import ReactMarkdown from 'react-markdown';
import remarkGfm from 'remark-gfm';
import { useState, useMemo } from 'react';
import { cn } from "@/lib/utils";
import { Message } from "@/hooks/use-chat";
import { Bot, User } from "lucide-react";
import { markdownRenderers } from "./markdown-renderers";
import { MessageActions } from "./message-actions";
import { MessageBackground } from "./message-background";
import { MessageStepThinking } from "./message-step-thinking";
import type { ThinkingMessageMetadata } from "@/hooks/use-chat";

interface ChatMessageProps {
  message: Message;
  isStreaming?: boolean;
}

export function ChatMessage({ message, isStreaming = false }: ChatMessageProps) {
  // Verificar se é mensagem de processo de pensamento
  const isThinkingMessage = message.metadata && 
    typeof message.metadata === 'object' && 
    'type' in message.metadata && 
    message.metadata.type === 'thinking';

  if (isThinkingMessage) {
    return <MessageStepThinking metadata={message.metadata as ThinkingMessageMetadata} />;
  }

  const isUser = message.role === 'user';
  const [selected, setSelected] = useState(false);
  const isEmpty = !message.content || message.content.trim() === '';
  
  // Memoizar processamento de conteúdo
  const processedContent = useMemo(() => {
    let content = message.content || '';
    // Remove metadata tags
    content = content.replace(/<metadata>[\s\S]*?<\/metadata>/gi, '').trim();
    
    // Also remove common prefixes
    const prefixes = [
      'Bloco oculto de metadados:', 'Metadata:', 'Metadados:',
      'Hidden metadata block:', 'JSON metadata:', '---'
    ];
    
    for (const prefix of prefixes) {
      const regex = new RegExp(`${prefix}\\s*$`, 'i');
      if (regex.test(content)) {
        content = content.replace(regex, '').trim();
      }
    }
    
    return content || message.content;
  }, [message.content]);

  return (
    <MessageBackground
      role={isUser ? 'user' : 'assistant'}
      state={selected ? 'selected' : 'normal'}
      className={cn(
        "cursor-default transition-colors rounded-xl", 
        selected && "bg-muted/40",
        isUser ? "mb-2" : "mb-8"
      )}
      onClick={() => setSelected((v) => !v)}
      tabIndex={0}
    >
      <div className="flex-shrink-0 mt-0.5">
        <div className={cn(
          "w-8 h-8 rounded-full flex items-center justify-center shadow-sm ring-1 ring-border/50 backdrop-blur-sm",
          isUser 
            ? "bg-background text-muted-foreground" 
            : "bg-primary/10 text-primary ring-primary/20"
        )}>
          {isUser ? <User className="w-4 h-4" /> : <Bot className="w-5 h-5" />}
        </div>
      </div>
      
      <div className="flex-1 overflow-hidden min-w-0 pt-1">
        {isUser ? (
             // Estilo específico para mensagem do usuário (mais destaque, fonte maior)
             <div className="text-lg sm:text-xl font-medium tracking-tight text-foreground/90 leading-relaxed break-words whitespace-pre-wrap">
                {processedContent}
             </div>
        ) : (
            // Estilo Assistant
            isEmpty && isStreaming ? (
              <div className="flex items-center gap-2 text-muted-foreground py-1">
                <div className="w-2 h-2 bg-primary rounded-full animate-pulse" />
                <span className="text-sm font-medium">Gerando resposta...</span>
              </div>
            ) : (
              <div className={cn(
                "prose prose-neutral dark:prose-invert max-w-none break-words leading-7 text-base text-foreground/90",
                "prose-headings:font-semibold prose-headings:tracking-tight prose-h1:text-2xl prose-h2:text-xl prose-h3:text-lg",
                "prose-p:leading-7 prose-li:leading-7",
                "prose-pre:bg-muted/50 prose-pre:border prose-pre:border-border/50 prose-pre:rounded-xl",
                isStreaming && "relative"
              )}>
                <ReactMarkdown 
                  remarkPlugins={[remarkGfm]}
                  components={markdownRenderers}
                >
                  {processedContent}
                </ReactMarkdown>
                {isStreaming && !isEmpty && (
                  <span className="inline-block w-2 h-4 bg-primary ml-1 animate-pulse rounded-full align-middle" />
                )}
              </div>
            )
        )}
      </div>
      
      {!isUser && !isStreaming && (
        <div className={cn(
            "absolute -bottom-8 left-12 flex items-center gap-2 opacity-0 transition-opacity duration-200",
            "group-hover:opacity-100",
            selected && "opacity-100"
        )}>
          <MessageActions content={message.content} role={message.role} />
        </div>
      )}
    </MessageBackground>
  );
}