// static/admin/js/customers.js
/**
 * Admin customer management page logic
 */

// Create logger for this module
const customersLog = window.LogConfig?.createLogger('CUSTOMERS') || console;

function adminCustomers() {
    return {
        // Inherit base layout state
        ...data(),

        // Page identifier
        currentPage: 'customers',

        // Loading states
        loading: true,
        loadingCustomers: false,

        // Error state
        error: '',

        // Data
        customers: [],
        vendors: [],
        stats: {
            total: 0,
            active: 0,
            inactive: 0,
            with_orders: 0,
            total_spent: 0,
            total_orders: 0,
            avg_order_value: 0
        },

        // Pagination
        page: 1,
        limit: 20,
        total: 0,
        skip: 0,

        // Filters
        filters: {
            search: '',
            is_active: '',
            vendor_id: ''
        },

        // Computed: total pages
        get totalPages() {
            return Math.ceil(this.total / this.limit);
        },

        async init() {
            customersLog.debug('Customers page initialized');

            // Load vendors for filter dropdown
            await this.loadVendors();

            // Load initial data
            await Promise.all([
                this.loadCustomers(),
                this.loadStats()
            ]);

            this.loading = false;
        },

        /**
         * Load vendors for filter dropdown
         */
        async loadVendors() {
            try {
                const response = await apiClient.get('/admin/vendors?limit=100');
                this.vendors = response.vendors || [];
            } catch (error) {
                customersLog.error('Failed to load vendors:', error);
                this.vendors = [];
            }
        },

        /**
         * Load customers with current filters
         */
        async loadCustomers() {
            this.loadingCustomers = true;
            this.error = '';
            this.skip = (this.page - 1) * this.limit;

            try {
                const params = new URLSearchParams({
                    skip: this.skip.toString(),
                    limit: this.limit.toString()
                });

                if (this.filters.search) {
                    params.append('search', this.filters.search);
                }

                if (this.filters.is_active !== '') {
                    params.append('is_active', this.filters.is_active);
                }

                if (this.filters.vendor_id) {
                    params.append('vendor_id', this.filters.vendor_id);
                }

                const response = await apiClient.get(`/admin/customers?${params}`);
                this.customers = response.customers || [];
                this.total = response.total || 0;
            } catch (error) {
                customersLog.error('Failed to load customers:', error);
                this.error = error.message || 'Failed to load customers';
                this.customers = [];
            } finally {
                this.loadingCustomers = false;
            }
        },

        /**
         * Load customer statistics
         */
        async loadStats() {
            try {
                const params = new URLSearchParams();
                if (this.filters.vendor_id) {
                    params.append('vendor_id', this.filters.vendor_id);
                }

                const response = await apiClient.get(`/admin/customers/stats?${params}`);
                this.stats = response;
            } catch (error) {
                customersLog.error('Failed to load stats:', error);
            }
        },

        /**
         * Reset pagination and reload
         */
        async resetAndLoad() {
            this.page = 1;
            await Promise.all([
                this.loadCustomers(),
                this.loadStats()
            ]);
        },

        /**
         * Go to specific page
         */
        goToPage(p) {
            this.page = p;
            this.loadCustomers();
        },

        /**
         * Get array of page numbers to display
         */
        getPageNumbers() {
            const total = this.totalPages;
            const current = this.page;
            const maxVisible = 5;

            if (total <= maxVisible) {
                return Array.from({length: total}, (_, i) => i + 1);
            }

            const half = Math.floor(maxVisible / 2);
            let start = Math.max(1, current - half);
            let end = Math.min(total, start + maxVisible - 1);

            if (end - start < maxVisible - 1) {
                start = Math.max(1, end - maxVisible + 1);
            }

            return Array.from({length: end - start + 1}, (_, i) => start + i);
        },

        /**
         * Toggle customer active status
         */
        async toggleStatus(customer) {
            const action = customer.is_active ? 'deactivate' : 'activate';
            if (!confirm(`Are you sure you want to ${action} this customer?`)) {
                return;
            }

            try {
                const response = await apiClient.patch(`/admin/customers/${customer.id}/toggle-status`);
                customer.is_active = response.is_active;

                // Update stats
                if (response.is_active) {
                    this.stats.active++;
                    this.stats.inactive--;
                } else {
                    this.stats.active--;
                    this.stats.inactive++;
                }

                customersLog.info(response.message);
            } catch (error) {
                customersLog.error('Failed to toggle status:', error);
                alert(error.message || 'Failed to toggle customer status');
            }
        },

        /**
         * Format currency for display
         */
        formatCurrency(amount) {
            if (amount == null) return '-';
            return new Intl.NumberFormat('de-DE', {
                style: 'currency',
                currency: 'EUR'
            }).format(amount);
        },

        /**
         * Format date for display
         */
        formatDate(dateString) {
            if (!dateString) return '-';
            try {
                const date = new Date(dateString);
                return date.toLocaleDateString('en-GB', {
                    year: 'numeric',
                    month: 'short',
                    day: 'numeric'
                });
            } catch {
                return dateString;
            }
        }
    };
}