"use client";

import { useState, useCallback, useRef, useEffect } from "react";
import { IconPlus, IconGripHorizontal, IconPlayerPlay } from "@tabler/icons-react";
import { Button } from "@kandev/ui/button";
import { Textarea } from "@kandev/ui/textarea";
import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@kandev/ui/tooltip";
import { cn } from "@/lib/utils";

type EditorCommentPopoverProps = {
  selectedText: string;
  lineRange: { start: number; end: number };
  position: { x: number; y: number };
  onSubmit: (comment: string) => void;
  onSubmitAndRun?: (comment: string) => void;
  onClose: () => void;
};

type DragState = { startX: number; startY: number; origLeft: number; origTop: number };

function computeInitialPos(position: { x: number; y: number }, width: number, height: number) {
  let left = position.x;
  let top = position.y;
  if (left + width > window.innerWidth - 16) left = Math.max(16, window.innerWidth - width - 16);
  if (top + height > window.innerHeight - 16) top = Math.max(16, position.y - height);
  return { left, top };
}

function useDraggablePos(position: { x: number; y: number }, width: number, height: number) {
  const [pos, setPos] = useState(() => computeInitialPos(position, width, height));
  const dragRef = useRef<DragState | null>(null);

  const onDragStart = useCallback(
    (e: React.MouseEvent) => {
      e.preventDefault();
      dragRef.current = {
        startX: e.clientX,
        startY: e.clientY,
        origLeft: pos.left,
        origTop: pos.top,
      };
      const onMove = (ev: MouseEvent) => {
        if (!dragRef.current) return;
        const dx = ev.clientX - dragRef.current.startX;
        const dy = ev.clientY - dragRef.current.startY;
        setPos({ left: dragRef.current.origLeft + dx, top: dragRef.current.origTop + dy });
      };
      const onUp = () => {
        dragRef.current = null;
        document.removeEventListener("mousemove", onMove);
        document.removeEventListener("mouseup", onUp);
      };
      document.addEventListener("mousemove", onMove);
      document.addEventListener("mouseup", onUp);
    },
    [pos.left, pos.top],
  );

  return { pos, onDragStart };
}

function usePopoverDismiss(
  onClose: () => void,
  popoverRef: React.RefObject<HTMLDivElement | null>,
) {
  useEffect(() => {
    const handleClickOutside = (e: MouseEvent) => {
      if (popoverRef.current && !popoverRef.current.contains(e.target as Node)) onClose();
    };
    const timer = setTimeout(() => {
      document.addEventListener("mousedown", handleClickOutside);
    }, 100);
    return () => {
      clearTimeout(timer);
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [onClose, popoverRef]);

  useEffect(() => {
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === "Escape") {
        e.stopPropagation();
        onClose();
      }
    };
    document.addEventListener("keydown", handleKeyDown, true);
    return () => document.removeEventListener("keydown", handleKeyDown, true);
  }, [onClose]);
}

function PopoverBody({
  selectedText,
  comment,
  setComment,
  handleSubmit,
  handleSubmitAndRun,
  textareaRef,
}: {
  selectedText: string;
  comment: string;
  setComment: (v: string) => void;
  handleSubmit: () => void;
  handleSubmitAndRun?: () => void;
  textareaRef: React.RefObject<HTMLTextAreaElement | null>;
}) {
  const previewText =
    selectedText.length > 100 ? selectedText.slice(0, 100).trim() + "…" : selectedText;
  const isDisabled = !comment.trim();
  const isMac = typeof navigator !== "undefined" && navigator.platform?.includes("Mac");
  const modKey = isMac ? "\u2318" : "Ctrl";

  const handleKeyDown = useCallback(
    (e: React.KeyboardEvent) => {
      if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) {
        e.preventDefault();
        if (e.shiftKey && handleSubmitAndRun) {
          handleSubmitAndRun();
        } else {
          handleSubmit();
        }
      }
    },
    [handleSubmit, handleSubmitAndRun],
  );

  return (
    <div className="px-4 pb-4">
      <pre className="mb-3 p-2 rounded-md bg-muted/50 text-xs text-muted-foreground font-mono line-clamp-3 overflow-hidden whitespace-pre-wrap">
        {previewText}
      </pre>
      <Textarea
        ref={textareaRef}
        value={comment}
        onChange={(e) => setComment(e.target.value)}
        onKeyDown={handleKeyDown}
        placeholder="Add your comment or instruction..."
        className="min-h-[72px] resize-none text-sm border-border/50 focus:border-primary/50"
      />
      <div className="mt-3 flex items-center justify-between">
        <span className="text-xs text-muted-foreground/70">
          {modKey}+Enter to add{handleSubmitAndRun ? `, ${modKey}+Shift+Enter to run` : ""}
        </span>
        <TooltipProvider delayDuration={400}>
          <div className="inline-flex">
            <Tooltip>
              <TooltipTrigger asChild>
                <Button
                  size="sm"
                  variant={handleSubmitAndRun ? "outline" : "default"}
                  onClick={handleSubmit}
                  disabled={isDisabled}
                  className={`gap-1.5 cursor-pointer ${handleSubmitAndRun ? "rounded-r-none border-r-0" : ""}`}
                >
                  <IconPlus className="h-3.5 w-3.5" />
                  Add
                </Button>
              </TooltipTrigger>
              <TooltipContent side="bottom">
                <p>Save comment for review ({modKey}+Enter)</p>
              </TooltipContent>
            </Tooltip>
            {handleSubmitAndRun && (
              <Tooltip>
                <TooltipTrigger asChild>
                  <Button
                    size="sm"
                    onClick={handleSubmitAndRun}
                    disabled={isDisabled}
                    className="gap-1.5 rounded-l-none cursor-pointer"
                  >
                    <IconPlayerPlay className="h-3.5 w-3.5" />
                    Run
                  </Button>
                </TooltipTrigger>
                <TooltipContent side="bottom">
                  <p>Save and send to agent ({modKey}+Shift+Enter)</p>
                </TooltipContent>
              </Tooltip>
            )}
          </div>
        </TooltipProvider>
      </div>
    </div>
  );
}

export function EditorCommentPopover({
  selectedText,
  lineRange,
  position,
  onSubmit,
  onSubmitAndRun,
  onClose,
}: EditorCommentPopoverProps) {
  const [comment, setComment] = useState("");
  const textareaRef = useRef<HTMLTextAreaElement>(null);
  const popoverRef = useRef<HTMLDivElement>(null);
  const { pos, onDragStart } = useDraggablePos(position, 384, 220);
  usePopoverDismiss(onClose, popoverRef);

  useEffect(() => {
    textareaRef.current?.focus();
  }, []);

  const handleSubmit = useCallback(() => {
    if (!comment.trim()) return;
    onSubmit(comment.trim());
  }, [comment, onSubmit]);

  const handleSubmitAndRun = useCallback(() => {
    if (!comment.trim() || !onSubmitAndRun) return;
    onSubmitAndRun(comment.trim());
  }, [comment, onSubmitAndRun]);

  const lineRangeText =
    lineRange.start === lineRange.end
      ? `Line ${lineRange.start}`
      : `Lines ${lineRange.start}-${lineRange.end}`;

  return (
    <div
      ref={popoverRef}
      className={cn(
        "fixed z-50 w-96 rounded-xl border border-border/50 bg-popover/95 backdrop-blur-sm shadow-xl",
        "animate-in fade-in-0 zoom-in-95 duration-150",
      )}
      style={{ left: pos.left, top: pos.top }}
    >
      <div
        className="flex items-center justify-between px-4 pt-3 pb-1 cursor-grab active:cursor-grabbing select-none"
        onMouseDown={onDragStart}
      >
        <span className="px-2 py-0.5 rounded-md bg-muted text-xs font-mono text-muted-foreground">
          {lineRangeText}
        </span>
        <IconGripHorizontal className="h-3.5 w-3.5 text-muted-foreground/40" />
      </div>
      <PopoverBody
        selectedText={selectedText}
        comment={comment}
        setComment={setComment}
        handleSubmit={handleSubmit}
        handleSubmitAndRun={onSubmitAndRun ? handleSubmitAndRun : undefined}
        textareaRef={textareaRef}
      />
    </div>
  );
}