"use client";

import { useState } from "react";
import { Scissors } from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { useToast } from "@/components/ui/use-toast";
import { updateVersionHandles } from "@/actions/versions";
import { cn } from "@/lib/utils";

interface VersionHandlesButtonProps {
  versionId: string;
  handleHead: number | null;
  handleTail: number | null;
  pictureStartFrame: number | null;
  onSaved?: () => void;
}

const DEFAULT_HANDLES = 8;

function toInt(value: string): number | null {
  if (value.trim() === "") return null;
  const n = Number(value);
  return Number.isInteger(n) && n >= 0 ? n : NaN;
}

/**
 * Top-bar control showing a version's handles, and a dialog to set them —
 * for manual uploads, or to correct a render. Review metadata only.
 */
export function VersionHandlesButton({
  versionId,
  handleHead,
  handleTail,
  pictureStartFrame,
  onSaved,
}: VersionHandlesButtonProps) {
  const marked = (handleHead ?? 0) > 0 || (handleTail ?? 0) > 0;
  const [open, setOpen] = useState(false);
  const [includes, setIncludes] = useState(marked);
  const [head, setHead] = useState(String(handleHead ?? DEFAULT_HANDLES));
  const [tail, setTail] = useState(String(handleTail ?? DEFAULT_HANDLES));
  const [slate, setSlate] = useState(pictureStartFrame == null ? "" : String(pictureStartFrame));
  const [saving, setSaving] = useState(false);
  const { toast } = useToast();

  const openDialog = () => {
    setIncludes(marked);
    setHead(String(handleHead ?? DEFAULT_HANDLES));
    setTail(String(handleTail ?? DEFAULT_HANDLES));
    setSlate(pictureStartFrame == null ? "" : String(pictureStartFrame));
    setOpen(true);
  };

  const headN = toInt(head);
  const tailN = toInt(tail);
  const slateN = toInt(slate);
  const invalid =
    (includes && (headN == null || Number.isNaN(headN) || tailN == null || Number.isNaN(tailN))) ||
    Number.isNaN(slateN);

  const save = async () => {
    if (invalid) return;
    setSaving(true);
    try {
      await updateVersionHandles({
        versionId,
        handleHead: includes ? headN! : 0,
        handleTail: includes ? tailN! : 0,
        pictureStartFrame: slateN,
      });
      setOpen(false);
      onSaved?.();
    } catch {
      toast({ title: "Couldn't save handles", variant: "destructive" });
    } finally {
      setSaving(false);
    }
  };

  const label = marked
    ? handleHead === handleTail
      ? `Handles ${handleHead}`
      : `Handles ${handleHead ?? 0}/${handleTail ?? 0}`
    : "No handles";

  return (
    <>
      <Button
        variant="ghost"
        size="sm"
        className={cn("h-7 gap-1 text-xs", marked ? "text-amber-400" : "text-muted-foreground")}
        onClick={openDialog}
        title={`${label} — frames past the cut that aren't in the edit`}
      >
        <Scissors className="h-3 w-3" />
        <span className="hidden lg:inline">{label}</span>
      </Button>

      <Dialog open={open} onOpenChange={setOpen}>
        <DialogContent className="sm:max-w-sm">
          <DialogHeader>
            <DialogTitle>Handles</DialogTitle>
            <DialogDescription>
              Frames rendered past the cut at each end. The player marks them “Handle · Not in
              edit” so reviewers don&apos;t flag them. Nothing is burned in.
            </DialogDescription>
          </DialogHeader>

          <label className="flex items-center gap-2 text-sm">
            <input
              type="checkbox"
              checked={includes}
              onChange={(e) => setIncludes(e.target.checked)}
              className="h-4 w-4 accent-amber-500"
            />
            This version includes handles
          </label>

          <div className="grid grid-cols-2 gap-3">
            <div className="space-y-1">
              <Label htmlFor="handle-head" className="text-xs">Head (frames)</Label>
              <Input
                id="handle-head"
                inputMode="numeric"
                value={head}
                disabled={!includes}
                onChange={(e) => setHead(e.target.value)}
              />
            </div>
            <div className="space-y-1">
              <Label htmlFor="handle-tail" className="text-xs">Tail (frames)</Label>
              <Input
                id="handle-tail"
                inputMode="numeric"
                value={tail}
                disabled={!includes}
                onChange={(e) => setTail(e.target.value)}
              />
            </div>
          </div>

          <div className="space-y-1">
            <Label htmlFor="handle-slate" className="text-xs">Slate frames before the picture</Label>
            <Input
              id="handle-slate"
              inputMode="numeric"
              placeholder="Auto"
              value={slate}
              onChange={(e) => setSlate(e.target.value)}
            />
            <p className="text-[11px] text-muted-foreground">
              Leave blank to detect it (pipeline previews have a 1-frame slate).
            </p>
          </div>

          <DialogFooter>
            <Button variant="ghost" onClick={() => setOpen(false)}>
              Cancel
            </Button>
            <Button onClick={save} disabled={saving || invalid}>
              {saving ? "Saving…" : "Save"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </>
  );
}