muonsoft / validation

import (

	"strconv"

	"github.com/muonsoft/validation"

	"github.com/muonsoft/validation/code"

	"github.com/muonsoft/validation/generic"

	"github.com/muonsoft/validation/message"

)

// CountConstraint checks that a given collection's (array, slice or a map) length is between some minimum and

// maximum value.

type CountConstraint struct {

	isIgnored              bool

	checkMin               bool

	checkMax               bool

	min                    int

	max                    int

	minCode                string

	maxCode                string

	exactCode              string

	minMessageTemplate     string

	minMessageParameters   validation.TemplateParameterList

	maxMessageTemplate     string

	maxMessageParameters   validation.TemplateParameterList

	exactMessageTemplate   string

	exactMessageParameters validation.TemplateParameterList

}

func newCountConstraint(min int, max int, checkMin bool, checkMax bool) CountConstraint {

	return CountConstraint{

		min:                  min,

		max:                  max,

		checkMin:             checkMin,

		checkMax:             checkMax,

		minCode:              code.CountTooFew,

		maxCode:              code.CountTooMany,

		exactCode:            code.CountExact,

		minMessageTemplate:   message.CountTooFew,

		maxMessageTemplate:   message.CountTooMany,

		exactMessageTemplate: message.CountExact,

	}

}

// HasMinCount creates a CountConstraint that checks the length of the iterable (slice, array, or map)

// is greater than the minimum value.

func HasMinCount(min int) CountConstraint {

	return newCountConstraint(min, 0, true, false)

}

// HasMaxCount creates a CountConstraint that checks the length of the iterable (slice, array, or map)

// is less than the maximum value.

func HasMaxCount(max int) CountConstraint {

	return newCountConstraint(0, max, false, true)

}

// HasCountBetween creates a CountConstraint that checks the length of the iterable (slice, array, or map)

// is between some minimum and maximum value.

func HasCountBetween(min int, max int) CountConstraint {

	return newCountConstraint(min, max, true, true)

}

// HasExactCount creates a CountConstraint that checks the length of the iterable (slice, array, or map)

// has exact value.

func HasExactCount(count int) CountConstraint {

	return newCountConstraint(count, count, true, true)

}

// Name is the constraint name.

func (c CountConstraint) Name() string {

	return "CountConstraint"

}

// SetUp always returns no error.

func (c CountConstraint) SetUp() error {

	return nil

}

// When enables conditional validation of this constraint. If the expression evaluates to false,

// then the constraint will be ignored.

func (c CountConstraint) When(condition bool) CountConstraint {

	c.isIgnored = !condition

	return c

}

// MinCode overrides default code for violation that will be shown if the

// collection length is less than the minimum value.

func (c CountConstraint) MinCode(code string) CountConstraint {

	c.minCode = code

	return c

}

// MaxCode overrides default code for violation that will be shown if the

// collection length is greater than the maximum value.

// ExactCode overrides default code for violation that will be shown if minimum and

// maximum values are equal and the length of the collection is not exactly this value.

func (c CountConstraint) ExactCode(code string) CountConstraint {

	c.exactCode = code

	return c

}

// MinMessage sets the violation message that will be shown if the collection length is less than

// the minimum value. You can set custom template parameters for injecting its values

// into the final message. Also, you can use default parameters:

//

//	{{ count }} - the current collection size;

//	{{ limit }} - the lower limit.

func (c CountConstraint) MinMessage(template string, parameters ...validation.TemplateParameter) CountConstraint {

	c.minMessageTemplate = template

	c.minMessageParameters = parameters

	return c

}

// MaxMessage sets the violation message that will be shown if the collection length is greater than

// the maximum value. You can set custom template parameters for injecting its values

// into the final message. Also, you can use default parameters:

//

//	{{ count }} - the current collection size;

//	{{ limit }} - the upper limit.

func (c CountConstraint) MaxMessage(template string, parameters ...validation.TemplateParameter) CountConstraint {

	c.maxMessageTemplate = template

	c.maxMessageParameters = parameters

	return c

}

// ExactMessage sets the violation message that will be shown if minimum and maximum values are equal and

// the length of the collection is not exactly this value. You can set custom template parameters

// for injecting its values into the final message. Also, you can use default parameters:

//

//	{{ count }} - the current collection size;

//	{{ limit }} - the exact expected collection size.

func (c CountConstraint) ExactMessage(template string, parameters ...validation.TemplateParameter) CountConstraint {

	c.exactMessageTemplate = template

	c.exactMessageParameters = parameters

	return c

}

func (c CountConstraint) ValidateIterable(value generic.Iterable, scope validation.Scope) error {

	return c.ValidateCountable(value.Count(), scope)

}

func (c CountConstraint) ValidateCountable(count int, scope validation.Scope) error {

	if c.isIgnored {

		return nil

	}

	if c.checkMax && count > c.max {

		return c.newViolation(count, c.max, c.maxCode, c.maxMessageTemplate, c.maxMessageParameters, scope)

	}

	if c.checkMin && count < c.min {

		return c.newViolation(count, c.min, c.minCode, c.minMessageTemplate, c.minMessageParameters, scope)

	}

	return nil

}

func (c CountConstraint) newViolation(

	count, limit int,

	violationCode, template string,

	parameters validation.TemplateParameterList,

	scope validation.Scope,

) validation.Violation {

	if c.checkMin && c.checkMax && c.min == c.max {

		template = c.exactMessageTemplate

		parameters = c.exactMessageParameters

		violationCode = c.exactCode

	}

	return scope.BuildViolation(violationCode, template).

		SetPluralCount(limit).

		SetParameters(

			parameters.Prepend(

				validation.TemplateParameter{Key: "{{ count }}", Value: strconv.Itoa(count)},

				validation.TemplateParameter{Key: "{{ limit }}", Value: strconv.Itoa(limit)},

			)...,

		).

		CreateViolation()

}