import { createFileRoute, Link, useNavigate } from "@tanstack/react-router";
import { useState } from "react";
import { CategoryHeader } from "../../components/CategoryHeader";
import { ItemCard } from "../../components/ItemCard";
import { ItemPicker } from "../../components/ItemPicker";
import { WeightSummaryCard } from "../../components/WeightSummaryCard";
import {
	useDeleteSetup,
	useRemoveSetupItem,
	useSetup,
	useUpdateItemClassification,
} from "../../hooks/useSetups";
import { useCurrency } from "../../hooks/useCurrency";
import { useWeightUnit } from "../../hooks/useWeightUnit";
import { formatPrice, formatWeight } from "../../lib/formatters";
import { LucideIcon } from "../../lib/iconData";

export const Route = createFileRoute("/setups/$setupId")({
	component: SetupDetailPage,
});

function SetupDetailPage() {
	const { setupId } = Route.useParams();
	const unit = useWeightUnit();
	const currency = useCurrency();
	const navigate = useNavigate();
	const numericId = Number(setupId);
	const { data: setup, isLoading } = useSetup(numericId);
	const deleteSetup = useDeleteSetup();
	const removeItem = useRemoveSetupItem(numericId);
	const updateClassification = useUpdateItemClassification(numericId);

	const [pickerOpen, setPickerOpen] = useState(false);
	const [confirmDelete, setConfirmDelete] = useState(false);

	if (isLoading) {
		return (
			<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6">
				<div className="animate-pulse space-y-6">
					<div className="h-8 bg-gray-200 rounded w-48" />
					<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
						{[1, 2, 3].map((i) => (
							<div key={i} className="h-40 bg-gray-200 rounded-xl" />
						))}
					</div>
				</div>
			</div>
		);
	}

	if (!setup) {
		return (
			<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-16 text-center">
				<p className="text-gray-500">Setup not found.</p>
			</div>
		);
	}

	// Compute totals from items
	const totalWeight = setup.items.reduce(
		(sum, item) => sum + (item.weightGrams ?? 0),
		0,
	);
	const totalCost = setup.items.reduce(
		(sum, item) => sum + (item.priceCents ?? 0),
		0,
	);
	const itemCount = setup.items.length;
	const currentItemIds = setup.items.map((item) => item.id);

	// Group items by category
	const groupedItems = new Map<
		number,
		{
			items: typeof setup.items;
			categoryName: string;
			categoryIcon: string;
		}
	>();

	for (const item of setup.items) {
		const group = groupedItems.get(item.categoryId);
		if (group) {
			group.items.push(item);
		} else {
			groupedItems.set(item.categoryId, {
				items: [item],
				categoryName: item.categoryName,
				categoryIcon: item.categoryIcon,
			});
		}
	}

	function nextClassification(current: string): string {
		const order = ["base", "worn", "consumable"];
		const idx = order.indexOf(current);
		return order[(idx + 1) % order.length];
	}

	function handleDelete() {
		deleteSetup.mutate(numericId, {
			onSuccess: () => navigate({ to: "/setups" }),
		});
	}

	return (
		<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
			{/* Setup-specific sticky bar */}
			<div className="sticky top-14 z-[9] bg-gray-50 border-b border-gray-100 -mx-4 sm:-mx-6 lg:-mx-8 px-4 sm:px-6 lg:px-8">
				<div className="flex items-center justify-between h-12">
					<div className="flex items-center gap-3 min-w-0">
						<Link
							to="/collection"
							search={{ tab: "setups" }}
							className="text-sm text-gray-500 hover:text-gray-700 shrink-0"
						>
							&larr;
						</Link>
						<h2 className="text-base font-semibold text-gray-900 truncate">
							{setup.name}
						</h2>
					</div>
					<div className="flex items-center gap-4 text-sm text-gray-500">
						<span>
							<span className="font-medium text-gray-700">{itemCount}</span>{" "}
							{itemCount === 1 ? "item" : "items"}
						</span>
						<span>
							<span className="font-medium text-gray-700">
								{formatWeight(totalWeight, unit)}
							</span>{" "}
							total
						</span>
						<span>
							<span className="font-medium text-gray-700">
								{formatPrice(totalCost, currency)}
							</span>{" "}
							cost
						</span>
					</div>
				</div>
			</div>

			{/* Actions */}
			<div className="flex items-center gap-3 py-4">
				<button
					type="button"
					onClick={() => setPickerOpen(true)}
					className="inline-flex items-center gap-2 px-4 py-2 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
				>
					<svg
						className="w-4 h-4"
						fill="none"
						stroke="currentColor"
						viewBox="0 0 24 24"
					>
						<path
							strokeLinecap="round"
							strokeLinejoin="round"
							strokeWidth={2}
							d="M12 4v16m8-8H4"
						/>
					</svg>
					Add Items
				</button>
				<button
					type="button"
					onClick={() => setConfirmDelete(true)}
					className="inline-flex items-center gap-2 px-4 py-2 text-sm font-medium text-red-600 bg-red-50 hover:bg-red-100 rounded-lg transition-colors"
				>
					Delete Setup
				</button>
			</div>

			{/* Empty state */}
			{itemCount === 0 && (
				<div className="py-16 text-center">
					<div className="max-w-md mx-auto">
						<div className="mb-4">
							<LucideIcon
								name="package"
								size={48}
								className="text-gray-400 mx-auto"
							/>
						</div>
						<h2 className="text-xl font-semibold text-gray-900 mb-2">
							No items in this setup
						</h2>
						<p className="text-sm text-gray-500 mb-6">
							Add items from your collection to build this loadout.
						</p>
						<button
							type="button"
							onClick={() => setPickerOpen(true)}
							className="inline-flex items-center gap-2 px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
						>
							Add Items
						</button>
					</div>
				</div>
			)}

			{/* Weight summary card + items grouped by category */}
			{itemCount > 0 && (
				<div className="pb-6">
					<WeightSummaryCard items={setup.items} />
					{Array.from(groupedItems.entries()).map(
						([
							categoryId,
							{ items: categoryItems, categoryName, categoryIcon },
						]) => {
							const catWeight = categoryItems.reduce(
								(sum, item) => sum + (item.weightGrams ?? 0),
								0,
							);
							const catCost = categoryItems.reduce(
								(sum, item) => sum + (item.priceCents ?? 0),
								0,
							);
							return (
								<div key={categoryId} className="mb-8">
									<CategoryHeader
										categoryId={categoryId}
										name={categoryName}
										icon={categoryIcon}
										totalWeight={catWeight}
										totalCost={catCost}
										itemCount={categoryItems.length}
									/>
									<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
										{categoryItems.map((item) => (
											<ItemCard
												key={item.id}
												id={item.id}
												name={item.name}
												weightGrams={item.weightGrams}
												priceCents={item.priceCents}
												categoryName={categoryName}
												categoryIcon={categoryIcon}
												imageFilename={item.imageFilename}
												productUrl={item.productUrl}
												onRemove={() => removeItem.mutate(item.id)}
												classification={item.classification}
												onClassificationCycle={() =>
													updateClassification.mutate({
														itemId: item.id,
														classification: nextClassification(
															item.classification,
														),
													})
												}
											/>
										))}
									</div>
								</div>
							);
						},
					)}
				</div>
			)}

			{/* Item Picker */}
			<ItemPicker
				setupId={numericId}
				currentItemIds={currentItemIds}
				isOpen={pickerOpen}
				onClose={() => setPickerOpen(false)}
			/>

			{/* Delete Confirmation Dialog */}
			{confirmDelete && (
				<div className="fixed inset-0 z-50 flex items-center justify-center">
					<div
						className="absolute inset-0 bg-black/30"
						onClick={() => setConfirmDelete(false)}
					/>
					<div className="relative bg-white rounded-xl shadow-lg p-6 max-w-sm mx-4 w-full">
						<h3 className="text-lg font-semibold text-gray-900 mb-2">
							Delete Setup
						</h3>
						<p className="text-sm text-gray-600 mb-6">
							Are you sure you want to delete{" "}
							<span className="font-medium">{setup.name}</span>? This will not
							remove items from your collection.
						</p>
						<div className="flex justify-end gap-3">
							<button
								type="button"
								onClick={() => setConfirmDelete(false)}
								className="px-4 py-2 text-sm font-medium text-gray-700 bg-gray-100 hover:bg-gray-200 rounded-lg transition-colors"
							>
								Cancel
							</button>
							<button
								type="button"
								onClick={handleDelete}
								disabled={deleteSetup.isPending}
								className="px-4 py-2 text-sm font-medium text-white bg-red-600 hover:bg-red-700 disabled:opacity-50 rounded-lg transition-colors"
							>
								{deleteSetup.isPending ? "Deleting..." : "Delete"}
							</button>
						</div>
					</div>
				</div>
			)}
		</div>
	);
}