import "dotenv/config";
import { SignalClient } from "./signal-crypto.js";
import { v4 as uuidv4 } from "uuid";

export class EncryptedTodoService {
  constructor() {
    // In-memory storage using Maps
    this.users = new Map(); // userId -> SignalClient
    this.userIds = new Set(); // Set of all user IDs
    this.todos = new Map(); // todoId -> todo object
    this.todoGroups = new Map(); // todoGroupId -> group info
    this.todoParticipants = new Map(); // todoGroupId -> Set of userIds
    this.userTodos = new Map(); // userId -> Set of todoGroupIds

    console.log("Initialized in-memory encrypted todo service");
  }

  async createUser(userId) {
    this.userIds.add(userId);
    if (!this.users.has(userId)) {
      this.users.set(userId, SignalClient.create(userId));
      this.userTodos.set(userId, new Set());
    }
    return { userId };
  }

  async getAllUsers() {
    return Array.from(this.userIds);
  }

  async addTodo(userId, todoText) {
    const todoGroupId = uuidv4();
    const client = this.users.get(userId);
    const todoId = uuidv4();
    const encryptedTodo = client.encrypt(todoText);
    const now = new Date().toISOString();

    // Create the todo group
    this.todoGroups.set(todoGroupId, {
      todoGroupId,
      createdBy: userId,
      createdAt: now,
    });

    // Add the creator as a participant
    this.todoParticipants.set(todoGroupId, new Set([userId]));

    // Create the todo entry for the creator
    const todoKey = `${todoGroupId}_${userId}`;
    this.todos.set(todoKey, {
      id: todoId,
      todoGroupId,
      userId,
      encrypted: encryptedTodo,
      createdAt: now,
      originalText: todoText,
      completed: false,
    });

    // Add to user's todo list
    this.userTodos.get(userId).add(todoGroupId);

    return todoGroupId;
  }

  async getTodos(userId) {
    const client = this.users.get(userId);
    if (!client) {
      console.error(`No client found for user ${userId}`);
      return [];
    }

    const userTodoGroups = this.userTodos.get(userId) || new Set();
    const todos = [];

    for (const todoGroupId of userTodoGroups) {
      try {
        const todoKey = `${todoGroupId}_${userId}`;
        const todoData = this.todos.get(todoKey);

        if (!todoData) {
          console.warn(`Todo data not found for ${todoKey}`);
          continue;
        }

        const decryptedText = client.decrypt(todoData.encrypted);
        const groupInfo = this.todoGroups.get(todoGroupId);
        const participants = Array.from(
          this.todoParticipants.get(todoGroupId) || new Set(),
        );

        todos.push({
          id: todoGroupId, // Use todoGroupId as the primary identifier
          text: decryptedText,
          createdAt: todoData.createdAt,
          completed: todoData.completed,
          participants,
          createdBy: groupInfo?.createdBy || userId,
          isCreator: (groupInfo?.createdBy || userId) === userId,
        });
      } catch (e) {
        console.error(`Error processing todo ${todoGroupId}:`, e);
      }
    }

    return todos.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
  }

  async getTodo(userId, todoGroupId) {
    const client = this.users.get(userId);
    const todoKey = `${todoGroupId}_${userId}`;
    const todoData = this.todos.get(todoKey);

    if (!todoData) throw new Error("Todo not found");

    const decryptedText = client.decrypt(todoData.encrypted);
    const groupInfo = this.todoGroups.get(todoGroupId);
    const participants = Array.from(
      this.todoParticipants.get(todoGroupId) || new Set(),
    );

    return {
      id: todoGroupId,
      text: decryptedText,
      createdAt: todoData.createdAt,
      completed: todoData.completed,
      participants,
      createdBy: groupInfo?.createdBy,
      isCreator: groupInfo?.createdBy === userId,
    };
  }

  async updateTodoStatus(userId, todoGroupId, completed) {
    console.log(
      `updateTodoStatus called: userId=${userId}, todoGroupId=${todoGroupId}, completed=${completed}`,
    );

    const participants = this.todoParticipants.get(todoGroupId);

    if (!participants || !participants.has(userId)) {
      throw new Error("User is not a participant in this todo group");
    }

    const participantIds = Array.from(participants);
    console.log(`Updating todo for all participants:`, participantIds);

    // Update todos for all participants
    for (const participantId of participantIds) {
      const todoKey = `${todoGroupId}_${participantId}`;
      const todoData = this.todos.get(todoKey);
      if (todoData) {
        todoData.completed = completed;
        this.todos.set(todoKey, todoData);
      }
    }

    console.log(`Affected users for todo update:`, participantIds);
    return participantIds;
  }

  async deleteTodo(userId, todoGroupId) {
    const participants = this.todoParticipants.get(todoGroupId);

    if (!participants || !participants.has(userId)) {
      throw new Error("User is not a participant in this todo group");
    }

    const groupInfo = this.todoGroups.get(todoGroupId);

    if (!groupInfo) {
      throw new Error("Todo group not found");
    }

    if (groupInfo.createdBy !== userId) {
      throw new Error("Only the creator can delete this todo");
    }

    const participantIds = Array.from(participants);
    console.log(
      `Deleting todo group ${todoGroupId} for all participants:`,
      participantIds,
    );

    // Delete all todo entries for this group
    for (const participantId of participantIds) {
      const todoKey = `${todoGroupId}_${participantId}`;
      this.todos.delete(todoKey);

      // Remove from user's todo list
      const userTodoSet = this.userTodos.get(participantId);
      if (userTodoSet) {
        userTodoSet.delete(todoGroupId);
      }
    }

    // Delete participants and group
    this.todoParticipants.delete(todoGroupId);
    this.todoGroups.delete(todoGroupId);

    return {
      deletedIds: [todoGroupId],
      affectedUsers: participantIds,
    };
  }

  async shareTodo(userId, todoGroupId, recipientId) {
    // Ensure recipient user exists
    if (!this.users.has(recipientId)) {
      this.users.set(recipientId, SignalClient.create(recipientId));
      this.userTodos.set(recipientId, new Set());
      this.userIds.add(recipientId);
    }

    const participants = this.todoParticipants.get(todoGroupId);

    if (!participants || !participants.has(userId)) {
      throw new Error("User is not a participant in this todo group");
    }

    const groupInfo = this.todoGroups.get(todoGroupId);

    if (!groupInfo) {
      throw new Error("Todo group not found");
    }

    if (groupInfo.createdBy !== userId) {
      throw new Error("Only the creator can add participants to this todo");
    }

    if (participants.has(recipientId)) {
      throw new Error("User is already a participant in this todo group");
    }

    // Get the original text from the sender's todo
    const senderTodoKey = `${todoGroupId}_${userId}`;
    const senderTodoData = this.todos.get(senderTodoKey);

    if (!senderTodoData) throw new Error("Todo not found");

    const recipientClient = this.users.get(recipientId);
    const encryptedForRecipient = recipientClient.encrypt(
      senderTodoData.originalText,
    );
    const recipientTodoId = uuidv4();
    const now = new Date().toISOString();

    // Add recipient as a participant
    participants.add(recipientId);
    this.todoParticipants.set(todoGroupId, participants);

    // Create todo entry for the recipient
    const recipientTodoKey = `${todoGroupId}_${recipientId}`;
    this.todos.set(recipientTodoKey, {
      id: recipientTodoId,
      todoGroupId,
      userId: recipientId,
      encrypted: encryptedForRecipient,
      createdAt: now,
      originalText: senderTodoData.originalText,
      completed: senderTodoData.completed,
    });

    // Add to recipient's todo list
    this.userTodos.get(recipientId).add(todoGroupId);

    return todoGroupId;
  }
}