package ginctx

import (
	"clapclap/internal/apperr"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/go-playground/validator/v10"
)

func GetDto[T any](c *gin.Context) (T, error) {
	return Get[T](c, "dto")
}

// handleBindError intercepts Gin crashes and turns them into beautiful AppErrors.
func handleBindError(err error) error {
	var valErrs validator.ValidationErrors
	var syntaxErr *json.SyntaxError
	var unmarshalTypeErr *json.UnmarshalTypeError

	// 1. Check for missing/invalid fields
	if errors.As(err, &valErrs) {
		var details []string
		for _, fieldErr := range valErrs {
			msg := fmt.Sprintf("Field '%s' failed validation on the '%s' tag", fieldErr.Field(), fieldErr.Tag())
			details = append(details, msg)
		}

		args := append([]string{"Validation failed"}, details...)
		return apperr.NewValidationError(err, args...)
	}

	// 2. Check for broken JSON text
	if errors.As(err, &syntaxErr) || errors.As(err, &unmarshalTypeErr) {
		return apperr.NewBadRequestError(err, "Malformed JSON payload", err.Error())
	}

	// 3. Fallback
	return apperr.NewBadRequestError(err, "Invalid request data")
}

// Binders
func ShouldBindJSON[T any](c *gin.Context) {
	var dto T
	if err := c.ShouldBindJSON(&dto); err != nil {
		appErr := handleBindError(err)
		apperr.AbortWithError(c, appErr)
		return
	}
	c.Set("dto", dto)
	c.Next()
}

func ShouldBindQuery[T any](c *gin.Context) {
	var dto T
	if err := c.ShouldBindQuery(&dto); err != nil {
		appErr := handleBindError(err)
		apperr.AbortWithError(c, appErr)
		return
	}
	c.Set("dto", dto)
	c.Next()
}