import { useState } from "react";
import { useMutation, useQuery } from "@tanstack/react-query";
import { queryClient } from "@/client/rpc-client";

export function BookingForm() {
  const [selectedTreatment, setSelectedTreatment] = useState("");
  const [customerName, setCustomerName] = useState("");
  const [customerEmail, setCustomerEmail] = useState("");
  const [customerPhone, setCustomerPhone] = useState("");
  const [appointmentDate, setAppointmentDate] = useState("");
  const [selectedSlotId, setSelectedSlotId] = useState<string>("");
  const [notes, setNotes] = useState("");
  const [agbAccepted, setAgbAccepted] = useState(false);
  const [inspirationPhoto, setInspirationPhoto] = useState<string>("");
  const [photoPreview, setPhotoPreview] = useState<string>("");
  const [errorMessage, setErrorMessage] = useState<string>("");

  const { data: treatments } = useQuery(
    queryClient.treatments.live.list.experimental_liveOptions()
  );

  // Lade alle Slots live und filtere freie Slots
  const { data: allSlots } = useQuery(
    queryClient.availability.live.list.experimental_liveOptions()
  );
  
  // Filtere freie Slots und entferne vergangene Termine
  const today = new Date().toISOString().split("T")[0]; // YYYY-MM-DD
  const freeSlots = (allSlots || []).filter((s) => {
    // Nur freie Slots
    if (s.status !== "free") return false;
    
    // Nur zukünftige oder heutige Termine
    if (s.date < today) return false;
    
    // Für heute: nur zukünftige Uhrzeiten
    if (s.date === today) {
      const now = new Date();
      const currentTime = `${String(now.getHours()).padStart(2, "0")}:${String(now.getMinutes()).padStart(2, "0")}`;
      if (s.time <= currentTime) return false;
    }
    
    return true;
  });
  
  const availableDates = Array.from(new Set(freeSlots.map((s) => s.date))).sort();
  const slotsByDate = appointmentDate
    ? freeSlots.filter((s) => s.date === appointmentDate)
    : [];

  const { mutate: createBooking, isPending } = useMutation(
    queryClient.bookings.create.mutationOptions()
  );

  const selectedTreatmentData = treatments?.find((t) => t.id === selectedTreatment);
  const availableSlots = slotsByDate || []; // Slots sind bereits gefiltert
  
  // Debug logging (commented out - uncomment if needed)
  // console.log("Debug - All slots:", allSlots);
  // console.log("Debug - Free slots:", freeSlots);
  // console.log("Debug - Available dates:", availableDates);
  // console.log("Debug - Selected date:", appointmentDate);
  // console.log("Debug - Slots by date:", slotsByDate);
  // console.log("Debug - Available slots:", availableSlots);
  
  // Additional debugging for slot status
  // if (allSlots && allSlots.length > 0) {
  //   const statusCounts = allSlots.reduce((acc, slot) => {
  //     acc[slot.status] = (acc[slot.status] || 0) + 1;
  //     return acc;
  //   }, {} as Record<string, number>);
  //   console.log("Debug - Slot status counts:", statusCounts);
  // }

  const handlePhotoUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;
    
    // Check file size (max 2MB for better performance)
    if (file.size > 2 * 1024 * 1024) {
      alert("Das Foto ist zu groß. Bitte wähle ein Bild unter 2MB.");
      return;
    }

    // Check file type
    if (!file.type.startsWith('image/')) {
      alert("Bitte wähle nur Bilddateien aus.");
      return;
    }

    // Compress the image before converting to base64
    const compressImage = (file: File, maxWidth: number = 800, quality: number = 0.8): Promise<string> => {
      return new Promise((resolve, reject) => {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        const img = new Image();
        
        img.onload = () => {
          // Calculate new dimensions
          let { width, height } = img;
          if (width > maxWidth) {
            height = (height * maxWidth) / width;
            width = maxWidth;
          }
          
          canvas.width = width;
          canvas.height = height;
          
          // Draw and compress
          ctx?.drawImage(img, 0, 0, width, height);
          const compressedDataUrl = canvas.toDataURL('image/jpeg', quality);
          resolve(compressedDataUrl);
        };
        
        img.onerror = reject;
        img.src = URL.createObjectURL(file);
      });
    };

    try {
      const compressedDataUrl = await compressImage(file);
      setInspirationPhoto(compressedDataUrl);
      setPhotoPreview(compressedDataUrl);
      // console.log(`Photo compressed: ${file.size} bytes → ${compressedDataUrl.length} chars`);
    } catch (error) {
      console.error('Photo compression failed:', error);
      alert('Fehler beim Verarbeiten des Bildes. Bitte versuche es mit einem anderen Bild.');
      return;
    }

  };

  const removePhoto = () => {
    setInspirationPhoto("");
    setPhotoPreview("");
    // Reset file input
    const fileInput = document.getElementById('photo-upload') as HTMLInputElement;
    if (fileInput) fileInput.value = '';
  };


  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setErrorMessage(""); // Clear any previous error messages
    
    // console.log("Form submitted with data:", {
    //   selectedTreatment,
    //   customerName,
    //   customerEmail,
    //   customerPhone,
    //   appointmentDate,
    //   selectedSlotId,
    //   agbAccepted
    // });
    
    if (!selectedTreatment || !customerName || !customerEmail || !customerPhone || !appointmentDate || !selectedSlotId) {
      setErrorMessage("Bitte fülle alle erforderlichen Felder aus.");
      return;
    }
    if (!agbAccepted) {
      setErrorMessage("Bitte bestätige die Kenntnisnahme der Allgemeinen Geschäftsbedingungen.");
      return;
    }

    // Email validation now handled in backend before slot reservation
    const slot = availableSlots.find((s) => s.id === selectedSlotId);
    const appointmentTime = slot?.time || "";
    // console.log("Creating booking with data:", {
    //   treatmentId: selectedTreatment,
    //   customerName,
    //   customerEmail,
    //   customerPhone,
    //   appointmentDate,
    //   appointmentTime,
    //   notes,
    //   inspirationPhoto,
    //   slotId: selectedSlotId,
    // });
    createBooking(
      {
        treatmentId: selectedTreatment,
        customerName,
        customerEmail,
        customerPhone,
        appointmentDate,
        appointmentTime,
        notes,
        inspirationPhoto,
        slotId: selectedSlotId,
      },
      {
        onSuccess: () => {
          setSelectedTreatment("");
          setCustomerName("");
          setCustomerEmail("");
          setCustomerPhone("");
          setAppointmentDate("");
          setSelectedSlotId("");
          setNotes("");
          setAgbAccepted(false);
          setInspirationPhoto("");
          setPhotoPreview("");
          setErrorMessage("");
          // Reset file input
          const fileInput = document.getElementById('photo-upload') as HTMLInputElement;
          if (fileInput) fileInput.value = '';
          alert("Buchung erfolgreich erstellt! Wir werden dich kontaktieren, um deinen Termin zu bestätigen.");
        },
        onError: (error: any) => {
          console.error("Booking error:", error);
          
          // Simple error handling for oRPC errors
          let errorText = "Ein unbekannter Fehler ist aufgetreten.";
          
          if (error?.cause?.message) {
            errorText = error.cause.message;
          } else if (error?.message && error.message !== "Internal server error") {
            errorText = error.message;
          }
          
          setErrorMessage(errorText);
        },
      }
    );
  };

  // Get minimum date (today) – nicht mehr genutzt, Datumsauswahl erfolgt aus freien Slots

  return (
    <div className="max-w-2xl mx-auto bg-white rounded-lg shadow-lg p-6">
      <h2 className="text-2xl font-bold text-gray-900 mb-6">Buche deine Nagelbehandlung</h2>
      
      <form onSubmit={handleSubmit} className="space-y-6">
        {/* Treatment Selection */}
        <div>
          <label className="block text-sm font-medium text-gray-700 mb-2">
            Behandlung auswählen *
          </label>
          <select
            value={selectedTreatment}
            onChange={(e) => setSelectedTreatment(e.target.value)}
            className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
            required
          >
            <option value="">Wähle eine Behandlung</option>
            {treatments?.map((treatment) => (
              <option key={treatment.id} value={treatment.id}>
                {treatment.name} - {(treatment.price / 100).toFixed(2)} € ({treatment.duration} Min)
              </option>
            ))}
          </select>
          {selectedTreatmentData && (
            <p className="mt-2 text-sm text-gray-600">{selectedTreatmentData.description}</p>
          )}
        </div>

        {/* Customer Information */}
        <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-2">
              Vollständiger Name *
            </label>
            <input
              type="text"
              value={customerName}
              onChange={(e) => setCustomerName(e.target.value)}
              className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
              required
            />
          </div>
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-2">
              E-Mail *
            </label>
            <input
              type="email"
              value={customerEmail}
              onChange={(e) => setCustomerEmail(e.target.value)}
              className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
              required
            />
          </div>
        </div>

        <div>
          <label className="block text-sm font-medium text-gray-700 mb-2">
            Telefonnummer *
          </label>
          <input
            type="tel"
            value={customerPhone}
            onChange={(e) => setCustomerPhone(e.target.value)}
            className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
            required
          />
        </div>

        {/* Date and Time Selection */}
        <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-2">
              Datum (nur freie Termine) *
            </label>
            <select
              value={appointmentDate}
              onChange={(e) => { setAppointmentDate(e.target.value); setSelectedSlotId(""); }}
              className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
              required
            >
              <option value="">Datum auswählen</option>
              {availableDates.map((d) => (
                <option key={d} value={d}>{d}</option>
              ))}
            </select>
            {availableDates.length === 0 && (
              <p className="mt-2 text-sm text-gray-500">Aktuell keine freien Termine verfügbar.</p>
            )}
          </div>
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-2">
              Verfügbare Uhrzeit *
            </label>
            <select
              value={selectedSlotId}
              onChange={(e) => setSelectedSlotId(e.target.value)}
              className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
              disabled={!appointmentDate || !selectedTreatment}
              required
            >
              <option value="">Zeit auswählen</option>
              {availableSlots
                .sort((a, b) => a.time.localeCompare(b.time))
                .map((slot) => (
                  <option key={slot.id} value={slot.id}>
                    {slot.time} ({slot.durationMinutes} min)
                  </option>
                ))}
            </select>
            {appointmentDate && availableSlots.length === 0 && (
              <p className="mt-2 text-sm text-gray-500">
                Keine freien Zeitslots für {appointmentDate} verfügbar.
              </p>
            )}
          </div>
        </div>

        {/* Notes */}
        <div>
          <label className="block text-sm font-medium text-gray-700 mb-2">
            Zusätzliche Notizen
          </label>
          <textarea
            value={notes}
            onChange={(e) => setNotes(e.target.value)}
            rows={3}
            className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
            placeholder="Besondere Wünsche oder Informationen, Allergien, etc..."
          />
        </div>

        {/* Inspiration Photo Upload */}
        <div>
          <label className="block text-sm font-medium text-gray-700 mb-2">
            Inspiration/Beispiel-Foto (optional)
          </label>
          <div className="space-y-3">
            <input
              id="photo-upload"
              type="file"
              accept="image/*"
              onChange={handlePhotoUpload}
              className="block w-full text-sm text-gray-500 file:mr-4 file:py-2 file:px-4 file:rounded-md file:border-0 file:text-sm file:font-medium file:bg-pink-50 file:text-pink-700 hover:file:bg-pink-100"
            />
            {photoPreview && (
              <div className="relative inline-block">
                <img
                  src={photoPreview}
                  alt="Inspiration Preview"
                  className="w-32 h-32 object-cover rounded-lg border border-gray-200"
                />
                <button
                  type="button"
                  onClick={removePhoto}
                  className="absolute -top-2 -right-2 bg-red-500 text-white rounded-full w-6 h-6 flex items-center justify-center text-sm hover:bg-red-600"
                >
                  ×
                </button>
              </div>
            )}
            <p className="text-xs text-gray-500">
              📸 Lade ein Foto hoch, das als Inspiration für deine Nagelbehandlung dienen soll. Max. 5MB, alle Bildformate erlaubt.
            </p>
          </div>
        </div>

        {/* AGB Acceptance */}
        <div className="bg-gray-50 border border-gray-200 rounded-lg p-4">
          <div className="flex items-start space-x-3">
            <input
              type="checkbox"
              id="agb-acceptance"
              checked={agbAccepted}
              onChange={(e) => setAgbAccepted(e.target.checked)}
              className="mt-1 h-4 w-4 text-pink-600 focus:ring-pink-500 border-gray-300 rounded"
              required
            />
            <div className="flex-1">
              <label htmlFor="agb-acceptance" className="text-sm font-medium text-gray-700 cursor-pointer">
                Ich habe die <a 
                  href="/AGB.pdf" 
                  target="_blank" 
                  rel="noopener noreferrer"
                  className="text-pink-600 hover:text-pink-700 underline font-semibold"
                >
                  Allgemeinen Geschäftsbedingungen (AGB)
                </a> gelesen und akzeptiere diese *
              </label>
              <p className="text-xs text-gray-500 mt-1">
                📋 Die AGB enthalten wichtige Informationen zu Buchungsgebühren, Stornierungsregeln und unseren Serviceleistungen.
              </p>
            </div>
          </div>
        </div>

        {/* Error Message */}
        {errorMessage && (
          <div className="bg-red-50 border border-red-200 text-red-700 px-4 py-3 rounded-md mb-4">
            <div className="flex items-center">
              <svg className="w-5 h-5 mr-2 flex-shrink-0" fill="currentColor" viewBox="0 0 20 20">
                <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
              </svg>
              <span className="font-medium">{errorMessage}</span>
            </div>
          </div>
        )}

        <button
          type="submit"
          disabled={isPending}
          className="w-full bg-pink-600 text-white py-3 px-4 rounded-md hover:bg-pink-700 focus:ring-2 focus:ring-pink-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed font-medium"
        >
          {isPending ? "Wird gebucht..." : "Termin buchen"}
        </button>
      </form>
    </div>
  );
}