package main

import (
	"encoding/xml"
	goonvif "github.com/IOTechSystems/onvif"
	"github.com/IOTechSystems/onvif/device"
	"github.com/IOTechSystems/onvif/event"
	"github.com/IOTechSystems/onvif/gosoap"
	"github.com/IOTechSystems/onvif/xsd"
	"io"
	"net/http"
)

type Connection struct {
	Params DeviceParams    `json:"params"`
	Device *goonvif.Device `json:"device"`
}

type DeviceParams struct {
	Xaddr              string `json:"xaddr"`
	EndpointRefAddress string `json:"endpointRefAddress"`
	Username           string `json:"username"`
	Password           string `json:"password"`
	AuthMode           string `json:"authMode"`
}

func readResponse(resp *http.Response) (string, error) {
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}

	return string(b), nil
}

func unmarshalResponse(resp *http.Response, target any) error {
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	if err = xml.Unmarshal(b, gosoap.NewSOAPEnvelope(target)); err != nil {
		return err
	}

	return nil
}

func NewConnection(addr string, username string, password string) (*Connection, error) {
	dev, err := goonvif.NewDevice(goonvif.DeviceParams{
		Xaddr:    addr,
		Username: username,
		Password: password,
		//AuthMode: goonvif.UsernameTokenAuth,
	})
	if err != nil {
		return nil, err
	}

	return &Connection{
		Params: DeviceParams{
			Xaddr:              dev.GetDeviceParams().Xaddr,
			EndpointRefAddress: dev.GetDeviceParams().EndpointRefAddress,
			Username:           dev.GetDeviceParams().Username,
			Password:           dev.GetDeviceParams().Password,
			AuthMode:           dev.GetDeviceParams().AuthMode,
		},
		Device: dev,
	}, nil
}

func (c *Connection) GetDeviceInformation() (*device.GetDeviceInformationResponse, error) {
	resp, err := c.Device.CallMethod(device.GetDeviceInformation{})
	if err != nil {
		return nil, err
	}

	result := &device.GetDeviceInformationResponse{}
	err = unmarshalResponse(resp, result)
	if err != nil {
		return nil, err
	}

	return result, nil
}

func (c *Connection) SubscribeEvents(
	consumerAddress event.AttributedURIType,
	terminationTime xsd.String, // PT60S
) (*event.SubscribeResponse, error) {
	resp, err := c.Device.CallMethod(event.Subscribe{
		ConsumerReference: &event.EndpointReferenceType{
			Address: consumerAddress,
		},
		Filter: &event.FilterType{
			TopicExpression: &event.TopicExpressionType{
				TopicKinds: "tns1:VideoSource//.",
			},
		},
		TerminationTime: &terminationTime,
	})
	if err != nil {
		return nil, err
	}

	result := &event.SubscribeResponse{}
	err = unmarshalResponse(resp, result)
	if err != nil {
		return nil, err
	}

	return result, nil
}