"use client";

import React from "react";
import { Check, ChevronsUpDown, X } from "lucide-react";

import { isValidBranchParam } from "@/lib/frontend/params";
import { cn } from "@/lib/utils";

import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Skeleton } from "@/components/ui/skeleton";
import {
	Popover,
	PopoverContent,
	PopoverTrigger,
} from "@/components/ui/popover";
import {
	Command,
	CommandEmpty,
	CommandGroup,
	CommandInput,
	CommandItem,
	CommandList,
} from "@/components/ui/command";

function normalizeTypedBranch(value) {
	if (typeof value !== "string") return null;
	const s = value.trim().toUpperCase();
	return s ? s : null;
}

export default function SearchMultiBranchPicker({
	branchesStatus,
	availableBranches,
	selectedBranches,
	onToggleBranch,
	isSubmitting,
}) {
	const [open, setOpen] = React.useState(false);
	const [manual, setManual] = React.useState("");

	const listReady = branchesStatus === "ready";
	const listLoading = branchesStatus === "loading";
	const listError = branchesStatus === "error";

	const branchOptions = Array.isArray(availableBranches)
		? availableBranches
		: [];

	const selected = Array.isArray(selectedBranches) ? selectedBranches : [];
	const selectedSet = React.useMemo(
		() => new Set(selected.map(String)),
		[selected]
	);

	const typed = normalizeTypedBranch(manual);
	const canAddTyped = Boolean(
		typed && isValidBranchParam(typed) && !selectedSet.has(typed)
	);

	return (
		<div className="rounded-lg border bg-card p-4 text-card-foreground shadow-sm">
			<div className="space-y-3">
				<p className="text-sm font-medium">Niederlassungen auswählen</p>
				<p className="text-xs text-muted-foreground">
					Wählen Sie eine oder mehrere Niederlassungen. Die Suche wird nach
					jeder Änderung aktualisiert.
				</p>

				<div className="flex flex-col gap-2 sm:flex-row sm:items-start sm:justify-between">
					<div className="flex flex-col gap-2">
						<Label>Niederlassung hinzufügen</Label>

						{listLoading ? (
							<Skeleton className="h-9 w-full sm:w-[18rem]" />
						) : (
							<Popover open={open} onOpenChange={setOpen}>
								<PopoverTrigger asChild>
									<Button
										type="button"
										variant="outline"
										role="combobox"
										aria-expanded={open}
										disabled={isSubmitting || !listReady}
										className="w-full justify-between sm:w-[18rem]"
										title={
											listReady
												? "Niederlassung hinzufügen"
												: "Niederlassungen konnten nicht geladen werden"
										}
									>
										Niederlassung hinzufügen…
										<ChevronsUpDown className="h-4 w-4 opacity-70" />
									</Button>
								</PopoverTrigger>

								<PopoverContent align="start" className="w-[18rem] p-0">
									<Command>
										<CommandInput placeholder="Suchen…" />
										<CommandList>
											<CommandEmpty>Keine Treffer.</CommandEmpty>
											<CommandGroup>
												{branchOptions.map((b) => {
													const id = String(b);
													const isSelected = selectedSet.has(id);

													return (
														<CommandItem
															key={id}
															value={id}
															onSelect={(value) => {
																const next = normalizeTypedBranch(value);
																if (!next || !isValidBranchParam(next)) return;

																if (!selectedSet.has(next))
																	onToggleBranch(next);
																setOpen(false);
															}}
														>
															<Check
																className={cn(
																	"mr-2 h-4 w-4",
																	isSelected ? "opacity-100" : "opacity-0"
																)}
															/>
															{id}
														</CommandItem>
													);
												})}
											</CommandGroup>
										</CommandList>
									</Command>
								</PopoverContent>
							</Popover>
						)}

						{listError ? (
							<div className="space-y-2">
								<p className="text-xs text-muted-foreground">
									Niederlassungen konnten nicht geladen werden. Sie können NLxx
									manuell hinzufügen.
								</p>

								<div className="flex gap-2">
									<Input
										value={manual}
										onChange={(e) => setManual(e.target.value)}
										onKeyDown={(e) => {
											if (e.key !== "Enter") return;
											if (!canAddTyped) return;

											e.preventDefault();
											onToggleBranch(typed);
											setManual("");
										}}
										placeholder="z. B. NL17"
										disabled={isSubmitting}
									/>
									<Button
										type="button"
										variant="outline"
										disabled={!canAddTyped || isSubmitting}
										onClick={() => {
											if (!canAddTyped) return;
											onToggleBranch(typed);
											setManual("");
										}}
									>
										Hinzufügen
									</Button>
								</div>
							</div>
						) : null}
					</div>

					<div className="w-full sm:w-auto">
						<Label>Ausgewählt ({selected.length})</Label>

						{selected.length === 0 ? (
							<p className="mt-2 text-xs text-muted-foreground">
								Keine Niederlassungen ausgewählt.
							</p>
						) : (
							<div className="mt-2 flex flex-wrap gap-2">
								{selected.map((b) => (
									<Badge key={b} variant="secondary" className="gap-1">
										<span>{b}</span>
										<button
											type="button"
											className="ml-1 inline-flex h-4 w-4 items-center justify-center rounded-sm hover:bg-muted/60"
											onClick={() => onToggleBranch(b)}
											disabled={isSubmitting}
											aria-label={`Entfernen: ${b}`}
											title={`Entfernen: ${b}`}
										>
											<X className="h-3 w-3" />
										</button>
									</Badge>
								))}
							</div>
						)}
					</div>
				</div>
			</div>
		</div>
	);
}