'use client';

import { useState, useRef } from 'react';
import { OrderItem } from '@/lib/types';
import { cn, formatCurrency } from '@/lib/utils';
import { getItemDisplayDescription, getItemDisplayQty } from '@/lib/pocketbase';
import { X, Minus, Plus, Check, Camera, ImagePlus, Trash2, AlertCircle, Loader2 } from 'lucide-react';

interface CollectModalProps {
  item: OrderItem | null;
  isOpen: boolean;
  onClose: () => void;
  onConfirm: (item: OrderItem, receivedQty: number, notes: string, photo: File | null) => Promise<void> | void;
  /** Invoice pages already uploaded for this item's PO (from the PO header). */
  invoicePages?: number;
}

// Reject absurd files at the UI so the driver sees the constraint
// immediately rather than after a long stalled upload. This is NOT the
// size that actually goes over the wire — `compressPhoto` (lib/image.ts)
// re-encodes to 1200px/q70 before upload, which lands in the low
// hundreds of KB. Raw camera files were multi-megabyte and every one of
// them was truncated in transit on 2026-10-12; the cap here just stops
// someone picking a 50MB file off a camera roll.
const MAX_PHOTO_BYTES = 10 * 1024 * 1024;
const ALLOWED_PHOTO_TYPES = ['image/jpeg', 'image/png', 'image/webp', 'image/heic', 'image/heif'];

export default function CollectModal({
  item,
  isOpen,
  onClose,
  onConfirm,
  invoicePages = 0,
}: CollectModalProps) {
  const [receivedQty, setReceivedQty] = useState('');
  const [notes, setNotes] = useState('');
  const [error, setError] = useState('');
  const [photo, setPhoto] = useState<File | null>(null);
  const [photoPreviewUrl, setPhotoPreviewUrl] = useState<string | null>(null);
  // Reason the driver is collecting less than the expected qty. We
  // require *something* on a partial — either a picked reason or a
  // photo — so a partial collection can't be silently submitted with
  // no audit trail. Over-collections still pass through with just
  // notes (the driver may genuinely have nothing visual to add).
  const [partialReason, setPartialReason] = useState('');
  // True while the collection + photo upload is in flight. The button
  // used to stay live: on slow mobile data the driver tapped again and
  // every tap re-ran the save and re-uploaded the photo (one item ended
  // up with 7 identical copies on 2026-10-16).
  const [submitting, setSubmitting] = useState(false);
  const cameraInputRef = useRef<HTMLInputElement>(null);
  const libraryInputRef = useRef<HTMLInputElement>(null);

  if (!isOpen || !item) return null;

  const expectedQty = getItemDisplayQty(item);
  const parsedQty = parseFloat(receivedQty) || 0;
  const isPartial = parsedQty > 0 && parsedQty < expectedQty;
  const isOverQty = parsedQty > expectedQty;
  // True once the driver has justified the partial one way or another.
  const partialJustified = partialReason.trim() !== '' || photo !== null;
  const displayDescription = getItemDisplayDescription(item);

  const handlePhotoSelected = (file: File | undefined | null) => {
    if (!file) return;
    if (!ALLOWED_PHOTO_TYPES.includes(file.type)) {
      setError(`Photo must be JPEG, PNG, WebP, or HEIC (got ${file.type || 'unknown'})`);
      return;
    }
    if (file.size > MAX_PHOTO_BYTES) {
      setError(`Photo is too large (${(file.size / 1024 / 1024).toFixed(1)}MB). Max is 10MB.`);
      return;
    }
    setError('');
    if (photoPreviewUrl) URL.revokeObjectURL(photoPreviewUrl);
    setPhotoPreviewUrl(URL.createObjectURL(file));
    setPhoto(file);
  };

  const handleRemovePhoto = () => {
    if (photoPreviewUrl) URL.revokeObjectURL(photoPreviewUrl);
    setPhoto(null);
    setPhotoPreviewUrl(null);
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (submitting) return;
    setError('');

    const qty = parseFloat(receivedQty);
    if (isNaN(qty) || qty <= 0) {
      setError('Please enter a valid quantity');
      return;
    }

    // Partial collections must be justified — either a picked reason
    // or a photo. Without one we refuse to submit so the operator
    // always has audit context for a short pickup.
    if (isPartial && !partialJustified) {
      setError('Please tell us why the quantity is short, or take a photo to continue');
      return;
    }

    // Prefix the driver's free-text notes with the structured reason
    // when provided, so the operator sees both in the problem note
    // without losing the original wording. The reason goes first
    // because that's the most actionable piece.
    const finalNotes = isPartial && partialReason
      ? `[${partialReason}] ${notes}`.trim()
      : notes;

    setSubmitting(true);
    try {
      await onConfirm(item, qty, finalNotes, photo);
    } finally {
      setSubmitting(false);
    }
  };

  const adjustQty = (delta: number) => {
    const current = parseFloat(receivedQty) || 0;
    const newQty = Math.max(0, current + delta);
    setReceivedQty(newQty.toString());
    setError('');
  };

  return (
    <div className="fixed inset-0 z-50 flex items-end sm:items-center justify-center">
      <div className="absolute inset-0 bg-black/50 modal-overlay" onClick={onClose} />
      <div className="relative bg-[#e6e5e0] bottom-sheet w-full max-w-md flex flex-col max-h-[calc(100dvh-1rem)] sm:max-h-[85vh] border border-[rgba(38,37,30,0.1)] animate-slide-up">
        <form
          onSubmit={handleSubmit}
          className="flex flex-col min-h-0 flex-1"
        >
          {/* Drag indicator */}
          <div className="sm:hidden flex justify-center pt-2 pb-1">
            <div className="w-10 h-1 bg-[rgba(38,37,30,0.2)] rounded-full" />
          </div>

          {/* Header */}
          <div className="flex items-center justify-between px-6 pt-2 pb-5">
            <div className="flex items-center gap-2.5">
              <div className="w-8 h-8 bg-[#e6f1ec] rounded-xl flex items-center justify-center">
                <Check size={18} className="text-[#18714f]" />
              </div>
              <h2 className="text-lg font-bold text-[#26251e]">Collect Item</h2>
            </div>
            <button
              type="button"
              onClick={onClose}
              aria-label="Close"
              className="p-2 rounded-xl hover:bg-[rgba(38,37,30,0.06)] active:bg-[rgba(38,37,30,0.12)] transition-colors"
            >
              <X size={18} className="text-[rgba(38,37,30,0.55)]" />
            </button>
          </div>

          {/* Scrollable body — overflow lives on a child so the form
              can still submit via Enter / native submit semantics. */}
          <div className="flex-1 min-h-0 overflow-y-auto custom-scrollbar px-6 pb-6 space-y-5">
            {/* Item info */}
            <div className="p-4 bg-[#ebeae5] rounded-xl">
              <p className="text-sm font-semibold text-[#26251e] truncate">{displayDescription}</p>
              {item.sku && (
                <p className="text-[10px] text-[rgba(38,37,30,0.5)] font-mono mt-0.5">#{item.sku}</p>
              )}
              <div className="flex items-center gap-3 mt-1.5 text-xs text-[rgba(38,37,30,0.55)]">
                <span className="font-medium text-[#26251e]">
                  {item.expand?.supplier?.suppliername || 'Unknown'}
                </span>
                <span>Expected: {expectedQty} units</span>
              </div>
              {item.selling_price && (
                <p className="text-xs text-[#18714f] font-medium mt-1">
                  Unit price: {formatCurrency(item.selling_price)}
                </p>
              )}
            </div>

            {/* Quantity */}
            <div>
              <label htmlFor="received-qty" className="block text-sm font-semibold text-[#26251e] mb-2">
                Received Quantity *
              </label>
              <div className="flex items-center gap-3 flex-wrap">
                <button
                  type="button"
                  onClick={() => adjustQty(-1)}
                  aria-label="Decrease quantity"
                  className="w-12 h-12 flex items-center justify-center rounded-xl bg-[#ebeae5] active:bg-[#e1e0db] transition-colors touch-manipulation press-feedback-sm"
                >
                  <Minus size={18} className="text-[#26251e]" />
                </button>
                <input
                  id="received-qty"
                  type="number"
                  step="0.01"
                  inputMode="decimal"
                  value={receivedQty}
                  onChange={(e) => { setReceivedQty(e.target.value); setError(''); }}
                  className="w-20 text-center text-2xl font-bold py-3 border-2 border-[rgba(38,37,30,0.1)] rounded-xl focus:ring-2 focus:ring-[#f54e00]/30 focus:border-[#f54e00] transition-all bg-[#f2f1ed] text-[#26251e]"
                  placeholder="0"
                  autoFocus
                />
                <button
                  type="button"
                  onClick={() => adjustQty(1)}
                  aria-label="Increase quantity"
                  className="w-12 h-12 flex items-center justify-center rounded-xl bg-[#ebeae5] active:bg-[#e1e0db] transition-colors touch-manipulation press-feedback-sm"
                >
                  <Plus size={18} className="text-[#26251e]" />
                </button>
                {expectedQty > 0 && (
                  <button
                    type="button"
                    onClick={() => { setReceivedQty(expectedQty.toString()); setError(''); }}
                    className="px-3 py-2 text-xs font-medium text-[#125a3e] bg-[#e6f1ec] rounded-lg active:bg-[#c2dfd0] transition-colors touch-manipulation"
                  >
                    Full ({expectedQty})
                  </button>
                )}
              </div>
              {isPartial && (
                <p className="text-xs text-[#8a5a02] mt-2 font-medium">
                  Partial collection: {parsedQty} of {expectedQty} units
                </p>
              )}
              {isOverQty && (
                <p className="text-xs text-[#26251e] mt-2 font-medium">
                  Over collection: {parsedQty} exceeds expected {expectedQty}
                </p>
              )}
            </div>

            {/* Partial-collection justification. Only shown when the
                driver enters a qty less than expected. We require EITHER
                a picked reason OR a photo so the operator always has
                some audit context for the short pickup. The reason
                flows through into the auto-generated problem note. */}
            {isPartial && (
              <div
                className="p-4 bg-[#fcf3d8] border border-[#f6e3a4] rounded-xl space-y-2"
                role="group"
                aria-label="Partial collection justification"
              >
                <div className="flex items-center gap-2">
                  <AlertCircle size={14} className="text-[#8a5a02] flex-shrink-0" aria-hidden="true" />
                  <p className="text-xs font-semibold text-[#8a5a02]">
                    Why are you short? Pick one or take a photo below.
                  </p>
                </div>
                <label htmlFor="partial-reason" className="sr-only">Reason for short collection</label>
                <select
                  id="partial-reason"
                  value={partialReason}
                  onChange={(e) => { setPartialReason(e.target.value); setError(''); }}
                  className={cn(
                    'w-full p-2.5 text-sm bg-[#f2f1ed] border rounded-lg text-[#26251e] focus:outline-none focus:ring-2 focus:ring-[#f54e00]/30 focus:border-[#f54e00] transition-all',
                    partialReason ? 'border-[rgba(38,37,30,0.2)]' : 'border-[#cf2d56]/40'
                  )}
                  aria-required="true"
                >
                  <option value="">Select a reason…</option>
                  <option value="Out of stock">Supplier out of stock</option>
                  <option value="Wrong item">Wrong item received</option>
                  <option value="Quality issue">Quality issue</option>
                  <option value="Damaged">Damaged goods</option>
                  <option value="Wrong qty packed">Wrong qty packed</option>
                  <option value="Other">Other (specify in notes)</option>
                </select>
                {!partialReason && !photo && (
                  <p className="text-[10px] text-[#8a5a02]">
                    Required: pick a reason or attach a photo below to continue.
                  </p>
                )}
              </div>
            )}

            {/* Notes */}
            <div>
              <label htmlFor="collect-notes" className="block text-sm font-semibold text-[#26251e] mb-2">
                Notes (optional)
              </label>
              <textarea
                id="collect-notes"
                value={notes}
                onChange={(e) => setNotes(e.target.value)}
                className="w-full p-3 text-sm bg-[#f2f1ed] border border-[rgba(38,37,30,0.1)] rounded-xl text-[#26251e] placeholder:text-[rgba(38,37,30,0.4)] focus:ring-2 focus:ring-[#f54e00]/30 focus:border-[#f54e00] focus:bg-[#f7f7f4] transition-all resize-none selectable"
                rows={2}
                placeholder="Add any notes about this collection..."
              />
            </div>

            {/* Photo (optional) — proof-of-pickup. Driver takes a
                snapshot of the goods so operators have a visual
                record when a quantity mismatch gets reported later. */}
            <div>
              <div className="flex items-center justify-between mb-2">
                <label className="text-sm font-semibold text-[#26251e]">
                  Photo (optional)
                </label>
                <span className="text-[10px] text-[rgba(38,37,30,0.5)] uppercase tracking-wider">
                  Proof of pickup
                </span>
              </div>
              {/* The invoice is photographed once per PO from the PO
                  header; this photo is for the item itself. */}
              <p className="text-[12px] text-[rgba(38,37,30,0.6)] mb-2">
                {invoicePages > 0
                  ? `Invoice already uploaded for this PO (${invoicePages} page${invoicePages === 1 ? '' : 's'}). Only add a photo here if something is wrong with this item.`
                  : 'Take the invoice photo once per PO with the Invoice button on the PO header.'}
              </p>

              {photoPreviewUrl ? (
                <div className="relative rounded-xl overflow-hidden border border-[rgba(38,37,30,0.1)] bg-[#f2f1ed]">
                  {/* eslint-disable-next-line @next/next/no-img-element */}
                  <img
                    src={photoPreviewUrl}
                    alt="Pickup photo preview"
                    className="w-full h-48 object-cover"
                  />
                  <button
                    type="button"
                    onClick={handleRemovePhoto}
                    aria-label="Remove photo"
                    className="absolute top-2 right-2 w-9 h-9 rounded-full bg-[rgba(38,37,30,0.85)] text-white flex items-center justify-center active:bg-[rgba(38,37,30,1)] transition-colors touch-manipulation"
                  >
                    <Trash2 size={16} aria-hidden="true" />
                  </button>
                  <div className="px-3 py-2 text-[11px] text-[rgba(38,37,30,0.55)] flex items-center justify-between">
                    <span className="truncate">{photo?.name}</span>
                    <span className="flex-shrink-0 ml-2 font-mono">
                      {photo ? `${(photo.size / 1024).toFixed(0)}KB` : ''}
                    </span>
                  </div>
                </div>
              ) : (
                <div className="grid grid-cols-2 gap-2">
                  {/* capture="environment" hints the camera (rear-facing)
                      on mobile. Desktop browsers ignore the attribute
                      and show the standard file picker. */}
                  <input
                    ref={cameraInputRef}
                    type="file"
                    accept="image/*"
                    capture="environment"
                    className="sr-only"
                    onChange={(e) => handlePhotoSelected(e.target.files?.[0])}
                  />
                  <input
                    ref={libraryInputRef}
                    type="file"
                    accept="image/*"
                    className="sr-only"
                    onChange={(e) => handlePhotoSelected(e.target.files?.[0])}
                  />
                  <button
                    type="button"
                    onClick={() => cameraInputRef.current?.click()}
                    className="flex flex-col items-center justify-center gap-1.5 py-4 rounded-xl border-2 border-dashed border-[rgba(38,37,30,0.18)] bg-[#ebeae5] active:bg-[#e1e0db] transition-colors touch-manipulation press-feedback-sm min-h-[88px]"
                  >
                    <Camera size={20} className="text-[#26251e]" aria-hidden="true" />
                    <span className="text-xs font-semibold text-[#26251e]">Take Photo</span>
                  </button>
                  <button
                    type="button"
                    onClick={() => libraryInputRef.current?.click()}
                    className="flex flex-col items-center justify-center gap-1.5 py-4 rounded-xl border-2 border-dashed border-[rgba(38,37,30,0.18)] bg-[#ebeae5] active:bg-[#e1e0db] transition-colors touch-manipulation press-feedback-sm min-h-[88px]"
                  >
                    <ImagePlus size={20} className="text-[#26251e]" aria-hidden="true" />
                    <span className="text-xs font-semibold text-[#26251e]">From Library</span>
                  </button>
                </div>
              )}
            </div>

            {error && <p className="text-xs text-[#b3224a]" role="alert">{error}</p>}
          </div>

          {/* Pinned footer — sits above BottomNav (z-50). pb accounts for
              the 4rem nav height + safe-area inset + visual gap so the
              button never hides under the tab bar. */}
          <div
            className="px-6 pt-3 pb-[calc(4rem+env(safe-area-inset-bottom,0px)+0.75rem)] border-t border-[rgba(38,37,30,0.08)] bg-[#e6e5e0] flex-shrink-0"
            style={{ boxShadow: '0 -8px 24px rgba(0,0,0,0.06)' }}
          >
            <button
              type="submit"
              disabled={submitting || !parsedQty || parsedQty < 0 || (isPartial && !partialJustified)}
              aria-busy={submitting}
              className={cn(
                'w-full py-4 px-4 rounded-xl text-white font-semibold text-[15px]',
                'bg-[#1f8a65] active:bg-[#125a3e] transition-all',
                'touch-manipulation press-feedback min-h-[56px] flex items-center justify-center gap-2',
                (submitting || !parsedQty || parsedQty < 0 || (isPartial && !partialJustified)) && 'opacity-50'
              )}
              style={{ boxShadow: '0 4px 12px rgba(31,138,101,0.3)' }}
            >
              {submitting ? (
                <>
                  <Loader2 size={18} className="animate-spin" aria-hidden="true" />
                  {photo ? 'Saving & uploading photo…' : 'Saving…'}
                </>
              ) : (
                'Confirm Collection'
              )}
            </button>
          </div>
        </form>
      </div>
    </div>
  );
}