package host

import (
	"fmt"
	"reflect"
	"time"

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

type postVNCPayload struct {
	// RequestID is the ID of the VNC request
	//
	// example: 11asd123a
	RequestID string `json:"requestId" binding:"required"`
	// VNC status of the node
	//
	// example: ACCEPTED
	Status VNCStatus `json:"status" binding:"required,oneof=REQUESTED ACCEPTED SUSPENDED REJECTED DROPPED CONNECTED"`
	// Number of active connections on the VNC request. Only expected alongside a CONNECTED status.
	//
	// example: 2
	Connections int `json:"connections" binding:"gte=0,is_zero_xor_is_connected"`
	// Timestamp of VNC state
	//
	// example: "2006-01-02T15:04:05Z07:00"
	TimeStamp time.Time `json:"timestamp,omitempty" time_format:"2006-01-02T15:04:05Z07:00"`
}

type putVNCPayload struct {
	// RequestID is the ID of the VNC request
	//
	// example: 11asd123a
	RequestID string `json:"requestId" binding:"required"`
	// VNC status of the node
	// in: body
	// enum: ["REQUESTED", "ACCEPTED", "SUSPENDED", "REJECTED", "CONNECTED"]
	//
	// example: ACCEPTED
	Status VNCStatus `json:"status" binding:"required,oneof=REQUESTED ACCEPTED SUSPENDED REJECTED CONNECTED"`
	// Number of active connections on the VNC request. Only expected alongside a CONNECTED status.
	//
	// example: 2
	Connections int `json:"connections" binding:"gte=0,is_zero_xor_is_connected"`
	// Timestamp of VNC state
	//
	// example: "2006-01-02T15:04:05Z07:00"
	TimeStamp time.Time `json:"timestamp" binding:"required" time_format:"2006-01-02T15:04:05Z07:00"`
}

type putVNCPayloads []putVNCPayload

// Validates the incoming payload for duplicate request IDs. Returns a [binding.SliceValidationError]
// to indicate this error is a validation error and should be treated as such in HandleBindingError.
func (payload putVNCPayloads) validateRequestIDs() binding.SliceValidationError {
	var err binding.SliceValidationError
	requestIDs := make(map[string]struct{})
	for _, p := range payload {
		if _, ok := requestIDs[p.RequestID]; ok {
			err = append(err, fmt.Errorf("Key: 'putVNCPayload.RequestID' Error: Duplicate request id %q", p.RequestID))
		}
		requestIDs[p.RequestID] = struct{}{}
	}
	if len(err) != 0 {
		return err
	}
	return nil
}

// Custom validator methods

func getIsConnected(fl validator.FieldLevel) (isConnected bool, ok bool) {
	status := fl.Parent().FieldByName("Status")
	if !status.CanConvert(reflect.TypeOf(Connected)) {
		return false, false
	}
	return status.Equal(reflect.ValueOf(Connected)), true
}

func validateFieldIsZeroXORStatusIsConnected(fl validator.FieldLevel) bool {
	isConnected, ok := getIsConnected(fl)
	if !ok {
		return false
	}
	intField := fl.Field().Int()
	// If status is not CONNECTED, there should not be any connections
	if !isConnected {
		return intField == 0
	}
	// And if status is CONNECTED, there must be at least one connection
	return intField != 0
}