/**
 * 表信息API接口
 * Table Information API Endpoint
 */
import { createSqlQueryBuilder } from '../lib/sql-query-builder'
import { prisma } from '../lib/prisma'

/**
 * 支持的表名映射
 * Supported table names mapping
 */
const ALLOWED_TABLES = {
  Post: 'posts'  // 支持Post表
} as const

/**
 * 字段类型映射
 * Field type mapping
 */
const FIELD_TYPES: Record<string, Record<string, string>> = {
  posts: {
    id: 'number',
    title: 'string',
    content: 'string',
    published: 'boolean',
    createdAt: 'datetime',
    updatedAt: 'datetime',
  },
}

/**
 * 默认搜索字段配置
 * Default search fields configuration
 */
const DEFAULT_SEARCH_FIELDS: Record<string, string[]> = {
  posts: ['title', 'content'], // posts表搜索字段
}

/**
 * 默认排序字段配置
 * Default sortable fields configuration
 */
const DEFAULT_SORTABLE_FIELDS: Record<string, string[]> = {
  posts: ['id', 'title', 'content', 'published', 'createdAt', 'updatedAt'], // posts表排序字段
}

/**
 * 表信息API处理器
 * Table information API handler
 */
export default defineEventHandler(async event => {
  try {
    // 获取查询参数
    const query = getQuery(event)
    const tableName = query.table as string

    // 如果没有指定表名，返回所有支持的表
    if (!tableName) {
      const supportedTables = Object.keys(ALLOWED_TABLES).map(key => ({
        key,
        name: ALLOWED_TABLES[key as keyof typeof ALLOWED_TABLES],
        searchFields:
          DEFAULT_SEARCH_FIELDS[ALLOWED_TABLES[key as keyof typeof ALLOWED_TABLES]] || [],
        sortableFields:
          DEFAULT_SORTABLE_FIELDS[ALLOWED_TABLES[key as keyof typeof ALLOWED_TABLES]] || [],
      }))

      return {
        success: true,
        data: {
          tables: supportedTables,
        },
        message: '获取支持的表列表成功',
      }
    }

    // 验证表名是否允许
    const actualTableName = ALLOWED_TABLES[tableName as keyof typeof ALLOWED_TABLES]
    if (!actualTableName) {
      throw createError({
        statusCode: 400,
        statusMessage: `不支持的表: ${tableName}`,
      })
    }

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

    // 获取表字段信息
    const fields = await queryBuilder.getTableFields(actualTableName)

    // 构建字段详细信息
    const fieldDetails = fields.map(field => ({
      name: field,
      type: FIELD_TYPES[actualTableName]?.[field] || 'string',
      searchable: DEFAULT_SEARCH_FIELDS[actualTableName]?.includes(field) || false,
      sortable: DEFAULT_SORTABLE_FIELDS[actualTableName]?.includes(field) || true,
    }))

    // 获取支持的操作符
    const operators = [
      { value: 'equals', label: '等于', types: ['string', 'number', 'boolean'] },
      { value: 'not_equals', label: '不等于', types: ['string', 'number', 'boolean'] },
      { value: 'greater_than', label: '大于', types: ['number', 'datetime'] },
      { value: 'greater_than_or_equal', label: '大于等于', types: ['number', 'datetime'] },
      { value: 'less_than', label: '小于', types: ['number', 'datetime'] },
      { value: 'less_than_or_equal', label: '小于等于', types: ['number', 'datetime'] },
      { value: 'contains', label: '包含', types: ['string'] },
      { value: 'starts_with', label: '开始于', types: ['string'] },
      { value: 'ends_with', label: '结束于', types: ['string'] },
      { value: 'in', label: '在列表中', types: ['string', 'number'] },
      { value: 'not_in', label: '不在列表中', types: ['string', 'number'] },
      { value: 'is_null', label: '为空', types: ['string', 'number', 'datetime'] },
      { value: 'is_not_null', label: '不为空', types: ['string', 'number', 'datetime'] },
      { value: 'between', label: '在范围内', types: ['number', 'datetime'] },
      { value: 'date_equals', label: '日期等于', types: ['datetime'] },
      { value: 'date_before', label: '日期之前', types: ['datetime'] },
      { value: 'date_after', label: '日期之后', types: ['datetime'] },
      { value: 'date_between', label: '日期范围', types: ['datetime'] },
    ]

    return {
      success: true,
      data: {
        table: {
          name: actualTableName,
          key: tableName,
          fields: fieldDetails,
          searchFields: DEFAULT_SEARCH_FIELDS[actualTableName] || [],
          sortableFields: DEFAULT_SORTABLE_FIELDS[actualTableName] || fields,
          operators,
        },
      },
      message: '获取表信息成功',
    }
  } catch (error) {
    console.error('Table info 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: `获取表信息失败: ${error instanceof Error ? error.message : '未知错误'}`,
    })
  }
})