package postgres

import (
	"fmt"
	"mayfly-go/internal/db/dbm/dbi"
	"mayfly-go/pkg/errorx"
	"mayfly-go/pkg/utils/anyx"
	"mayfly-go/pkg/utils/collx"
	"regexp"
	"strings"
	"time"
)

const (
	PGSQL_META_FILE      = "metasql/pgsql_meta.sql"
	PGSQL_DB_SCHEMAS     = "PGSQL_DB_SCHEMAS"
	PGSQL_TABLE_INFO_KEY = "PGSQL_TABLE_INFO"
	PGSQL_INDEX_INFO_KEY = "PGSQL_INDEX_INFO"
	PGSQL_COLUMN_MA_KEY  = "PGSQL_COLUMN_MA"
	PGSQL_TABLE_DDL_KEY  = "PGSQL_TABLE_DDL_FUNC"
)

type PgsqlMetaData struct {
	dbi.DefaultMetaData

	dc *dbi.DbConn
}

func (pd *PgsqlMetaData) GetDbServer() (*dbi.DbServer, error) {
	_, res, err := pd.dc.Query("SELECT version() as server_version")
	if err != nil {
		return nil, err
	}
	ds := &dbi.DbServer{
		Version: anyx.ConvString(res[0]["server_version"]),
	}
	return ds, nil
}

func (pd *PgsqlMetaData) GetDbNames() ([]string, error) {
	_, res, err := pd.dc.Query("SELECT datname AS dbname FROM pg_database WHERE datistemplate = false AND has_database_privilege(datname, 'CONNECT')")
	if err != nil {
		return nil, err
	}

	databases := make([]string, 0)
	for _, re := range res {
		databases = append(databases, anyx.ConvString(re["dbname"]))
	}

	return databases, nil
}

// 获取表基础元信息, 如表名等
func (pd *PgsqlMetaData) GetTables() ([]dbi.Table, error) {
	_, res, err := pd.dc.Query(dbi.GetLocalSql(PGSQL_META_FILE, PGSQL_TABLE_INFO_KEY))
	if err != nil {
		return nil, err
	}

	tables := make([]dbi.Table, 0)
	for _, re := range res {
		tables = append(tables, dbi.Table{
			TableName:    re["tableName"].(string),
			TableComment: anyx.ConvString(re["tableComment"]),
			CreateTime:   anyx.ConvString(re["createTime"]),
			TableRows:    anyx.ConvInt(re["tableRows"]),
			DataLength:   anyx.ConvInt64(re["dataLength"]),
			IndexLength:  anyx.ConvInt64(re["indexLength"]),
		})
	}
	return tables, nil
}

// 获取列元信息, 如列名等
func (pd *PgsqlMetaData) GetColumns(tableNames ...string) ([]dbi.Column, error) {
	tableName := strings.Join(collx.ArrayMap[string, string](tableNames, func(val string) string {
		return fmt.Sprintf("'%s'", dbi.RemoveQuote(pd, val))
	}), ",")

	_, res, err := pd.dc.Query(fmt.Sprintf(dbi.GetLocalSql(PGSQL_META_FILE, PGSQL_COLUMN_MA_KEY), tableName))
	if err != nil {
		return nil, err
	}

	columns := make([]dbi.Column, 0)
	for _, re := range res {
		columns = append(columns, dbi.Column{
			TableName:     anyx.ConvString(re["tableName"]),
			ColumnName:    anyx.ConvString(re["columnName"]),
			ColumnType:    anyx.ConvString(re["columnType"]),
			ColumnComment: anyx.ConvString(re["columnComment"]),
			Nullable:      anyx.ConvString(re["nullable"]),
			IsPrimaryKey:  anyx.ConvInt(re["isPrimaryKey"]) == 1,
			IsIdentity:    anyx.ConvInt(re["isIdentity"]) == 1,
			ColumnDefault: anyx.ConvString(re["columnDefault"]),
			NumScale:      anyx.ConvString(re["numScale"]),
		})
	}
	return columns, nil
}

func (pd *PgsqlMetaData) GetPrimaryKey(tablename string) (string, error) {
	columns, err := pd.GetColumns(tablename)
	if err != nil {
		return "", err
	}
	if len(columns) == 0 {
		return "", errorx.NewBiz("[%s] 表不存在", tablename)
	}
	for _, v := range columns {
		if v.IsPrimaryKey {
			return v.ColumnName, nil
		}
	}

	return columns[0].ColumnName, nil
}

// 获取表索引信息
func (pd *PgsqlMetaData) GetTableIndex(tableName string) ([]dbi.Index, error) {
	_, res, err := pd.dc.Query(fmt.Sprintf(dbi.GetLocalSql(PGSQL_META_FILE, PGSQL_INDEX_INFO_KEY), tableName))
	if err != nil {
		return nil, err
	}

	indexs := make([]dbi.Index, 0)
	for _, re := range res {
		indexs = append(indexs, dbi.Index{
			IndexName:    anyx.ConvString(re["indexName"]),
			ColumnName:   anyx.ConvString(re["columnName"]),
			IndexType:    anyx.ConvString(re["IndexType"]),
			IndexComment: anyx.ConvString(re["indexComment"]),
			IsUnique:     anyx.ConvInt(re["isUnique"]) == 1,
			SeqInIndex:   anyx.ConvInt(re["seqInIndex"]),
		})
	}
	// 把查询结果以索引名分组，索引字段以逗号连接
	result := make([]dbi.Index, 0)
	key := ""
	for _, v := range indexs {
		// 当前的索引名
		in := v.IndexName
		if key == in {
			// 索引字段已根据名称和顺序排序，故取最后一个即可
			i := len(result) - 1
			// 同索引字段以逗号连接
			result[i].ColumnName = result[i].ColumnName + "," + v.ColumnName
		} else {
			key = in
			result = append(result, v)
		}
	}
	return result, nil
}

// 获取建表ddl
func (pd *PgsqlMetaData) GetTableDDL(tableName string) (string, error) {
	_, err := pd.dc.Exec(dbi.GetLocalSql(PGSQL_META_FILE, PGSQL_TABLE_DDL_KEY))
	if err != nil {
		return "", err
	}

	ddlSql := fmt.Sprintf("select showcreatetable('%s','%s') as sql", pd.dc.Info.CurrentSchema(), tableName)
	_, res, err := pd.dc.Query(ddlSql)
	if err != nil {
		return "", err
	}

	return res[0]["sql"].(string), nil
}

// 获取pgsql当前连接的库可访问的schemaNames
func (pd *PgsqlMetaData) GetSchemas() ([]string, error) {
	sql := dbi.GetLocalSql(PGSQL_META_FILE, PGSQL_DB_SCHEMAS)
	_, res, err := pd.dc.Query(sql)
	if err != nil {
		return nil, err
	}
	schemaNames := make([]string, 0)
	for _, re := range res {
		schemaNames = append(schemaNames, anyx.ConvString(re["schemaName"]))
	}
	return schemaNames, nil
}

func (pd *PgsqlMetaData) DefaultDb() string {
	switch pd.dc.Info.Type {
	case dbi.DbTypePostgres, dbi.DbTypeGauss:
		return "postgres"
	case dbi.DbTypeKingbaseEs:
		return "security"
	case dbi.DbTypeVastbase:
		return "vastbase"
	default:
		return ""
	}
}

func (pd *PgsqlMetaData) GetDataConverter() dbi.DataConverter {
	return converter
}

var (
	// 数字类型
	numberRegexp = regexp.MustCompile(`(?i)int|double|float|number|decimal|byte|bit`)
	// 日期时间类型
	datetimeRegexp = regexp.MustCompile(`(?i)datetime|timestamp`)
	// 日期类型
	dateRegexp = regexp.MustCompile(`(?i)date`)
	// 时间类型
	timeRegexp = regexp.MustCompile(`(?i)time`)

	converter = new(DataConverter)
)

type DataConverter struct {
}

func (dc *DataConverter) GetDataType(dbColumnType string) dbi.DataType {
	if numberRegexp.MatchString(dbColumnType) {
		return dbi.DataTypeNumber
	}
	// 日期时间类型
	if datetimeRegexp.MatchString(dbColumnType) {
		return dbi.DataTypeDateTime
	}
	// 日期类型
	if dateRegexp.MatchString(dbColumnType) {
		return dbi.DataTypeDate
	}
	// 时间类型
	if timeRegexp.MatchString(dbColumnType) {
		return dbi.DataTypeTime
	}
	return dbi.DataTypeString
}

func (dc *DataConverter) FormatData(dbColumnValue any, dataType dbi.DataType) string {
	str := fmt.Sprintf("%v", dbColumnValue)
	switch dataType {
	case dbi.DataTypeDateTime: // "2024-01-02T22:16:28.545377+08:00"
		res, _ := time.Parse(time.RFC3339, str)
		return res.Format(time.DateTime)
	case dbi.DataTypeDate: //  "2024-01-02T00:00:00Z"
		res, _ := time.Parse(time.RFC3339, str)
		return res.Format(time.DateOnly)
	case dbi.DataTypeTime: // "0000-01-01T22:16:28.545075+08:00"
		res, _ := time.Parse(time.RFC3339, str)
		return res.Format(time.TimeOnly)
	}
	return anyx.ConvString(dbColumnValue)
}

func (dc *DataConverter) ParseData(dbColumnValue any, dataType dbi.DataType) any {
	// 如果dataType是datetime而dbColumnValue是string类型，则需要转换为time.Time类型
	_, ok := dbColumnValue.(string)
	if dataType == dbi.DataTypeDateTime && ok {
		res, _ := time.Parse(time.RFC3339, anyx.ToString(dbColumnValue))
		return res
	}
	if dataType == dbi.DataTypeDate && ok {
		res, _ := time.Parse(time.DateOnly, anyx.ToString(dbColumnValue))
		return res
	}
	if dataType == dbi.DataTypeTime && ok {
		res, _ := time.Parse(time.TimeOnly, anyx.ToString(dbColumnValue))
		return res
	}
	return dbColumnValue
}