/*
Copyright 2021 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package common

import (
	"context"
	"io"
	//"log"
	"math/rand"
	"net/url"
	"reflect"
	"strconv"
	"strings"
	"time"
)

const (
	POST = "POST"
	GET  = "GET"

	HTTP  = "http"
	HTTPS = "https"

	RootDomain = "tencentcloudapi.com"
	Path       = "/"
)

type Request interface {
	GetAction() string
	GetBodyReader() io.Reader
	GetScheme() string
	GetRootDomain() string
	GetServiceDomain(string) string
	GetDomain() string
	GetHttpMethod() string
	GetParams() map[string]string
	GetBody() []byte
	GetPath() string
	GetService() string
	GetUrl() string
	GetVersion() string
	GetContentType() string
	GetContext() context.Context
	GetHeader() map[string]string
	GetSkipSign() bool
	SetScheme(string)
	SetRootDomain(string)
	SetDomain(string)
	SetHttpMethod(string)
	SetPath(string)
	SetContentType(string)
	SetBody([]byte)
	SetContext(context.Context)
	SetHeader(header map[string]string)
	SetSkipSign(skip bool)
}

type BaseRequest struct {
	context    context.Context
	httpMethod string
	scheme     string
	rootDomain string
	domain     string
	path       string
	skipSign   bool
	params     map[string]string
	formParams map[string]string
	header     map[string]string

	service string
	version string
	action  string

	contentType string
	body        []byte
}

func (r *BaseRequest) GetAction() string {
	return r.action
}

func (r *BaseRequest) GetHttpMethod() string {
	return r.httpMethod
}

func (r *BaseRequest) GetParams() map[string]string {
	return r.params
}

func (r *BaseRequest) GetPath() string {
	return r.path
}

func (r *BaseRequest) GetDomain() string {
	return r.domain
}

func (r *BaseRequest) GetScheme() string {
	return r.scheme
}

func (r *BaseRequest) GetRootDomain() string {
	return r.rootDomain
}

func (r *BaseRequest) GetServiceDomain(service string) (domain string) {
	rootDomain := r.rootDomain
	if rootDomain == "" {
		rootDomain = RootDomain
	}
	domain = service + "." + rootDomain
	return
}

func (r *BaseRequest) GetBody() []byte {
	return r.body
}

func (r *BaseRequest) SetBody(body []byte) {
	r.body = body
}

func (r *BaseRequest) GetContentType() string {
	return r.contentType
}

func (r *BaseRequest) SetContentType(contentType string) {
	r.contentType = contentType
}

func (r *BaseRequest) SetDomain(domain string) {
	r.domain = domain
}

func (r *BaseRequest) SetScheme(scheme string) {
	scheme = strings.ToLower(scheme)
	switch scheme {
	case HTTP:
		r.scheme = HTTP
	default:
		r.scheme = HTTPS
	}
}

func (r *BaseRequest) SetRootDomain(rootDomain string) {
	r.rootDomain = rootDomain
}

func (r *BaseRequest) SetHttpMethod(method string) {
	switch strings.ToUpper(method) {
	case POST:
		{
			r.httpMethod = POST
		}
	case GET:
		{
			r.httpMethod = GET
		}
	default:
		{
			r.httpMethod = GET
		}
	}
}

func (r *BaseRequest) SetPath(path string) {
	r.path = path
}

func (r *BaseRequest) GetService() string {
	return r.service
}

func (r *BaseRequest) GetUrl() string {
	if r.httpMethod == GET {
		return r.GetScheme() + "://" + r.domain + r.path + "?" + GetUrlQueriesEncoded(r.params)
	} else if r.httpMethod == POST {
		return r.GetScheme() + "://" + r.domain + r.path
	} else {
		return ""
	}
}

func (r *BaseRequest) GetVersion() string {
	return r.version
}

func (r *BaseRequest) GetContext() context.Context {
	if r.context == nil {
		return context.Background()
	}
	return r.context
}

func (r *BaseRequest) SetContext(ctx context.Context) {
	r.context = ctx
}

func (r *BaseRequest) GetHeader() map[string]string {
	return r.header
}

func (r *BaseRequest) SetHeader(header map[string]string) {
	if header == nil {
		return
	}
	r.header = header
}

func (r *BaseRequest) GetSkipSign() bool {
	return r.skipSign
}

func (r *BaseRequest) SetSkipSign(skip bool) {
	r.skipSign = skip
}

func GetUrlQueriesEncoded(params map[string]string) string {
	values := url.Values{}
	for key, value := range params {
		values.Add(key, value)
	}
	return values.Encode()
}

func (r *BaseRequest) GetBodyReader() io.Reader {
	if r.httpMethod == POST {
		s := GetUrlQueriesEncoded(r.params)
		return strings.NewReader(s)
	} else {
		return strings.NewReader("")
	}
}

func (r *BaseRequest) Init() *BaseRequest {
	r.domain = ""
	r.path = Path
	r.params = make(map[string]string)
	r.formParams = make(map[string]string)
	return r
}

func (r *BaseRequest) WithApiInfo(service, version, action string) *BaseRequest {
	r.service = service
	r.version = version
	r.action = action
	return r
}

func (r *BaseRequest) WithContentType(contentType string) *BaseRequest {
	r.contentType = contentType
	return r
}

// Deprecated, use request.GetServiceDomain instead
func GetServiceDomain(service string) (domain string) {
	domain = service + "." + RootDomain
	return
}

func CompleteCommonParams(request Request, region string, requestClient string) {
	params := request.GetParams()
	params["Region"] = region
	if request.GetVersion() != "" {
		params["Version"] = request.GetVersion()
	}
	params["Action"] = request.GetAction()
	params["Timestamp"] = strconv.FormatInt(time.Now().Unix(), 10)
	params["Nonce"] = strconv.Itoa(rand.Int())
	params["RequestClient"] = "SDK_GO_1.0.721"
	if requestClient != "" {
		params["RequestClient"] += ": " + requestClient
	}
}

func ConstructParams(req Request) (err error) {
	value := reflect.ValueOf(req).Elem()
	err = flatStructure(value, req, "")
	//log.Printf("[DEBUG] params=%s", req.GetParams())
	return
}

func flatStructure(value reflect.Value, request Request, prefix string) (err error) {
	//log.Printf("[DEBUG] reflect value: %v", value.Type())
	valueType := value.Type()
	for i := 0; i < valueType.NumField(); i++ {
		tag := valueType.Field(i).Tag
		nameTag, hasNameTag := tag.Lookup("name")
		if !hasNameTag {
			continue
		}
		field := value.Field(i)
		kind := field.Kind()
		if kind == reflect.Ptr && field.IsNil() {
			continue
		}
		if kind == reflect.Ptr {
			field = field.Elem()
			kind = field.Kind()
		}
		key := prefix + nameTag
		if kind == reflect.String {
			s := field.String()
			if s != "" {
				request.GetParams()[key] = s
			}
		} else if kind == reflect.Bool {
			request.GetParams()[key] = strconv.FormatBool(field.Bool())
		} else if kind == reflect.Int || kind == reflect.Int64 {
			request.GetParams()[key] = strconv.FormatInt(field.Int(), 10)
		} else if kind == reflect.Uint || kind == reflect.Uint64 {
			request.GetParams()[key] = strconv.FormatUint(field.Uint(), 10)
		} else if kind == reflect.Float64 {
			request.GetParams()[key] = strconv.FormatFloat(field.Float(), 'f', -1, 64)
		} else if kind == reflect.Slice {
			list := value.Field(i)
			for j := 0; j < list.Len(); j++ {
				vj := list.Index(j)
				key := prefix + nameTag + "." + strconv.Itoa(j)
				kind = vj.Kind()
				if kind == reflect.Ptr && vj.IsNil() {
					continue
				}
				if kind == reflect.Ptr {
					vj = vj.Elem()
					kind = vj.Kind()
				}
				if kind == reflect.String {
					request.GetParams()[key] = vj.String()
				} else if kind == reflect.Bool {
					request.GetParams()[key] = strconv.FormatBool(vj.Bool())
				} else if kind == reflect.Int || kind == reflect.Int64 {
					request.GetParams()[key] = strconv.FormatInt(vj.Int(), 10)
				} else if kind == reflect.Uint || kind == reflect.Uint64 {
					request.GetParams()[key] = strconv.FormatUint(vj.Uint(), 10)
				} else if kind == reflect.Float64 {
					request.GetParams()[key] = strconv.FormatFloat(vj.Float(), 'f', -1, 64)
				} else {
					if err = flatStructure(vj, request, key+"."); err != nil {
						return
					}
				}
			}
		} else {
			if err = flatStructure(reflect.ValueOf(field.Interface()), request, prefix+nameTag+"."); err != nil {
				return
			}
		}
	}
	return
}