package mohwhelper

import (
	"bytes"
	"crypto/tls"
	"crypto/x509"
	"encoding/base64"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"math"
	"net/http"
	"os"
	"time"

	"gitlab-ce.niaulang.com/niau-lang/golanghelper"
)

type FeeAuditUtils struct {
	UnitNo       string
	RequestAt    string
	SourceSystem string
	Hash         string
	Url          string
	Cert         []byte
}

// NewFeeAuditUtils 用來産生 FeeAuditUtils
func NewFeeAuditUtils(unitNo, sourceSystem, hash, url, certPath string) (feeAuditUtils FeeAuditUtils, err error) {
	stringutils := golanghelper.StringUtils{}
	if stringutils.IsEmpty(unitNo) || stringutils.IsEmpty(sourceSystem) || stringutils.IsEmpty(hash) ||
		stringutils.IsEmpty(url) || stringutils.IsEmpty(certPath) {
		err = errors.New("Invalid params")
	} else {
		feeAuditUtils.Cert, err = os.ReadFile(certPath)
		if err != nil {
			return
		}

		feeAuditUtils.UnitNo = unitNo
		feeAuditUtils.SourceSystem = sourceSystem
		feeAuditUtils.Hash = hash
		feeAuditUtils.Url = url
		feeAuditUtils.RequestAt = time.Now().Format("20060102150405")
	}

	return
}

// getChecksum 用 apData 來取得校驗碼
func (f *FeeAuditUtils) getChecksum(apData string) string {
	apDataBytes := []byte(apData)
	timeBytes := []byte(f.RequestAt)
	hashBytes := []byte(f.Hash)

	timeByteLen := float64(len(timeBytes))
	hashByteLen := float64(len(hashBytes))

	var sum int
	var m1 int
	var m2 int

	for i := 0; i < len(apDataBytes); i++ {
		m1 = int(math.Mod(float64(i), hashByteLen))
		m2 = int(math.Mod(float64(i), timeByteLen))
		sum += int(apDataBytes[i])*int(hashBytes[m1]) + int(timeBytes[m2])*int(hashBytes[m1])

		if sum>>16 > 0 {
			sum = (sum >> 16) + (sum & 0xFFFF)
		}
	}

	hex := fmt.Sprintf("%X", sum)

	var stringutils golanghelper.StringUtils
	return stringutils.LeftPad(hex, 4, "0")
}

// httpsPost 用來上傳 WriteoffResponse
func (f *FeeAuditUtils) httpsPost(funcName string, writeoffRequest WriteoffRequest) (writeoffResponse WriteoffResponse, err error) {
	data, err := json.Marshal(&writeoffRequest)
	if err != nil {
		return
	}

	caCertPool := x509.NewCertPool()
	caCertPool.AppendCertsFromPEM(f.Cert)

	client := &http.Client{
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{
				RootCAs: caCertPool,
			},
		},
	}

	request, err := http.NewRequest("POST", f.Url+"/"+funcName, bytes.NewBuffer(data))
	if err != nil {
		return
	}

	request.Header.Set("Content-Type", "application/json; charset=UTF-8")

	response, err := client.Do(request)
	if err != nil {
		return
	}
	defer response.Body.Close()

	responseData, err := io.ReadAll(response.Body)
	if err != nil {
		return
	}

	err = json.Unmarshal(responseData, &writeoffResponse)

	return
}

// NewRequest 用來産生 WirteoffRequest
func (f *FeeAuditUtils) NewRequest(data []byte) WriteoffRequest {
	apData := base64.StdEncoding.EncodeToString(data)

	checksum := f.getChecksum(apData)

	return WriteoffRequest{
		UnitNo:       f.UnitNo,
		RequestAt:    f.RequestAt,
		SourceSystem: f.SourceSystem,
		ApData:       apData,
		Checksum:     checksum,
	}
}

// SendFeeApply 傳送服務記錄申報
func (f *FeeAuditUtils) SendFeeApply(writeoffRequest WriteoffRequest) (feeApplyResult FeeApplyResult, err error) {
	//uploadData, err := json.Marshal(&feeApply)
	//if err != nil {
	//	return
	//}

	writeoffResponse, err := f.httpsPost("FeeApply", writeoffRequest)
	if err != nil {
		return
	}

	resultData, err := base64.StdEncoding.DecodeString(writeoffResponse.Result)

	err = json.Unmarshal(resultData, &feeApplyResult)

	return
}

// SendObjDel 傳送服務紀錄刪除
func (f *FeeAuditUtils) SendObjDel(writeoffRequest WriteoffRequest) (err error) {
	_, err = f.httpsPost("ObjDel", writeoffRequest)

	return
}

// SendAppCompletionNotice 傳送申報確認通知
func (f *FeeAuditUtils) SendAppCompletionNotice(writeoffRequest WriteoffRequest) (err error) {
	_, err = f.httpsPost("appCompletionNotice", writeoffRequest)

	return
}

// SendAppResultQuery 傳送「服務單位各分案審核狀態查詢」或「分案審核明細查詢」
func (f *FeeAuditUtils) SendAppResultQuery(writeoffRequest WriteoffRequest) (appResultQueryResult AppResultQueryResult, err error) {
	writeoffResponse, err := f.httpsPost("appResultQuery", writeoffRequest)
	if err != nil {
		return
	}

	resultData, err := base64.StdEncoding.DecodeString(writeoffResponse.Result)

	err = json.Unmarshal(resultData, &appResultQueryResult)

	return
}

// SendAppCancel 傳送撤回服務記錄
func (f *FeeAuditUtils) SendAppCancel(writeoffRequest WriteoffRequest) (err error) {
	_, err = f.httpsPost("appCancel", writeoffRequest)

	return
}

// SendCancelResultResponse 傳送取消交易單處理結果回報
func (f *FeeAuditUtils) SendCancelResultResponse(writeoffRequest WriteoffRequest) (err error) {
	_, err = f.httpsPost("CancelResultResponse", writeoffRequest)

	return
}