/**
 * Form validation utilities
 */

export function validateEmail(email) {
  const regex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return regex.test(email);
}

export function validatePhone(phone) {
  const regex = /^[6-9]\d{9}$/;
  return regex.test(phone.replace(/\s|-/g, ''));
}

export function validatePAN(pan) {
  const regex = /^[A-Z]{5}[0-9]{4}[A-Z]{1}$/;
  return regex.test(pan.toUpperCase());
}

export function validatePassword(password) {
  // Minimum 8 characters, at least 1 uppercase, 1 lowercase, 1 number
  const regex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}$/;
  return regex.test(password);
}

export function validateRequired(value) {
  return value !== undefined && value !== null && value.toString().trim() !== '';
}

export function validateMinLength(value, min) {
  return value && value.length >= min;
}

export function validateMaxLength(value, max) {
  return !value || value.length <= max;
}

export function validateAmount(amount) {
  const num = parseFloat(amount);
  return !isNaN(num) && num > 0 && num <= 10000000;
}

export function validatePincode(pincode) {
  return /^\d{6}$/.test(pincode);
}

/**
 * Validate full form
 * @param {Object} fields - { fieldName: { value, validators: [{ fn, message }] } }
 * @returns {{ isValid, errors }}
 */
export function validateForm(fields) {
  const errors = {};
  let isValid = true;

  Object.entries(fields).forEach(([field, config]) => {
    const { value, validators = [] } = config;
    for (const { fn, message } of validators) {
      if (!fn(value)) {
        errors[field] = message;
        isValid = false;
        break;
      }
    }
  });

  return { isValid, errors };
}