"use client";

import { useState } from "react";
import { AlertTriangle, ChevronDown, ChevronRight, UtensilsCrossed } from "lucide-react";
import { PantryItemDialog } from "./pantry-item-dialog";
import { UseItemDialog } from "./use-item-dialog";

export type PantryItem = {
  id: string;
  name: string;
  description: string | null;
  quantity: number;
  unit: string | null;
  packageSize: string | null;
  storedAt: Date | null;
  bestBefore: Date | null;
  source: string | null;
  locationId: string | null;
  locationName: string | null;
  plantId: string | null;
  plantName: string | null;
  pantryCategory: string | null;
  pantrySubcategory: string | null;
  pricePaid: number | null;
  priceUnit: string | null;
  notes: string | null;
};

export type LocationOption = { id: string; name: string; path: string | null };
export type PlantOption = { id: string; commonName: string; variety: string | null };

const SOURCE_LABELS: Record<string, string> = {
  GARDEN: "Our garden", HOMEMADE: "Homemade", STORE: "Store",
  FARMERS_MARKET: "Farmers market", GIFTED: "Gifted", OTHER: "Other",
};

function daysUntil(date: Date) {
  return Math.ceil((new Date(date).getTime() - Date.now()) / 86_400_000);
}

function ExpiryBadge({ date }: { date: Date }) {
  const days = daysUntil(date);
  if (days < 0) return <span className="text-xs font-medium text-red-600 bg-red-50 border border-red-200 px-1.5 py-0.5 rounded">Expired</span>;
  if (days <= 7) return <span className="text-xs font-medium text-red-600 bg-red-50 border border-red-200 px-1.5 py-0.5 rounded">Expires in {days}d</span>;
  if (days <= 30) return <span className="text-xs font-medium text-amber-600 bg-amber-50 border border-amber-200 px-1.5 py-0.5 rounded">Expires in {days}d</span>;
  return <span className="text-xs text-muted-foreground">{new Date(date).toLocaleDateString()}</span>;
}

function ItemRow({ item, locations, plants, onRefresh }: {
  item: PantryItem; locations: LocationOption[]; plants: PlantOption[]; onRefresh: () => void;
}) {
  const priceStr = item.pricePaid != null
    ? `$${item.pricePaid.toFixed(2)}${item.priceUnit && item.priceUnit !== "package" ? `/${item.priceUnit}` : ""}`
    : null;

  return (
    <div className="flex items-center gap-3 px-4 py-3 border-b last:border-0 hover:bg-muted/30 transition-colors">
      <div className="flex-1 min-w-0">
        <div className="flex items-center gap-2 flex-wrap">
          <span className="font-medium text-sm">{item.name}</span>
          {item.description && <span className="text-xs text-muted-foreground">{item.description}</span>}
          {item.source && <span className="text-xs text-muted-foreground bg-muted px-1.5 py-0.5 rounded">{SOURCE_LABELS[item.source] ?? item.source}</span>}
          {item.plantName && <span className="text-xs text-green-700 bg-green-50 border border-green-200 px-1.5 py-0.5 rounded">🌱 {item.plantName}</span>}
        </div>
        <div className="flex items-center gap-3 mt-0.5 flex-wrap">
          <span className="text-sm text-muted-foreground">
            {item.quantity} {item.unit ?? ""}
          </span>
          {priceStr && <span className="text-xs text-muted-foreground">{priceStr}</span>}
          {item.locationName && <span className="text-xs text-muted-foreground">· {item.locationName}</span>}
          {item.storedAt && <span className="text-xs text-muted-foreground">Stored {new Date(item.storedAt).toLocaleDateString()}</span>}
          {item.bestBefore && <ExpiryBadge date={item.bestBefore} />}
        </div>
        {item.notes && <p className="text-xs text-muted-foreground mt-0.5 italic">{item.notes}</p>}
      </div>
      <div className="flex items-center gap-1 shrink-0">
        <UseItemDialog item={item} onSuccess={onRefresh} />
        <PantryItemDialog item={item} locations={locations} plants={plants} onSuccess={onRefresh} />
      </div>
    </div>
  );
}

function SubcategoryGroup({ name, items, locations, plants, onRefresh }: {
  name: string; items: PantryItem[]; locations: LocationOption[]; plants: PlantOption[]; onRefresh: () => void;
}) {
  const [open, setOpen] = useState(true);
  return (
    <div>
      <button onClick={() => setOpen(o => !o)} className="w-full flex items-center gap-2 px-4 py-2 hover:bg-muted/20 transition-colors">
        {open ? <ChevronDown className="h-3.5 w-3.5 text-muted-foreground" /> : <ChevronRight className="h-3.5 w-3.5 text-muted-foreground" />}
        <span className="text-sm font-medium text-muted-foreground">{name}</span>
        <span className="text-xs text-muted-foreground">({items.length})</span>
      </button>
      {open && items.map(item => (
        <ItemRow key={item.id} item={item} locations={locations} plants={plants} onRefresh={onRefresh} />
      ))}
    </div>
  );
}

function CategoryGroup({ name, items, locations, plants, onRefresh }: {
  name: string; items: PantryItem[]; locations: LocationOption[]; plants: PlantOption[]; onRefresh: () => void;
}) {
  const [open, setOpen] = useState(true);
  const expiring = items.filter(i => i.bestBefore && daysUntil(i.bestBefore) <= 30);

  // Group by subcategory
  const subcats = items.reduce<Record<string, PantryItem[]>>((acc, item) => {
    const key = item.pantrySubcategory ?? "—";
    if (!acc[key]) acc[key] = [];
    acc[key].push(item);
    return acc;
  }, {});
  const hasSubcats = Object.keys(subcats).length > 1 || !subcats["—"];

  return (
    <div className="rounded-lg border bg-card overflow-hidden">
      <button
        onClick={() => setOpen(o => !o)}
        className="w-full flex items-center justify-between px-4 py-3 hover:bg-muted/30 transition-colors"
      >
        <div className="flex items-center gap-2">
          {open ? <ChevronDown className="h-4 w-4 text-muted-foreground" /> : <ChevronRight className="h-4 w-4 text-muted-foreground" />}
          <span className="font-semibold">{name}</span>
          <span className="text-sm text-muted-foreground">{items.length} {items.length === 1 ? "item" : "items"}</span>
        </div>
        {expiring.length > 0 && (
          <span className="flex items-center gap-1 text-xs text-amber-600">
            <AlertTriangle className="h-3 w-3" />
            {expiring.length} expiring soon
          </span>
        )}
      </button>

      {open && (
        <div className="border-t">
          {hasSubcats
            ? Object.entries(subcats).sort(([a], [b]) => a.localeCompare(b)).map(([sub, subItems]) => (
                <SubcategoryGroup key={sub} name={sub === "—" ? "Other" : sub} items={subItems} locations={locations} plants={plants} onRefresh={onRefresh} />
              ))
            : items.map(item => (
                <ItemRow key={item.id} item={item} locations={locations} plants={plants} onRefresh={onRefresh} />
              ))
          }
        </div>
      )}
    </div>
  );
}

export function PantryClient({ initialItems, locations, plants }: {
  initialItems: PantryItem[]; locations: LocationOption[]; plants: PlantOption[];
}) {
  const [items, setItems] = useState(initialItems);

  async function refresh() {
    const res = await fetch("/api/pantry");
    if (res.ok) setItems(await res.json());
  }

  const grouped = items.reduce<Record<string, PantryItem[]>>((acc, item) => {
    const key = item.pantryCategory ?? "Uncategorized";
    if (!acc[key]) acc[key] = [];
    acc[key].push(item);
    return acc;
  }, {});

  const expiringCount = items.filter(i => i.bestBefore && daysUntil(i.bestBefore) <= 30).length;

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="font-display text-2xl font-semibold">Pantry & Freezer</h1>
          {expiringCount > 0 && (
            <p className="text-sm text-amber-600 mt-0.5 flex items-center gap-1">
              <AlertTriangle className="h-3.5 w-3.5" />
              {expiringCount} {expiringCount === 1 ? "item" : "items"} expiring within 30 days
            </p>
          )}
        </div>
        <PantryItemDialog locations={locations} plants={plants} onSuccess={refresh} />
      </div>

      {items.length === 0 ? (
        <div className="text-center py-16 text-muted-foreground">
          <UtensilsCrossed className="h-10 w-10 mx-auto mb-3 opacity-30" />
          <p className="text-sm">Nothing in the pantry yet — add your first item.</p>
        </div>
      ) : (
        <div className="space-y-4">
          {Object.entries(grouped)
            .sort(([a], [b]) => a === "Uncategorized" ? 1 : b === "Uncategorized" ? -1 : a.localeCompare(b))
            .map(([name, catItems]) => (
              <CategoryGroup key={name} name={name} items={catItems} locations={locations} plants={plants} onRefresh={refresh} />
            ))}
        </div>
      )}
    </div>
  );
}