package dbs

import (
	"encoding/json"
	"fmt"
	"strings"
	"time"

	"git.x2erp.com/qdy/go-svc-mcp/internal/mcp"
)

func init() {
	mcp.Register("get_oracle_columns", "根据表名称获取Oracle表的所有字段相关信息",
		map[string]interface{}{
			"type": "object",
			"properties": map[string]interface{}{
				"table_name": map[string]interface{}{
					"type":        "string",
					"description": "表名称（支持大小写敏感）",
				},
				"schema": map[string]interface{}{
					"type":        "string",
					"description": "模式名称（默认为当前用户）",
					"default":     "",
				},
				"include_comments": map[string]interface{}{
					"type":        "boolean",
					"description": "是否包含字段注释",
					"default":     true,
				},
				"database_key": map[string]interface{}{
					"type":        "string",
					"description": "数据库配置键名（如：business），可选，默认使用主数据库",
					"enum":        []string{"warehouse", "business"},
					"default":     "warehouse",
				},
			},
			"required": []string{"table_name"},
		},
		func(input json.RawMessage, deps *mcp.ToolDependencies) (interface{}, error) {
			var params struct {
				TableName       string `json:"table_name"`
				Schema          string `json:"schema"`
				IncludeComments bool   `json:"include_comments"`
				DatabaseKey     string `json:"database_key"`
			}

			if len(input) > 0 {
				if err := json.Unmarshal(input, &params); err != nil {
					return nil, err
				}
			}

			// 获取数据库工厂
			dbFactory, err := GetDBFactory(params.DatabaseKey, deps)
			if err != nil {
				return nil, err
			}

			// 获取数据库类型，确保是Oracle
			dbType := dbFactory.GetDBType()
			if dbType != "oracle" {
				return nil, fmt.Errorf("当前数据库类型为 %s，此工具仅支持Oracle数据库", dbType)
			}

			// 清理表名和模式名
			tableName := strings.TrimSpace(params.TableName)
			schema := strings.TrimSpace(params.Schema)

			if tableName == "" {
				return nil, fmt.Errorf("表名称不能为空")
			}

			// 构建查询SQL
			var query string
			if schema == "" {
				// 查询当前用户下的表字段信息
				if params.IncludeComments {
					query = `
						SELECT 
							c.column_id,
							c.column_name,
							c.data_type,
							c.data_length,
							c.data_precision,
							c.data_scale,
							c.nullable,
							c.data_default as column_default,
							cc.comments as column_comment
						FROM user_tab_columns c
						LEFT JOIN user_col_comments cc ON c.table_name = cc.table_name AND c.column_name = cc.column_name
						WHERE c.table_name = UPPER(:1)
						ORDER BY c.column_id`
				} else {
					query = `
						SELECT 
							column_id,
							column_name,
							data_type,
							data_length,
							data_precision,
							data_scale,
							nullable,
							data_default as column_default
						FROM user_tab_columns
						WHERE table_name = UPPER(:1)
						ORDER BY column_id`
				}
			} else {
				// 查询指定模式下的表字段信息
				if params.IncludeComments {
					query = `
						SELECT 
							c.column_id,
							c.column_name,
							c.data_type,
							c.data_length,
							c.data_precision,
							c.data_scale,
							c.nullable,
							c.data_default as column_default,
							cc.comments as column_comment
						FROM all_tab_columns c
						LEFT JOIN all_col_comments cc ON c.owner = cc.owner AND c.table_name = cc.table_name AND c.column_name = cc.column_name
						WHERE c.table_name = UPPER(:1)
						AND c.owner = UPPER(:2)
						ORDER BY c.column_id`
				} else {
					query = `
						SELECT 
							column_id,
							column_name,
							data_type,
							data_length,
							data_precision,
							data_scale,
							nullable,
							data_default as column_default
						FROM all_tab_columns
						WHERE table_name = UPPER(:1)
						AND owner = UPPER(:2)
						ORDER BY column_id`
				}
			}

			// 执行查询
			var results []map[string]interface{}

			if schema == "" {
				results, err = dbFactory.QuerySliceMapWithParams(query, tableName)
			} else {
				results, err = dbFactory.QuerySliceMapWithParams(query, tableName, schema)
			}

			if err != nil {
				return nil, fmt.Errorf("查询表字段信息失败: %v", err)
			}

			if len(results) == 0 {
				// 尝试查询表是否存在
				var tableExistsQuery string
				if schema == "" {
					tableExistsQuery = `SELECT COUNT(*) as table_count FROM user_tables WHERE table_name = UPPER(:1)`
				} else {
					tableExistsQuery = `SELECT COUNT(*) as table_count FROM all_tables WHERE table_name = UPPER(:1) AND owner = UPPER(:2)`
				}

				var tableCheckResults []map[string]interface{}
				if schema == "" {
					tableCheckResults, err = dbFactory.QuerySliceMapWithParams(tableExistsQuery, tableName)
				} else {
					tableCheckResults, err = dbFactory.QuerySliceMapWithParams(tableExistsQuery, tableName, schema)
				}

				if err == nil && len(tableCheckResults) > 0 {
					if count, ok := tableCheckResults[0]["table_count"].(int64); ok && count == 0 {
						return nil, fmt.Errorf("表 '%s' 不存在", tableName)
					}
				}

				return nil, fmt.Errorf("表 '%s' 存在但没有字段信息或表为空", tableName)
			}

			// 处理字段信息，确保null值转换为空字符串
			for i := range results {
				// 处理NULLABLE字段
				if nullable, ok := results[i]["nullable"].(string); ok {
					results[i]["is_nullable"] = nullable == "Y"
					delete(results[i], "nullable")
				}

				// 处理注释字段
				if params.IncludeComments {
					if comment, ok := results[i]["column_comment"]; ok && comment == nil {
						results[i]["column_comment"] = ""
					}
				}

				// 处理默认值
				if defaultValue, ok := results[i]["column_default"]; ok && defaultValue == nil {
					results[i]["column_default"] = ""
				}

				// 构建完整的数据类型
				dataType := ""
				if dt, ok := results[i]["data_type"].(string); ok {
					dataType = dt
					if precision, ok := results[i]["data_precision"].(int64); ok && precision > 0 {
						if scale, ok := results[i]["data_scale"].(int64); ok && scale > 0 {
							dataType = fmt.Sprintf("%s(%d,%d)", dt, precision, scale)
						} else {
							dataType = fmt.Sprintf("%s(%d)", dt, precision)
						}
					} else if length, ok := results[i]["data_length"].(int64); ok && length > 0 {
						// 对于VARCHAR2/CHAR等类型
						dataType = fmt.Sprintf("%s(%d)", dt, length)
					}
					results[i]["full_data_type"] = dataType
				}
			}

			// 获取表注释
			var tableComment string
			if schema == "" {
				tableCommentQuery := `SELECT comments FROM user_tab_comments WHERE table_name = UPPER(:1)`
				commentResults, err := dbFactory.QuerySliceMapWithParams(tableCommentQuery, tableName)
				if err == nil && len(commentResults) > 0 {
					if comment, ok := commentResults[0]["comments"].(string); ok {
						tableComment = comment
					}
				}
			} else {
				tableCommentQuery := `SELECT comments FROM all_tab_comments WHERE table_name = UPPER(:1) AND owner = UPPER(:2)`
				commentResults, err := dbFactory.QuerySliceMapWithParams(tableCommentQuery, tableName, schema)
				if err == nil && len(commentResults) > 0 {
					if comment, ok := commentResults[0]["comments"].(string); ok {
						tableComment = comment
					}
				}
			}

			return map[string]interface{}{
				"tenant_id":        deps.ReqCtx.TenantID,
				"user_id":          deps.ReqCtx.UserID,
				"database_type":    dbType,
				"database_name":    dbFactory.GetDatabaseName(),
				"schema":           schema,
				"table_name":       tableName,
				"table_comment":    tableComment,
				"include_comments": params.IncludeComments,
				"columns":          results,
				"total_columns":    len(results),
				"timestamp":        time.Now().Format(time.RFC3339),
			}, nil
		},
	)
}