'use client'

import { User, Bot, Loader2 } from 'lucide-react'
import { cn } from '@/lib/utils'
import ReactMarkdown from 'react-markdown'
import remarkGfm from 'remark-gfm'
import { Avatar, AvatarFallback } from '@/components/ui/avatar'
import { useLanguage } from '@/lib/i18n'

interface ChatMessagesProps {
  messages: any[]
  isLoading?: boolean
}

function getMessageContent(msg: any): string {
  if (typeof msg.content === 'string') return msg.content
  if (msg.parts && Array.isArray(msg.parts)) {
    return msg.parts
      .filter((p: any) => p.type === 'text')
      .map((p: any) => p.text)
      .join('')
  }
  return ''
}

export function ChatMessages({ messages, isLoading }: ChatMessagesProps) {
  const { t } = useLanguage()

  return (
    <div className="w-full max-w-4xl flex flex-col pt-8 pb-4">
      {messages.length === 0 && !isLoading && (
        <div className="flex flex-col items-center justify-center h-[60vh] text-center space-y-6">
          <div className="p-5 bg-gradient-to-br from-primary/10 to-primary/5 rounded-full shadow-inner ring-1 ring-primary/10">
            <Bot className="h-12 w-12 text-primary opacity-60" />
          </div>
          <p className="text-muted-foreground text-sm md:text-base max-w-md px-4 font-medium">
            {t('chat.welcome')}
          </p>
        </div>
      )}

      {messages.map((msg, index) => {
        const content = getMessageContent(msg)
        const isLastAssistant = msg.role === 'assistant' && index === messages.length - 1 && isLoading

        return (
          <div
            key={msg.id || index}
            className={cn(
              "flex w-full px-4 md:px-0 py-6 my-2 group",
              msg.role === 'user' ? "justify-end" : "justify-start border-y border-transparent dark:border-transparent"
            )}
          >
            {msg.role === 'user' ? (
              <div dir="auto" className="max-w-[85%] md:max-w-[70%] bg-muted text-foreground rounded-3xl rounded-br-md px-6 py-4 shadow-sm border border-border/50">
                <div className="prose prose-sm dark:prose-invert max-w-none text-[15px] leading-relaxed">
                  <ReactMarkdown remarkPlugins={[remarkGfm]}>{content}</ReactMarkdown>
                </div>
              </div>
            ) : (
              <div className="flex gap-4 md:gap-6 w-full max-w-3xl">
                <Avatar className="h-8 w-8 shrink-0 bg-transparent border border-primary/20 text-primary mt-1 shadow-sm">
                  <AvatarFallback className="bg-transparent"><Bot className="h-4 w-4" /></AvatarFallback>
                </Avatar>
                <div dir="auto" className="flex-1 overflow-hidden pt-1">
                  {content ? (
                    <div className="prose prose-slate dark:prose-invert max-w-none prose-p:leading-relaxed prose-pre:bg-slate-900 prose-pre:shadow-sm prose-pre:border prose-pre:border-slate-800 prose-headings:font-semibold marker:text-primary/50 text-[15px] prose-table:border prose-table:border-slate-300 prose-th:border prose-th:border-slate-300 prose-th:px-3 prose-th:py-2 prose-th:bg-slate-100 dark:prose-th:bg-slate-800 prose-td:border prose-td:border-slate-300 prose-td:px-3 prose-td:py-2">
                      <ReactMarkdown remarkPlugins={[remarkGfm]}>{content}</ReactMarkdown>
                    </div>
                  ) : isLastAssistant ? (
                    <div className="flex items-center gap-3 text-muted-foreground">
                      <Loader2 className="h-4 w-4 animate-spin text-primary" />
                      <span className="text-[15px] animate-pulse">{t('chat.searching')}</span>
                    </div>
                  ) : null}
                </div>
              </div>
            )}
          </div>
        )
      })}
    </div>
  )
}
