"use client";

import Link from "next/link";
import { useRouter } from "next/navigation";
import { closestCenter, DndContext, KeyboardSensor, PointerSensor, useSensor, useSensors, type DragEndEvent } from "@dnd-kit/core";
import { arrayMove, rectSortingStrategy, SortableContext, sortableKeyboardCoordinates, useSortable } from "@dnd-kit/sortable";
import { CSS } from "@dnd-kit/utilities";
import {
  ArrowUpRightIcon,
  GripVerticalIcon,
  PlusIcon,
} from "lucide-react";
import { useState, type ComponentProps } from "react";
import { toast } from "sonner";

import {
  createGuideExtra,
  reorderGuideExtras,
} from "@/app/admin/actions";
import { Button } from "@/components/ui/button";
import {
  Card,
  CardAction,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Field, FieldGroup, FieldLabel } from "@/components/ui/field";
import { ClearableInput as Input } from "@/components/admin/ui/clearable-input";
import { Spinner } from "@/components/ui/spinner";
import { cn } from "@/lib/utils";

type ExtraLink = { id: string; slug: string; title: string };

function SortableExtraCard({ extra, index, characterKey, disabled }: { extra: ExtraLink; index: number; characterKey: string; disabled: boolean }) {
  const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({ id: extra.id, disabled });
  return (
    <Card ref={setNodeRef} style={{ transform: CSS.Transform.toString(transform), transition }} className={cn(isDragging && "relative z-10 opacity-70 shadow-lg")}>
      <CardHeader>
        <CardTitle>{extra.title}</CardTitle>
        <CardDescription>Extra section {index + 1}</CardDescription>
        <CardAction>
          <Button type="button" variant="ghost" size="icon-sm" disabled={disabled} className="touch-none cursor-grab active:cursor-grabbing" aria-label={`จัดลำดับ ${extra.title}`} {...attributes} {...listeners}>
            <GripVerticalIcon />
          </Button>
        </CardAction>
      </CardHeader>
      <CardContent>
        <Button variant="outline" render={<Link href={`/admin/${characterKey}/${extra.slug}`} />} nativeButton={false}>
          แก้ไข Extra
          <ArrowUpRightIcon data-icon="inline-end" />
        </Button>
      </CardContent>
    </Card>
  );
}

export function AddExtraButton({
  guideId,
  characterKey,
  variant = "ghost",
  size = "sm",
  label = "เพิ่ม Extra",
}: {
  guideId: string;
  characterKey: string;
  variant?: ComponentProps<typeof Button>["variant"];
  size?: ComponentProps<typeof Button>["size"];
  label?: string;
}) {
  const router = useRouter();
  const [open, setOpen] = useState(false);
  const [title, setTitle] = useState("");
  const [pending, setPending] = useState(false);

  const create = async () => {
    const trimmedTitle = title.trim();
    if (!trimmedTitle) return;
    const browserWindow = window as Window & { __guideHasUnsavedChanges?: boolean };
    if (
      browserWindow.__guideHasUnsavedChanges &&
      !window.confirm("ข้อมูลยังบันทึกไม่เสร็จ ต้องการสร้าง Extra ใหม่หรือไม่?")
    ) {
      return;
    }

    setPending(true);
    const result = await createGuideExtra(guideId, { title: trimmedTitle });
    setPending(false);
    if (result.status === "error") {
      toast.error(result.message);
      return;
    }
    setOpen(false);
    setTitle("");
    toast.success("สร้าง Extra แล้ว");
    router.push(`/admin/${characterKey}/${result.section.slug}`);
    router.refresh();
  };

  return (
    <>
      <Button
        type="button"
        variant={variant}
        size={size}
        aria-label={label || "เพิ่ม Extra"}
        onClick={() => setOpen(true)}
      >
        <PlusIcon data-icon="inline-start" />
        {label}
      </Button>
      <Dialog open={open} onOpenChange={setOpen}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>เพิ่ม Extra section</DialogTitle>
            <DialogDescription>
              ตั้งชื่อส่วนเสริม ระบบจะสร้างและเปิดหน้าแก้ไขให้ทันที
            </DialogDescription>
          </DialogHeader>
          <form
            onSubmit={(event) => {
              event.preventDefault();
              void create();
            }}
          >
            <FieldGroup>
              <Field>
                <FieldLabel htmlFor="new-extra-title">ชื่อ Extra</FieldLabel>
                <Input
                  id="new-extra-title"
                  value={title}
                  maxLength={160}
                  autoFocus
                  onChange={(event) => setTitle(event.target.value)}
                />
              </Field>
            </FieldGroup>
            <DialogFooter className="mt-4">
              <Button type="submit" disabled={!title.trim() || pending}>
                {pending ? <Spinner data-icon="inline-start" /> : <PlusIcon data-icon="inline-start" />}
                สร้าง Extra
              </Button>
            </DialogFooter>
          </form>
        </DialogContent>
      </Dialog>
    </>
  );
}

export function ExtraOverview({
  guideId,
  characterKey,
  initialVersion,
  initialExtras,
}: {
  guideId: string;
  characterKey: string;
  initialVersion: number;
  initialExtras: ExtraLink[];
}) {
  const router = useRouter();
  const [extras, setExtras] = useState(initialExtras);
  const [version, setVersion] = useState(initialVersion);
  const [pending, setPending] = useState(false);
  const sensors = useSensors(useSensor(PointerSensor), useSensor(KeyboardSensor, { coordinateGetter: sortableKeyboardCoordinates }));

  const reorder = async (event: DragEndEvent) => {
    if (pending || !event.over || event.active.id === event.over.id) return;
    const oldIndex = extras.findIndex((extra) => extra.id === event.active.id);
    const newIndex = extras.findIndex((extra) => extra.id === event.over?.id);
    if (oldIndex < 0 || newIndex < 0) return;
    const previous = extras;
    const next = arrayMove(extras, oldIndex, newIndex);
    setExtras(next);
    setPending(true);
    const result = await reorderGuideExtras(guideId, {
      expectedVersion: version,
      sectionIds: next.map((extra) => extra.id),
    });
    setPending(false);
    if (result.status !== "saved") {
      setExtras(previous);
      toast.error(result.message);
      if (result.status === "conflict") window.location.reload();
      return;
    }
    if (result.version) setVersion(result.version);
    router.refresh();
  };

  return (
    <section className="flex flex-col gap-4">
      <div className="flex flex-wrap items-center justify-between gap-3">
        <div>
          <h2 className="font-heading text-xl font-semibold">Extra sections</h2>
          <p className="text-sm text-muted-foreground">แต่ละ Extra มีหน้าแก้ไขและบันทึกแยกจากกัน</p>
        </div>
        <AddExtraButton
          guideId={guideId}
          characterKey={characterKey}
          variant="outline"
        />
      </div>
      {extras.length ? (
        <DndContext sensors={sensors} collisionDetection={closestCenter} onDragEnd={(event) => void reorder(event)}>
          <SortableContext items={extras.map((extra) => extra.id)} strategy={rectSortingStrategy}>
            <div className="grid gap-4 md:grid-cols-2">
              {extras.map((extra, index) => <SortableExtraCard key={extra.id} extra={extra} index={index} characterKey={characterKey} disabled={pending} />)}
            </div>
          </SortableContext>
        </DndContext>
      ) : (
        <Card>
          <CardHeader>
            <CardTitle>ยังไม่มี Extra</CardTitle>
            <CardDescription>กดเพิ่ม Extra เพื่อสร้างส่วนเสริมแรกของ Guide นี้</CardDescription>
          </CardHeader>
        </Card>
      )}
    </section>
  );
}