package authentication

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/golang-jwt/jwt"
	"github.com/google/uuid"
	dg "github.com/karincake/apem/db-gorm-pg"
	d "github.com/karincake/dodol"
	l "github.com/karincake/lepet"

	a "github.com/karincake/apem"
	ms "github.com/karincake/apem/ms-redis"

	el "simrs-vx/pkg/logger"
	p "simrs-vx/pkg/password"

	mu "simrs-vx/internal/domain/main-entities/user"
	erc "simrs-vx/internal/domain/references/common"
)

var authCfg AuthCfg

func init() {
	a.RegisterExtCall(GetConfig)
}

// Generates token and store in redis at one place
// just return the error code
func GenToken(input mu.LoginDto) (*d.Data, error) {
	// Get User
	user := &mu.User{Name: input.Name}
	// if input.Position_Code != "" {
	// 	user.Position_Code = input.Position_Code
	// }
	if errCode := GetAndCheck(user, user); errCode != "" {
		return nil, d.FieldErrors{"authentication": d.FieldError{Code: errCode, Message: el.GenMessage(errCode)}}
	}

	if user.LoginAttemptCount > 5 {
		if user.LastSuccessLogin != nil {
			now := time.Now()
			lastAllowdLogin := user.LastAllowdLogin
			if lastAllowdLogin.After(now.Add(-time.Hour * 1)) {
				return nil, d.FieldErrors{"authentication": d.FieldError{Code: "auth-login-tooMany", Message: el.GenMessage("auth-login-tooMany")}}
			} else {
				tn := time.Now()
				user.LastAllowdLogin = &tn
				user.LoginAttemptCount = 0
				dg.I.Save(&user)
			}
		} else {
			tn := time.Now()
			user.LastAllowdLogin = &tn
			dg.I.Save(&user)
			return nil, d.FieldErrors{"authentication": d.FieldError{Code: "auth-login-tooMany", Message: el.GenMessage("auth-login-tooMany")}}
		}
	}

	if !p.Check(input.Password, user.Password) {
		user.LoginAttemptCount++
		dg.I.Save(&user)
		return nil, d.FieldErrors{"authentication": d.FieldError{Code: "auth-login-incorrect", Message: el.GenMessage("auth-login-incorrect")}}
	} else if user.Status_Code == erc.SCBlocked {
		return nil, d.FieldErrors{"authentication": d.FieldError{Code: "auth-login-blocked", Message: el.GenMessage("auth-login-blocked")}}
	} else if user.Status_Code == erc.SCNew {
		return nil, d.FieldErrors{"authentication": d.FieldError{Code: "auth-login-unverified", Message: el.GenMessage("auth-login-unverified")}}
	}

	// Access token prep
	id, err := uuid.NewRandom()
	if err != nil {
		panic(fmt.Sprintf(l.I.Msg("uuid-gen-fail"), err))
	}
	if input.Duration == 0 {
		input.Duration = 24 * 60
	}
	duration := time.Minute * time.Duration(input.Duration)
	aUuid := id.String()
	atExpires := time.Now().Add(duration).Unix()
	atSecretKey := authCfg.AtSecretKey

	// extra
	// if input.Position_Code == "doc" {

	// }

	// Creating Access Token
	atClaims := jwt.MapClaims{}
	atClaims["user_id"] = user.Id
	atClaims["user_name"] = user.Name
	// atClaims["user_email"] = user.Email
	// atClaims["user_position_code"] = user.Position_Code
	// atClaims["user_ref_id"] = user.Ref_Id
	atClaims["exp"] = atExpires
	atClaims["uuid"] = aUuid
	at := jwt.NewWithClaims(jwt.SigningMethodHS256, atClaims)
	ats, err := at.SignedString([]byte(atSecretKey))
	if err != nil {
		return nil, d.FieldErrors{"user": d.FieldError{Code: "token-sign-err", Message: el.GenMessage("token-sign-err")}}
	}

	// Save to redis
	now := time.Now()
	atx := time.Unix(atExpires, 0) //converting Unix to UTC(to Time object)
	err = ms.I.Set(aUuid, strconv.Itoa(int(user.Id)), atx.Sub(now)).Err()
	if err != nil {
		panic(fmt.Sprintf(l.I.Msg("redis-store-fail"), err.Error()))
	}

	tn := time.Now()
	user.LoginAttemptCount = 0
	user.LastSuccessLogin = &tn
	user.LastAllowdLogin = &tn
	dg.I.Save(&user)

	// Current data
	return &d.Data{
		Meta: d.IS{
			"source":    "authentication",
			"structure": "single-data",
			"status":    "verified",
		},
		Data: d.II{
			"user_id":   strconv.Itoa(int(user.Id)),
			"user_name": user.Name,
			// "user_email":         user.Email,
			// "user_position_code": user.Position_Code,
			// "user_ref_id":        user.Ref_Id,
			"accessToken": ats,
		},
	}, nil
}

func RevokeToken(uuid string) {
	ms.I.Del(uuid)
}

func VerifyToken(r *http.Request, tokenType TokenType) (data *jwt.Token, errCode, errDetail string) {
	auth := r.Header.Get("Authorization")
	if auth == "" {
		return nil, "auth-missingHeader", ""
	}
	authArr := strings.Split(auth, " ")
	if len(authArr) == 2 {
		auth = authArr[1]
	}

	token, err := jwt.Parse(auth, func(token *jwt.Token) (any, error) {
		//Make sure that the token method conform to "SigningMethodHMAC"
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf(l.I.Msg("token-sign-unexcpeted"), token.Header["alg"])
		}
		if tokenType == AccessToken {
			return []byte(authCfg.AtSecretKey), nil
		} else {
			return []byte(authCfg.RtSecretKey), nil
		}
	})
	if err != nil {
		return nil, "token-parse-fail", err.Error()
	}
	return token, "", ""
}

func ExtractToken(r *http.Request, tokenType TokenType) (data *AuthInfo, err error) {
	token, errCode, errDetail := VerifyToken(r, tokenType)
	if errCode != "" {
		return nil, d.FieldError{Code: errCode, Message: el.GenMessage(errCode, errDetail)}
	}
	claims, ok := token.Claims.(jwt.MapClaims)
	if ok && token.Valid {
		accessUuid, ok := claims["uuid"].(string)
		if !ok {
			return nil, d.FieldError{Code: "token-invalid", Message: el.GenMessage("token-invalid", "uuid not available")}
		}
		user_id, myErr := strconv.ParseInt(fmt.Sprintf("%.f", claims["user_id"]), 10, 64)
		if myErr != nil {
			return nil, d.FieldError{Code: "token-invalid", Message: el.GenMessage("token-invalid", "uuid is not available")}
		}
		accessUuidRedis := ms.I.Get(accessUuid)
		if accessUuidRedis.String() == "" {
			return nil, d.FieldError{Code: "token-unidentified", Message: el.GenMessage("token-unidentified")}
		}
		user_name := fmt.Sprintf("%v", claims["user_name"])
		// user_email := ""
		// if v, exist := claims["user_email"]; exist && v != nil {
		// 	user_email = v.(string)
		// }
		// ref_id := 0
		// if v, exist := claims["user_ref_id"]; exist && v != nil {
		// 	tmp := v.(float64)
		// 	ref_id = int(tmp)
		// }
		// position_code := ""
		// if v, exist := claims["user_position_code"]; exist && v != nil {
		// 	position_code = v.(string)
		// }
		data = &AuthInfo{
			Uuid:      accessUuid,
			User_Id:   int(user_id),
			User_Name: user_name,
			// User_Email:         user_email,
			// User_Ref_Id:        ref_id,
			// User_Position_Code: position_code,
		}
		return
	}
	return nil, d.FieldError{Code: "token", Message: "token-invalid"}
}

func GetConfig() {
	a.ParseCfg(&authCfg)
}