import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { TokenUsageORM } from '../../../infrastructure/database/postgres/entities/token-usage.orm';
import { ITokenUsageRepository } from '../../../domain/repositories/token-usage.repository.interface';
import { TokenUsageEntity } from '../../../domain/entities/token-usage.entity';

@Injectable()
export class TokenUsagePostgresRepository implements ITokenUsageRepository {
  constructor(
    @InjectRepository(TokenUsageORM)
    private readonly repo: Repository<TokenUsageORM>,
  ) {}

  async save(tokenUsage: TokenUsageEntity): Promise<TokenUsageEntity> {
    const orm = this.toORM(tokenUsage);
    const saved = await this.repo.save(orm);
    return this.toEntity(saved);
  }

  async findByConversationId(conversationId: string): Promise<TokenUsageEntity[]> {
    const orms = await this.repo.find({
      where: { conversationId },
      order: { createdAt: 'ASC' },
    });
    return orms.map((orm) => this.toEntity(orm));
  }

  async findByUserId(userId: string, options?: { limit?: number }): Promise<TokenUsageEntity[]> {
    const queryBuilder = this.repo
      .createQueryBuilder('token_usage')
      .where('token_usage.user_id = :userId', { userId })
      .orderBy('token_usage.created_at', 'DESC');

    if (options?.limit) {
      queryBuilder.limit(options.limit);
    }

    const orms = await queryBuilder.getMany();
    return orms.map((orm) => this.toEntity(orm));
  }

  async sumByConversationId(conversationId: string): Promise<{
    totalInputTokens: number;
    totalOutputTokens: number;
    totalCost: number;
  }> {
    const result = await this.repo
      .createQueryBuilder('token_usage')
      .select('SUM(token_usage.input_tokens)', 'totalInputTokens')
      .addSelect('SUM(token_usage.output_tokens)', 'totalOutputTokens')
      .addSelect('SUM(token_usage.estimated_cost)', 'totalCost')
      .where('token_usage.conversation_id = :conversationId', { conversationId })
      .getRawOne();

    return {
      totalInputTokens: parseInt(result?.totalInputTokens || '0', 10),
      totalOutputTokens: parseInt(result?.totalOutputTokens || '0', 10),
      totalCost: parseFloat(result?.totalCost || '0'),
    };
  }

  async sumByUserId(userId: string): Promise<{
    totalInputTokens: number;
    totalOutputTokens: number;
    totalCost: number;
  }> {
    const result = await this.repo
      .createQueryBuilder('token_usage')
      .select('SUM(token_usage.input_tokens)', 'totalInputTokens')
      .addSelect('SUM(token_usage.output_tokens)', 'totalOutputTokens')
      .addSelect('SUM(token_usage.estimated_cost)', 'totalCost')
      .where('token_usage.user_id = :userId', { userId })
      .getRawOne();

    return {
      totalInputTokens: parseInt(result?.totalInputTokens || '0', 10),
      totalOutputTokens: parseInt(result?.totalOutputTokens || '0', 10),
      totalCost: parseFloat(result?.totalCost || '0'),
    };
  }

  private toORM(entity: TokenUsageEntity): TokenUsageORM {
    const orm = new TokenUsageORM();
    orm.id = entity.id;
    orm.userId = entity.userId;
    orm.conversationId = entity.conversationId;
    orm.messageId = entity.messageId;
    orm.model = entity.model;
    orm.inputTokens = entity.inputTokens;
    orm.outputTokens = entity.outputTokens;
    orm.cacheCreationTokens = entity.cacheCreationTokens;
    orm.cacheReadTokens = entity.cacheReadTokens;
    orm.totalTokens = entity.totalTokens;
    orm.estimatedCost = entity.estimatedCost;
    orm.intentType = entity.intentType;
    orm.toolCalls = entity.toolCalls;
    orm.responseLength = entity.responseLength;
    orm.latencyMs = entity.latencyMs;
    orm.createdAt = entity.createdAt;
    return orm;
  }

  private toEntity(orm: TokenUsageORM): TokenUsageEntity {
    return TokenUsageEntity.fromPersistence({
      id: orm.id,
      userId: orm.userId,
      conversationId: orm.conversationId,
      messageId: orm.messageId,
      model: orm.model,
      inputTokens: orm.inputTokens,
      outputTokens: orm.outputTokens,
      cacheCreationTokens: orm.cacheCreationTokens,
      cacheReadTokens: orm.cacheReadTokens,
      totalTokens: orm.totalTokens,
      estimatedCost: Number(orm.estimatedCost),
      intentType: orm.intentType,
      toolCalls: orm.toolCalls,
      responseLength: orm.responseLength,
      latencyMs: orm.latencyMs,
      createdAt: orm.createdAt,
    });
  }
}