package cvm

import (
	"fmt"
	"os"

	"github.com/hashicorp/packer/template/interpolate"
	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common"
	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common/profile"
	cvm "github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/cvm/v20170312"
	vpc "github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/vpc/v20170312"
)

type Region string

// below would be moved to tencentcloud sdk git repo
const (
	Bangkok       = Region("ap-bangkok")
	Beijing       = Region("ap-beijing")
	Chengdu       = Region("ap-chengdu")
	Chongqing     = Region("ap-chongqing")
	Guangzhou     = Region("ap-guangzhou")
	GuangzhouOpen = Region("ap-guangzhou-open")
	Hongkong      = Region("ap-hongkong")
	Mumbai        = Region("ap-mumbai")
	Seoul         = Region("ap-seoul")
	Shanghai      = Region("ap-shanghai")
	ShanghaiFsi   = Region("ap-shanghai-fsi")
	ShenzhenFsi   = Region("ap-shenzhen-fsi")
	Singapore     = Region("ap-singapore")
	Tokyo         = Region("ap-tokyo")
	Frankfurt     = Region("eu-frankfurt")
	Moscow        = Region("eu-moscow")
	Ashburn       = Region("na-ashburn")
	Siliconvalley = Region("na-siliconvalley")
	Toronto       = Region("na-toronto")
)

var ValidRegions = []Region{
	Bangkok, Beijing, Chengdu, Chongqing, Guangzhou, GuangzhouOpen, Hongkong, Shanghai,
	ShanghaiFsi, ShenzhenFsi,
	Mumbai, Seoul, Singapore, Tokyo, Moscow,
	Frankfurt, Ashburn, Siliconvalley, Toronto,
}

type TencentCloudAccessConfig struct {
	SecretId       string `mapstructure:"secret_id"`
	SecretKey      string `mapstructure:"secret_key"`
	Region         string `mapstructure:"region"`
	Zone           string `mapstructure:"zone"`
	SkipValidation bool   `mapstructure:"skip_region_validation"`
}

func (cf *TencentCloudAccessConfig) Client() (*cvm.Client, *vpc.Client, error) {
	var (
		err        error
		cvm_client *cvm.Client
		vpc_client *vpc.Client
		resp       *cvm.DescribeZonesResponse
	)
	if err = cf.validateRegion(); err != nil {
		return nil, nil, err
	}
	credential := common.NewCredential(
		cf.SecretId, cf.SecretKey)
	cpf := profile.NewClientProfile()
	if cvm_client, err = cvm.NewClient(credential, cf.Region, cpf); err != nil {
		return nil, nil, err
	}
	if vpc_client, err = vpc.NewClient(credential, cf.Region, cpf); err != nil {
		return nil, nil, err
	}
	if resp, err = cvm_client.DescribeZones(nil); err != nil {
		return nil, nil, err
	}
	if cf.Zone != "" {
		for _, zone := range resp.Response.ZoneSet {
			if cf.Zone == *zone.Zone {
				return cvm_client, vpc_client, nil
			}
		}
		return nil, nil, fmt.Errorf("unknown zone: %s", cf.Zone)
	} else {
		return nil, nil, fmt.Errorf("zone must be set")
	}
}

func (cf *TencentCloudAccessConfig) Prepare(ctx *interpolate.Context) []error {
	var errs []error
	if err := cf.Config(); err != nil {
		errs = append(errs, err)
	}

	if cf.Region == "" {
		errs = append(errs, fmt.Errorf("region must be set"))
	} else if !cf.SkipValidation {
		if err := cf.validateRegion(); err != nil {
			errs = append(errs, err)
		}
	}
	if len(errs) > 0 {
		return errs
	}
	return nil
}

func (cf *TencentCloudAccessConfig) Config() error {
	if cf.SecretId == "" {
		cf.SecretId = os.Getenv("TENCENTCLOUD_SECRET_ID")
	}
	if cf.SecretKey == "" {
		cf.SecretKey = os.Getenv("TENCENTCLOUD_SECRET_KEY")
	}
	if cf.SecretId == "" || cf.SecretKey == "" {
		return fmt.Errorf("TENCENTCLOUD_SECRET_ID and TENCENTCLOUD_SECRET_KEY must be set")
	}
	return nil
}

func (cf *TencentCloudAccessConfig) validateRegion() error {
	for _, valid := range ValidRegions {
		if valid == Region(cf.Region) {
			return nil
		}
	}
	return fmt.Errorf("unknown region: %s", cf.Region)
}