/**
 * 通用高级查询API接口
 * Universal Advanced Query API Endpoint
 */
import type { AdvancedQueryOptions } from '@nuxt4crud/shared'
import { prisma } from '../lib/prisma'
import { createSqlQueryBuilder } from '../lib/sql-query-builder'

/**
 * 通用查询请求体接口
 * Universal query request body interface
 */
interface UniversalQueryRequest {
  table: string
  options: AdvancedQueryOptions
  searchFields?: string[]
  mode?: 'query' | 'aggregate'
}

/**
 * 支持的表名映射（安全检查）
 * Supported table names mapping (security check)
 */
const ALLOWED_TABLES = {
  Post: 'posts', // 支持 Post 表
  User: 'users', // 支持 User 表
  // 可以在这里添加更多允许查询的表
} as const

/**
 * 默认搜索字段配置
 * Default search fields configuration
 */
const DEFAULT_SEARCH_FIELDS: Record<string, string[]> = {
  posts: ['title', 'content'], // Post 表搜索字段
  users: ['name', 'email'], // User 表搜索字段
  // 可以为其他表配置默认搜索字段
}

/**
 * 通用高级查询API处理器
 * Universal advanced query API handler
 */
export default defineEventHandler(async event => {
  try {
    // 只允许POST方法
    assertMethod(event, 'POST')

    // 获取请求体
    const body = (await readBody(event)) as UniversalQueryRequest

    // 验证请求参数
    if (!body.table || !body.options) {
      throw createError({
        statusCode: 400,
        statusMessage: '缺少必要参数: table 和 options',
      })
    }

    // 安全检查：验证表名是否允许
    const tableName = ALLOWED_TABLES[body.table as keyof typeof ALLOWED_TABLES]
    if (!tableName) {
      throw createError({
        statusCode: 400,
        statusMessage: `不允许查询表: ${body.table}`,
      })
    }

    // 创建SQL查询构造器
    const queryBuilder = createSqlQueryBuilder(prisma)

    // 获取表字段信息
    const availableFields = await queryBuilder.getTableFields(tableName)

    // 验证查询选项
    const validationErrors = queryBuilder.validateQueryOptions(body.options, availableFields)
    if (validationErrors.length > 0) {
      throw createError({
        statusCode: 400,
        statusMessage: `查询参数验证失败: ${validationErrors.join(', ')}`,
      })
    }

    // 获取搜索字段
    const searchFields = body.searchFields || DEFAULT_SEARCH_FIELDS[tableName] || []

    // 执行查询
    let result: any

    if (body.mode === 'aggregate') {
      // 执行聚合查询
      result = await queryBuilder.executeAggregateQuery(tableName, body.options)

      return {
        success: true,
        data: {
          table: tableName,
          mode: 'aggregate',
          result,
          options: body.options,
          availableFields,
          searchFields,
        },
        message: '聚合查询执行成功',
      }
    } else {
      // 执行普通查询
      result = await queryBuilder.executeQuery(tableName, body.options, searchFields)

      return {
        success: true,
        data: {
          table: tableName,
          mode: 'query',
          ...result,
          availableFields,
          searchFields,
        },
        message: '查询执行成功',
      }
    }
  } catch (error) {
    console.error('Universal query API error:', error)

    // 如果是已知错误，直接抛出
    if (error && typeof error === 'object' && 'statusCode' in error) {
      throw error
    }

    // 处理未知错误
    throw createError({
      statusCode: 500,
      statusMessage: `查询执行失败: ${error instanceof Error ? error.message : '未知错误'}`,
    })
  }
})