import React, { useState } from "react";
import Layout from "@/components/layout/layout";
import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Button } from "@/components/ui/button";
import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { ScrollArea } from "@/components/ui/scroll-area";
import { Badge } from "@/components/ui/badge";
import { Separator } from "@/components/ui/separator";
import { Send, Search, Phone, Video, MessageSquare, Inbox, Paperclip, MoreHorizontal, Plus, Users } from "lucide-react";

interface Message {
  id: string;
  sender: string;
  content: string;
  timestamp: string;
  isRead: boolean;
  isOutgoing: boolean;
  avatar?: string;
}

interface Conversation {
  id: string;
  participant: string;
  lastMessage: string;
  timestamp: string;
  unreadCount: number;
  avatar?: string;
  isOnline: boolean;
  isGroup?: boolean;
  members?: string[];
}

const Messages = () => {
  const [conversations, setConversations] = useState<Conversation[]>([
    {
      id: "1",
      participant: "Team Alpha",
      lastMessage: "Let's discuss the project timeline",
      timestamp: "10:30 AM",
      unreadCount: 3,
      isOnline: true,
      isGroup: true,
      members: ["Jane Smith", "Alex Johnson", "Sarah Williams"]
    },
    {
      id: "2",
      participant: "Jane Smith",
      lastMessage: "I've finished the UI designs",
      timestamp: "Yesterday",
      unreadCount: 0,
      isOnline: true
    },
    {
      id: "3", 
      participant: "Alex Johnson",
      lastMessage: "Can we review the backlog items?",
      timestamp: "Yesterday",
      unreadCount: 2,
      isOnline: false
    },
    {
      id: "4",
      participant: "Sarah Williams",
      lastMessage: "The API integration is complete",
      timestamp: "Oct 15",
      unreadCount: 0,
      isOnline: false
    },
    {
      id: "5",
      participant: "Project Leads",
      lastMessage: "Meeting scheduled for tomorrow",
      timestamp: "Oct 14",
      unreadCount: 0,
      isOnline: true,
      isGroup: true,
      members: ["Michael Brown", "Emma Davis", "David Wilson"]
    }
  ]);

  const [activeConversation, setActiveConversation] = useState<string>("1");
  const [messageInput, setMessageInput] = useState("");
  const [searchQuery, setSearchQuery] = useState("");

  const [messages, setMessages] = useState<Record<string, Message[]>>({
    "1": [
      {
        id: "1-1",
        sender: "Alex Johnson",
        content: "Hey team, we should discuss the project timeline",
        timestamp: "10:15 AM",
        isRead: true,
        isOutgoing: false
      },
      {
        id: "1-2",
        sender: "Sarah Williams",
        content: "I agree. I'm available this afternoon",
        timestamp: "10:20 AM",
        isRead: true,
        isOutgoing: false
      },
      {
        id: "1-3",
        sender: "You",
        content: "Let's schedule a meeting for 2 PM",
        timestamp: "10:25 AM",
        isRead: true,
        isOutgoing: true
      },
      {
        id: "1-4",
        sender: "Jane Smith",
        content: "Works for me. I'll prepare the agenda",
        timestamp: "10:30 AM",
        isRead: false,
        isOutgoing: false
      }
    ],
    "2": [
      {
        id: "2-1",
        sender: "Jane Smith",
        content: "I've been working on the UI designs",
        timestamp: "Yesterday, 4:30 PM",
        isRead: true,
        isOutgoing: false
      },
      {
        id: "2-2",
        sender: "You",
        content: "How's it coming along?",
        timestamp: "Yesterday, 4:35 PM",
        isRead: true,
        isOutgoing: true
      },
      {
        id: "2-3",
        sender: "Jane Smith",
        content: "Just finished! I'll share the files",
        timestamp: "Yesterday, 4:40 PM",
        isRead: true,
        isOutgoing: false
      },
      {
        id: "2-4",
        sender: "Jane Smith",
        content: "I've finished the UI designs and shared them in the design folder",
        timestamp: "Yesterday, 4:45 PM",
        isRead: true,
        isOutgoing: false
      }
    ]
  });

  const filteredConversations = conversations.filter(
    (conversation) =>
      conversation.participant.toLowerCase().includes(searchQuery.toLowerCase())
  );

  const handleSendMessage = () => {
    if (messageInput.trim() === "") return;

    const newMessage: Message = {
      id: `${activeConversation}-${Date.now()}`,
      sender: "You",
      content: messageInput,
      timestamp: "Just now",
      isRead: true,
      isOutgoing: true
    };

    setMessages((prevMessages) => ({
      ...prevMessages,
      [activeConversation]: [
        ...(prevMessages[activeConversation] || []),
        newMessage
      ]
    }));

    // Update last message in conversation list
    setConversations(
      conversations.map((conversation) =>
        conversation.id === activeConversation
          ? {
              ...conversation,
              lastMessage: messageInput,
              timestamp: "Just now",
              unreadCount: 0
            }
          : conversation
      )
    );

    setMessageInput("");
  };

  const markAsRead = (conversationId: string) => {
    setConversations(
      conversations.map((conversation) =>
        conversation.id === conversationId
          ? { ...conversation, unreadCount: 0 }
          : conversation
      )
    );
  };

  const handleConversationClick = (conversationId: string) => {
    setActiveConversation(conversationId);
    markAsRead(conversationId);
  };

  const getInitials = (name: string) => {
    return name
      .split(" ")
      .map((n) => n[0])
      .join("")
      .toUpperCase();
  };

  const currentConversation = conversations.find(
    (conversation) => conversation.id === activeConversation
  );

  return (
    <Layout>
      <div className="container mx-auto py-6">
        <div className="flex h-[calc(100vh-12rem)] overflow-hidden rounded-lg border">
          {/* Sidebar */}
          <div className="w-full max-w-xs border-r flex flex-col">
            <div className="p-4 border-b">
              <div className="relative">
                <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
                <Input
                  placeholder="Search conversations..."
                  className="pl-8"
                  value={searchQuery}
                  onChange={(e) => setSearchQuery(e.target.value)}
                />
              </div>
            </div>

            <Tabs defaultValue="all" className="flex-1 flex flex-col">
              <TabsList className="grid grid-cols-3 px-4 py-2">
                <TabsTrigger value="all">All</TabsTrigger>
                <TabsTrigger value="unread">Unread</TabsTrigger>
                <TabsTrigger value="groups">Groups</TabsTrigger>
              </TabsList>

              <ScrollArea className="flex-1">
                <TabsContent value="all" className="m-0">
                  {filteredConversations.map((conversation) => (
                    <div
                      key={conversation.id}
                      className={`flex items-center gap-3 p-3 cursor-pointer hover:bg-muted/50 ${
                        activeConversation === conversation.id ? "bg-muted" : ""
                      }`}
                      onClick={() => handleConversationClick(conversation.id)}
                    >
                      <div className="relative">
                        <Avatar>
                          <AvatarImage src={conversation.avatar} />
                          <AvatarFallback>
                            {conversation.isGroup ? (
                              <Users className="h-4 w-4" />
                            ) : (
                              getInitials(conversation.participant)
                            )}
                          </AvatarFallback>
                        </Avatar>
                        {conversation.isOnline && (
                          <span className="absolute bottom-0 right-0 h-3 w-3 rounded-full bg-green-500 border-2 border-background"></span>
                        )}
                      </div>
                      <div className="flex-1 min-w-0">
                        <div className="flex justify-between items-center">
                          <span className="font-medium truncate">
                            {conversation.participant}
                          </span>
                          <span className="text-xs text-muted-foreground">
                            {conversation.timestamp}
                          </span>
                        </div>
                        <div className="flex justify-between items-center mt-1">
                          <p className="text-sm text-muted-foreground truncate">
                            {conversation.lastMessage}
                          </p>
                          {conversation.unreadCount > 0 && (
                            <Badge variant="default" className="ml-auto">
                              {conversation.unreadCount}
                            </Badge>
                          )}
                        </div>
                      </div>
                    </div>
                  ))}
                </TabsContent>

                <TabsContent value="unread" className="m-0">
                  {filteredConversations
                    .filter((c) => c.unreadCount > 0)
                    .map((conversation) => (
                      <div
                        key={conversation.id}
                        className={`flex items-center gap-3 p-3 cursor-pointer hover:bg-muted/50 ${
                          activeConversation === conversation.id ? "bg-muted" : ""
                        }`}
                        onClick={() => handleConversationClick(conversation.id)}
                      >
                        <Avatar>
                          <AvatarImage src={conversation.avatar} />
                          <AvatarFallback>
                            {conversation.isGroup ? (
                              <Users className="h-4 w-4" />
                            ) : (
                              getInitials(conversation.participant)
                            )}
                          </AvatarFallback>
                        </Avatar>
                        <div className="flex-1 min-w-0">
                          <div className="flex justify-between items-center">
                            <span className="font-medium truncate">
                              {conversation.participant}
                            </span>
                            <span className="text-xs text-muted-foreground">
                              {conversation.timestamp}
                            </span>
                          </div>
                          <div className="flex justify-between items-center mt-1">
                            <p className="text-sm text-muted-foreground truncate">
                              {conversation.lastMessage}
                            </p>
                            <Badge variant="default">
                              {conversation.unreadCount}
                            </Badge>
                          </div>
                        </div>
                      </div>
                    ))}
                </TabsContent>

                <TabsContent value="groups" className="m-0">
                  {filteredConversations
                    .filter((c) => c.isGroup)
                    .map((conversation) => (
                      <div
                        key={conversation.id}
                        className={`flex items-center gap-3 p-3 cursor-pointer hover:bg-muted/50 ${
                          activeConversation === conversation.id ? "bg-muted" : ""
                        }`}
                        onClick={() => handleConversationClick(conversation.id)}
                      >
                        <Avatar>
                          <AvatarImage src={conversation.avatar} />
                          <AvatarFallback>
                            <Users className="h-4 w-4" />
                          </AvatarFallback>
                        </Avatar>
                        <div className="flex-1 min-w-0">
                          <div className="flex justify-between items-center">
                            <span className="font-medium truncate">
                              {conversation.participant}
                            </span>
                            <span className="text-xs text-muted-foreground">
                              {conversation.timestamp}
                            </span>
                          </div>
                          <div className="flex justify-between items-center mt-1">
                            <p className="text-sm text-muted-foreground truncate">
                              {conversation.members?.join(", ")}
                            </p>
                            {conversation.unreadCount > 0 && (
                              <Badge variant="default">
                                {conversation.unreadCount}
                              </Badge>
                            )}
                          </div>
                        </div>
                      </div>
                    ))}
                </TabsContent>
              </ScrollArea>

              <div className="p-3 border-t">
                <Button className="w-full">
                  <Plus className="h-4 w-4 mr-2" />
                  New Message
                </Button>
              </div>
            </Tabs>
          </div>

          {/* Main Content */}
          <div className="flex-1 flex flex-col">
            {currentConversation ? (
              <>
                {/* Chat Header */}
                <div className="p-4 border-b flex items-center justify-between">
                  <div className="flex items-center">
                    <Avatar className="h-10 w-10 mr-3">
                      <AvatarImage src={currentConversation.avatar} />
                      <AvatarFallback>
                        {currentConversation.isGroup ? (
                          <Users className="h-4 w-4" />
                        ) : (
                          getInitials(currentConversation.participant)
                        )}
                      </AvatarFallback>
                    </Avatar>
                    <div>
                      <h2 className="font-semibold flex items-center">
                        {currentConversation.participant}
                        {currentConversation.isOnline && (
                          <span className="ml-2 h-2 w-2 rounded-full bg-green-500"></span>
                        )}
                      </h2>
                      {currentConversation.isGroup && (
                        <p className="text-xs text-muted-foreground">
                          {currentConversation.members?.join(", ")}
                        </p>
                      )}
                    </div>
                  </div>
                  <div className="flex items-center gap-2">
                    <Button variant="ghost" size="icon">
                      <Phone className="h-4 w-4" />
                    </Button>
                    <Button variant="ghost" size="icon">
                      <Video className="h-4 w-4" />
                    </Button>
                    <Button variant="ghost" size="icon">
                      <MoreHorizontal className="h-4 w-4" />
                    </Button>
                  </div>
                </div>

                {/* Messages */}
                <ScrollArea className="flex-1 p-4">
                  <div className="space-y-4">
                    {messages[activeConversation]?.map((message) => (
                      <div
                        key={message.id}
                        className={`flex ${
                          message.isOutgoing ? "justify-end" : "justify-start"
                        }`}
                      >
                        {!message.isOutgoing && (
                          <Avatar className="h-8 w-8 mr-2 mt-1">
                            <AvatarFallback>
                              {getInitials(message.sender)}
                            </AvatarFallback>
                          </Avatar>
                        )}
                        <div
                          className={`max-w-[70%] ${
                            message.isOutgoing
                              ? "bg-primary text-primary-foreground"
                              : "bg-muted"
                          } rounded-lg p-3`}
                        >
                          {!message.isOutgoing && (
                            <p className="text-xs font-medium mb-1">
                              {message.sender}
                            </p>
                          )}
                          <p>{message.content}</p>
                          <p className="text-xs mt-1 opacity-70 text-right">
                            {message.timestamp}
                          </p>
                        </div>
                      </div>
                    ))}
                  </div>
                </ScrollArea>

                {/* Message Input */}
                <div className="p-4 border-t">
                  <div className="flex gap-2">
                    <Button variant="outline" size="icon">
                      <Paperclip className="h-4 w-4" />
                    </Button>
                    <Input
                      placeholder="Type a message..."
                      value={messageInput}
                      onChange={(e) => setMessageInput(e.target.value)}
                      onKeyPress={(e) => {
                        if (e.key === "Enter") handleSendMessage();
                      }}
                    />
                    <Button
                      size="icon"
                      onClick={handleSendMessage}
                      disabled={messageInput.trim() === ""}
                    >
                      <Send className="h-4 w-4" />
                    </Button>
                  </div>
                </div>
              </>
            ) : (
              <div className="flex-1 flex items-center justify-center flex-col p-4">
                <MessageSquare className="h-12 w-12 text-muted-foreground mb-4" />
                <h3 className="text-xl font-semibold mb-2">Your Messages</h3>
                <p className="text-muted-foreground text-center mb-4">
                  Select a conversation or start a new one
                </p>
                <Button>
                  <Plus className="h-4 w-4 mr-2" />
                  New Message
                </Button>
              </div>
            )}
          </div>
        </div>
      </div>
    </Layout>
  );
};

export default Messages;