import { Injectable, Logger, NotFoundException, ConflictException } from '@nestjs/common';
import { InjectModel } from '@nestjs/sequelize';
import { Op } from 'sequelize';
import { UserPushToken } from './models/user-push-token.model';
import { DeviceType } from './enums/device-type.enum';
import { RegisterDeviceTokenDto } from './dto/register-device-token.dto';
import { UpdateDeviceTokenDto } from './dto/update-device-token.dto';

@Injectable()
export class PushTokenService {
  private readonly logger = new Logger(PushTokenService.name);

  constructor(
    @InjectModel(UserPushToken)
    private readonly pushTokenModel: typeof UserPushToken,
  ) { }

  /**
   * 注册设备令牌
   */
  async registerToken(tokenData: RegisterDeviceTokenDto, userId?: string): Promise<UserPushToken> {
    try {
      this.logger.log(`Registering push token for device ${tokenData.deviceToken}`);

      // 检查是否已存在相同的令牌
      const existingToken = await this.pushTokenModel.findOne({
        where: {
          deviceToken: tokenData.deviceToken,
        },
      });

      if (existingToken) {
        // 更新现有令牌信息
        await existingToken.update({
          deviceType: tokenData.deviceType,
          appVersion: tokenData.appVersion,
          osVersion: tokenData.osVersion,
          deviceName: tokenData.deviceName,
          isActive: true,
          lastUsedAt: new Date(),
        });

        this.logger.log(`Updated existing push token for device ${tokenData.deviceToken}`);
        return existingToken;
      }


      // 创建新令牌
      const newToken = await this.pushTokenModel.create({
        userId,
        deviceToken: tokenData.deviceToken,
        deviceType: tokenData.deviceType,
        appVersion: tokenData.appVersion,
        osVersion: tokenData.osVersion,
        deviceName: tokenData.deviceName,
        isActive: true,
        lastUsedAt: new Date(),
      });

      this.logger.log(`Successfully registered new push token for device ${tokenData.deviceToken}`);
      return newToken;
    } catch (error) {
      this.logger.error(`Failed to register push token for device ${tokenData.deviceToken}: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 更新设备令牌
   */
  async updateToken(userId: string, tokenData: UpdateDeviceTokenDto): Promise<UserPushToken> {
    try {
      this.logger.log(`Updating push token for user ${userId}`);

      // 查找当前令牌
      const currentToken = await this.pushTokenModel.findOne({
        where: {
          userId,
          deviceToken: tokenData.currentDeviceToken,
          isActive: true,
        },
      });

      if (!currentToken) {
        throw new NotFoundException('Current device token not found or inactive');
      }

      // 检查新令牌是否已存在
      const existingNewToken = await this.pushTokenModel.findOne({
        where: {
          userId,
          deviceToken: tokenData.newDeviceToken,
        },
      });

      if (existingNewToken) {
        // 如果新令牌已存在，激活它并停用当前令牌
        await existingNewToken.update({
          isActive: true,
          lastUsedAt: new Date(),
          appVersion: tokenData.appVersion || existingNewToken.appVersion,
          osVersion: tokenData.osVersion || existingNewToken.osVersion,
          deviceName: tokenData.deviceName || existingNewToken.deviceName,
        });

        await currentToken.update({
          isActive: false,
        });

        this.logger.log(`Activated existing new token and deactivated old token for user ${userId}`);
        return existingNewToken;
      }

      // 更新当前令牌为新令牌
      await currentToken.update({
        deviceToken: tokenData.newDeviceToken,
        appVersion: tokenData.appVersion,
        osVersion: tokenData.osVersion,
        deviceName: tokenData.deviceName,
        lastUsedAt: new Date(),
      });

      this.logger.log(`Successfully updated push token for user ${userId}`);
      return currentToken;
    } catch (error) {
      this.logger.error(`Failed to update push token for user ${userId}: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 注销设备令牌
   */
  async unregisterToken(userId: string, deviceToken: string): Promise<void> {
    try {
      this.logger.log(`Unregistering push token for user ${userId}`);

      const token = await this.pushTokenModel.findOne({
        where: {
          userId,
          deviceToken,
          isActive: true,
        },
      });

      if (!token) {
        throw new NotFoundException('Device token not found or inactive');
      }

      await token.update({
        isActive: false,
      });

      this.logger.log(`Successfully unregistered push token for user ${userId}`);
    } catch (error) {
      this.logger.error(`Failed to unregister push token for user ${userId}: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 获取用户的所有有效令牌
   */
  async getActiveTokens(userId: string): Promise<UserPushToken[]> {
    try {
      const tokens = await this.pushTokenModel.findAll({
        where: {
          userId,
          isActive: true,
        },
        order: [['lastUsedAt', 'DESC']],
      });

      this.logger.log(`Found ${tokens.length} active tokens for user ${userId}`);
      return tokens;
    } catch (error) {
      this.logger.error(`Failed to get active tokens for user ${userId}: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 获取用户的所有令牌（包括非活跃的）
   */
  async getAllTokens(userId: string): Promise<UserPushToken[]> {
    try {
      const tokens = await this.pushTokenModel.findAll({
        where: {
          userId,
        },
        order: [['createdAt', 'DESC']],
      });

      this.logger.log(`Found ${tokens.length} total tokens for user ${userId}`);
      return tokens;
    } catch (error) {
      this.logger.error(`Failed to get all tokens for user ${userId}: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 验证令牌有效性
   */
  async validateToken(deviceToken: string): Promise<boolean> {
    try {
      const token = await this.pushTokenModel.findOne({
        where: {
          deviceToken,
          isActive: true,
        },
      });

      return !!token;
    } catch (error) {
      this.logger.error(`Failed to validate token: ${error.message}`, error);
      return false;
    }
  }

  /**
   * 清理无效令牌
   */
  async cleanupInvalidTokens(): Promise<number> {
    try {
      this.logger.log('Starting cleanup of invalid tokens');

      // 清理超过30天未使用的令牌
      const thirtyDaysAgo = new Date();
      thirtyDaysAgo.setDate(thirtyDaysAgo.getDate() - 30);

      const result = await this.pushTokenModel.update(
        {
          isActive: false,
        },
        {
          where: {
            isActive: true,
            lastUsedAt: {
              [Op.lt]: thirtyDaysAgo,
            },
          },
        },
      );

      const cleanedCount = result[0];
      this.logger.log(`Cleaned up ${cleanedCount} inactive tokens`);
      return cleanedCount;
    } catch (error) {
      this.logger.error(`Failed to cleanup invalid tokens: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 根据设备令牌获取用户ID
   */
  async getUserIdByDeviceToken(deviceToken: string): Promise<string | null> {
    try {
      const token = await this.pushTokenModel.findOne({
        where: {
          deviceToken,
          isActive: true,
        },
      });

      return token ? token.userId : null;
    } catch (error) {
      this.logger.error(`Failed to get user ID by device token: ${error.message}`, error);
      return null;
    }
  }

  /**
   * 批量获取用户的设备令牌
   */
  async getDeviceTokensByUserIds(userIds: string[]): Promise<Map<string, string[]>> {
    try {
      const tokens = await this.pushTokenModel.findAll({
        where: {
          userId: {
            [Op.in]: userIds,
          },
          isActive: true,
        },
      });

      const userTokensMap = new Map<string, string[]>();

      tokens.forEach((token) => {
        if (!userTokensMap.has(token.userId)) {
          userTokensMap.set(token.userId, []);
        }
        userTokensMap.get(token.userId)!.push(token.deviceToken);
      });

      return userTokensMap;
    } catch (error) {
      this.logger.error(`Failed to get device tokens by user IDs: ${error.message}`, error);
      throw error;
    }
  }

  /**
   * 更新令牌最后使用时间
   */
  async updateLastUsedTime(deviceToken: string): Promise<void> {
    try {
      await this.pushTokenModel.update(
        {
          lastUsedAt: new Date(),
        },
        {
          where: {
            deviceToken,
            isActive: true,
          },
        },
      );
    } catch (error) {
      this.logger.error(`Failed to update last used time: ${error.message}`, error);
    }
  }

  /**
   * 直接停用设备令牌（不需要用户ID）
   */
  async deactivateToken(deviceToken: string): Promise<void> {
    try {
      this.logger.log(`Deactivating push token: ${deviceToken}`);

      const token = await this.pushTokenModel.findOne({
        where: {
          deviceToken,
          isActive: true,
        },
      });

      if (!token) {
        this.logger.warn(`Device token not found or already inactive: ${deviceToken}`);
        return;
      }

      await token.update({
        isActive: false,
      });

      this.logger.log(`Successfully deactivated push token: ${deviceToken}`);
    } catch (error) {
      this.logger.error(`Failed to deactivate push token: ${deviceToken}: ${error.message}`, error);
      throw error;
    }
  }
}