import React, { useState, useRef, useEffect } from 'react';
import { 
  ChevronRight, 
  ChevronLeft, 
  Check, 
  Copy, 
  Terminal, 
  Rocket, 
  Settings,
  AlertCircle,
  RefreshCw
} from 'lucide-react';

interface OnboardingWizardProps {
  onComplete?: () => void;
}

export const OnboardingWizard: React.FC<OnboardingWizardProps> = ({ onComplete }) => {
  const [currentStep, setCurrentStep] = useState(1);
  const [webhookUrl, setWebhookUrl] = useState('');
  const [copied, setCopied] = useState(false);
  const [isGenerating, setIsGenerating] = useState(false);
  const stepRef = useRef<HTMLDivElement>(null);

  // Focus management for accessibility - only when step changes, not on initial mount
  useEffect(() => {
    // Only focus if this is a step change (not initial mount)
    // This prevents auto-scroll to the onboarding section on page load
    if (stepRef.current && document.activeElement !== document.body) {
      stepRef.current.focus({ preventScroll: true });
    }
  }, [currentStep]);

// Environment configuration
const API_URL = import.meta.env.VITE_API_URL || 'http://localhost:3001';
const WEBHOOK_BASE_URL = import.meta.env.VITE_WEBHOOK_BASE_URL || `${API_URL}/webhook`;
const INSTALL_SCRIPT_URL = import.meta.env.VITE_INSTALL_SCRIPT_URL || `${API_URL}/install.sh`;
const APP_NAME = import.meta.env.VITE_APP_NAME || 'LogWhispererAI';

  const generateWebhook = async () => {
    setIsGenerating(true);
    
    try {
      const response = await fetch(`${API_URL}/api/webhook`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
      });

      if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
      }

      const data = await response.json();
      
      if (data.success && data.uuid) {
        // Use configured webhook base URL instead of API response
        setWebhookUrl(`${WEBHOOK_BASE_URL}/${data.uuid}`);
      } else {
        throw new Error(data.message || 'Errore nella generazione del webhook');
      }
    } catch (error) {
      console.error('Error generating webhook:', error);
      // Fallback: generate locally if API fails
      const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
        const r = Math.random() * 16 | 0;
        const v = c === 'x' ? r : (r & 0x3 | 0x8);
        return v.toString(16);
      });
      setWebhookUrl(`${WEBHOOK_BASE_URL}/${uuid}`);
    } finally {
      setIsGenerating(false);
    }
  };

  const copyWebhook = () => {
    navigator.clipboard.writeText(webhookUrl);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  const copyCurlCommand = () => {
    const command = `curl -fsSL ${INSTALL_SCRIPT_URL} | bash -s -- --webhook ${webhookUrl}`;
    navigator.clipboard.writeText(command);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  const nextStep = () => {
    if (currentStep < 3) {
      setCurrentStep(currentStep + 1);
    } else {
      onComplete?.();
    }
  };

  const prevStep = () => {
    if (currentStep > 1) {
      setCurrentStep(currentStep - 1);
    }
  };

  const getInstallCommand = () => {
    return webhookUrl 
      ? `curl -fsSL ${INSTALL_SCRIPT_URL} | bash -s -- --webhook ${webhookUrl}`
      : `curl -fsSL ${INSTALL_SCRIPT_URL} | bash`;
  };

  const steps = [
    { number: 1, title: 'Benvenuto', icon: <Rocket className="w-5 h-5" /> },
    { number: 2, title: 'Webhook', icon: <Settings className="w-5 h-5" /> },
    { number: 3, title: 'Setup', icon: <Terminal className="w-5 h-5" /> },
  ];

  return (
    <section 
      id="onboarding"
      className="w-full py-24 lg:py-32 bg-gradient-to-b from-indigo-50 to-white"
      aria-labelledby="onboarding-heading"
    >
      <div className="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8">
        {/* Section Header */}
        <div className="text-center mb-12">
          <h2 
            id="onboarding-heading" 
            className="text-3xl sm:text-4xl font-bold text-slate-900 mb-4"
          >
            Inizia in 3 semplici passi
          </h2>
          <p className="text-lg text-slate-600 max-w-2xl mx-auto">
            Configura LogWhispererAI sul tuo server in meno di 5 minuti.
          </p>
        </div>

        {/* Step Indicator */}
        <nav aria-label="Progresso onboarding" className="mb-12">
          <ol className="flex items-center justify-center gap-4">
            {steps.map((step, index) => (
              <li key={step.number} className="flex items-center">
                <div 
                  className={`flex items-center gap-2 px-4 py-2 rounded-full font-medium text-sm transition-colors ${
                    currentStep === step.number
                      ? 'bg-indigo-600 text-white'
                      : currentStep > step.number
                      ? 'bg-green-100 text-green-700'
                      : 'bg-slate-200 text-slate-600'
                  }`}
                  aria-current={currentStep === step.number ? 'step' : undefined}
                >
                  <span className="flex items-center justify-center w-6 h-6 rounded-full bg-white/20">
                    {currentStep > step.number ? (
                      <Check className="w-4 h-4" />
                    ) : (
                      step.number
                    )}
                  </span>
                  <span className="hidden sm:inline">{step.title}</span>
                </div>
                {index < steps.length - 1 && (
                  <ChevronRight className="w-5 h-5 text-slate-300 mx-2" aria-hidden="true" />
                )}
              </li>
            ))}
          </ol>
        </nav>

        {/* Wizard Content */}
        <div 
          ref={stepRef}
          tabIndex={-1}
          className="bg-white rounded-2xl shadow-xl border border-slate-200 p-8 outline-none"
          aria-live="polite"
        >
          {/* Step 1: Welcome */}
          {currentStep === 1 && (
            <div className="space-y-6">
              <div className="text-center">
                <div className="w-20 h-20 bg-indigo-100 rounded-full flex items-center justify-center mx-auto mb-6">
                  <Rocket className="w-10 h-10 text-indigo-600" aria-hidden="true" />
                </div>
                <h3 className="text-2xl font-bold text-slate-900 mb-4">
                  Benvenuto su LogWhispererAI
                </h3>
                <p className="text-slate-600 mb-6 max-w-lg mx-auto">
                  Il tuo assistente DevOps personale che monitora i log del server 
                  e ti avvisa immediatamente quando qualcosa va storto, suggerendoti 
                  il comando esatto per risolvere il problema.
                </p>
              </div>

              <div className="bg-slate-50 rounded-xl p-6">
                <h4 className="font-semibold text-slate-900 mb-4 flex items-center gap-2">
                  <AlertCircle className="w-5 h-5 text-indigo-600" />
                  Cosa succederà:
                </h4>
                <ul className="space-y-3 text-slate-600">
                  <li className="flex items-start gap-3">
                    <span className="text-indigo-600 font-bold">1.</span>
                    <span>Genereremo un webhook URL univoco per il tuo account</span>
                  </li>
                  <li className="flex items-start gap-3">
                    <span className="text-indigo-600 font-bold">2.</span>
                    <span>Installerai uno script leggero sul tuo server</span>
                  </li>
                  <li className="flex items-start gap-3">
                    <span className="text-indigo-600 font-bold">3.</span>
                    <span>Inizierai a ricevere notifiche intelligenti su Telegram</span>
                  </li>
                </ul>
              </div>

              <div className="text-center text-sm text-slate-500">
                <p>⏱️ Tempo stimato: 5 minuti</p>
                <p>💰 Nessuna carta di credito richiesta</p>
              </div>
            </div>
          )}

          {/* Step 2: Webhook Generation */}
          {currentStep === 2 && (
            <div className="space-y-6">
              <div className="text-center">
                <div className="w-20 h-20 bg-indigo-100 rounded-full flex items-center justify-center mx-auto mb-6">
                  <Settings className="w-10 h-10 text-indigo-600" aria-hidden="true" />
                </div>
                <h3 className="text-2xl font-bold text-slate-900 mb-4">
                  Genera il tuo Webhook
                </h3>
                <p className="text-slate-600 mb-6 max-w-lg mx-auto">
                  Clicca il pulsante qui sotto per generare il tuo webhook URL univoco. 
                  Questo URL riceverà i log dal tuo server.
                </p>
              </div>

              {!webhookUrl ? (
                <div className="text-center">
                  <button
                    onClick={generateWebhook}
                    disabled={isGenerating}
                    className="inline-flex items-center gap-2 px-8 py-4 bg-indigo-600 hover:bg-indigo-700 disabled:bg-indigo-400 text-white font-bold rounded-xl transition-colors focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2"
                  >
                    {isGenerating ? (
                      <>
                        <RefreshCw className="w-5 h-5 animate-spin" />
                        Generazione...
                      </>
                    ) : (
                      <>
                        <Rocket className="w-5 h-5" />
                        Genera Webhook URL
                      </>
                    )}
                  </button>
                </div>
              ) : (
                <div className="space-y-4">
                  <div className="bg-slate-900 rounded-xl p-4">
                    <div className="flex items-center justify-between mb-2">
                      <span className="text-slate-400 text-sm">Il tuo webhook URL:</span>
                      <button
                        onClick={copyWebhook}
                        className="flex items-center gap-1 text-indigo-400 hover:text-indigo-300 text-sm"
                      >
                        {copied ? (
                          <><Check className="w-4 h-4" /> Copiato!</>
                        ) : (
                          <><Copy className="w-4 h-4" /> Copia</>
                        )}
                      </button>
                    </div>
                    <code className="text-green-400 font-mono text-sm break-all">
                      {webhookUrl}
                    </code>
                  </div>
                  
                  <div className="bg-green-50 border border-green-200 rounded-lg p-4">
                    <p className="text-green-800 text-sm flex items-center gap-2">
                      <Check className="w-5 h-5" />
                      Webhook generato con successo! Procedi allo step successivo per installare lo script.
                    </p>
                  </div>
                </div>
              )}
            </div>
          )}

          {/* Step 3: Setup Instructions */}
          {currentStep === 3 && (
            <div className="space-y-6">
              <div className="text-center">
                <div className="w-20 h-20 bg-indigo-100 rounded-full flex items-center justify-center mx-auto mb-6">
                  <Terminal className="w-10 h-10 text-indigo-600" aria-hidden="true" />
                </div>
                <h3 className="text-2xl font-bold text-slate-900 mb-4">
                  Installa sul tuo Server
                </h3>
                <p className="text-slate-600 mb-6 max-w-lg mx-auto">
                  Esegui questo comando sul tuo server per installare LogWhisperer. 
                  Lo script configurerà automaticamente il monitoraggio dei log.
                </p>
              </div>

              <div className="bg-slate-900 rounded-xl p-6">
                <div className="flex items-center justify-between mb-3">
                  <span className="text-slate-400 text-sm">Comando di installazione:</span>
                  <button
                    onClick={copyCurlCommand}
                    className="flex items-center gap-1 text-indigo-400 hover:text-indigo-300 text-sm"
                  >
                    {copied ? (
                      <><Check className="w-4 h-4" /> Copiato!</>
                    ) : (
                      <><Copy className="w-4 h-4" /> Copia comando</>
                    )}
                  </button>
                </div>
                <code className="text-green-400 font-mono text-sm block break-all">
                  {getInstallCommand()}
                </code>
              </div>

              <div className="space-y-4">
                <h4 className="font-semibold text-slate-900">Istruzioni:</h4>
                <ol className="space-y-3 text-slate-600">
                  <li className="flex items-start gap-3">
                    <span className="w-6 h-6 bg-indigo-100 text-indigo-600 rounded-full flex items-center justify-center text-sm font-bold flex-shrink-0">1</span>
                    <span>Connettiti al tuo server via SSH</span>
                  </li>
                  <li className="flex items-start gap-3">
                    <span className="w-6 h-6 bg-indigo-100 text-indigo-600 rounded-full flex items-center justify-center text-sm font-bold flex-shrink-0">2</span>
                    <span>Esegui il comando copiato sopra</span>
                  </li>
                  <li className="flex items-start gap-3">
                    <span className="w-6 h-6 bg-indigo-100 text-indigo-600 rounded-full flex items-center justify-center text-sm font-bold flex-shrink-0">3</span>
                    <span>Segui la configurazione guidata</span>
                  </li>
                  <li className="flex items-start gap-3">
                    <span className="w-6 h-6 bg-indigo-100 text-indigo-600 rounded-full flex items-center justify-center text-sm font-bold flex-shrink-0">4</span>
                    <span>Controlla Telegram per il messaggio di conferma</span>
                  </li>
                </ol>
              </div>

              <div className="bg-blue-50 border border-blue-200 rounded-lg p-4">
                <p className="text-blue-800 text-sm">
                  <strong>Nota:</strong> Lo script richiede privilegi sudo per installare il servizio di sistema. 
                  Nessun dato sensibile viene inviato durante l'installazione.
                </p>
              </div>
            </div>
          )}

          {/* Navigation Buttons */}
          <div className="flex items-center justify-between mt-8 pt-8 border-t border-slate-200">
            <button
              onClick={prevStep}
              disabled={currentStep === 1}
              className="flex items-center gap-2 px-6 py-3 text-slate-600 hover:text-slate-900 disabled:opacity-50 disabled:cursor-not-allowed font-medium transition-colors focus:outline-none focus:ring-2 focus:ring-slate-400 rounded-lg"
            >
              <ChevronLeft className="w-5 h-5" />
              Indietro
            </button>

            <button
              onClick={nextStep}
              disabled={currentStep === 2 && !webhookUrl}
              className="flex items-center gap-2 px-8 py-3 bg-indigo-600 hover:bg-indigo-700 disabled:bg-slate-300 text-white font-bold rounded-xl transition-colors focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2"
            >
              {currentStep === 3 ? (
                <>
                  <Check className="w-5 h-5" />
                  Completa
                </>
              ) : (
                <>
                  Avanti
                  <ChevronRight className="w-5 h-5" />
                </>
              )}
            </button>
          </div>
        </div>
      </div>
    </section>
  );
};

export default OnboardingWizard;