import React, { useState, useMemo } from 'react';
import { Copy, Check } from 'lucide-react';
import { NotificationPlatform } from '../../types';
import { parseMarkdownToHtml, isHtmlContent, stripMarkdown } from '../../lib/markdownUtils';

export interface MessageViewerProps {
  content?: string;
  message?: string;
  platform?: NotificationPlatform | number | string;
  subject?: string;
  className?: string;
  showFormatHeader?: boolean;
  maxHeightClass?: string;
  variant?: string;
  createdDate?: string;
}

export const MessageViewer: React.FC<MessageViewerProps> = ({
  content,
  message,
  platform,
  subject,
  className = '',
  maxHeightClass = 'max-h-[65vh]',
}) => {
  const rawContent = (content !== undefined && content !== null ? content : message) ?? '';
  const [copied, setCopied] = useState(false);

  // Determine whether this message represents an Email (HTML) or In-App (Markdown)
  const isEmail = useMemo(() => {
    if (
      platform === NotificationPlatform.Email ||
      platform === 1 ||
      platform === '1' ||
      String(platform).toLowerCase() === 'email'
    ) {
      return true;
    }
    if (
      platform !== NotificationPlatform.InApp &&
      platform !== 5 &&
      platform !== '5' &&
      String(platform).toLowerCase() !== 'inapp' &&
      isHtmlContent(rawContent)
    ) {
      return true;
    }
    return false;
  }, [platform, rawContent]);

  // Requirement #1: In-App message contents encoded as markdown, rendered for user; Email in HTML
  // Requirement #8: User is none the wiser of raw form or format in any Messages UI
  const renderedHtml = useMemo(() => {
    if (!rawContent || !rawContent.trim()) {
      return '<p class="text-slate-400 italic">No message content</p>';
    }

    if (isEmail) {
      if (isHtmlContent(rawContent)) {
        return rawContent.replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '');
      }
      return parseMarkdownToHtml(rawContent);
    }

    // In-App: parsed from Markdown to styled HTML
    return parseMarkdownToHtml(rawContent);
  }, [rawContent, isEmail]);

  const handleCopy = () => {
    const textToCopy = stripMarkdown(rawContent) || rawContent;
    navigator.clipboard.writeText(textToCopy);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  return (
    <div className={`flex flex-col rounded-2xl bg-slate-900/60 border border-white/10 overflow-hidden w-full max-w-full ${className}`}>
      {/* Top action toolbar - clean without technical format metadata */}
      <div className="px-5 py-3 border-b border-white/[0.08] bg-[#0b101d]/90 flex items-center justify-between text-xs text-slate-400 gap-3 shrink-0">
        <span className="text-xs font-semibold text-slate-200 truncate">
          {subject || 'Message Content'}
        </span>

        {/* Copy Clean Text */}
        <button
          type="button"
          onClick={handleCopy}
          className="flex items-center gap-1.5 px-3 py-1.5 rounded-xl bg-slate-800/90 hover:bg-slate-700 text-slate-300 hover:text-white text-xs font-medium transition cursor-pointer border border-white/10"
          title="Copy message content"
        >
          {copied ? (
            <>
              <Check className="w-3.5 h-3.5 text-emerald-400" />
              <span className="text-emerald-300">Copied</span>
            </>
          ) : (
            <>
              <Copy className="w-3.5 h-3.5 text-slate-400" />
              <span>Copy</span>
            </>
          )}
        </button>
      </div>

      {/* Rendered Body - Prose & Markdown styling */}
      <div
        className={`w-full max-w-full p-5 sm:p-7 overflow-x-auto overflow-y-auto ${maxHeightClass} text-sm leading-relaxed text-slate-200 [scrollbar-width:thin] [scrollbar-color:#334155_transparent]`}
      >
        <div
          className="prose prose-invert max-w-full w-full break-words [word-break:break-word] text-xs sm:text-sm leading-relaxed text-slate-200 [&_h1]:text-white [&_h1]:text-xl [&_h1]:font-bold [&_h1]:mb-3 [&_h2]:text-white [&_h2]:text-lg [&_h2]:font-bold [&_h2]:mb-2 [&_h3]:text-white [&_h3]:text-base [&_h3]:font-bold [&_h3]:mb-2 [&_h4]:text-white [&_h4]:font-semibold [&_a]:text-emerald-400 [&_a:hover]:underline [&_ul]:list-disc [&_ul]:pl-5 [&_ul]:my-2 [&_ol]:list-decimal [&_ol]:pl-5 [&_ol]:my-2 [&_li]:text-slate-300 [&_table]:w-full [&_table]:max-w-full [&_table]:border-collapse [&_table]:my-3 [&_th]:border [&_th]:border-slate-700 [&_th]:bg-slate-800/80 [&_th]:p-2.5 [&_th]:break-words [&_td]:border [&_td]:border-slate-800 [&_td]:p-2.5 [&_td]:break-words [&_blockquote]:border-l-4 [&_blockquote]:border-emerald-500 [&_blockquote]:pl-4 [&_blockquote]:italic [&_blockquote]:my-2 [&_code]:bg-slate-800 [&_code]:px-1.5 [&_code]:py-0.5 [&_code]:rounded [&_code]:text-emerald-300 [&_code]:break-all [&_pre]:max-w-full [&_pre]:overflow-x-auto [&_img]:max-w-full [&_img]:h-auto [&_iframe]:max-w-full"
          dangerouslySetInnerHTML={{ __html: renderedHtml }}
        />
      </div>
    </div>
  );
};