import { useState, useEffect, useRef } from 'react';
import { useNavigate, useLocation } from 'react-router';
import { motion } from 'motion/react';
import { Check, AlertCircle } from 'lucide-react';
import { generateMarketingReport } from '../lib/supabase';

const steps = [
  { label: 'Scanning website...', key: 'scrape' },
  { label: 'Analyzing social media presence...', key: 'social' },
  { label: 'Researching competitors & keywords...', key: 'analyze' },
  { label: 'Generating AI marketing report...', key: 'generate' },
  { label: 'Finalizing report...', key: 'finalize' },
];

export default function AnalysisLoadingPage() {
  const [currentStep, setCurrentStep] = useState(0);
  const [error, setError] = useState<string | null>(null);
  const navigate = useNavigate();
  const location = useLocation();
  const url = (location.state as { url?: string })?.url;
  const hasStarted = useRef(false);

  useEffect(() => {
    if (hasStarted.current) return;
    hasStarted.current = true;

    if (!url) {
      navigate('/', { replace: true });
      return;
    }

    const runAnalysis = async () => {
      try {
        // Step 1: Scraping
        setCurrentStep(1);

        // Simulate step progression while waiting for API
        const stepTimer = setInterval(() => {
          setCurrentStep((prev) => (prev < steps.length - 1 ? prev + 1 : prev));
        }, 5000);

        const result = await generateMarketingReport(url);

        clearInterval(stepTimer);
        setCurrentStep(steps.length);

        if (result.success && result.report) {
          const reportPath = result.reportId
            ? `/report/${result.reportId}`
            : '/report/live';

          // Brief delay to show completion
          setTimeout(() => {
            navigate(reportPath, {
              replace: true,
              state: {
                report: result.report,
                metadata: result.metadata,
                reportId: result.reportId,
              },
            });
          }, 800);
        } else {
          throw new Error(result.error || 'Report generation failed');
        }
      } catch (err) {
        setError(err instanceof Error ? err.message : 'An error occurred');
      }
    };

    runAnalysis();
  }, [url, navigate]);

  return (
    <div className="relative min-h-screen bg-primary-900 flex flex-col items-center justify-center px-6 overflow-hidden">
      <div className="absolute inset-0 bg-[radial-gradient(ellipse_at_center,_rgba(79,29,161,0.25)_0%,_transparent_70%)]" />
      <div className="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-[500px] h-[500px] bg-purple-600/20 rounded-full blur-[120px] pointer-events-none" />

      <div className="relative z-10 flex flex-col items-center w-full max-w-lg">
        <motion.h1
          initial={{ opacity: 0, y: 20 }}
          animate={{ opacity: 1, y: 0 }}
          transition={{ duration: 0.6 }}
          className="text-4xl md:text-5xl font-serif font-bold mb-4"
          style={{
            background: 'linear-gradient(to right, #fff3eb, #e4cfff, #f5f9ff)',
            WebkitBackgroundClip: 'text',
            WebkitTextFillColor: 'transparent',
          }}
        >
          INFINITH
        </motion.h1>

        {url && (
          <motion.p
            initial={{ opacity: 0, y: 20 }}
            animate={{ opacity: 1, y: 0 }}
            transition={{ duration: 0.6, delay: 0.1 }}
            className="text-purple-300/80 text-sm font-mono mb-12 truncate max-w-full"
          >
            {url}
          </motion.p>
        )}

        {error ? (
          <motion.div
            initial={{ opacity: 0, scale: 0.95 }}
            animate={{ opacity: 1, scale: 1 }}
            className="w-full p-6 rounded-2xl bg-red-500/10 border border-red-500/20 text-center"
          >
            <AlertCircle className="w-10 h-10 text-red-400 mx-auto mb-3" />
            <p className="text-red-300 text-sm mb-4">{error}</p>
            <button
              onClick={() => navigate('/', { replace: true })}
              className="px-6 py-2 text-sm font-medium text-white bg-white/10 rounded-lg hover:bg-white/20 transition-colors"
            >
              Try Again
            </button>
          </motion.div>
        ) : (
          <>
            <div className="w-full space-y-5 mb-14">
              {steps.map((step, index) => {
                const isCompleted = currentStep > index;
                const isActive = currentStep === index + 1 && currentStep <= steps.length;

                return (
                  <motion.div
                    key={step.key}
                    initial={{ opacity: 0, x: -20 }}
                    animate={{ opacity: isActive || isCompleted ? 1 : 0.3, x: 0 }}
                    transition={{ duration: 0.4, delay: index * 0.15 }}
                    className="flex items-center gap-4"
                  >
                    <div className="w-7 h-7 flex-shrink-0 flex items-center justify-center">
                      {isCompleted ? (
                        <motion.div
                          initial={{ scale: 0 }}
                          animate={{ scale: 1 }}
                          transition={{ type: 'spring', stiffness: 300, damping: 20 }}
                          className="w-7 h-7 rounded-full bg-gradient-to-r from-[#4F1DA1] to-[#6C5CE7] flex items-center justify-center"
                        >
                          <Check className="w-4 h-4 text-white" strokeWidth={3} />
                        </motion.div>
                      ) : isActive ? (
                        <div className="w-7 h-7 rounded-full border-2 border-purple-400 border-t-transparent animate-spin" />
                      ) : (
                        <div className="w-7 h-7 rounded-full border-2 border-white/10" />
                      )}
                    </div>
                    <span
                      className={`text-base font-sans transition-colors duration-300 ${
                        isCompleted
                          ? 'text-white'
                          : isActive
                            ? 'text-purple-200'
                            : 'text-white/30'
                      }`}
                    >
                      {step.label}
                    </span>
                  </motion.div>
                );
              })}
            </div>

            <div className="w-full h-2 bg-white/10 rounded-full overflow-hidden">
              <motion.div
                initial={{ width: '0%' }}
                animate={{ width: `${(currentStep / steps.length) * 100}%` }}
                transition={{ duration: 0.8, ease: 'easeInOut' }}
                className="h-full bg-gradient-to-r from-[#4F1DA1] to-[#6C5CE7] rounded-full"
              />
            </div>

            <p className="text-white/40 text-xs mt-4">
              AI가 마케팅 데이터를 분석하고 있습니다. 약 20~30초 소요됩니다.
            </p>
          </>
        )}
      </div>
    </div>
  );
}