import type { FastifyRequest, FastifyReply } from 'fastify';
import * as knowledgeBaseService from '../services/knowledgeBaseService.js';

/**
 * 获取用户ID（从JWT Token中获取）
 */
function getUserId(request: FastifyRequest): string {
  const userId = (request as any).user?.userId;
  if (!userId) {
    throw new Error('User not authenticated');
  }
  return userId;
}

/**
 * 创建知识库
 */
export async function createKnowledgeBase(
  request: FastifyRequest<{
    Body: {
      name: string;
      description?: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { name, description } = request.body;

    if (!name || name.trim().length === 0) {
      return reply.status(400).send({
        success: false,
        message: 'Knowledge base name is required',
      });
    }

    const userId = getUserId(request);
    const knowledgeBase = await knowledgeBaseService.createKnowledgeBase(
      userId,
      name,
      description
    );

    return reply.status(201).send({
      success: true,
      data: knowledgeBase,
    });
  } catch (error: any) {
    console.error('Failed to create knowledge base:', error);
    
    // 处理配额超限错误
    if (error.code === 'QUOTA_EXCEEDED') {
      return reply.status(400).send({
        success: false,
        code: 'QUOTA_EXCEEDED',
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || '创建知识库失败，请稍后重试',
    });
  }
}

/**
 * 获取知识库列表
 */
export async function getKnowledgeBases(
  request: FastifyRequest,
  reply: FastifyReply
) {
  try {
    const userId = getUserId(request);
    const knowledgeBases = await knowledgeBaseService.getKnowledgeBases(
      userId
    );

    return reply.send({
      success: true,
      data: knowledgeBases,
    });
  } catch (error: any) {
    console.error('Failed to get knowledge bases:', error);
    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to get knowledge bases',
    });
  }
}

/**
 * 获取知识库详情
 */
export async function getKnowledgeBaseById(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;

    const userId = getUserId(request);
    const knowledgeBase = await knowledgeBaseService.getKnowledgeBaseById(
      userId,
      id
    );

    return reply.send({
      success: true,
      data: knowledgeBase,
    });
  } catch (error: any) {
    console.error('Failed to get knowledge base:', error);
    
    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to get knowledge base',
    });
  }
}

/**
 * 更新知识库
 */
export async function updateKnowledgeBase(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
    Body: {
      name?: string;
      description?: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;
    const updateData = request.body;

    const userId = getUserId(request);
    const knowledgeBase = await knowledgeBaseService.updateKnowledgeBase(
      userId,
      id,
      updateData
    );

    return reply.send({
      success: true,
      data: knowledgeBase,
    });
  } catch (error: any) {
    console.error('Failed to update knowledge base:', error);

    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to update knowledge base',
    });
  }
}

/**
 * 删除知识库
 */
export async function deleteKnowledgeBase(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;

    const userId = getUserId(request);
    await knowledgeBaseService.deleteKnowledgeBase(userId, id);

    return reply.send({
      success: true,
      message: 'Knowledge base deleted successfully',
    });
  } catch (error: any) {
    console.error('Failed to delete knowledge base:', error);

    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to delete knowledge base',
    });
  }
}

/**
 * 检索知识库
 */
export async function searchKnowledgeBase(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
    Querystring: {
      query: string;
      top_k?: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;
    const { query, top_k } = request.query;

    if (!query || query.trim().length === 0) {
      return reply.status(400).send({
        success: false,
        message: 'Query parameter is required',
      });
    }

    const topK = top_k ? parseInt(top_k, 10) : 15;  // Phase 1优化：默认从3增加到15

    const userId = getUserId(request);
    const results = await knowledgeBaseService.searchKnowledgeBase(
      userId,
      id,
      query,
      topK
    );

    return reply.send({
      success: true,
      data: results,
    });
  } catch (error: any) {
    console.error('Failed to search knowledge base:', error);

    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to search knowledge base',
    });
  }
}

/**
 * 获取知识库统计信息
 */
export async function getKnowledgeBaseStats(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;

    const userId = getUserId(request);
    const stats = await knowledgeBaseService.getKnowledgeBaseStats(
      userId,
      id
    );

    return reply.send({
      success: true,
      data: stats,
    });
  } catch (error: any) {
    console.error('Failed to get knowledge base stats:', error);

    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to get knowledge base stats',
    });
  }
}

/**
 * 获取知识库文档选择（Phase 2: 全文阅读模式）
 */
export async function getDocumentSelection(
  request: FastifyRequest<{
    Params: {
      id: string;
    };
    Querystring: {
      max_files?: string;
      max_tokens?: string;
    };
  }>,
  reply: FastifyReply
) {
  try {
    const { id } = request.params;
    const { max_files, max_tokens } = request.query;

    const maxFiles = max_files ? parseInt(max_files, 10) : undefined;
    const maxTokens = max_tokens ? parseInt(max_tokens, 10) : undefined;

    const userId = getUserId(request);
    const selection = await knowledgeBaseService.getDocumentSelection(
      userId,
      id,
      maxFiles,
      maxTokens
    );

    return reply.send({
      success: true,
      data: selection,
    });
  } catch (error: any) {
    console.error('Failed to get document selection:', error);

    if (error.message.includes('not found')) {
      return reply.status(404).send({
        success: false,
        message: error.message,
      });
    }

    return reply.status(500).send({
      success: false,
      message: error.message || 'Failed to get document selection',
    });
  }
}