import { Download, Loader2 } from 'lucide-react';
import { useState, useRef, useEffect } from 'react';
import { LayoutType, CanvasSize } from '../../types/canvas.types';

interface ExportButtonProps {
  onExport: (filename: string) => void;
  isExporting?: boolean;
  currentLayout: LayoutType | null;
  canvasSize: CanvasSize;
}

export default function ExportButton({ onExport, isExporting = false, currentLayout, canvasSize }: ExportButtonProps) {
  // Map canvas size to friendly name
  const getCanvasSizeName = (size: CanvasSize): string => {
    switch (size) {
      case '1200x675':
        return 'Twitter';
      case 'linkedin':
        return 'LinkedIn';
      case 'hf':
        return 'HF';
      default:
        return 'Twitter';
    }
  };

  // Generate smart default filename
  const generateDefaultFilename = () => {
    const sizeName = getCanvasSizeName(canvasSize);
    if (currentLayout) {
      return `${currentLayout}_${sizeName}`;
    }
    return `thumbnail_${sizeName}`;
  };

  const [filename, setFilename] = useState(generateDefaultFilename());
  const [isFocused, setIsFocused] = useState(false);
  const [inputWidth, setInputWidth] = useState(0);
  const [isHoveringButton, setIsHoveringButton] = useState(false);
  const spanRef = useRef<HTMLSpanElement>(null);

  // Update filename when layout or canvas size changes
  useEffect(() => {
    setFilename(generateDefaultFilename());
  }, [currentLayout, canvasSize]);

  // Calculate input width based on text content
  useEffect(() => {
    if (spanRef.current) {
      setInputWidth(spanRef.current.offsetWidth);
    }
  }, [filename]);

  const handleExport = () => {
    if (isExporting) return;
    onExport(filename);
  };

  return (
    <div
      className="fixed top-[7px] lg:top-[10px] right-[20px] lg:right-[22px] z-50 p-[4px] lg:p-[5px] inline-flex items-stretch gap-[4px] lg:gap-[5px]"
      style={{
        backgroundColor: '#262933',
        borderRadius: '10px',
        boxShadow: '0px 0px 0px 0px rgba(0,0,0,0), 0px 0px 0px 0px rgba(0,0,0,0.03), 0px 0px 6.417px 0px rgba(0,0,0,0.09), 0px 0px 4.583px 0px rgba(0,0,0,0.15), 0px 0px 2.75px 0px rgba(0,0,0,0.17), 0px 16.847px 21.059px -4.212px rgba(14,13,13,0.1), 0px 8.423px 8.423px -4.212px rgba(0,0,0,0.04)',
        opacity: isExporting ? 0.5 : 1,
        transition: 'all 0.2s ease-in-out',
        width: 'fit-content'
      }}
    >
      {/* Download/Loading Icon with Blue Background - Clickable */}
      <button
        onClick={handleExport}
        disabled={isExporting}
        onMouseEnter={() => setIsHoveringButton(true)}
        onMouseLeave={() => setIsHoveringButton(false)}
        className="flex items-center justify-center rounded-[5px] w-[29px] lg:w-[32px] aspect-square flex-shrink-0 border-none p-0"
        style={{
          backgroundColor: isHoveringButton ? '#0d6ecc' : '#1888ff',
          cursor: isExporting ? 'not-allowed' : 'pointer',
          transition: 'all 0.2s ease-in-out',
          transform: isHoveringButton && !isExporting ? 'scale(1.05)' : 'scale(1)'
        }}
      >
        {isExporting ? (
          <Loader2 className="w-[14px] lg:w-4 h-[14px] lg:h-4" color="white" style={{ animation: 'spin 1s linear infinite' }} />
        ) : (
          <Download className="w-[14px] lg:w-4 h-[14px] lg:h-4" color="white" />
        )}
      </button>

      {/* Filename Container */}
      <div className="flex items-center gap-[2px] pr-[4px] lg:pr-[5px] min-h-[29px] lg:min-h-[32px]">
        {/* Hidden span to measure text width */}
        <span
          ref={spanRef}
          className="absolute invisible whitespace-pre text-[14px] lg:text-[16px] font-normal p-[4px] lg:p-[5px]"
          style={{
            fontFamily: 'Inter, sans-serif'
          }}
        >
          {filename || 'thumbnail_name'}
        </span>

        <input
          type="text"
          value={filename}
          onChange={(e) => setFilename(e.target.value)}
          onFocus={() => setIsFocused(true)}
          onBlur={() => setIsFocused(false)}
          disabled={isExporting}
          placeholder="thumbnail_name"
          className="bg-white/5 text-white text-[14px] lg:text-[16px] font-normal outline-none border-none p-[4px] lg:p-[5px] rounded"
          style={{
            fontFamily: 'Inter, sans-serif',
            width: `${inputWidth}px`,
            cursor: isExporting ? 'not-allowed' : 'text',
            opacity: isFocused ? 1 : 0.5,
            transition: 'all 0.2s ease-in-out',
            backgroundColor: isFocused ? 'rgba(255, 255, 255, 0.1)' : 'rgba(255, 255, 255, 0.05)'
          }}
          onClick={(e) => e.stopPropagation()}
        />
        <span
          className="text-white text-[14px] lg:text-[16px] font-normal"
          style={{
            fontFamily: 'Inter, sans-serif',
            opacity: isFocused ? 1 : 0.5,
            transition: 'opacity 0.2s ease-in-out'
          }}
        >
          .png
        </span>
      </div>
    </div>
  );
}