yoyo-project/yoyo

package template

const NodeFile = `package query

import (
    "fmt"
)

type ComparisonOperator string
type LogicalOperator string

const (
    Equals         ComparisonOperator = "="
    NotEquals      ComparisonOperator = "!="
    Like           ComparisonOperator = "LIKE"
    NotLike        ComparisonOperator = "NOT LIKE"
    GreaterThan    ComparisonOperator = ">"
    GreaterOrEqual ComparisonOperator = ">="
    LessThan       ComparisonOperator = "<"
    LessOrEqual    ComparisonOperator = "<="

    Before        = LessThan
    After         = GreaterThan
    BeforeOrEqual = LessOrEqual
    AfterOrEqual  = GreaterOrEqual

    IsNull    ComparisonOperator = "IS NULL"
    IsNotNull ComparisonOperator = "IS NOT NULL"

    And LogicalOperator = "AND"
    Or  LogicalOperator = "OR"
)

type Condition struct {
    Column   string
    Value    interface{}
    Operator ComparisonOperator
}

func (c Condition) SQL() (string, []interface{}) {
    switch c.Operator {
    case IsNull, IsNotNull:
        return fmt.Sprintf("%s %s", c.Column, c.Operator), []interface{}{}
    default:
        return fmt.Sprintf("%s %s ?", c.Column, c.Operator), []interface{}{c.Value}
    }
}

type Node struct {
    Children  *[2]Node
    Operator  LogicalOperator
    Condition Condition
}

func (n Node) SQL() (s string, args []interface{}) {
    if n.Children != nil {
        sql1, args1 := n.Children[0].SQL()
        sql2, args2 := n.Children[1].SQL()
        if n.Operator == Or {
            sql1 = fmt.Sprintf("(%s)", sql1)
            sql2 = fmt.Sprintf("(%s)", sql2)
        }
        s, args = fmt.Sprintf("%s %s %s", sql1, n.Operator, sql2), append(args1, args2...)
        return s, args
    }

    return n.Condition.SQL()
}
`