export default class FormValidator {
    static rules = {
        required: (value) => {
            if (!value || (typeof value === 'string' && value.trim() === '')) {
                return 'This field is required';
            }
            return null;
        },
        email: (value) => {
            const regex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
            return regex.test(value) ? null : 'Invalid email address';
        },
        minLength: (min) => (value) => {
            return (value?.length || 0) >= min ? null : `Minimum ${min} characters required`;
        },
        maxLength: (max) => (value) => {
            return (value?.length || 0) <= max ? null : `Maximum ${max} characters allowed`;
        },
        pattern: (regex, message = 'Invalid format') => (value) => {
            return regex.test(value) ? null : message;
        },
        custom: (fn) => (value) => {
            try {
                const error = fn(value);
                return error || null;
            } catch (err) {
                return 'Validation error';
            }
        }
    };

    static validate(formData, schema) {
        const errors = {};

        for (const [field, rules] of Object.entries(schema)) {
            const value = formData[field];

            for (const rule of rules) {
                let error = null;

                if (typeof rule === 'function') {
                    error = rule(value);
                }

                if (error) {
                    errors[field] = error;
                    break;
                }
            }
        }

        return {
            isValid: Object.keys(errors).length === 0,
            errors
        };
    }

    static createSchema() {
        return {};
    }
}