"use client";

import { useEffect, useRef, useState } from "react";
import { Input } from "@/components/ui/input";

interface SearchInputProps {
  onSearch: (query: string) => void;
  initialValue?: string;
  isLoading?: boolean;
  debounceMs?: number;
  placeholder?: string;
}

/**
 * Search input component with keyboard shortcuts and debouncing
 * Supports Cmd+K (Mac) and Ctrl+K (Windows/Linux) to focus
 * Press Escape to clear input
 */
export function SearchInput({
  onSearch,
  initialValue = "",
  isLoading = false,
  debounceMs = 300,
  placeholder = "Search knowledge entries...",
}: SearchInputProps): React.JSX.Element {
  const [value, setValue] = useState(initialValue);
  const inputRef = useRef<HTMLInputElement>(null);
  const debounceTimerRef = useRef<NodeJS.Timeout | null>(null);

  // Handle keyboard shortcuts
  useEffect((): (() => void) => {
    const handleKeyDown = (e: KeyboardEvent): void => {
      // Cmd+K (Mac) or Ctrl+K (Windows/Linux)
      if (e.key === "k" && (e.metaKey || e.ctrlKey)) {
        e.preventDefault();
        inputRef.current?.focus();
      }
    };

    document.addEventListener("keydown", handleKeyDown);
    return () => {
      document.removeEventListener("keydown", handleKeyDown);
    };
  }, []);

  // Handle input changes with debouncing
  const handleChange = (e: React.ChangeEvent<HTMLInputElement>): void => {
    const newValue = e.target.value;
    setValue(newValue);

    // Clear existing timer
    if (debounceTimerRef.current) {
      clearTimeout(debounceTimerRef.current);
    }

    // Set new timer - only search for non-empty trimmed values
    debounceTimerRef.current = setTimeout(() => {
      const trimmed = newValue.trim();
      if (trimmed) {
        onSearch(trimmed);
      }
    }, debounceMs);
  };

  // Handle Escape key to clear input
  const handleKeyDown = (e: React.KeyboardEvent<HTMLInputElement>): void => {
    if (e.key === "Escape") {
      setValue("");
      if (debounceTimerRef.current) {
        clearTimeout(debounceTimerRef.current);
      }
    }
  };

  // Cleanup timer on unmount
  useEffect((): (() => void) => {
    return (): void => {
      if (debounceTimerRef.current) {
        clearTimeout(debounceTimerRef.current);
      }
    };
  }, []);

  // Detect platform for keyboard hint
  const isMac = typeof window !== "undefined" && /Mac|iPhone|iPad|iPod/.test(navigator.userAgent);
  const shortcutHint = isMac ? "⌘K" : "Ctrl+K";

  return (
    <div className="relative w-full">
      <div className="relative">
        <Input
          ref={inputRef}
          type="text"
          value={value}
          onChange={handleChange}
          onKeyDown={handleKeyDown}
          placeholder={placeholder}
          className="w-full pr-20"
          aria-label="Search"
        />
        {isLoading && (
          <div data-testid="search-loading" className="absolute right-12 top-1/2 -translate-y-1/2">
            <div className="animate-spin rounded-full h-4 w-4 border-2 border-gray-300 border-t-gray-600" />
          </div>
        )}
        <div className="absolute right-3 top-1/2 -translate-y-1/2 text-xs text-gray-400">
          {shortcutHint}
        </div>
      </div>
    </div>
  );
}