package deploy

import (
	"fmt"
	"strings"
)

func FormatShardAdvert(region string, shardIndex int) string {
	return fmt.Sprintf("%s:%d", strings.TrimSpace(region), shardIndex)
}

func ParseShardAdvert(advert string) (region string, index int, ok bool) {
	advert = strings.TrimSpace(advert)
	colon := strings.LastIndex(advert, ":")
	if colon <= 0 {
		return "", 0, false
	}
	region = strings.TrimSpace(advert[:colon])
	if _, err := fmt.Sscanf(strings.TrimSpace(advert[colon+1:]), "%d", &index); err != nil {
		return "", 0, false
	}
	return region, index, region != ""
}

func ResolveLocalAWSRegion(policyFallback string) string {
	if meta := ReadEC2InstanceMeta(); strings.TrimSpace(meta.Region) != "" {
		return strings.TrimSpace(meta.Region)
	}
	return strings.TrimSpace(policyFallback)
}

func cloudFrontShardURL(domain, token, region string, index int, shardHash string) string {
	domain = strings.TrimRight(strings.TrimSpace(domain), "/")
	shardHash = strings.TrimSpace(strings.ToLower(shardHash))
	if domain == "" || token == "" || region == "" || shardHash == "" {
		return ""
	}
	if !strings.HasPrefix(domain, "http") {
		domain = "https://" + domain
	}
	return fmt.Sprintf("%s/shards/%s/%s/%d-%s.bin", domain, token, region, index, shardHash)
}