/**
 * Input Utilities Module
 * Handles input formatting, validation, and parsing
 */
class InputUtils {
    static formatNumberWithCommas(num, currency = null) {
        try {
            // Get current currency if not provided
            if (!currency) {
                const currencyElement = document.getElementById('currency');
                currency = currencyElement ? currencyElement.value : 'CHF';
            }

            // Use appropriate locale for number formatting
            const locale = currency === 'EUR' ? 'de-DE' : 'de-CH';
            return parseInt(num).toLocaleString(locale);
        } catch (error) {
            console.error('Error formatting number with commas:', error);
            return String(num);
        }
    }

    static parseFormattedNumber(str) {
        if (typeof str !== 'string') {
            return 0;
        }
        
        try {
            // Remove all non-numeric characters except decimal points and commas
            const cleaned = str.replace(/[^\d,.-]/g, '');
            
            // Handle empty string
            if (!cleaned) {
                return 0;
            }
            
            // Remove commas and parse as float
            const result = parseFloat(cleaned.replace(/,/g, ''));
            
            // Return 0 for invalid numbers or NaN
            return isNaN(result) ? 0 : result;
        } catch (error) {
            console.error('Error parsing formatted number:', error);
            return 0;
        }
    }

    static handleInvestmentAmountInput(input) {
        if (!input || typeof input.value !== 'string') {
            console.error('Invalid input element provided to handleInvestmentAmountInput');
            return;
        }

        try {
            // Allow only digits, no immediate formatting during typing
            let value = input.value.replace(/[^\d]/g, '');
            
            // Handle empty input
            if (!value) {
                input.setAttribute('data-value', '0');
                return;
            }

            // Parse the numeric value
            let numericValue = parseInt(value) || 0;

            // Update the data attribute with the raw numeric value (no limits during typing)
            input.setAttribute('data-value', numericValue.toString());

            // Update the input value (keep it clean, no commas during typing)
            input.value = value;

            // Update the slider if it exists (with limits)
            const slider = document.getElementById('investment-slider');
            if (slider) {
                const minValue = parseInt(slider.min) || 100000;
                const maxValue = parseInt(slider.max) || 2000000;
                const sliderValue = Math.max(minValue, Math.min(maxValue, numericValue));
                slider.value = sliderValue;
            }

            // Trigger calculations with debouncing
            if (window.ROICalculatorApp && window.ROICalculatorApp.calculator) {
                clearTimeout(input._calculationTimeout);
                input._calculationTimeout = setTimeout(() => {
                    window.ROICalculatorApp.calculator.updateCalculations();
                }, 300); // 300ms delay to avoid excessive calculations during typing
            }
        } catch (error) {
            console.error('Error handling investment amount input:', error);
            // Set a safe default value
            input.setAttribute('data-value', '500000');
            input.value = '500000';
        }
    }

    static handleInvestmentAmountBlur(input) {
        if (!input) return;

        try {
            // Get the numeric value
            let numericValue = parseInt(input.getAttribute('data-value')) || 500000;

            // Enforce min/max limits on blur
            const minValue = 100000;
            const maxValue = 2000000;
            
            if (numericValue < minValue) {
                numericValue = minValue;
            } else if (numericValue > maxValue) {
                numericValue = maxValue;
            }

            // Update the data attribute with the corrected value
            input.setAttribute('data-value', numericValue.toString());

            // Format and display the value with commas on blur
            input.value = InputUtils.formatNumberWithCommas(numericValue);

            // Update the slider
            const slider = document.getElementById('investment-slider');
            if (slider) {
                slider.value = numericValue;
            }

            // Trigger immediate calculation on blur
            if (window.ROICalculatorApp && window.ROICalculatorApp.calculator) {
                clearTimeout(input._calculationTimeout);
                window.ROICalculatorApp.calculator.updateCalculations();
            }
        } catch (error) {
            console.error('Error handling investment amount blur:', error);
            // Set a safe default value
            input.setAttribute('data-value', '500000');
            input.value = '500,000';
        }
    }

    static handleInvestmentAmountFocus(input) {
        if (!input) return;

        try {
            // Remove commas when focusing for easier editing
            const numericValue = input.getAttribute('data-value') || '500000';
            input.value = numericValue;
        } catch (error) {
            console.error('Error handling investment amount focus:', error);
        }
    }

    static getCSRFToken() {
        try {
            // Try to get CSRF token from meta tag first
            const metaTag = document.querySelector('meta[name="csrf-token"]');
            if (metaTag) {
                return metaTag.getAttribute('content');
            }
            
            // Fallback to cookie method
            const cookies = document.cookie.split(';');
            for (let cookie of cookies) {
                const [name, value] = cookie.trim().split('=');
                if (name === 'csrftoken') {
                    return decodeURIComponent(value);
                }
            }
            
            // If no CSRF token found, return empty string (will cause server error, but won't break JS)
            console.error('CSRF token not found');
            return '';
        } catch (error) {
            console.error('Error getting CSRF token:', error);
            return '';
        }
    }
}