import React, { useState, useCallback } from 'react';
import { X, ChevronLeft, ChevronRight } from 'lucide-react';

export interface WizardStep {
  id: string;
  title: string;
  description?: string;
  component: React.ComponentType<WizardStepProps>;
  isOptional?: boolean;
  validate?: () => Promise<boolean> | boolean;
}

export interface WizardStepProps {
  onNext: () => void;
  onBack: () => void;
  onComplete: () => void;
  isFirstStep: boolean;
  isLastStep: boolean;
  currentStepIndex: number;
  totalSteps: number;
  goToStep: (index: number) => void;
}

interface WizardModalProps {
  isOpen: boolean;
  onClose: () => void;
  onComplete: (data?: any) => void;
  title: string;
  steps: WizardStep[];
  icon?: React.ReactNode;
  size?: 'sm' | 'md' | 'lg' | 'xl' | '2xl';
}

export const WizardModal: React.FC<WizardModalProps> = ({
  isOpen,
  onClose,
  onComplete,
  title,
  steps,
  icon,
  size = 'xl'
}) => {
  const [currentStepIndex, setCurrentStepIndex] = useState(0);
  const [isValidating, setIsValidating] = useState(false);

  const currentStep = steps[currentStepIndex];
  const isFirstStep = currentStepIndex === 0;
  const isLastStep = currentStepIndex === steps.length - 1;

  const sizeClasses = {
    sm: 'max-w-md',
    md: 'max-w-2xl',
    lg: 'max-w-4xl',
    xl: 'max-w-5xl',
    '2xl': 'max-w-7xl'
  };

  const handleNext = useCallback(async () => {
    // Validate current step if validator exists
    if (currentStep.validate) {
      setIsValidating(true);
      try {
        const isValid = await currentStep.validate();
        if (!isValid) {
          setIsValidating(false);
          return;
        }
      } catch (error) {
        console.error('Validation error:', error);
        setIsValidating(false);
        return;
      }
      setIsValidating(false);
    }

    if (isLastStep) {
      handleComplete();
    } else {
      setCurrentStepIndex(prev => Math.min(prev + 1, steps.length - 1));
    }
  }, [currentStep, isLastStep, steps.length]);

  const handleBack = useCallback(() => {
    setCurrentStepIndex(prev => Math.max(prev - 1, 0));
  }, []);

  const handleComplete = useCallback(() => {
    onComplete();
    handleClose();
  }, [onComplete]);

  const handleClose = useCallback(() => {
    setCurrentStepIndex(0);
    onClose();
  }, [onClose]);

  const goToStep = useCallback((index: number) => {
    if (index >= 0 && index < steps.length) {
      setCurrentStepIndex(index);
    }
  }, [steps.length]);

  if (!isOpen) return null;

  const StepComponent = currentStep.component;
  const progressPercentage = ((currentStepIndex + 1) / steps.length) * 100;

  return (
    <>
      {/* Backdrop */}
      <div
        className="fixed inset-0 bg-black/50 z-50 animate-fadeIn"
        onClick={handleClose}
      />

      {/* Modal */}
      <div className="fixed inset-0 z-50 flex items-center justify-center p-4 pointer-events-none">
        <div
          className={`bg-[var(--bg-primary)] rounded-xl shadow-2xl ${sizeClasses[size]} w-full max-h-[90vh] overflow-hidden pointer-events-auto animate-slideUp`}
          onClick={(e) => e.stopPropagation()}
        >
          {/* Header */}
          <div className="sticky top-0 z-10 bg-[var(--bg-primary)] border-b border-[var(--border-secondary)]">
            {/* Title Bar */}
            <div className="flex items-center justify-between p-6 pb-4">
              <div className="flex items-center gap-3">
                {icon && (
                  <div className="w-10 h-10 rounded-full bg-[var(--color-primary)]/10 flex items-center justify-center text-[var(--color-primary)]">
                    {icon}
                  </div>
                )}
                <div>
                  <h2 className="text-xl font-semibold text-[var(--text-primary)]">
                    {title}
                  </h2>
                  <p className="text-sm text-[var(--text-secondary)] mt-0.5">
                    {currentStep.description || `Step ${currentStepIndex + 1} of ${steps.length}`}
                  </p>
                </div>
              </div>
              <button
                onClick={handleClose}
                className="p-2 text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-secondary)] rounded-lg transition-colors"
              >
                <X className="w-5 h-5" />
              </button>
            </div>

            {/* Progress Bar */}
            <div className="px-6 pb-4">
              <div className="flex items-center gap-2 mb-2">
                {steps.map((step, index) => (
                  <React.Fragment key={step.id}>
                    <button
                      onClick={() => index < currentStepIndex && goToStep(index)}
                      disabled={index > currentStepIndex}
                      className={`flex-1 h-2 rounded-full transition-all duration-300 ${
                        index < currentStepIndex
                          ? 'bg-[var(--color-success)] cursor-pointer hover:bg-[var(--color-success)]/80'
                          : index === currentStepIndex
                          ? 'bg-[var(--color-primary)]'
                          : 'bg-[var(--bg-tertiary)] cursor-not-allowed'
                      }`}
                      title={step.title}
                    />
                  </React.Fragment>
                ))}
              </div>
              <div className="flex items-center justify-between text-xs text-[var(--text-secondary)]">
                <span className="font-medium">{currentStep.title}</span>
                <span>{currentStepIndex + 1} / {steps.length}</span>
              </div>
            </div>
          </div>

          {/* Step Content */}
          <div className="p-6 overflow-y-auto" style={{ maxHeight: 'calc(90vh - 220px)' }}>
            <StepComponent
              onNext={handleNext}
              onBack={handleBack}
              onComplete={handleComplete}
              isFirstStep={isFirstStep}
              isLastStep={isLastStep}
              currentStepIndex={currentStepIndex}
              totalSteps={steps.length}
              goToStep={goToStep}
            />
          </div>

          {/* Footer Navigation */}
          <div className="sticky bottom-0 border-t border-[var(--border-secondary)] bg-[var(--bg-secondary)]/50 backdrop-blur-sm px-6 py-4">
            <div className="flex items-center justify-between gap-3">
              {/* Back Button */}
              {!isFirstStep && (
                <button
                  onClick={handleBack}
                  disabled={isValidating}
                  className="px-4 py-2.5 text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-primary)] rounded-lg transition-colors font-medium disabled:opacity-50 disabled:cursor-not-allowed inline-flex items-center gap-2"
                >
                  <ChevronLeft className="w-4 h-4" />
                  Back
                </button>
              )}

              <div className="flex-1" />

              {/* Skip Button (for optional steps) */}
              {currentStep.isOptional && !isLastStep && (
                <button
                  onClick={() => setCurrentStepIndex(prev => prev + 1)}
                  disabled={isValidating}
                  className="px-4 py-2.5 text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-primary)] rounded-lg transition-colors font-medium disabled:opacity-50"
                >
                  Skip This Step
                </button>
              )}

              {/* Next/Complete Button */}
              <button
                onClick={handleNext}
                disabled={isValidating}
                className="px-6 py-2.5 bg-[var(--color-primary)] text-white rounded-lg hover:bg-[var(--color-primary-dark)] disabled:opacity-50 disabled:cursor-not-allowed transition-colors font-medium inline-flex items-center gap-2 min-w-[140px] justify-center"
              >
                {isValidating ? (
                  <>
                    <div className="w-4 h-4 border-2 border-white border-t-transparent rounded-full animate-spin" />
                    Validating...
                  </>
                ) : isLastStep ? (
                  <>
                    Complete
                    <ChevronRight className="w-4 h-4" />
                  </>
                ) : (
                  <>
                    Next
                    <ChevronRight className="w-4 h-4" />
                  </>
                )}
              </button>
            </div>
          </div>
        </div>
      </div>

      {/* Animation Styles */}
      <style>{`
        @keyframes fadeIn {
          from { opacity: 0; }
          to { opacity: 1; }
        }
        @keyframes slideUp {
          from {
            opacity: 0;
            transform: translateY(20px);
          }
          to {
            opacity: 1;
            transform: translateY(0);
          }
        }
        .animate-fadeIn {
          animation: fadeIn 0.2s ease-out;
        }
        .animate-slideUp {
          animation: slideUp 0.3s ease-out;
        }
      `}</style>
    </>
  );
};