active tab
     * @param {string} tabId - Tab identifier to activate
     */
    setActiveTab(tabId) {
        // Remove active class from all tabs
        document.querySelectorAll('.hm-tabs .nav-link').forEach(link => {
            link.classList.remove('active');
        });

        // Add active class to target tab
        const targetLink = document.querySelector(`.hm-tabs .nav-link[data-tab="${tabId}"]`);
        if (targetLink) {
            targetLink.classList.add('active');
        }
    },

    /**
     * Check if a tab has new content/notifications
     * @param {string} tabId - Tab identifier
     * @returns {boolean} True if tab has notifications
     */
    hasNotification(tabId) {
        const state = this.loadState(tabId);
        return state && state.hasNotification === true;
    },

    /**
     * Set notification status for a tab
     * @param {string} tabId - Tab identifier
     * @param {boolean} hasNotification - Notification status
     */
    setNotification(tabId, hasNotification) {
        const state = this.loadState(tabId) || {};
        state.hasNotification = hasNotification;
        this.saveState(tabId, state);

        // Update UI to show notification indicator
        this.updateNotificationIndicator(tabId, hasNotification);
    },

    /**
     * Update notification indicator in tab UI
     * @param {string} tabId - Tab identifier
     * @param {boolean} show - Whether to show indicator
     */
    updateNotificationIndicator(tabId, show) {
        const tabLink = document.querySelector(`.hm-tabs .nav-link[data-tab="${tabId}"]`);
        if (!tabLink) return;

        // Remove existing indicator
        const existingIndicator = tabLink.querySelector('.notification-indicator');
        if (existingIndicator) {
            existingIndicator.remove();
        }

        // Add new indicator if needed
        if (show) {
            const indicator = document.createElement('span');
            indicator.className = 'notification-indicator';
            indicator.innerHTML = '<i class="bi bi-dot"></i>';
            indicator.style.cssText = 'color: #dc3545; font-size: 2rem; line-height: 0; margin-left: -8px;';
            tabLink.appendChild(indicator);
        }
    }
};

/**
 * Initialize tab management when DOM is loaded
 */
document.addEventListener('DOMContentLoaded', function() {
    console.log('Tab management initialized');

    // Handle tab click events
    document.querySelectorAll('.hm-tabs .nav-link').forEach(link => {
        link.addEventListener('click', function(e) {
            const currentTab = TabManager.getActiveTab();
            const targetTab = this.dataset.tab;

            // Don't do anything if clicking the same tab
            if (currentTab === targetTab) {
                e.preventDefault();
                return;
            }

            // Save current tab state before switching
            if (currentTab) {
                const currentState = getCurrentTabState(currentTab);
                if (currentState) {
                    TabManager.saveState(currentTab, currentState);
                }
            }

            // Clear notification when switching to a tab
            TabManager.setNotification(targetTab, false);

            console.log(`Switching from ${currentTab} to ${targetTab}`);
        });
    });

    // Restore state for current active tab
    const activeTab = TabManager.getActiveTab();
    if (activeTab) {
        const state = TabManager.loadState(activeTab);
        if (state) {
            console.log(`Restoring state for ${activeTab}:`, state);
            restoreTabState(activeTab, state);
        }
    }

    // Check for notifications from other tabs
    checkForNotifications();
});

/**
 * Get current state for a tab (to be implemented per module)
 * @param {string} tabId - Tab identifier
 * @returns {object} Current state object
 */
function getCurrentTabState(tabId) {
    // This function should be overridden by each module
    // to return its current state
    return {
        scrollPosition: window.scrollY,
        timestamp: new Date().toISOString()
    };
}

/**
 * Restore state for a tab (to be implemented per module)
 * @param {string} tabId - Tab identifier
 * @param {object} state - State to restore
 */
function restoreTabState(tabId, state) {
    // This function should be overridden by each module
    // to restore its state
    if (state.scrollPosition) {
        window.scrollTo(0, state.scrollPosition);
    }
}

/**
 * Check for notifications from other tabs
 */
function checkForNotifications() {
    const tabs = ['hm-qc', 'video-qc', 'video-master', 'reporting'];

    tabs.forEach(tabId => {
        if (TabManager.hasNotification(tabId)) {
            TabManager.updateNotificationIndicator(tabId, true);
        }
    });
}

/**
 * Show notification toast
 * @param {string} message - Notification message
 * @param {string} type - Notification type (success, error, warning, info)
 */
function showNotification(message, type = 'info') {
    // Create toast container if it doesn't exist
    let toastContainer = document.querySelector('.toast-container');

    if (!toastContainer) {
        toastContainer = document.createElement('div');
        toastContainer.className = 'toast-container position-fixed top-0 end-0 p-3';
        toastContainer.style.zIndex = '9999';
        document.body.appendChild(toastContainer);
    }

    // Create toast element
    const toast = document.createElement('div');
    toast.className = `toast align-items-center text-white bg-${type === 'error' ? 'danger' : type} border-0`;
    toast.setAttribute('role', 'alert');
    toast.setAttribute('aria-live', 'assertive');
    toast.setAttribute('aria-atomic', 'true');

    toast.innerHTML = `
        <div class="d-flex">
            <div class="toast-body">
                ${message}
            </div>
            <button type="button" class="btn-close btn-close-white me-2 m-auto" data-bs-dismiss="toast"></button>
        </div>
    `;

    toastContainer.appendChild(toast);

    // Show toast
    const bsToast = new bootstrap.Toast(toast, {
        delay: 5000,
        autohide: true
    });

    bsToast.show();

    // Remove toast after it's hidden
    toast.addEventListener('hidden.bs.toast', function() {
        toast.remove();
    });
}

// Make TabManager available globally
window.TabManager = TabManager;
window.showNotification = showNotification;