package main

import (
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gin-gonic/gin/binding"
	"github.com/go-playground/validator/v10"
)

// Booking struct with validated time fields
type Booking struct {
	CheckIn  time.Time `form:"check_in" binding:"required,bookabledate" time_format:"2006-01-02"`
	CheckOut time.Time `form:"check_out" binding:"required,gtfield=CheckIn,bookabledate" time_format:"2006-01-02"`
}

/**
请求的header类型需要是:application/x-www-form-urlencoded
*/

// bookableDate is a custom validator
var bookableDate = func(fl validator.FieldLevel) bool {
	date, ok := fl.Field().Interface().(time.Time)
	if ok {
		today := time.Now()
		if today.After(date) {
			return false
		}
	}
	return true
}

func main() {
	g := gin.Default()
	g.POST("/bookable", func(c *gin.Context) {
		var b Booking
		if err := c.ShouldBindWith(&b, binding.FormPost); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}

		// Validation successful
		c.JSON(http.StatusOK, gin.H{"data": b})
	})

	// Register the custom validator
	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
		v.RegisterValidation("bookabledate", bookableDate)
	}
	g.Run(":8080")
}