package mssql

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

type SQLGenerator struct {
	dc *dbi.DbConn
}

func (sg *SQLGenerator) GenTableDDL(table dbi.Table, columns []dbi.Column, dropBeforeCreate bool) []string {
	tbName := table.TableName
	schemaName := sg.dc.Info.CurrentSchema()

	quoter := sg.dc.GetDialect().Quoter()
	quote := quoter.Quote

	sqlArr := make([]string, 0)

	// 删除表
	if dropBeforeCreate {
		sqlArr = append(sqlArr, fmt.Sprintf("DROP TABLE IF EXISTS %s.%s", quote(schemaName), quote(tbName)))
	}

	// 组装建表语句
	createSql := fmt.Sprintf("CREATE TABLE %s.%s (\n", quote(schemaName), quote(tbName))
	fields := make([]string, 0)
	pks := make([]string, 0)
	columnComments := make([]string, 0)

	for _, column := range columns {
		if column.IsPrimaryKey {
			pks = append(pks, quote(column.ColumnName))
		}
		fields = append(fields, sg.genColumnBasicSql(quoter, column))
		commentTmp := "EXECUTE sp_addextendedproperty N'MS_Description', N'%s', N'SCHEMA', N'%s', N'TABLE', N'%s', N'COLUMN', N'%s'"

		// 防止注释内含有特殊字符串导致sql出错
		if column.ColumnComment != "" {
			comment := dbi.QuoteEscape(column.ColumnComment)
			columnComments = append(columnComments, fmt.Sprintf(commentTmp, comment, sg.dc.Info.CurrentSchema(), tbName, column.ColumnName))
		}
	}

	// create
	createSql += strings.Join(fields, ",\n")
	if len(pks) > 0 {
		createSql += fmt.Sprintf(", \n PRIMARY KEY CLUSTERED (%s)", strings.Join(pks, ","))
	}
	createSql += "\n)"

	// comment
	tableCommentSql := ""
	if table.TableComment != "" {
		commentTmp := "EXECUTE sp_addextendedproperty N'MS_Description', N'%s', N'SCHEMA', N'%s', N'TABLE', N'%s'"

		tableCommentSql = fmt.Sprintf(commentTmp, dbi.QuoteEscape(table.TableComment), sg.dc.Info.CurrentSchema(), tbName)
	}

	sqlArr = append(sqlArr, createSql)

	if tableCommentSql != "" {
		sqlArr = append(sqlArr, tableCommentSql)
	}
	if len(columnComments) > 0 {
		sqlArr = append(sqlArr, columnComments...)
	}

	return sqlArr
}

func (sg *SQLGenerator) GenIndexDDL(table dbi.Table, indexs []dbi.Index) []string {
	quote := sg.dc.GetDialect().Quoter().Quote
	tbName := table.TableName
	sqls := make([]string, 0)
	comments := make([]string, 0)
	for _, index := range indexs {
		unique := ""
		if index.IsUnique {
			unique = "unique"
		}
		// 取出列名，添加引号
		cols := strings.Split(index.ColumnName, ",")
		colNames := make([]string, len(cols))
		for i, name := range cols {
			colNames[i] = quote(name)
		}

		sqls = append(sqls, fmt.Sprintf("create %s NONCLUSTERED index %s on %s.%s(%s)", unique, quote(index.IndexName), quote(sg.dc.Info.CurrentSchema()), quote(tbName), strings.Join(colNames, ",")))
		if index.IndexComment != "" {
			comment := dbi.QuoteEscape(index.IndexComment)
			comments = append(comments, fmt.Sprintf("EXECUTE sp_addextendedproperty N'MS_Description', N'%s', N'SCHEMA', N'%s', N'TABLE', N'%s', N'INDEX', N'%s'", comment, sg.dc.Info.CurrentSchema(), tbName, index.IndexName))
		}
	}
	if len(comments) > 0 {
		sqls = append(sqls, comments...)
	}

	return sqls
}

func (sg *SQLGenerator) GenInsert(tableName string, columns []dbi.Column, values [][]any, duplicateStrategy int) []string {
	return collx.AsArray("")
}

func (msg *SQLGenerator) genColumnBasicSql(quoter dbi.Quoter, column dbi.Column) string {
	colName := quoter.Quote(column.ColumnName)
	dataType := string(column.DataType)

	incr := ""
	if column.IsIdentity {
		incr = " IDENTITY(1,1)"
	}

	nullAble := ""
	if !column.Nullable {
		nullAble = " NOT NULL"
	}

	defVal := "" // 默认值需要判断引号，如函数是不需要引号的 // 为了防止跨源函数不支持 当默认值是函数时，不需要设置默认值
	if column.ColumnDefault != "" && !strings.Contains(column.ColumnDefault, "(") {
		// 哪些字段类型默认值需要加引号
		mark := false
		if collx.ArrayAnyMatches([]string{"char", "text", "date", "time", "lob"}, dataType) {
			// 当数据类型是日期时间，默认值是日期时间函数时，默认值不需要引号
			if collx.ArrayAnyMatches([]string{"date", "time"}, strings.ToLower(dataType)) &&
				collx.ArrayAnyMatches([]string{"DATE", "TIME"}, strings.ToUpper(column.ColumnDefault)) {
				mark = false
			} else {
				mark = true
			}
		}

		if mark {
			defVal = fmt.Sprintf(" DEFAULT '%s'", column.ColumnDefault)
		} else {
			defVal = fmt.Sprintf(" DEFAULT %s", column.ColumnDefault)
		}
	}

	columnSql := fmt.Sprintf(" %s %s%s%s%s", colName, column.GetColumnType(), incr, nullAble, defVal)
	return columnSql
}