package config

import (
	"log"
	"net"
	"regexp"
	"strconv"
	"strings"

	"git.apinb.com/bsm-sdk/core/conf"
)

var (
	Spec             SrvConfig
	configNameRegexp = regexp.MustCompile(`^[a-z0-9-]+$`)
)

type SrvConfig struct {
	conf.Base      `yaml:",inline"`
	Databases      *conf.DBConf             `yaml:"Databases"`
	MicroService   *conf.MicroServiceConf   `yaml:"MicroService"`
	Etcd           *conf.EtcdConf           `yaml:"Etcd"`
	ObjectStorage  ObjectStorageConf        `yaml:"ObjectStorage"`
	Namespaces     map[string]NamespaceConf `yaml:"Namespaces"`
	ServiceClients map[string]string        `yaml:"ServiceClients"`
	Cleanup        CleanupConf              `yaml:"Cleanup"`
}

type ObjectStorageConf struct {
	Provider          string `yaml:"Provider"`
	Endpoint          string `yaml:"Endpoint"`
	Region            string `yaml:"Region"`
	Bucket            string `yaml:"Bucket"`
	PublicBaseURL     string `yaml:"PublicBaseURL"`
	AccessKeyID       string `yaml:"AccessKeyID"`
	AccessKeySecret   string `yaml:"AccessKeySecret"`
	PresignTTLSeconds int64  `yaml:"PresignTTLSeconds"`
}

type NamespaceConf struct {
	Prefix            string   `yaml:"Prefix"`
	MaxSizeMB         int64    `yaml:"MaxSizeMB"`
	AllowedExtensions []string `yaml:"AllowedExtensions"`
}

type CleanupConf struct {
	IntervalSeconds int64 `yaml:"IntervalSeconds"`
}

func New(srvKey string) {
	conf.New(srvKey, &Spec)

	Spec.Port = conf.CheckPort(Spec.Port)
	Spec.BindIP = conf.CheckIP(Spec.BindIP)
	Spec.Addr = net.JoinHostPort(Spec.BindIP, Spec.Port)

	validate()
	conf.PrintInfo(Spec.Addr)
}

func validate() {
	validateRequired("Service", Spec.Service)
	validateRequired("Cache", Spec.Cache)

	if Spec.ObjectStorage.Provider != "aliyun" {
		configError("ObjectStorage.Provider", "必须为 aliyun")
	}

	validateRequired("ObjectStorage.Endpoint", Spec.ObjectStorage.Endpoint)
	validateRequired("ObjectStorage.Region", Spec.ObjectStorage.Region)
	validateRequired("ObjectStorage.Bucket", Spec.ObjectStorage.Bucket)
	validateRequired("ObjectStorage.PublicBaseURL", Spec.ObjectStorage.PublicBaseURL)
	validateRequired("ObjectStorage.AccessKeyID", Spec.ObjectStorage.AccessKeyID)
	validateRequired("ObjectStorage.AccessKeySecret", Spec.ObjectStorage.AccessKeySecret)

	if Spec.ObjectStorage.PresignTTLSeconds < 60 || Spec.ObjectStorage.PresignTTLSeconds > 3600 {
		configError("ObjectStorage.PresignTTLSeconds", "必须在 60 到 3600 秒之间")
	}

	if len(Spec.Namespaces) == 0 {
		configError("Namespaces", "不能为空")
	}
	for name, namespace := range Spec.Namespaces {
		path := "Namespaces." + name
		if !configNameRegexp.MatchString(name) {
			configError(path, "名称仅允许小写字母、数字和连字符")
		}
		if !isSafeRelativeObjectPath(namespace.Prefix) {
			configError(path+".Prefix", "必须是安全的相对对象路径")
		}
		if namespace.MaxSizeMB <= 0 {
			configError(path+".MaxSizeMB", "必须大于 0")
		}
		if len(namespace.AllowedExtensions) == 0 {
			configError(path+".AllowedExtensions", "不能为空")
		}
		for index, extension := range namespace.AllowedExtensions {
			extensionPath := path + ".AllowedExtensions[" + stringIndex(index) + "]"
			if !strings.HasPrefix(extension, ".") {
				configError(extensionPath, "必须以 . 开头")
			}
			namespace.AllowedExtensions[index] = strings.ToLower(extension)
		}
		Spec.Namespaces[name] = namespace
	}

	if len(Spec.ServiceClients) == 0 {
		configError("ServiceClients", "不能为空")
	}
	for name, secret := range Spec.ServiceClients {
		path := "ServiceClients." + name
		if !configNameRegexp.MatchString(name) {
			configError(path, "服务名仅允许小写字母、数字和连字符")
		}
		validateRequired(path, secret)
	}

	if Spec.Cleanup.IntervalSeconds <= 0 {
		configError("Cleanup.IntervalSeconds", "必须大于 0")
	}
}

func validateRequired(path, value string) {
	if strings.TrimSpace(value) == "" {
		configError(path, "不能为空")
	}
}

func isSafeRelativeObjectPath(path string) bool {
	if path == "" || strings.HasPrefix(path, "/") || strings.Contains(path, "\\") {
		return false
	}
	for _, segment := range strings.Split(path, "/") {
		if segment == "." || segment == ".." {
			return false
		}
	}
	return true
}

func configError(path, message string) {
	log.Fatalf("配置项 %s 无效：%s", path, message)
}

func stringIndex(index int) string {
	return strconv.Itoa(index)
}