new-server/internal/drivers/hue2/client.go

package hue2

import (
	"bytes"
	"context"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"io"
	"net"
	"net/http"
	"strings"
	"time"
)

func NewClient(host, token string) *Client {
	ch := make(chan struct{}, 5)
	for i := 0; i < 3; i++ {
		ch <- struct{}{}
	}

	return &Client{
		host:  host,
		token: token,
		ch:    ch,
	}
}

type Client struct {
	host  string
	token string
	ch    chan struct{}
}

func (c *Client) AllResources(ctx context.Context) ([]ResourceData, error) {
	res := struct {
		Error interface{}
		Data  []ResourceData
	}{}

	err := c.get(ctx, "clip/v2/resource", &res)
	if err != nil {
		return nil, err
	}

	return res.Data, nil
}

func (c *Client) Resources(ctx context.Context, kind string) ([]ResourceData, error) {
	res := struct {
		Error interface{}
		Data  []ResourceData
	}{}

	err := c.get(ctx, "clip/v2/resource/"+kind, &res)
	if err != nil {
		return nil, err
	}

	return res.Data, nil
}

func (c *Client) UpdateResource(ctx context.Context, link ResourceLink, update ResourceUpdate) error {
	return c.put(ctx, link.Path(), update, nil)
}

func (c *Client) get(ctx context.Context, path string, target interface{}) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-c.ch:
		defer func() {
			c.ch <- struct{}{}
		}()
	}

	req, err := http.NewRequest("GET", fmt.Sprintf("https://%s/%s", c.host, path), nil)
	if err != nil {
		return err
	}

	req.Header.Set("hue-application-key", c.token)

	res, err := httpClient.Do(req.WithContext(ctx))
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if target == nil {
		return nil
	}

	return json.NewDecoder(res.Body).Decode(&target)
}

func (c *Client) put(ctx context.Context, path string, body interface{}, target interface{}) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-c.ch:
		defer func() {
			c.ch <- struct{}{}
		}()
	}

	rb, err := reqBody(body)
	if err != nil {
		return err
	}

	req, err := http.NewRequest("PUT", fmt.Sprintf("https://%s/%s", c.host, path), rb)
	if err != nil {
		return err
	}

	req.Header.Set("hue-application-key", c.token)

	res, err := httpClient.Do(req.WithContext(ctx))
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if target == nil {
		return nil
	}

	return json.NewDecoder(res.Body).Decode(&target)
}

func reqBody(body interface{}) (io.Reader, error) {
	if body == nil {
		return nil, nil
	}

	switch v := body.(type) {
	case []byte:
		return bytes.NewReader(v), nil
	case string:
		return strings.NewReader(v), nil
	case io.Reader:
		return v, nil
	default:
		jsonData, err := json.Marshal(v)
		if err != nil {
			return nil, err
		}

		return bytes.NewReader(jsonData), nil
	}
}

var httpClient = &http.Client{
	Transport: &http.Transport{
		Proxy: http.ProxyFromEnvironment,
		DialContext: (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
		}).DialContext,
		MaxIdleConns:        256,
		MaxIdleConnsPerHost: 16,
		IdleConnTimeout:     10 * time.Minute,
		TLSClientConfig:     &tls.Config{InsecureSkipVerify: true},
	},
	Timeout: time.Minute,
}