'use client';

import ReactMarkdown from 'react-markdown';
import remarkGfm from 'remark-gfm';
import rehypeHighlight from 'rehype-highlight';
import rehypeRaw from 'rehype-raw';
import type { Draft } from '@/lib/db/draft-service';

interface DraftContentProps {
  draft: Draft;
}

/**
 * DraftContent Component - Markdown renderer for draft content
 *
 * Renders draft content with:
 * - Merriweather serif font for "published" feel
 * - Markdown parsing with GFM support
 * - Syntax highlighting for code blocks
 * - Tag display
 * - Generous whitespace for comfortable reading
 */
export function DraftContent({ draft }: DraftContentProps) {
  // Strip the first heading from content if it matches the title
  const processedContent = (() => {
    const lines = draft.content.split('\n');
    const firstLine = lines[0]?.trim() || '';

    // Check if first line is a heading that matches the title
    const headingMatch = firstLine.match(/^#+\s*(.+)$/);
    if (headingMatch) {
      const headingText = headingMatch[1].trim();
      if (headingText.toLowerCase() === draft.title.toLowerCase()) {
        // Remove the first line (and any immediate blank lines after it)
        let startIndex = 1;
        while (startIndex < lines.length && lines[startIndex].trim() === '') {
          startIndex++;
        }
        return lines.slice(startIndex).join('\n');
      }
    }
    return draft.content;
  })();

  return (
    <article className="draft-content px-4 sm:px-6 py-6 bg-card">
      {/* Title - using Merriweather serif font */}
      <h2 className="draft-title text-2xl sm:text-3xl font-bold text-foreground mb-6 font-serif leading-tight">
        {draft.title}
      </h2>

      {/* Body content - Markdown with prose styling */}
      <div className="draft-body prose prose-slate dark:prose-invert max-w-none font-serif">
        <ReactMarkdown
          remarkPlugins={[remarkGfm]}
          rehypePlugins={[rehypeHighlight, rehypeRaw]}
          components={{
            // Custom heading styles
            h1: ({ node, ...props }) => (
              <h1 className="text-2xl font-bold text-foreground mt-8 mb-4 first:mt-0" {...props} />
            ),
            h2: ({ node, ...props }) => (
              <h2 className="text-xl font-bold text-foreground mt-6 mb-3" {...props} />
            ),
            h3: ({ node, ...props }) => (
              <h3 className="text-lg font-semibold text-foreground mt-5 mb-2" {...props} />
            ),
            // Paragraph styling
            p: ({ node, ...props }) => (
              <p className="text-base leading-relaxed text-muted-foreground mb-4" {...props} />
            ),
            // Code blocks
            code: ({ node, inline, className, children, ...props }: any) => {
              if (inline) {
                return (
                  <code
                    className="px-1.5 py-0.5 bg-muted text-foreground rounded text-sm font-mono"
                    {...props}
                  >
                    {children}
                  </code>
                );
              }
              return (
                <code
                  className={`block bg-muted text-foreground p-4 rounded-lg text-sm font-mono overflow-x-auto ${className || ''}`}
                  {...props}
                >
                  {children}
                </code>
              );
            },
            // Pre tags
            pre: ({ node, ...props }) => (
              <pre className="bg-muted p-4 rounded-lg overflow-x-auto mb-4" {...props} />
            ),
            // Links
            a: ({ node, ...props }) => (
              <a className="text-primary hover:underline" {...props} />
            ),
            // Lists
            ul: ({ node, ...props }) => (
              <ul className="list-disc list-inside mb-4 text-muted-foreground space-y-1" {...props} />
            ),
            ol: ({ node, ...props }) => (
              <ol className="list-decimal list-inside mb-4 text-muted-foreground space-y-1" {...props} />
            ),
            // Blockquotes
            blockquote: ({ node, ...props }) => (
              <blockquote className="border-l-4 border-muted-foreground/30 pl-4 italic text-muted-foreground my-4" {...props} />
            ),
          }}
        >
          {processedContent}
        </ReactMarkdown>
      </div>

      {/* Tags section */}
      {draft.tags && draft.tags.length > 0 && (
        <div className="flex flex-wrap gap-2 mt-6 pt-4 border-t border-border">
          {draft.tags.map((tag) => (
            <span
              key={tag}
              className="tag-chip px-3 py-1 bg-secondary text-secondary-foreground rounded-full text-sm font-sans"
            >
              #{tag}
            </span>
          ))}
        </div>
      )}
    </article>
  );
}