package godruid

type Having struct {
	Type        string      `json:"type"`
	Aggregation string      `json:"aggregation,omitempty"`
	Value       interface{} `json:"value,omitempty"`
	HavingSpec  *Having     `json:"havingSpec,omitempty"`
	HavingSpecs []*Having   `json:"havingSpecs,omitempty"`
}

func HavingEqualTo(agg string, value interface{}) *Having {
	return &Having{
		Type:        "equalTo",
		Aggregation: agg,
		Value:       value,
	}
}

func HavingGreaterThan(agg string, value interface{}) *Having {
	return &Having{
		Type:        "greaterThan",
		Aggregation: agg,
		Value:       value,
	}
}

func HavingLessThan(agg string, value interface{}) *Having {
	return &Having{
		Type:        "lessThan",
		Aggregation: agg,
		Value:       value,
	}
}

func HavingAnd(havings ...*Having) *Having {
	return joinHavings(havings, "and")
}

func HavingOr(havings ...*Having) *Having {
	return joinHavings(havings, "or")
}

func HavingNot(having *Having) *Having {
	return &Having{
		Type:       "not",
		HavingSpec: having,
	}
}

func joinHavings(havings []*Having, connector string) *Having {
	// Remove null havings.
	p := 0
	for _, h := range havings {
		if h != nil {
			havings[p] = h
			p++
		}
	}
	havings = havings[0:p]

	fLen := len(havings)
	if fLen == 0 {
		return nil
	}
	if fLen == 1 {
		return havings[0]
	}

	return &Having{
		Type:        connector,
		HavingSpecs: havings,
	}
}