"use client"

import { Button } from "@/components/ui/button"
import { Card } from "@/components/ui/card"
import { EmptyState } from "@/components/ui/empty-state"
import { Input } from "@/components/ui/input"
import { ScrollArea } from "@/components/ui/scroll-area"
import { uploadFile } from "@/lib/api"
import { useChatSocket } from "@/lib/hooks/use-chat-socket"
import { notifyInfo } from "@/lib/toast"
import { cn } from "@/lib/utils"
import { useAuthStore } from "@/store/auth"
import { ArrowLeft, ImagePlus, MessageSquare, Send } from "lucide-react"
import Image from "next/image"
import Link from "next/link"
import { use, useEffect, useRef, useState } from "react"

export default function ChatDetailPage({ params }: { params: Promise<{ id: string }> }) {
  const { id: targetUserId } = use(params)
  const [input, setInput] = useState("")
  const [uploading, setUploading] = useState(false)
  const imageInputRef = useRef<HTMLInputElement>(null)
  const { user } = useAuthStore()
  const {
    connected,
    sessionId,
    messages,
    error,
    createDM,
    joinSession,
    leaveSession,
    sendTextMessage,
    sendImageMessage,
  } = useChatSocket()

  const cacheKey = user?.id ? `chat:dm:${user.id}:${targetUserId}` : null

  useEffect(() => {
    if (!connected || !cacheKey) return
    const cached = window.localStorage.getItem(cacheKey)
    if (cached) {
      joinSession(cached)
    } else {
      createDM(targetUserId)
    }
  }, [connected, cacheKey, createDM, joinSession, targetUserId])

  useEffect(() => {
    if (!sessionId || !cacheKey) return
    window.localStorage.setItem(cacheKey, sessionId)
  }, [sessionId, cacheKey])

  useEffect(
    () => () => {
      if (sessionId) leaveSession(sessionId)
    },
    [leaveSession, sessionId],
  )

  if (!user?.id) {
    return (
      <div className="container mx-auto max-w-2xl px-4 py-8">
        <EmptyState
          title="请先登录"
          description="登录后可查看会话并发送消息。"
          icon={MessageSquare}
        />
      </div>
    )
  }

  return (
    <div className="container mx-auto flex h-[calc(100vh-3.5rem)] max-w-2xl flex-col px-4 py-8">
      <Card className="flex flex-1 flex-col overflow-hidden border-border/80 shadow-sm">
        <div className="flex items-center gap-3 border-b border-border/60 bg-background px-4 py-3">
          <Link href="/chat" className="text-muted-foreground hover:text-foreground">
            <ArrowLeft className="h-5 w-5" />
          </Link>
          <div className="flex h-8 w-8 items-center justify-center rounded-full bg-muted text-muted-foreground">
            <MessageSquare className="h-4 w-4" />
          </div>
          <div>
            <span className="text-sm font-medium">会话 {targetUserId}</span>
            <p className="text-xs text-muted-foreground">
              {connected ? (sessionId ? "已连接" : "正在创建会话") : "连接中"}
            </p>
          </div>
        </div>

        <ScrollArea className="flex-1 p-4">
          <div className="space-y-4">
            {error && <p className="text-center text-xs text-destructive">{error}</p>}
            {messages.length === 0 && (
              <EmptyState
                title="暂无消息"
                description="发送第一条消息开始沟通。"
                icon={MessageSquare}
              />
            )}
            {messages.map((msg) => {
              if (msg.type === "system") {
                return (
                  <div key={msg.id} className="text-center">
                    <span className="rounded-full bg-muted/60 px-2 py-1 text-xs text-muted-foreground">
                      {msg.content}
                    </span>
                  </div>
                )
              }
              const isMine = msg.senderId === user.id
              return (
                <div key={msg.id} className={cn("flex gap-2", isMine && "flex-row-reverse")}>
                  <div className={cn("max-w-[70%]", isMine && "text-right")}>
                    {msg.type === "image" ? (
                      <Image
                        src={msg.content}
                        alt="聊天图片"
                        width={256}
                        height={192}
                        unoptimized
                        className="inline-block max-h-48 max-w-64 rounded-lg border"
                      />
                    ) : (
                      <p
                        className={cn(
                          "inline-block rounded-xl border px-3 py-2 text-sm",
                          isMine
                            ? "border-primary bg-primary text-primary-foreground"
                            : "border-border/60 bg-muted/60",
                        )}
                      >
                        {msg.content}
                      </p>
                    )}
                    <p className="mt-1 text-[10px] text-muted-foreground">
                      {new Date(msg.createdAt).toLocaleTimeString("zh-CN", {
                        hour: "2-digit",
                        minute: "2-digit",
                      })}
                    </p>
                  </div>
                </div>
              )
            })}
          </div>
        </ScrollArea>

        <div className="border-t border-border/60 bg-background p-4">
          <input
            ref={imageInputRef}
            type="file"
            accept="image/*"
            className="hidden"
            onChange={(event) => {
              const target = event.currentTarget
              const file = target.files?.[0]
              if (!file) return

              setUploading(true)
              void uploadFile(file, "chat")
                .then((imageUrl) => sendImageMessage(imageUrl))
                .catch(() => notifyInfo("图片发送失败"))
                .finally(() => {
                  setUploading(false)
                  target.value = ""
                })
            }}
          />
          <form
            className="flex gap-2"
            onSubmit={(event) => {
              event.preventDefault()
              const text = input.trim()
              if (!text || !sessionId) return
              sendTextMessage(text)
              setInput("")
            }}
          >
            <Input
              value={input}
              onChange={(event) => setInput(event.target.value)}
              placeholder="输入消息..."
              className="flex-1 border-border/60"
            />
            <Button
              type="button"
              size="icon"
              variant="outline"
              disabled={!sessionId || uploading}
              onClick={() => imageInputRef.current?.click()}
            >
              <ImagePlus className="h-4 w-4" />
            </Button>
            <Button type="submit" size="icon" disabled={!sessionId || !input.trim()}>
              <Send className="h-4 w-4" />
            </Button>
          </form>
        </div>
      </Card>
    </div>
  )
}