import * as React from 'react'
import { cn } from '@/lib/utils'
import { Button } from '@/components/ui/button'
import { Textarea } from '@/components/ui/textarea'
import { Send, Square, User, Bot } from 'lucide-react'
import ReactMarkdown from 'react-markdown'

export interface ChatProps extends React.HTMLAttributes<HTMLDivElement> {
  messages: Array<{
    id: string
    role: 'user' | 'assistant' | 'system'
    content: string
    createdAt?: Date
  }>
  input: string
  handleInputChange: (e: React.ChangeEvent<HTMLTextAreaElement>) => void
  handleSubmit: (e: React.FormEvent<HTMLFormElement>) => void
  isGenerating?: boolean
  stop?: () => void
}

const Chat = React.forwardRef<HTMLDivElement, ChatProps>(
  ({ className, messages, input, handleInputChange, handleSubmit, isGenerating, stop, ...props }, ref) => {
    const messagesEndRef = React.useRef<HTMLDivElement>(null)

    const scrollToBottom = () => {
      messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' })
    }

    React.useEffect(() => {
      console.log('Chat component - messages updated:', messages.length, messages.map(m => ({ id: m.id, role: m.role, content: m.content.slice(0, 50) + '...' })))
      scrollToBottom()
    }, [messages])

    return (
      <div
        className={cn('flex h-full flex-col', className)}
        ref={ref}
        {...props}
      >
        {/* Messages */}
        <div className="flex-1 overflow-y-auto p-4 space-y-4">
          {messages.length === 0 ? (
            <div className="flex items-center justify-center h-full text-muted-foreground">
              <p>No messages yet. Start a conversation!</p>
            </div>
          ) : (
            messages.map((message, index) => (
              <div
                key={`${message.id}-${index}`}
                className={cn(
                  'flex gap-3 w-full',
                  message.role === 'user' ? 'justify-end' : 'justify-start'
                )}
              >
                {/* Avatar for assistant */}
                {message.role !== 'user' && (
                  <div className="w-8 h-8 rounded-full bg-primary flex items-center justify-center flex-shrink-0">
                    <Bot className="h-4 w-4 text-primary-foreground" />
                  </div>
                )}
                
                {/* Message content */}
                <div
                  className={cn(
                    'max-w-[75%] flex flex-col gap-2 rounded-lg px-3 py-2 text-sm',
                    message.role === 'user'
                      ? 'bg-primary text-primary-foreground'
                      : 'bg-muted'
                  )}
                >
                  <div className="text-xs opacity-70">
                    {message.role === 'user' ? 'You' : 'Assistant'} • #{index + 1}
                  </div>
                  <div className="leading-relaxed prose prose-sm dark:prose-invert max-w-none">
                    <ReactMarkdown
                      components={{
                        // Customize components for better styling
                        p: ({ children }) => <p className="mb-2 last:mb-0">{children}</p>,
                        ul: ({ children }) => <ul className="mb-2 last:mb-0 list-disc pl-4">{children}</ul>,
                        ol: ({ children }) => <ol className="mb-2 last:mb-0 list-decimal pl-4">{children}</ol>,
                        li: ({ children }) => <li className="mb-1">{children}</li>,
                        code: ({ children, className }) => {
                          const isInline = !className;
                          return isInline ? (
                            <code className="bg-muted px-1 py-0.5 rounded text-xs font-mono">{children}</code>
                          ) : (
                            <code className="block bg-muted p-2 rounded text-xs font-mono overflow-x-auto whitespace-pre">{children}</code>
                          )
                        },
                        pre: ({ children }) => <div className="mb-2 last:mb-0">{children}</div>,
                        strong: ({ children }) => <strong className="font-semibold">{children}</strong>,
                        em: ({ children }) => <em className="italic">{children}</em>,
                        blockquote: ({ children }) => <blockquote className="border-l-4 border-muted pl-4 italic mb-2 last:mb-0">{children}</blockquote>,
                        h1: ({ children }) => <h1 className="text-lg font-bold mb-2 last:mb-0">{children}</h1>,
                        h2: ({ children }) => <h2 className="text-base font-bold mb-2 last:mb-0">{children}</h2>,
                        h3: ({ children }) => <h3 className="text-sm font-bold mb-2 last:mb-0">{children}</h3>,
                      }}
                    >
                      {message.content}
                    </ReactMarkdown>
                  </div>
                </div>
                
                {/* Avatar for user */}
                {message.role === 'user' && (
                  <div className="w-8 h-8 rounded-full bg-muted flex items-center justify-center flex-shrink-0">
                    <User className="h-4 w-4" />
                  </div>
                )}
              </div>
            ))
          )}
          <div ref={messagesEndRef} />
        </div>

        {/* Input */}
        <div className="border-t p-4">
          <form onSubmit={handleSubmit} className="flex gap-2">
            <Textarea
              value={input}
              onChange={handleInputChange}
              placeholder="Type your message..."
              className="min-h-[60px] resize-none"
              onKeyDown={(e) => {
                if (e.key === 'Enter' && !e.shiftKey) {
                  e.preventDefault()
                  handleSubmit(e as any)
                }
              }}
            />
            {isGenerating ? (
              <Button type="button" onClick={stop} variant="outline" size="icon">
                <Square className="h-4 w-4" />
              </Button>
            ) : (
              <Button type="submit" disabled={!input.trim()} size="icon">
                <Send className="h-4 w-4" />
              </Button>
            )}
          </form>
        </div>
      </div>
    )
  }
)
Chat.displayName = 'Chat'

export { Chat }