s3.go

// Package model contains the definitions of domain models and business logic.
package model

import (
	"fmt"
	"strings"
	"time"

	"github.com/nao1215/rainbow/utils/errfmt"
	"github.com/nao1215/rainbow/utils/xregex"
)

// Region is the name of the AWS region.
type Region string

const (
	// RegionUSEast1 US East (N. Virginia)
	RegionUSEast1 Region = "us-east-1"
	// RegionUSEast2 US East (Ohio)
	RegionUSEast2 Region = "us-east-2"
	// RegionUSWest1 US West (N. California)
	RegionUSWest1 Region = "us-west-1"
	// RegionUSWest2 US West (Oregon)
	RegionUSWest2 Region = "us-west-2"
	// RegionAFSouth1 Africa (Cape Town)
	RegionAFSouth1 Region = "af-south-1"
	// RegionAPEast1 Asia Pacific (Hong Kong)
	RegionAPEast1 Region = "ap-east-1"
	// RegionAPSouth1 Asia Pacific (Mumbai)
	RegionAPSouth1 Region = "ap-south-1"
	// RegionAPNortheast1 Asia Pacific (Tokyo)
	RegionAPNortheast1 Region = "ap-northeast-1"
	// RegionAPNortheast2 Asia Pacific (Seoul)
	RegionAPNortheast2 Region = "ap-northeast-2"
	// RegionAPNortheast3 Asia Pacific (Osaka-Local)
	RegionAPNortheast3 Region = "ap-northeast-3"
	// RegionAPSoutheast1 Asia Pacific (Singapore)
	RegionAPSoutheast1 Region = "ap-southeast-1"
	// RegionAPSoutheast2 Asia Pacific (Sydney)
	RegionAPSoutheast2 Region = "ap-southeast-2"
	// RegionCACentral1 Canada (Central)
	RegionCACentral1 Region = "ca-central-1"
	// RegionCNNorth1 China (Beijing)
	RegionCNNorth1 Region = "cn-north-1"
	// RegionCNNorthwest1 China (Ningxia)
	RegionCNNorthwest1 Region = "cn-northwest-1"
	// RegionEUCentral1 Europe (Frankfurt)
	RegionEUCentral1 Region = "eu-central-1"
	// RegionEUNorth1 Europe (Stockholm)
	RegionEUNorth1 Region = "eu-north-1"
	// RegionEUSouth1 Europe (Milan)
	RegionEUSouth1 Region = "eu-south-1"
	// RegionEUWest1 Europe (Ireland)
	RegionEUWest1 Region = "eu-west-1"
	// RegionEUWest2 Europe (London)
	RegionEUWest2 Region = "eu-west-2"
	// RegionEUWest3 Europe (Paris)
	RegionEUWest3 Region = "eu-west-3"
	// RegionMESouth1 Middle East (Bahrain)
	RegionMESouth1 Region = "me-south-1"
	// RegionSASouth1 South America (São Paulo)
	RegionSASouth1 Region = "sa-south-1"
	// RegionUSGovEast1 AWS GovCloud (US-East)
	RegionUSGovEast1 Region = "us-gov-east-1"
	// RegionUSGovWest1 AWS GovCloud (US)
	RegionUSGovWest1 Region = "us-gov-west-1"
)

var regions = []Region{
	RegionUSEast1, RegionUSEast2, RegionUSWest1, RegionUSWest2, RegionAFSouth1, RegionAPEast1,
	RegionAPSouth1, RegionAPNortheast1, RegionAPNortheast2, RegionAPNortheast3, RegionAPSoutheast1,
	RegionAPSoutheast2, RegionCACentral1, RegionCNNorth1, RegionCNNorthwest1, RegionEUCentral1,
	RegionEUNorth1, RegionEUSouth1, RegionEUWest1, RegionEUWest2, RegionEUWest3, RegionMESouth1,
	RegionSASouth1, RegionUSGovEast1, RegionUSGovWest1,
}

// Validate returns true if the Region exists.
func (r Region) Validate() error {
	switch r {
	case
		RegionUSEast1, RegionUSEast2, RegionUSWest1, RegionUSWest2, RegionAFSouth1,
		RegionAPEast1, RegionAPSouth1, RegionAPNortheast1, RegionAPNortheast2,
		RegionAPNortheast3, RegionAPSoutheast1, RegionAPSoutheast2, RegionCACentral1,
		RegionCNNorth1, RegionCNNorthwest1, RegionEUCentral1, RegionEUNorth1,
		RegionEUSouth1, RegionEUWest1, RegionEUWest2, RegionEUWest3, RegionMESouth1,
		RegionSASouth1, RegionUSGovEast1, RegionUSGovWest1:
		return nil
	case Region(""):
		return ErrEmptyRegion
	default:
		return ErrInvalidRegion
	}
}

// String returns the string representation of the Region.
func (r Region) String() string {
	return string(r)
}

// Next returns the next region.
// If the region is the last one, it returns the first region.
// If the region is invalid, it returns "ap-northeast-1".
func (r Region) Next() Region {
	for i, region := range regions {
		if r == region {
			if i == len(regions)-1 {
				return regions[0]
			}
			return regions[i+1]
		}
	}
	return RegionAPNortheast1
}

// Prev returns the previous region.
// If the region is the first one, it returns the last region.
// If the region is invalid, it returns "ap-northeast-1".
func (r Region) Prev() Region {
	for i, region := range regions {
		if r == region {
			if i == 0 {
				return regions[len(regions)-1]
			}
			return regions[i-1]
		}
	}
	return RegionAPNortheast1
}

// Bucket is the name of the S3 bucket.
type Bucket string

// String returns the string representation of the Bucket.
func (b Bucket) String() string {
	return string(b)
}

// Empty is whether bucket name is empty
func (b Bucket) Empty() bool {
	return b == ""
}

// Domain returns the domain name of the Bucket.
func (b Bucket) Domain() string {
	return fmt.Sprintf("%s.s3.amazonaws.com", b.String())
}

// Validate returns true if the Bucket is valid.
// Bucket naming rules: https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucketnamingrules.html
func (b Bucket) Validate() error {
	if b.Empty() {
		return errfmt.Wrap(ErrInvalidBucketName, "s3 bucket name is empty")
	}

	validators := []func() error{
		b.validateLength,
		b.validatePattern,
		b.validatePrefix,
		b.validateSuffix,
		b.validateCharSequence,
	}
	for _, v := range validators {
		if err := v(); err != nil {
			return err
		}
	}
	return nil
}

const (
	// BucketMinLength is the minimum length of the bucket name.
	BucketMinLength = 3
	// BucketMaxLength is the maximum length of the bucket name.
	BucketMaxLength = 63
)

// validateLength validates the length of the bucket name.
func (b Bucket) validateLength() error {
	if len(b) < 3 || len(b) > 63 {
		return fmt.Errorf("s3 bucket name must be between 3 and 63 characters long")
	}
	return nil
}

var s3RegexPattern xregex.Regex //nolint:gochecknoglobals

// validatePattern validates the pattern of the bucket name.
func (b Bucket) validatePattern() error {
	s3RegexPattern.InitOnce(`^[a-z0-9][a-z0-9.-]*[a-z0-9]$`)
	if err := s3RegexPattern.MatchString(string(b)); err != nil {
		return errfmt.Wrap(ErrInvalidBucketName, "s3 bucket name must use only lowercase letters, numbers, periods, and hyphens")
	}
	return nil
}

// validatePrefix validates the prefix of the bucket name.
func (b Bucket) validatePrefix() error {
	for _, prefix := range []string{"xn--", "sthree-", "sthree-configurator"} {
		if strings.HasPrefix(string(b), prefix) {
			return errfmt.Wrap(ErrInvalidBucketName, "s3 bucket name must not start with \"xn--\", \"sthree-\", or \"sthree-configurator\"")
		}
	}
	return nil
}

// validateSuffix validates the suffix of the bucket name.
func (b Bucket) validateSuffix() error {
	for _, suffix := range []string{"-s3alias", "--ol-s3"} {
		if strings.HasSuffix(string(b), suffix) {
			return errfmt.Wrap(ErrInvalidBucketName, "s3 bucket name must not end with \"-s3alias\" or \"--ol-s3\"")
		}
	}
	return nil
}

// validateCharSequence validates the character sequence of the bucket name.
func (b Bucket) validateCharSequence() error {
	if strings.Contains(string(b), "..") || strings.Contains(string(b), "--") {
		return errfmt.Wrap(ErrInvalidBucketName, "s3 bucket name must not contain consecutive periods or hyphens")
	}
	return nil
}

// BucketSets is the set of the BucketSet.
type BucketSets []BucketSet

// BucketSet is the set of the Bucket and the Region.
type BucketSet struct {
	// Bucket is the name of the S3 bucket.
	Bucket Bucket
	// Region is the name of the AWS region.
	Region Region
	// CreationDate is date the bucket was created.
	// This date can change when making changes to your bucket, such as editing its bucket policy.
	CreationDate time.Time
}

// Len returns the length of the BucketSets.
func (b BucketSets) Len() int {
	return len(b)
}

// Empty returns true if the BucketSets is empty.
func (b BucketSets) Empty() bool {
	return b.Len() == 0
}