/**
 * Payment Manager for Easy Invoice
 * Handles payment calculations, discounts, and tax calculations
 */
(function($) {
    'use strict';

    // Payment Manager object
    window.EasyInvoicePayment = {
        // Default settings
        settings: {
            discountType: 'none', // none, percentage or fixed
            discountValue: 0,
            taxRate: 0,
            calculationMethod: 'before_tax', // before_tax or after_tax
            pricesIncludeTax: 'no', // yes or no
            currency: 'USD',
            currencySymbol: '$'
        },

        // Initialize the payment manager
        init: function() {
    
            
            // Load settings from form fields first (preserves PHP-set values)
            this.loadSettingsFromForm();
            
            // Then override with localized data if available
            if (typeof easyInvoicePayment !== 'undefined') {
                this.settings.discountType = easyInvoicePayment.discountType || this.settings.discountType;
                this.settings.discountValue = parseFloat(easyInvoicePayment.discountValue) || this.settings.discountValue;
                this.settings.taxRate = parseFloat(easyInvoicePayment.taxRate) || this.settings.taxRate;
                this.settings.calculationMethod = easyInvoicePayment.calculationMethod || this.settings.calculationMethod;
                this.settings.currency = easyInvoicePayment.currency || this.settings.currency;
                this.settings.currencySymbol = easyInvoicePayment.currencySymbol || this.settings.currencySymbol;
            }
            
            // Set up event handlers
            this.setupEventHandlers();
            
            // Update totals (but don't overwrite field values)
            this.updateTotals();
        },

        // Load settings from form fields
        loadSettingsFromForm: function() {
            // Read values from form fields if they exist
            var discountType = $('#discount_type').val();
            if (discountType) {
                this.settings.discountType = discountType;
            }
            
            var discountValue = parseFloat($('#discount_value').val());
            if (!isNaN(discountValue)) {
                this.settings.discountValue = discountValue;
            }
            
            var taxRate = parseFloat($('#tax_rate').val());
            if (!isNaN(taxRate)) {
                this.settings.taxRate = taxRate;
            }
            
            var calculationMethod = $('select[name="discount_calculation_method"]').val();
            if (calculationMethod) {
                this.settings.calculationMethod = calculationMethod;
            }

            var pricesIncludeTax = $('select[name="prices_include_tax"]').val();
            if (pricesIncludeTax) {
                this.settings.pricesIncludeTax = pricesIncludeTax;
            }
            
            var currency = $('#currency').val();
            if (currency) {
                this.settings.currency = currency;
            }
        },

        // Set up event handlers for payment-related elements
        setupEventHandlers: function() {
            var self = this;
            
            // Discount type change
            $('#discount_type').on('change', function() {
                self.settings.discountType = $(this).val();
                self.updateTotals();
            });
            
            // Discount value change
            $('#discount_value').on('input', function() {
                self.settings.discountValue = parseFloat($(this).val()) || 0;
                self.updateTotals();
            });
            
            // Tax rate change
            $('#tax_rate').on('input', function() {
                self.settings.taxRate = parseFloat($(this).val()) || 0;
                self.updateTotals();
            });
            
            // Calculation method change
            $('select[name="discount_calculation_method"]').on('change', function() {
                self.settings.calculationMethod = $(this).val();
                self.updateTotals();
            });

            // Prices include tax change
            $('select[name="prices_include_tax"]').on('change', function() {
                self.settings.pricesIncludeTax = $(this).val();
                self.updateTotals();
            });
            
            // Currency change
            $('#currency_code').on('change', function() {
                self.settings.currency = $(this).val();
                
                // Get the currency symbol for the selected currency
                switch($(this).val()) {
                    case 'USD':
                        self.settings.currencySymbol = '$';
                        break;
                    case 'EUR':
                        self.settings.currencySymbol = '€';
                        break;
                    case 'GBP':
                        self.settings.currencySymbol = '£';
                        break;
                    default:
                        self.settings.currencySymbol = '$';
                }
                
                self.updateTotals();
            });
        },

        // Update UI with current settings
        updateUI: function() {
            // Only set form field values if they are empty or if we have explicit settings
            // This preserves values set by PHP/HTML
            if (!$('#discount_type').val()) {
                $('#discount_type').val(this.settings.discountType);
            }
            if (!$('#discount_value').val()) {
                $('#discount_value').val(this.settings.discountValue);
            }
            if (!$('#tax_rate').val()) {
                $('#tax_rate').val(this.settings.taxRate);
            }
            if (!$('input[name="calculation_method"]:checked').val()) {
                $('input[name="calculation_method"][value="' + this.settings.calculationMethod + '"]').prop('checked', true);
            }
            if (!$('#currency_code').val()) {
                $('#currency_code').val(this.settings.currency);
            }
            
            // Update totals
            this.updateTotals();
        },

        // Update totals based on invoice items and settings
        updateTotals: function() {
            // Calculate subtotal from invoice items
            var subtotal = 0;
            var taxableSubtotal = 0;
            
            // Get items from invoice builder if available
            if (window.EasyInvoiceBuilder && typeof window.EasyInvoiceBuilder.getItems === 'function') {
                var items = window.EasyInvoiceBuilder.getItems();
                
                items.forEach(function(item) {
                    var baseTotal = item.quantity * item.price;
                    var adjustPercentage = 0;
                    // Only apply adjust percentage if the adjust field is enabled
                    if (window.easyInvoice && window.easyInvoice.showAdjustField) {
                        adjustPercentage = parseFloat(item.adjust_percentage) || 0;
                    }
                    var itemTotal = baseTotal * (1 + adjustPercentage / 100);
                    subtotal += itemTotal;
                    
                    if (item.taxable) {
                        taxableSubtotal += itemTotal;
                    }
                });
            } else {
                // Fallback: Calculate directly from DOM using dynamic field helpers
                $('.invoice-item, .quote-item').each(function(index) {
                    var $item = $(this);
                    
                    // Use dynamic field helpers if available
                    if (window.EasyInvoiceFieldHelpers) {
                        var quantity = parseFloat(window.EasyInvoiceFieldHelpers.getFieldValue('quantity', $item)) || 0;
                        var price = parseFloat(window.EasyInvoiceFieldHelpers.getFieldValue('price', $item)) || 0;
                        var adjustPercentage = 0;
                        // Only apply adjust percentage if the adjust field is enabled
                        if (window.easyInvoice && window.easyInvoice.showAdjustField) {
                            adjustPercentage = parseFloat(window.EasyInvoiceFieldHelpers.getFieldValue('adjust_percentage', $item)) || 0;
                        }
                        var baseTotal = quantity * price;
                        var itemTotal = baseTotal * (1 + adjustPercentage / 100);
                        var isTaxable = window.EasyInvoiceFieldHelpers.getFieldValue('taxable', $item) === '1';
                        
                        subtotal += itemTotal;
                        
                        if (isTaxable) {
                            taxableSubtotal += itemTotal;
                        }
                    } else {
                        // Fallback to hardcoded field names
                        var quantity = parseFloat($(this).find('input[name*="[quantity]"]').val()) || 0;
                        var price = parseFloat($(this).find('input[name*="[price]"]').val()) || 0;
                        var adjustPercentage = 0;
                        // Only apply adjust percentage if the adjust field is enabled
                        if (window.easyInvoice && window.easyInvoice.showAdjustField) {
                            adjustPercentage = parseFloat($(this).find('input[name*="[adjust_percentage]"]').val()) || 0;
                        }
                        var baseTotal = quantity * price;
                        var itemTotal = baseTotal * (1 + adjustPercentage / 100);
                        var isTaxable = $(this).find('input[name*="[taxable]"]').is(':checked');
                        
                        subtotal += itemTotal;
                        
                        if (isTaxable) {
                            taxableSubtotal += itemTotal;
                        }
                    }
                });
            }
            
            // Calculate discount amount
            var discountAmount = 0;
            if (this.settings.discountType === 'none') {
                discountAmount = 0;
            } else if (this.settings.discountType === 'percentage') {
                discountAmount = subtotal * (this.settings.discountValue / 100);
            } else { // fixed amount
                discountAmount = Math.min(this.settings.discountValue, subtotal); // Don't discount more than subtotal
            }
            
            // Calculate after discount amount
            var afterDiscountAmount = subtotal - discountAmount;
            
            // Calculate tax amount
            var taxAmount = 0;
            var total = 0;
            var pricesIncludeTax = this.settings.pricesIncludeTax === 'yes';
            var discountRatio = (subtotal > 0) ? (discountAmount / subtotal) : 0;

            if (pricesIncludeTax && this.settings.taxRate > 0) {
                // Tax is already included in prices: extract it from the taxable portion after discount
                var taxableAfterDiscount = taxableSubtotal * (1 - discountRatio);
                taxAmount = taxableAfterDiscount - (taxableAfterDiscount / (1 + this.settings.taxRate / 100));
                total = afterDiscountAmount;
            } else if (this.settings.taxRate > 0) {
                if (this.settings.calculationMethod === 'before_tax') {
                    // Discount first, then tax on remaining taxable amount
                    var taxableAfterDiscount = taxableSubtotal * (1 - discountRatio);
                    taxAmount = taxableAfterDiscount * (this.settings.taxRate / 100);
                } else { // after_tax
                    // Tax first on full taxable subtotal, then discount
                    taxAmount = taxableSubtotal * (this.settings.taxRate / 100);
                    // Recalculate percentage discount based on total including tax
                    if (this.settings.discountType === 'percentage') {
                        var totalBeforeDiscount = subtotal + taxAmount;
                        discountAmount = (totalBeforeDiscount * this.settings.discountValue) / 100;
                        afterDiscountAmount = subtotal - discountAmount;
                    }
                }
                total = afterDiscountAmount + taxAmount;
            } else {
                total = afterDiscountAmount;
            }
            
            // Update UI
            $('#subtotal_value').text(this.formatCurrency(subtotal));
            $('#discount_amount_value').text(this.formatCurrency(discountAmount));
            $('#after_discount_value').text(this.formatCurrency(afterDiscountAmount));
            $('#tax_amount_value').text(this.formatCurrency(taxAmount));
            $('#total_value').text(this.formatCurrency(total));
            
            // Update hidden fields for form submission
            $('#subtotal_field').val(subtotal);
            $('#discount_amount_field').val(discountAmount);
            $('#tax_amount_field').val(taxAmount);
            $('#total_field').val(total);
        },

        // Format currency value
        formatCurrency: function(value) {
            return this.settings.currencySymbol + parseFloat(value).toFixed(2);
        },

        // Get payment settings for saving
        getPaymentSettings: function() {
            return {
                discountType: this.settings.discountType,
                discountValue: this.settings.discountValue,
                taxRate: this.settings.taxRate,
                calculationMethod: this.settings.calculationMethod,
                currency: this.settings.currency,
                currencySymbol: this.settings.currencySymbol
            };
        }
    };

    // Initialize payment manager when document is ready
    $(document).ready(function() {
        EasyInvoicePayment.init();
    });

})(jQuery);