package myvalidator

import (
	"errors"
	"fmt"
	"net/http"

	"git.artlef.fr/bibliomane/internal/appcontext"
	"git.artlef.fr/bibliomane/internal/i18nresource"
	"github.com/gin-gonic/gin"
	"github.com/go-playground/validator/v10"
	"gorm.io/gorm"
)

type HttpError struct {
	StatusCode int
	Err        error
}

func ValidateId(db *gorm.DB, id uint, value any) error {
	//id = 0 means empty id, so no check
	if id == 0 {
		return nil
	}
	record := map[string]any{}
	result := db.Model(value).First(&record, id)
	if result.Error == nil {
		return nil
	}
	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return HttpError{
			StatusCode: http.StatusNotFound,
			Err:        fmt.Errorf("Id %d could not be found for model %s", id, value),
		}
	} else {
		return HttpError{
			StatusCode: http.StatusInternalServerError,
			Err:        result.Error,
		}
	}
}

func ReturnErrorsAsJsonResponse(ac *appcontext.AppContext, err error) {
	var httpError HttpError
	var ve validator.ValidationErrors
	if errors.As(err, &ve) {
		ac.C.JSON(http.StatusBadRequest, getValidationErrors(ac, &ve))
	} else if errors.As(err, &httpError) {
		ac.C.JSON(httpError.StatusCode, gin.H{"error": httpError.Err.Error()})
	} else {
		ac.C.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
	}
}

func (h HttpError) Error() string {
	return fmt.Sprintf("%d: err %v", h.StatusCode, h.Err)
}

type apiValidationError struct {
	Field string `json:"field"`
	Err   string `json:"error"`
}

func getValidationErrors(ac *appcontext.AppContext, ve *validator.ValidationErrors) []apiValidationError {
	errors := make([]apiValidationError, len(*ve))
	for i, fe := range *ve {
		errors[i] = apiValidationError{
			Field: fe.Field(),
			Err:   computeValidationMessage(ac, &fe),
		}
	}
	return errors
}

func computeValidationMessage(ac *appcontext.AppContext, fe *validator.FieldError) string {
	tag := (*fe).Tag()
	switch tag {
	case "required":
		return i18nresource.GetTranslatedMessage(ac, "ValidationRequired")
	case "min":
		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationTooShort"), (*fe).Param())
	case "max":
		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationTooLong"), (*fe).Param())
	case "lte":
		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationLowerThan"), (*fe).Param())
	case "gte":
		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationGreaterThan"), (*fe).Param())
	default:
		return fmt.Sprintf(i18nresource.GetTranslatedMessage(ac, "ValidationPropertyFail"), tag)
	}
}