'use client';

import * as React from 'react';
import { toPng } from 'html-to-image';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Skeleton } from '@/components/ui/skeleton';
import { Badge } from '@/components/ui/badge';
import { ToggleGroup, ToggleGroupItem } from '@/components/ui/toggle-group';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
} from '@/components/ui/tooltip';
import {
  Empty,
  EmptyDescription,
  EmptyHeader,
  EmptyMedia,
  EmptyTitle,
} from "@/components/ui/empty"
import { Copy, Download, Share2, Image as ImageIcon, AlignLeft, AlignCenter, AlignRight, Type, MessageSquareCode } from 'lucide-react';
import { cn } from '@/lib/utils/cn';
import { toast } from 'sonner';

export type CommentStyle = 'none' | '//' | '#' | '--' | ';' | '/* */' | '<!-- -->' | '"""';

const COMMENT_STYLES: { value: CommentStyle; label: string }[] = [
  { value: 'none', label: 'None' },
  { value: '//', label: '// C, JS, Go' },
  { value: '#', label: '# Python, Shell' },
  { value: '--', label: '-- SQL, Lua' },
  { value: ';', label: '; Lisp, ASM' },
  { value: '/* */', label: '/* */ Block' },
  { value: '<!-- -->', label: '<!-- --> HTML' },
  { value: '"""', label: '""" Docstring' },
];

function applyCommentStyle(text: string, style: CommentStyle): string {
  if (style === 'none' || !text) return text;
  const lines = text.split('\n');
  switch (style) {
    case '//':
    case '#':
    case '--':
    case ';':
      return lines.map(line => `${style} ${line}`).join('\n');
    case '/* */':
      return ['/*', ...lines.map(line => ` * ${line}`), ' */'].join('\n');
    case '<!-- -->':
      return ['<!--', ...lines, '-->'].join('\n');
    case '"""':
      return ['"""', ...lines, '"""'].join('\n');
  }
}

export interface FontPreviewProps {
  text: string;
  font?: string;
  isLoading?: boolean;
  onCopy?: () => void;
  onDownload?: () => void;
  onShare?: () => void;
  onCommentedTextChange?: (commentedText: string) => void;
  className?: string;
}

type TextAlign = 'left' | 'center' | 'right';

export function FontPreview({ text, font, isLoading, onCopy, onDownload, onShare, onCommentedTextChange, className }: FontPreviewProps) {
  const previewRef = React.useRef<HTMLDivElement>(null);
  const [textAlign, setTextAlign] = React.useState<TextAlign>('left');
  const [fontSize, setFontSize] = React.useState<'xs' | 'sm' | 'base'>('sm');
  const [commentStyle, setCommentStyle] = React.useState<CommentStyle>('none');

  const commentedText = React.useMemo(() => applyCommentStyle(text, commentStyle), [text, commentStyle]);
  const lineCount = commentedText ? commentedText.split('\n').length : 0;
  const charCount = commentedText ? commentedText.length : 0;

  React.useEffect(() => {
    onCommentedTextChange?.(commentedText);
  }, [commentedText, onCommentedTextChange]);

  const handleExportPNG = async () => {
    if (!previewRef.current || !text) return;

    try {
      const dataUrl = await toPng(previewRef.current, {
        backgroundColor: getComputedStyle(previewRef.current).backgroundColor,
        pixelRatio: 2,
      });

      const link = document.createElement('a');
      link.download = `ascii-${font || 'export'}-${Date.now()}.png`;
      link.href = dataUrl;
      link.click();

      toast.success('Exported as PNG!');
    } catch (error) {
      console.error('Failed to export PNG:', error);
      toast.error('Failed to export PNG');
    }
  };

  return (
    <Card className={cn('relative', className)}>
      <CardHeader className="flex flex-row items-center justify-between flex-wrap gap-2">
        <div className="flex items-center gap-2">
          <CardTitle>Preview</CardTitle>
          {font && (
            <Badge className="text-[10px] font-mono">
              {font}
            </Badge>
          )}
        </div>
        <div className="flex gap-1.5 flex-wrap">
          {onCopy && (
            <Tooltip>
              <TooltipTrigger asChild>
                <Button variant="outline" size="xs" onClick={onCopy}>
                  <Copy className="h-3 w-3 mr-1" />
                  Copy
                </Button>
              </TooltipTrigger>
              <TooltipContent>Copy to clipboard</TooltipContent>
            </Tooltip>
          )}
          {onShare && (
            <Tooltip>
              <TooltipTrigger asChild>
                <Button variant="outline" size="xs" onClick={onShare}>
                  <Share2 className="h-3 w-3 mr-1" />
                  Share
                </Button>
              </TooltipTrigger>
              <TooltipContent>Copy shareable URL</TooltipContent>
            </Tooltip>
          )}
          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="outline" size="xs" onClick={handleExportPNG}>
                <ImageIcon className="h-3 w-3 mr-1" />
                PNG
              </Button>
            </TooltipTrigger>
            <TooltipContent>Export as PNG</TooltipContent>
          </Tooltip>
          {onDownload && (
            <Tooltip>
              <TooltipTrigger asChild>
                <Button variant="outline" size="xs" onClick={onDownload}>
                  <Download className="h-3 w-3 mr-1" />
                  TXT
                </Button>
              </TooltipTrigger>
              <TooltipContent>Download as text file</TooltipContent>
            </Tooltip>
          )}
        </div>
      </CardHeader>
      <CardContent className="space-y-3">
        {/* Controls */}
        <div className="flex items-center gap-2 flex-wrap">
          <ToggleGroup
            type="single"
            value={textAlign}
            onValueChange={(v) => v && setTextAlign(v as TextAlign)}
            variant="outline"
            size="sm"
            disabled={commentStyle !== 'none'}
          >
            <ToggleGroupItem value="left" aria-label="Align left" className="px-1.5">
              <AlignLeft className="h-3 w-3" />
            </ToggleGroupItem>
            <ToggleGroupItem value="center" aria-label="Align center" className="px-1.5">
              <AlignCenter className="h-3 w-3" />
            </ToggleGroupItem>
            <ToggleGroupItem value="right" aria-label="Align right" className="px-1.5">
              <AlignRight className="h-3 w-3" />
            </ToggleGroupItem>
          </ToggleGroup>

          <ToggleGroup
            type="single"
            value={fontSize}
            onValueChange={(v) => v && setFontSize(v as 'xs' | 'sm' | 'base')}
            variant="outline"
            size="sm"
          >
            <ToggleGroupItem value="xs" aria-label="Extra small font" className="px-1.5 text-[10px] uppercase">
              xs
            </ToggleGroupItem>
            <ToggleGroupItem value="sm" aria-label="Small font" className="px-1.5 text-[10px] uppercase">
              sm
            </ToggleGroupItem>
            <ToggleGroupItem value="base" aria-label="Medium font" className="px-1.5 text-[10px] uppercase">
              md
            </ToggleGroupItem>
          </ToggleGroup>

          <Select value={commentStyle} onValueChange={(v) => setCommentStyle(v as CommentStyle)}>
            <SelectTrigger size="sm" className="h-8 w-auto gap-1 text-xs">
              <MessageSquareCode className="h-3 w-3 text-foreground shrink-0" />
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              {COMMENT_STYLES.map((s) => (
                <SelectItem key={s.value} value={s.value}>
                  {s.label}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>

          {!isLoading && text && (
            <div className="flex gap-2 text-[10px] text-muted-foreground ml-auto">
              <span>{lineCount} lines</span>
              <span>{charCount} chars</span>
            </div>
          )}
        </div>

        <div
          ref={previewRef}
          className={cn(
            'relative min-h-[200px] bg-muted/50 rounded-lg p-4 overflow-x-auto',
            commentStyle === 'none' && textAlign === 'center' && 'text-center',
            commentStyle === 'none' && textAlign === 'right' && 'text-right'
          )}
        >
          {isLoading ? (
            <div className="space-y-3">
              <Skeleton className="h-6 w-3/4" />
              <Skeleton className="h-6 w-full" />
              <Skeleton className="h-6 w-5/6" />
              <Skeleton className="h-6 w-2/3" />
              <Skeleton className="h-6 w-full" />
              <Skeleton className="h-6 w-4/5" />
            </div>
          ) : text ? (
            <pre className={cn(
              'font-mono whitespace-pre overflow-x-auto animate-in',
              fontSize === 'xs' && 'text-[10px]',
              fontSize === 'sm' && 'text-xs sm:text-sm',
              fontSize === 'base' && 'text-sm sm:text-base'
            )}>
              {commentedText}
            </pre>
          ) : (
            <Empty>
              <EmptyHeader>
                <EmptyMedia variant="icon">
                  <Type />
                </EmptyMedia>
                <EmptyTitle>Start typing to see your ASCII art</EmptyTitle>
                <EmptyDescription>Enter text in the input field above to generate ASCII art with the selected font</EmptyDescription>
              </EmptyHeader>
            </Empty>
          )}
        </div>
      </CardContent>
    </Card>
  );
}