import { useState, useRef, useEffect, useCallback } from "react";
import { ArrowLeft, Settings, Search } from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  Tooltip,
  TooltipTrigger,
  TooltipContent,
} from "@/components/ui/tooltip";
import { useAppStore } from "@/stores/app-store";
import { useBoardStore } from "@/stores/board-store";

export function TopBar() {
  const view = useAppStore((s) => s.view);
  const setView = useAppStore((s) => s.setView);
  const board = useBoardStore((s) => s.board);
  const updateBoardTitle = useBoardStore((s) => s.updateBoardTitle);
  const saving = useBoardStore((s) => s.saving);
  const lastSaved = useBoardStore((s) => s.lastSaved);

  const isBoardView = view.type === "board";

  const [editing, setEditing] = useState(false);
  const [editValue, setEditValue] = useState("");
  const inputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    if (editing && inputRef.current) {
      inputRef.current.focus();
      inputRef.current.select();
    }
  }, [editing]);

  const startEditing = useCallback(() => {
    if (board) {
      setEditValue(board.title);
      setEditing(true);
    }
  }, [board]);

  const commitEdit = useCallback(() => {
    const trimmed = editValue.trim();
    if (trimmed && trimmed !== board?.title) {
      updateBoardTitle(trimmed);
    }
    setEditing(false);
  }, [editValue, board?.title, updateBoardTitle]);

  const handleKeyDown = useCallback(
    (e: React.KeyboardEvent) => {
      if (e.key === "Enter") {
        commitEdit();
      } else if (e.key === "Escape") {
        setEditing(false);
      }
    },
    [commitEdit]
  );

  const savingStatus = saving
    ? "Saving..."
    : lastSaved
      ? `Saved ${formatTimeAgo(lastSaved)}`
      : null;

  return (
    <header
      data-tauri-drag-region
      className="flex h-12 shrink-0 items-center gap-2 border-b border-border bg-pylon-surface px-3"
    >
      {/* Left section */}
      <div className="flex items-center gap-2">
        {isBoardView && (
          <Tooltip>
            <TooltipTrigger asChild>
              <Button
                variant="ghost"
                size="sm"
                onClick={() => {
                  useBoardStore.getState().closeBoard();
                  setView({ type: "board-list" });
                }}
                className="text-pylon-text-secondary hover:text-pylon-text"
              >
                <ArrowLeft className="size-4" />
                <span>Boards</span>
              </Button>
            </TooltipTrigger>
            <TooltipContent>Back to board list</TooltipContent>
          </Tooltip>
        )}
      </div>

      {/* Center section */}
      <div className="flex flex-1 items-center justify-center">
        {isBoardView && board ? (
          editing ? (
            <input
              ref={inputRef}
              value={editValue}
              onChange={(e) => setEditValue(e.target.value)}
              onBlur={commitEdit}
              onKeyDown={handleKeyDown}
              className="h-7 rounded-md border border-border bg-transparent px-2 text-center font-heading text-lg text-pylon-text outline-none focus:border-pylon-accent"
            />
          ) : (
            <button
              onClick={startEditing}
              className="rounded-md px-2 py-0.5 font-heading text-lg text-pylon-text hover:bg-pylon-column transition-colors"
            >
              {board.title}
            </button>
          )
        ) : (
          <span className="font-heading text-lg text-pylon-text">
            OpenPylon
          </span>
        )}
      </div>

      {/* Right section */}
      <div className="flex items-center gap-1">
        {savingStatus && (
          <span className="mr-2 font-mono text-xs text-pylon-text-secondary">
            {savingStatus}
          </span>
        )}

        <Tooltip>
          <TooltipTrigger asChild>
            <Button
              variant="ghost"
              size="icon-sm"
              className="text-pylon-text-secondary hover:text-pylon-text"
              onClick={() =>
                document.dispatchEvent(new CustomEvent("open-command-palette"))
              }
            >
              <Search className="size-4" />
            </Button>
          </TooltipTrigger>
          <TooltipContent>
            Command palette{" "}
            <kbd className="ml-1 font-mono text-[10px] opacity-60">Ctrl+K</kbd>
          </TooltipContent>
        </Tooltip>

        <Tooltip>
          <TooltipTrigger asChild>
            <Button
              variant="ghost"
              size="icon-sm"
              className="text-pylon-text-secondary hover:text-pylon-text"
              onClick={() =>
                document.dispatchEvent(new CustomEvent("open-settings-dialog"))
              }
            >
              <Settings className="size-4" />
            </Button>
          </TooltipTrigger>
          <TooltipContent>Settings</TooltipContent>
        </Tooltip>
      </div>
    </header>
  );
}

function formatTimeAgo(timestamp: number): string {
  const seconds = Math.floor((Date.now() - timestamp) / 1000);
  if (seconds < 5) return "just now";
  if (seconds < 60) return `${seconds}s ago`;
  const minutes = Math.floor(seconds / 60);
  return `${minutes}m ago`;
}