package simpleorm

import "strings"

type Constraint struct {
	Name       string
	Type       string
	Columns    []Column
	RefTable   *Table
	RefColumns []Column
}

func (c *Constraint) ToDDL() string {
	switch c.Type {
	case "pk":
		return c.toPkDDL()
	case "fk":
		return c.toFkDDL()
	}

	return ""
}

func (c *Constraint) toPkDDL() string {
	var ddl strings.Builder
	ddl.WriteString("CONSTRAINT " + c.Name + " PRIMARY KEY(")
	for i, col := range c.Columns {
		if i != 0 {
			ddl.WriteString(", ")
		}
		ddl.WriteString(col.Name)
	}
	ddl.WriteString(")")
	return ddl.String()
}

func (c *Constraint) toFkDDL() string {
	var ddl strings.Builder
	ddl.WriteString("CONSTRAINT " + c.Name + " FOREIGN KEY(")

	for i, col := range c.Columns {
		if i != 0 {
			ddl.WriteString(", ")
		}
		ddl.WriteString(col.Name)
	}
	ddl.WriteString(") REFERENCES " + c.RefTable.Name + "(")

	for i, col := range c.RefColumns {
		if i != 0 {
			ddl.WriteString(", ")
		}
		ddl.WriteString(col.Name)
	}

	ddl.WriteString(")")

	return ddl.String()
}