package auth

import (
	"net/url"
	"nixcn-cms/data"
	"nixcn-cms/internal/exception"
	"nixcn-cms/pkgs/authcode"
	"nixcn-cms/utils"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
	"gorm.io/gorm"
)

func Redirect(c *gin.Context) {
	clientId := c.Query("client_id")
	if clientId == "" {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}

	redirectUri := c.Query("redirect_uri")
	if redirectUri == "" {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}

	state := c.Query("state")
	if state == "" {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}

	code := c.Query("code")

	// Verify email token
	authCode, ok := authcode.VerifyAuthCode(code)
	if !ok {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeSpecific).
			SetOriginal(exception.AuthRedirectTokenInvalid).
			Build()
		utils.HttpResponse(c, 403, errorCode)
		return
	}

	// Verify if user exists
	userData := new(data.User)
	user, err := userData.GetByEmail(authCode.Email)

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			// Create user
			user.UUID = uuid.New()
			user.UserId = uuid.New()
			user.Email = authCode.Email
			user.Username = user.UserId.String()
			user.PermissionLevel = 10
			if err := user.Create(); err != nil {
				errorCode := new(exception.Builder).
					SetStatus(exception.ErrorStatusServer).
					SetService(exception.AuthService).
					SetEndpoint(exception.AuthRedirectEndpoint).
					SetType(exception.ErrorTypeCommon).
					SetOriginal(exception.CommonErrorInternal).
					Build()
				utils.HttpResponse(c, 500, errorCode)
				return
			}
		} else {
			errorCode := new(exception.Builder).
				SetStatus(exception.ErrorStatusServer).
				SetService(exception.AuthService).
				SetEndpoint(exception.AuthRedirectEndpoint).
				SetType(exception.ErrorTypeCommon).
				SetOriginal(exception.CommonErrorInternal).
				Build()
			utils.HttpResponse(c, 500, errorCode)
			return
		}
	}

	clientData := new(data.Client)
	client, err := clientData.GetClientByClientId(clientId)
	if err != nil {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeSpecific).
			SetOriginal(exception.AuthRedirectClientNotFound).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}

	err = client.ValidateRedirectURI(redirectUri)
	if err != nil {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeSpecific).
			SetOriginal(exception.AuthRedirectUriMismatch).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}

	newCode, err := authcode.NewAuthCode(clientId, authCode.Email)
	if err != nil {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusServer).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeCommon).
			SetOriginal(exception.CommonErrorInternal).
			Build()
		utils.HttpResponse(c, 500, errorCode)
		return
	}

	url, err := url.Parse(redirectUri)
	if err != nil {
		errorCode := new(exception.Builder).
			SetStatus(exception.ErrorStatusClient).
			SetService(exception.AuthService).
			SetEndpoint(exception.AuthRedirectEndpoint).
			SetType(exception.ErrorTypeSpecific).
			SetOriginal(exception.AuthRedirectInvalidUri).
			Build()
		utils.HttpResponse(c, 400, errorCode)
		return
	}
	query := url.Query()
	query.Set("code", newCode)
	url.RawQuery = query.Encode()

	c.Redirect(302, url.String())
}