import { useState, useEffect, useRef, useCallback } from 'react';
import { useTranslation } from 'react-i18next';
import { ScanLine, StopCircle, CheckCircle2, AlertTriangle } from 'lucide-react';
import { useEmailScan } from '@/hooks/useEmailScan';
import { useScanEvents } from '@/hooks/useRealtime';
import type { ScanPreset } from '@icc/shared';

interface LogEntry {
  id: string;
  time: string;
  type: 'found' | 'duplicate' | 'info' | 'error';
  sender?: string;
  amount?: string;
  ref?: string;
  branch?: string;
  message?: string;
}

interface ScanModalProps {
  onClose: () => void;
  onMinimize: () => void;
  preset?: ScanPreset;
  forceRescan?: boolean;
  startDate?: string;
  endDate?: string;
}

function formatTime(date?: Date): string {
  const d = date ?? new Date();
  return d.toLocaleTimeString('fr-CA', { hour: '2-digit', minute: '2-digit', second: '2-digit' });
}

export default function ScanModal({ onClose, onMinimize, preset = 'today', forceRescan = false, startDate, endDate }: ScanModalProps) {
  const { t } = useTranslation();
  const { startScan, activeJobId, scanStatus, scanError, isStarting } = useEmailScan();
  const [logEntries, setLogEntries] = useState<LogEntry[]>([]);
  const [stats, setStats] = useState({ processed: 0, skipped: 0, errored: 0, total: 0 });
  const [status, setStatus] = useState<'starting' | 'scanning' | 'completed' | 'failed'>('starting');
  const [dateRange, setDateRange] = useState<{ startDate?: string; endDate?: string }>({});
  const logContainerRef = useRef<HTMLDivElement>(null);
  const scanStarted = useRef(false);

  // Start scan on mount
  useEffect(() => {
    if (scanStarted.current) return;
    scanStarted.current = true;
    startScan(preset, { forceRescan, startDate, endDate });
  }, [preset, forceRescan, startScan]);

  // Add log entry helper
  const addLog = useCallback((entry: Omit<LogEntry, 'id'>) => {
    setLogEntries(prev => {
      const newEntries = [{ ...entry, id: `${Date.now()}_${Math.random().toString(36).slice(2)}` }, ...prev];
      return newEntries.slice(0, 50);
    });
  }, []);

  // Listen to WebSocket events
  useScanEvents({
    onStarted: useCallback((data: any) => {
      setStatus('scanning');
      setStats(prev => ({ ...prev, total: data.newEmails ?? 0, skipped: data.skipped ?? 0 }));
      setDateRange({ startDate: data.dateRange?.startDate, endDate: data.dateRange?.endDate });
      addLog({
        time: formatTime(),
        type: 'info',
        message: `${data.totalEmails ?? 0} ${t('scanModal.logEmailsFound')}, ${data.newEmails ?? 0} ${t('scanModal.logNewToProcess')}`,
      });
      if (data.skipped > 0) {
        addLog({
          time: formatTime(),
          type: 'duplicate',
          message: `${data.skipped} ${t('scanModal.logAlreadyProcessed')}`,
        });
      }
    }, [addLog, t]),

    onProgress: useCallback((data: any) => {
      setStatus('scanning');
      setStats({
        processed: data.processed ?? 0,
        total: data.total ?? 0,
        skipped: data.skipped ?? 0,
        errored: data.errored ?? 0,
      });

      if (data.latest) {
        const tx = data.latest;
        addLog({
          time: formatTime(),
          type: 'found',
          sender: tx.sender || 'Inconnu',
          amount: tx.amount ? `${Number(tx.amount).toFixed(2)}$` : undefined,
          ref: tx.reference,
          branch: tx.branch,
        });
      }

      if (data.error) {
        addLog({
          time: formatTime(),
          type: 'error',
          message: data.error.message || 'Erreur de traitement',
        });
      }
    }, [addLog]),

    onCompleted: useCallback((data: any) => {
      setStatus('completed');
      addLog({
        time: formatTime(),
        type: 'info',
        message: `${t('scanModal.logScanComplete')} (${data.duration ?? ''}) — ${data.summary?.parsed ?? 0} ${t('scanModal.logTransactionsExtracted')}`,
      });
    }, [addLog, t]),

    onError: useCallback((data: any) => {
      setStatus('failed');
      addLog({
        time: formatTime(),
        type: 'error',
        message: data.message || t('scanModal.logScanError'),
      });
    }, [addLog, t]),
  });

  // Also update from polling status (fallback)
  useEffect(() => {
    if (scanStatus) {
      if (scanStatus.status === 'completed') setStatus('completed');
      if (scanStatus.status === 'failed') setStatus('failed');
      if (scanStatus.status === 'scanning' || scanStatus.status === 'parsing') setStatus('scanning');
    }
  }, [scanStatus]);

  // Track error from mutation
  useEffect(() => {
    if (scanError) {
      setStatus('failed');
      addLog({ time: formatTime(), type: 'error', message: scanError.message });
    }
  }, [scanError, addLog]);

  const emailsDone = stats.processed + stats.errored;
  const progressPercent = stats.total > 0
    ? Math.round((emailsDone / stats.total) * 100)
    : 0;

  const totalProcessed = emailsDone + stats.skipped;
  const grandTotal = stats.total + stats.skipped;
  const totalPercent = grandTotal > 0
    ? Math.round((totalProcessed / grandTotal) * 100)
    : 0;

  const isActive = status === 'starting' || status === 'scanning';

  return (
    <div className="absolute inset-0 z-50 flex items-center justify-center bg-slate-900/40 backdrop-blur-sm p-4">
      <div className="w-full max-w-2xl transform overflow-hidden rounded-2xl bg-white p-8 text-left shadow-2xl border border-white/20">
        {/* Header */}
        <div className="flex items-center justify-between mb-8">
          <div className="flex items-center gap-4">
            <div className="relative flex h-12 w-12 items-center justify-center rounded-xl bg-blue-50 text-primary">
              {status === 'completed' ? (
                <CheckCircle2 className="h-7 w-7 text-emerald-600" />
              ) : status === 'failed' ? (
                <AlertTriangle className="h-7 w-7 text-red-600" />
              ) : (
                <ScanLine className="h-7 w-7 animate-pulse" />
              )}
              {isActive && (
                <div className="absolute -right-1 -top-1 h-3 w-3 rounded-full bg-green-500 ring-2 ring-white" />
              )}
            </div>
            <div>
              <h3 className="text-xl font-bold text-slate-900">
                {status === 'completed' ? t('scanModal.titleComplete') : status === 'failed' ? t('scanModal.titleError') : t('scanModal.title')}
              </h3>
              <p className="text-sm text-slate-500 flex items-center gap-1.5">
                {isActive && <span className="h-1.5 w-1.5 rounded-full bg-green-500 animate-pulse" />}
                {t('scanModal.engine', 'Scan Engine active')}
              </p>
            </div>
          </div>
          {activeJobId && (
            <div className="rounded-lg bg-slate-50 px-3 py-1.5 text-xs font-medium text-slate-600 border border-slate-100">
              {t('scanModal.sessionId')}: #{activeJobId.slice(-8).toUpperCase()}
            </div>
          )}
        </div>

        {/* Progress section */}
        <div className="mb-8 space-y-6">
          <div className="flex justify-between items-end text-sm mb-2">
            <span className="font-semibold text-slate-900">
              {isStarting ? t('scanModal.starting') : `${emailsDone} / ${stats.total} ${t('scanModal.emailsLabel')}`}
            </span>
            {dateRange.startDate && dateRange.endDate && (
              <span className="text-slate-500">
                {t('scanModal.processing')} {dateRange.startDate.slice(0, 10)} {t('scanModal.toDate')} {dateRange.endDate.slice(0, 10)}
              </span>
            )}
          </div>

          <div className="space-y-4">
            {/* Current progress */}
            <div>
              <div className="flex justify-between text-xs mb-1.5">
                <span className="text-slate-600 font-medium">{t('scanModal.batchProgress')}</span>
                <span className="text-primary font-bold">{progressPercent}%</span>
              </div>
              <div className="h-2.5 w-full rounded-full bg-slate-100 overflow-hidden">
                <div
                  className="h-full rounded-full bg-primary transition-all duration-500 ease-out relative overflow-hidden"
                  style={{ width: `${progressPercent}%` }}
                >
                  {isActive && <div className="absolute inset-0 bg-white/20 animate-pulse" />}
                </div>
              </div>
            </div>

            {/* Total progress */}
            <div>
              <div className="flex justify-between text-xs mb-1.5">
                <span className="text-slate-500">{t('scanModal.totalProgress')}</span>
                <span className="text-slate-700 font-semibold">{totalPercent}%</span>
              </div>
              <div className="h-1.5 w-full rounded-full bg-slate-100">
                <div
                  className={`h-full rounded-full transition-all duration-500 ${
                    status === 'completed' ? 'bg-emerald-500' : status === 'failed' ? 'bg-red-400' : 'bg-slate-400/60'
                  }`}
                  style={{ width: `${totalPercent}%` }}
                />
              </div>
            </div>
          </div>
        </div>

        {/* Stats grid */}
        <div className="grid grid-cols-3 gap-4 mb-8">
          <div className="rounded-xl bg-slate-50 p-4 border border-slate-100">
            <div className="text-slate-500 text-xs font-medium mb-1 uppercase tracking-wide">{t('scanModal.emailsAnalyzed')}</div>
            <div className="text-2xl font-bold text-slate-900">{stats.processed}</div>
          </div>
          <div className="rounded-xl bg-slate-50 p-4 border border-slate-100">
            <div className="text-slate-500 text-xs font-medium mb-1 uppercase tracking-wide">{t('scanModal.duplicatesSkipped')}</div>
            <div className="text-2xl font-bold text-slate-700">{stats.skipped}</div>
          </div>
          <div className={`rounded-xl p-4 border ${stats.errored > 0 ? 'bg-red-50 border-red-100' : 'bg-slate-50 border-slate-100'}`}>
            <div className={`text-xs font-medium mb-1 uppercase tracking-wide ${stats.errored > 0 ? 'text-red-600' : 'text-slate-500'}`}>
              {t('scanModal.errors')}
            </div>
            <div className={`text-2xl font-bold ${stats.errored > 0 ? 'text-red-700' : 'text-slate-700'}`}>{stats.errored}</div>
          </div>
        </div>

        {/* Extraction log */}
        <div className="mb-8 rounded-xl border border-slate-200 bg-slate-50 overflow-hidden">
          <div className="border-b border-slate-200 bg-slate-100/50 px-4 py-2 text-xs font-semibold text-slate-500 uppercase tracking-wider flex justify-between items-center">
            <span>{t('scanModal.extractionLog', 'Extraction Log')}</span>
            {isActive && <span className="h-1.5 w-1.5 rounded-full bg-green-500 animate-pulse" />}
          </div>
          <div ref={logContainerRef} className="h-40 overflow-y-auto p-4 space-y-2 font-mono text-sm">
            {logEntries.length === 0 ? (
              <div className="flex items-center justify-center h-full text-slate-400 text-xs">
                {isStarting ? t('scanModal.logWaiting') : t('scanModal.logEmpty')}
              </div>
            ) : (
              logEntries.map((entry, index) => (
                <div key={entry.id} className="flex items-start gap-3" style={{ opacity: Math.max(0.4, 1 - index * 0.08) }}>
                  <span className="text-slate-400 text-xs mt-0.5">{entry.time}</span>
                  <div className="flex-1">
                    {entry.type === 'found' && (
                      <>
                        <span className="text-emerald-600 font-semibold">{t('scanModal.logFound')}:</span>{' '}
                        <span className="text-slate-800">{entry.sender}</span>
                        {entry.amount && (
                          <>
                            <span className="mx-2 text-slate-300">|</span>
                            <span className="text-slate-600">{t('scanModal.logAmount')}:</span>{' '}
                            <span className="text-slate-900 font-bold">{entry.amount}</span>
                          </>
                        )}
                        {entry.ref && (
                          <>
                            <span className="mx-2 text-slate-300">|</span>
                            <span className="text-slate-500 text-xs">Ref: {entry.ref}</span>
                          </>
                        )}
                      </>
                    )}
                    {entry.type === 'duplicate' && (
                      <>
                        <span className="text-amber-600 font-semibold">{t('scanModal.logDuplicate')}:</span>{' '}
                        <span className="text-slate-600">{entry.message}</span>
                      </>
                    )}
                    {entry.type === 'info' && (
                      <span className="text-slate-500">{entry.message}</span>
                    )}
                    {entry.type === 'error' && (
                      <>
                        <span className="text-red-600 font-semibold">{t('scanModal.logError')}:</span>{' '}
                        <span className="text-red-700">{entry.message}</span>
                      </>
                    )}
                  </div>
                </div>
              ))
            )}
          </div>
        </div>

        {/* Action buttons */}
        <div className="flex justify-end gap-3">
          <button
            onClick={onMinimize}
            className="rounded-lg bg-white px-5 py-2.5 text-sm font-medium text-slate-600 hover:bg-slate-50 hover:text-slate-800 border border-slate-200 shadow-sm transition-colors"
          >
            {t('scan.minimize')}
          </button>
          {status === 'completed' || status === 'failed' ? (
            <button
              onClick={onClose}
              className="group flex items-center gap-2 rounded-lg bg-primary px-6 py-2.5 text-sm font-semibold text-white hover:bg-primary/90 shadow-sm transition-all"
            >
              {t('common.close')}
            </button>
          ) : (
            <button
              onClick={onClose}
              className="group flex items-center gap-2 rounded-lg bg-red-50 px-6 py-2.5 text-sm font-semibold text-red-600 hover:bg-red-100 hover:shadow-sm border border-red-100 transition-all"
            >
              <StopCircle className="h-[18px] w-[18px] group-hover:scale-110 transition-transform" />
              {t('scanModal.stop')}
            </button>
          )}
        </div>
      </div>
    </div>
  );
}