muonsoft / validation

import (

	"github.com/muonsoft/validation"

	"github.com/muonsoft/validation/code"

	"github.com/muonsoft/validation/is"

	"github.com/muonsoft/validation/message"

)

// URLConstraint is used to validate URL string. This constraint doesn’t check that the host of the

// given URL really exists, because the information of the DNS records is not reliable.

//

// This constraint doesn't check the length of the URL. Use LengthConstraint to check the length of the given value.

type URLConstraint struct {

	isIgnored       bool

	isValid         func(value string, protocols ...string) bool

	protocols       []string

	messageTemplate string

}

// IsURL creates a URLConstraint to validate an absolute URL, which means a protocol (or scheme) is required.

// By default, constraint checks only for the http:// and https:// protocols. Use the Protocols method to configure

// the list of expected protocols.

//

// Example

//	v := "http://example.com"

//	err := validator.ValidateString(&v, it.IsURL())

func IsURL() URLConstraint {

	return URLConstraint{

		isValid:         is.URL,

		protocols:       []string{"http", "https"},

		messageTemplate: message.InvalidURL,

	}

}

// IsRelativeURL creates a URLConstraint to validate an absolute or relative URL. The protocol is considered

// optional when validating the syntax of the given URL. This means that both http:// and https:// are valid

// but also relative URLs that contain no protocol (e.g. //example.com).

// By default, constraint checks only for the http:// and https:// protocols. Use the Protocols method to configure

// the list of expected protocols.

//

// Example

//	v := "//example.com"

//	err := validator.ValidateString(&v, it.IsRelativeURL())

func IsRelativeURL() URLConstraint {

	return URLConstraint{

		isValid:         is.RelativeURL,

		protocols:       []string{"http", "https"},

		messageTemplate: message.InvalidURL,

	}

}

// SetUp will return an error if the list of protocols is empty.

func (c URLConstraint) SetUp() error {

	if len(c.protocols) == 0 {

		return errEmptyProtocols

	}

	return nil

}

// Name is the constraint name.

func (c URLConstraint) Name() string {

	return "URLConstraint"

}

// Protocols is used to set up a list of accepted protocols. For example, if you also consider the ftp:// type URLs

// to be valid, redefine the protocols list, listing http, https, and also ftp.

// If the list is empty, then an error will be returned by the SetUp method.

//

// Example

//	v := "ftp://example.com"

//	err := validator.ValidateString(&v, it.IsURL().Protocols("http", "https", "ftp"))

func (c URLConstraint) Protocols(protocols ...string) URLConstraint {

	c.protocols = protocols

	return c

}

// Message sets the violation message template. You can use template parameters

// for injecting its values into the final message:

//

//	{{ value }} - the current (invalid) value.

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

// then the constraint will be ignored.

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

	c.isIgnored = !condition

	return c

}

func (c URLConstraint) ValidateString(value *string, scope validation.Scope) error {

	if c.isIgnored || value == nil || *value == "" || c.isValid(*value, c.protocols...) {

		return nil

	}

	return scope.BuildViolation(code.InvalidURL, c.messageTemplate).

		AddParameter("{{ value }}", *value).

		CreateViolation()

}