"use client";

import { useEffect, useState } from "react";
import { useRouter } from "next/navigation";
import type { Loadout } from "@/payload-types";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Textarea } from "@/components/ui/textarea";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import {
  LOADOUT_SLOTS,
  type LockerGridItem,
  type LoadoutSlots,
} from "@/lib/locker";
import {
  createLoadout,
  setLoadoutSlot,
  updateLoadout,
} from "@/app/(frontend)/locker/actions";

interface LoadoutEditorProps {
  mode: "create" | "edit";
  loadout?: Loadout | null;
  ownedItems: LockerGridItem[];
  open: boolean;
  onOpenChange: (open: boolean) => void;
}

function assetIdOf(value: unknown): string {
  if (value == null) return "";
  if (typeof value === "object" && "id" in value) return String(value.id);
  return String(value);
}

export function LoadoutEditor({
  mode,
  loadout,
  ownedItems,
  open,
  onOpenChange,
}: LoadoutEditorProps) {
  const router = useRouter();
  const [name, setName] = useState("");
  const [description, setDescription] = useState("");
  const [slots, setSlots] = useState<Record<string, string>>({});
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (!open) return;
    setLoading(false);
    setName(loadout?.name ?? "");
    setDescription(loadout?.description ?? "");
    const initial: Record<string, string> = {};
    if (loadout) {
      const current = (loadout.slots ?? {}) as LoadoutSlots;
      for (const slot of LOADOUT_SLOTS) {
        initial[slot.name] = assetIdOf(current[slot.name]);
      }
    }
    setSlots(initial);
    setError(null);
  }, [open, loadout]);

  const ownedByType = (assetTypes: readonly string[]) => {
    const types = new Set(assetTypes);
    const seen = new Set<number>();
    return ownedItems.filter((item) => {
      if (seen.has(item.assetId)) return false;
      if (!types.has(item.asset.assetType as string)) return false;
      seen.add(item.assetId);
      return true;
    });
  };

  async function handleSubmit() {
    if (!name.trim()) {
      setError("A loadout name is required.");
      return;
    }
    setLoading(true);
    setError(null);

    if (mode === "create") {
      const res = await createLoadout({
        name: name.trim(),
        description: description.trim() || undefined,
      });
      if (!res.success || res.data == null) {
        setError(res.error ?? "Failed to create loadout.");
        setLoading(false);
        return;
      }
      const loadoutId = res.data;
      for (const slot of LOADOUT_SLOTS) {
        const value = slots[slot.name];
        if (value) {
          await setLoadoutSlot(loadoutId, slot.name, Number(value));
        }
      }
      setLoading(false);
      onOpenChange(false);
      router.refresh();
      return;
    }

    if (!loadout) return;
    const res = await updateLoadout(loadout.id, {
      name: name.trim(),
      description: description.trim() || undefined,
    });
    if (!res.success) {
      setError(res.error ?? "Failed to update loadout.");
      setLoading(false);
      return;
    }
    for (const slot of LOADOUT_SLOTS) {
      const value = slots[slot.name];
      await setLoadoutSlot(loadout.id, slot.name, value ? Number(value) : null);
    }
    setLoading(false);
    onOpenChange(false);
    router.refresh();
  }

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="max-h-[85vh] overflow-y-auto">
        <DialogHeader>
          <DialogTitle>{mode === "create" ? "New Loadout" : "Edit Loadout"}</DialogTitle>
          <DialogDescription>
            Define a loadout and assign assets from your locker to each equipment slot.
          </DialogDescription>
        </DialogHeader>
        <div className="flex flex-col gap-4">
          <div className="flex flex-col gap-1.5">
            <Label>Name</Label>
            <Input value={name} onChange={(e) => setName(e.target.value)} placeholder="e.g., CQB" />
          </div>
          <div className="flex flex-col gap-1.5">
            <Label>Description</Label>
            <Textarea
              value={description}
              onChange={(e) => setDescription(e.target.value)}
              placeholder="Optional notes"
              rows={2}
            />
          </div>

          <div className="flex flex-col gap-3">
            {LOADOUT_SLOTS.map((slot) => {
              const options = ownedByType(slot.assetTypes);
              return (
                <div key={slot.name} className="flex flex-col gap-1.5">
                  <Label>{slot.label}</Label>
                  <Select
                    value={slots[slot.name] ?? ""}
                    onValueChange={(v) =>
                      setSlots((prev) => ({ ...prev, [slot.name]: v === "none" ? "" : v }))
                    }
                  >
                    <SelectTrigger>
                      <SelectValue placeholder={slot.description} />
                    </SelectTrigger>
                    <SelectContent>
                      <SelectItem value="none">Empty</SelectItem>
                      {options.map((item) => (
                        <SelectItem key={item.assetId} value={String(item.assetId)}>
                          {item.asset.name}
                        </SelectItem>
                      ))}
                    </SelectContent>
                  </Select>
                  {options.length === 0 && (
                    <span className="text-xs text-muted-foreground">
                      No matching assets in your locker.
                    </span>
                  )}
                </div>
              );
            })}
          </div>

          {error && <p className="text-sm text-red-400">{error}</p>}
        </div>
        <DialogFooter>
          <Button variant="outline" onClick={() => onOpenChange(false)}>
            Cancel
          </Button>
          <Button onClick={handleSubmit} disabled={loading}>
            {loading ? "Saving..." : "Save"}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}