"use client";

import { ChatData, ChatState, Conversation, Message, ResearchOptions, ResearchResults, ResearchTree, StatusUpdate } from "@/lib/types";
import { ReactNode, createContext, useCallback, useContext, useEffect, useRef, useState } from "react";
import { v4 as uuidv4 } from "uuid";
import { disconnectSocket, getSocket, initializeSocket, initializeSse, closeSse } from "@/lib/socket";

// Utility functions for local storage
const saveToStorage = (data: ChatData) => {
  if (typeof window !== "undefined") {
    localStorage.setItem("chatData", JSON.stringify(data));
  }
};

const loadFromStorage = (): ChatData => {
  if (typeof window === "undefined") {
    return { conversations: [], currentConversationId: null };
  }
  const data = localStorage.getItem("chatData");
  if (!data) {
    return { conversations: [], currentConversationId: null };
  }
  try {
    const parsed = JSON.parse(data);
    return {
      conversations: Array.isArray(parsed.conversations)
        ? parsed.conversations.map((conv: Conversation) => ({
            ...conv,
            messages: Array.isArray(conv.messages)
              ? conv.messages.map((msg: Message) => ({
                  ...msg,
                  // Ensure media property is preserved if it exists
                  media: msg.media || undefined,
                }))
              : [],
          }))
        : [],
      currentConversationId: parsed.currentConversationId,
    };
  } catch (e) {
    return { conversations: [], currentConversationId: null };
  }
};

// Define the context type
interface ChatContextType {
  // State
  chatState: ChatState;
  conversations: Conversation[];
  currentConversationId: string | null;
  researchOptions: ResearchOptions;
  userInputRef: React.RefObject<HTMLTextAreaElement>;
  connectionMode: "agent" | "workflow";

  // Actions
  setResearchOptions: (options: ResearchOptions) => void;
  sendMessage: (content: string) => void;
  newConversation: () => void;
  selectConversation: (id: string) => void;
  deleteConversation: (id: string) => void;
  deleteAllConversations: () => void;
  abortResearch: () => void; // New function to abort research
  setConnectionMode: (mode: "agent" | "workflow") => void;
}

// Create the context with a default value
const ChatContext = createContext<ChatContextType | undefined>(undefined);

// Provider component
export const ChatProvider = ({ children }: { children: ReactNode }) => {
  const [chatState, setChatState] = useState<ChatState>({ messages: [], isLoading: false, error: null });
  const [conversations, setConversations] = useState<Conversation[]>([]);
  const [currentConversationId, setCurrentConversationId] = useState<string | null>(null);
  const [connectionMode, setConnectionMode] = useState<"agent" | "workflow">("agent");
  const [researchOptions, setResearchOptions] = useState<ResearchOptions>({
    depth: "basic",
    sources: true,
    citations: false,
    max_depth: 1,
    num_sites_per_query: 3,
    create_report: false,
  });

  const userInputRef = useRef<HTMLTextAreaElement>(null);

  // Focus management
  useEffect(() => {
    const focusInput = () => {
      setTimeout(() => {
        userInputRef.current?.focus();
      }, 100);
    };

    focusInput();
  }, [currentConversationId]);

  // Load initial data
  useEffect(() => {
    const data = loadFromStorage();
    setConversations(data.conversations);
    setCurrentConversationId(data.currentConversationId);

    if (data.currentConversationId) {
      const conversation = data.conversations.find((c) => c.id === data.currentConversationId);
      if (conversation) {
        // Check if any loaded message has isProgress true
        let messages = conversation.messages;
        if (messages.some((msg) => msg.isProgress === true)) {
          // Convert any progress messages to error messages
          messages = messages.map((msg) => (msg.isProgress === true ? { ...msg, content: "Connection error", isProgress: false } : msg));
        }

        setChatState((prev) => ({ ...prev, messages, isLoading: false }));
      }
    }
  }, []);

  // Socket initialization - REMOVED as we are using HTTP/SSE for both modes
  // useEffect(() => {
  //   if (connectionMode === "workflow") {
  //     const socket = initializeSocket();

  //     socket.on("connect", () => {
  //       console.log("Connected to research server");
  //     });

  //     socket.on("disconnect", () => {
  //       console.log("Disconnected from research server");

  //       // When socket disconnects, update any progress messages to show connection error
  //       setChatState((prevState) => {
  //         const updatedMessages = prevState.messages.map((msg) => (msg.isProgress === true ? { ...msg, content: "Connection error", isProgress: false } : msg));

  //         return {
  //           ...prevState,
  //           messages: updatedMessages,
  //           isLoading: false,
  //           error: "Lost connection to research server",
  //         };
  //       });
  //     });

  //     socket.on("status", (data: StatusUpdate) => {
  //       setChatState((prevState) => {
  //         const messages = [...prevState.messages];
  //         const progressText = data.message;
  //         const progress = data.progress;

  //         // Find the last assistant message that is a progress update
  //         const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

  //         if (lastProgressIndex !== -1) {
  //           // Update existing progress message with research_tree data
  //           messages[lastProgressIndex] = {
  //             ...messages[lastProgressIndex],
  //             content: progressText,
  //             progress: progress,
  //             timestamp: new Date(),
  //             research_tree: data.research_tree, // Update the research_tree in real-time
  //           };
  //         } else {
  //           // Add new progress message with research_tree
  //           messages.push({
  //             id: uuidv4(),
  //             content: progressText,
  //             role: "assistant",
  //             timestamp: new Date(),
  //             progress: progress,
  //             isProgress: true,
  //             research_tree: data.research_tree, // Include the research_tree
  //             media: {}, // Initialize empty media object
  //           });
  //         }

  //         return {
  //           ...prevState,
  //           messages,
  //           isLoading: true,
  //         };
  //       });
  //     });

  //     socket.on("research_complete", (results: ResearchResults) => {
  //       setChatState((prevState) => {
  //         const messages = [...prevState.messages];

  //         // Remove the last progress message if it exists
  //         const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

  //         if (lastProgressIndex !== -1) {
  //           messages.splice(lastProgressIndex, 1);
  //         }

  //         const newMessages = [
  //           ...messages,
  //           {
  //             id: uuidv4(),
  //             content: results.content || "Error: No content available",
  //             role: "assistant" as const,
  //             timestamp: new Date(results.timestamp),
  //             media: results.media,
  //             research_tree: results.research_tree,
  //           },
  //         ];

  //         // Save updated messages to localStorage
  //         const updatedState = {
  //           ...prevState,
  //           isLoading: false,
  //           messages: newMessages,
  //         };

  //         // Update localStorage with the new messages
  //         const updatedData: ChatData = {
  //           conversations: conversations.map((conv) => ({
  //             ...conv,
  //             messages: conv.id === currentConversationId ? newMessages : conv.messages || [],
  //             lastUpdated: conv.id === currentConversationId ? new Date().toISOString() : conv.lastUpdated,
  //           })),
  //           currentConversationId,
  //         };

  //         saveToStorage(updatedData);

  //         return updatedState;
  //       });
  //     });

  //     socket.on("research_aborted", () => {
  //       setChatState((prevState) => {
  //         const messages = [...prevState.messages];
  //         const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

  //         if (lastProgressIndex !== -1) {
  //           messages.splice(lastProgressIndex, 1);
  //         }

  //         // Add a message indicating the research was canceled
  //         messages.push({
  //           id: uuidv4(),
  //           content: "Research has been canceled.",
  //           role: "assistant",
  //           timestamp: new Date(),
  //         });

  //         return {
  //           ...prevState,
  //           isLoading: false,
  //           messages,
  //         };
  //       });
  //     });

  //     socket.on("error", (error: { message: string }) => {
  //       setChatState((prevState) => ({
  //         ...prevState,
  //         error: error.message,
  //         isLoading: false,
  //       }));
  //     });

  //     return () => {
  //       disconnectSocket();
  //     };
  //   }
  // }, [connectionMode]);

  // Save data whenever conversations or messages change
  useEffect(() => {
    const data: ChatData = {
      conversations: conversations.map((conv) => ({
        ...conv,
        messages: conv.id === currentConversationId ? chatState.messages : conv.messages || [],
      })),
      currentConversationId,
    };

    saveToStorage(data);
  }, [conversations, currentConversationId, chatState.messages]);

  // Action handlers
  const sendMessage = useCallback(
    async (content: string) => {
      if (!content.trim()) return;

      let conversationId = currentConversationId;
      const newMessage: Message = {
        id: uuidv4(),
        content,
        role: "user",
        timestamp: new Date(),
      };
      const newLoadingMessage: Message = {
        id: uuidv4(),
        content: "Loading...",
        role: "assistant",
        timestamp: new Date(),
        isProgress: true,
      };

      // Create a new conversation if none exists
      if (!conversationId) {
        conversationId = uuidv4();
        setCurrentConversationId(conversationId);
        setConversations((prev) => [
          {
            id: conversationId as string,
            title: content.length > 30 ? `${content.substring(0, 30)}...` : content,
            lastUpdated: new Date().toISOString(),
            messages: [newMessage],
            active: true,
          },
          ...prev.map((c) => ({ ...c, active: false })),
        ]);
      } else {
        // Update the existing conversation
        setConversations((prev) =>
          prev.map((conv) => ({
            ...conv,
            lastUpdated: conv.id === conversationId ? new Date().toISOString() : conv.lastUpdated,
            active: conv.id === conversationId,
            messages: conv.id === conversationId ? [...(conv.messages || []), newMessage] : conv.messages || [],
          }))
        );
      }

      // Add loading message immediately for workflow mode
      const messagesToAdd = connectionMode === "workflow" ? [newMessage, newLoadingMessage] : [newMessage];

      setChatState((prevState) => ({
        ...prevState,
        messages: [...prevState.messages, ...messagesToAdd],
        isLoading: true,
        error: null,
      }));

      try {
        const sseUrl = process.env.NEXT_PUBLIC_LANGGRAPH_BACKEND || "http://127.0.0.1:5000";
        const endpoint = connectionMode === "agent" ? "/chat" : "/start_research";
        const body =
          connectionMode === "agent"
            ? {
                message: content,
                thread_id: currentConversationId,
                create_report: researchOptions.create_report,
              }
            : {
                topic: content,
                max_depth: researchOptions.max_depth,
                num_sites_per_query: researchOptions.num_sites_per_query,
                session_id: currentConversationId,
              };

        const response = await fetch(`${sseUrl}${endpoint}`, {
          method: "POST",
          headers: {
            "Content-Type": "application/json",
          },
          body: JSON.stringify(body),
        });

        if (!response.body) {
          return;
        }

        const reader = response.body.getReader();
        const decoder = new TextDecoder();

        let done = false;
        while (!done) {
          const { value, done: readerDone } = await reader.read();
          done = readerDone;
          const chunk = decoder.decode(value, { stream: true });
          const lines = chunk.split("\n\n");

          for (const line of lines) {
            if (line.startsWith("data: ")) {
              const jsonStr = line.substring(6);
              if (jsonStr) {
                try {
                  const data = JSON.parse(jsonStr);
                  if (data.event === "progress") {
                    setChatState((prevState) => {
                      const messages = [...prevState.messages];

                      if (connectionMode === "agent") {
                        const eventData = data.data[0]; // Assuming data.data is an array with one element

                        if (eventData.type === "ai_msg" || eventData.type === "ai_msg_report") {
                          messages.push({
                            id: uuidv4(),
                            content: eventData.content,
                            role: "assistant",
                            timestamp: new Date(),
                            tool_calls: eventData.tool_calls, // Store tool calls
                          });
                        } else if (eventData.type === "tool_resp") {
                          // Do not display tool responses directly in chat
                          return prevState;
                        }
                      } else {
                        // Workflow mode progress
                        const eventData = data.data;
                        const progress = eventData.progress;
                        const progressText = eventData.message;

                        // Find the last progress message
                        const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

                        if (lastProgressIndex !== -1) {
                          // Update existing progress message with research_tree data
                          messages[lastProgressIndex] = {
                            ...messages[lastProgressIndex],
                            content: progressText,
                            progress: progress,
                            timestamp: new Date(),
                            research_tree: eventData.research_tree, // Update the research_tree in real-time
                          };
                        } else {
                          // Add new progress message with research_tree
                          messages.push({
                            id: uuidv4(),
                            content: progressText,
                            role: "assistant",
                            timestamp: new Date(),
                            progress: progress,
                            isProgress: true,
                            research_tree: eventData.research_tree, // Include the research_tree
                            media: {}, // Initialize empty media object
                          });
                        }
                      }

                      return {
                        ...prevState,
                        messages,
                        isLoading: true, // Keep loading until stream ends
                      };
                    });
                  } else if (data.event === "result") {
                    setChatState((prevState) => {
                      const messages = [...prevState.messages];

                      // Remove the last progress message if it exists
                      const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

                      if (lastProgressIndex !== -1) {
                        messages.splice(lastProgressIndex, 1);
                      }

                      const resultData = connectionMode === "agent" ? data.data : data.data; // Both seem to be object in result event?
                      // Wait, agent mode result handling was:
                      // content: data.data.content || "Error: No content available",
                      // media: data.data.media,
                      // research_tree: data.data.research_tree,
                      //
                      // Workflow mode result handling was:
                      // content: results.content || "Error: No content available",
                      // media: results.media,
                      // research_tree: results.research_tree,
                      //
                      // They look compatible.

                      const newMessages = [
                        ...messages,
                        {
                          id: uuidv4(),
                          content: resultData.content || "Error: No content available",
                          role: "assistant" as const,
                          timestamp: new Date(resultData.timestamp || new Date()),
                          media: resultData.media,
                          research_tree: resultData.research_tree,
                        },
                      ];

                      // Save updated messages to localStorage
                      const updatedState = {
                        ...prevState,
                        isLoading: false,
                        messages: newMessages,
                      };

                      // Update localStorage with the new messages
                      const updatedData: ChatData = {
                        conversations: conversations.map((conv) => ({
                          ...conv,
                          messages: conv.id === currentConversationId ? newMessages : conv.messages || [],
                          lastUpdated: conv.id === currentConversationId ? new Date().toISOString() : conv.lastUpdated,
                        })),
                        currentConversationId,
                      };

                      saveToStorage(updatedData);

                      return updatedState;
                    });
                  }
                } catch (e) {
                  console.error("Failed to parse SSE data", e);
                }
              }
            }
          }
        }
      } catch (error) {
        setChatState((prevState) => ({
          ...prevState,
          error: "Failed to connect to server",
          isLoading: false,
        }));
      }
    },
    [currentConversationId, conversations, researchOptions, connectionMode]
  );

  const newConversation = useCallback(() => {
    userInputRef.current?.focus();
    setCurrentConversationId(null);
    setChatState(() => ({
      messages: [],
      isLoading: false,
      error: null,
    }));
  }, []);

  const selectConversation = useCallback((id: string) => {
    const data = loadFromStorage();
    const conversation = data.conversations.find((c) => c.id === id);

    setCurrentConversationId(id);
    setChatState((prev) => ({
      ...prev,
      messages: conversation?.messages || [],
      isLoading: false,
      error: null,
    }));
    setConversations((prev) =>
      prev.map((conv) => ({
        ...conv,
        active: conv.id === id,
      }))
    );
  }, []);

  const deleteConversation = useCallback(
    (id: string) => {
      setConversations((prev) => prev.filter((conv) => conv.id !== id));
      if (currentConversationId === id) {
        newConversation();
      }
    },
    [currentConversationId, newConversation]
  );

  const deleteAllConversations = useCallback(() => {
    setConversations([]);
    newConversation();
  }, [newConversation]);

  const abortResearch = useCallback(async () => {
    try {
      const sseUrl = process.env.NEXT_PUBLIC_LANGGRAPH_BACKEND || "http://127.0.0.1:5000";
      await fetch(`${sseUrl}/abort_research`, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({ session_id: currentConversationId }),
      });

      setChatState((prevState) => {
        const messages = [...prevState.messages];
        const lastProgressIndex = messages.findLastIndex((msg) => msg.role === "assistant" && msg.isProgress === true);

        if (lastProgressIndex !== -1) {
          messages.splice(lastProgressIndex, 1);
        }

        // Add a message indicating the research was canceled
        messages.push({
          id: uuidv4(),
          content: "Research has been canceled.",
          role: "assistant",
          timestamp: new Date(),
        });

        return {
          ...prevState,
          isLoading: false,
          messages,
        };
      });
    } catch (error) {
      console.error("Failed to abort research:", error);
      setChatState((prevState) => ({
        ...prevState,
        error: "Failed to abort research",
      }));
    }
  }, [currentConversationId]);

  // Keyboard shortcuts | Ctrl + I to new chat
  useEffect(() => {
    const handleKeyDown = (event: KeyboardEvent) => {
      if (event.ctrlKey && event.key === "i") {
        event.preventDefault();
        newConversation();
      }
    };

    window.addEventListener("keydown", handleKeyDown);
    return () => {
      window.removeEventListener("keydown", handleKeyDown);
    };
  }, []);

  const value = {
    chatState,
    conversations,
    currentConversationId,
    researchOptions,
    userInputRef,
    connectionMode,
    setResearchOptions,
    sendMessage,
    newConversation,
    selectConversation,
    deleteConversation,
    deleteAllConversations,
    abortResearch,
    setConnectionMode,
  };

  return <ChatContext.Provider value={value}>{children}</ChatContext.Provider>;
};

// Custom hook for using the chat context
export const useChatContext = () => {
  const context = useContext(ChatContext);
  if (context === undefined) {
    throw new Error("useChatContext must be used within a ChatProvider");
  }
  return context;
};