Adding upstream version 0.8.9.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pkg/services/slack/slack.go

@@ -0,0 +1,142 @@
+package slack
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/nicholas-fedor/shoutrrr/pkg/format"
+	"github.com/nicholas-fedor/shoutrrr/pkg/services/standard"
+	"github.com/nicholas-fedor/shoutrrr/pkg/types"
+	"github.com/nicholas-fedor/shoutrrr/pkg/util/jsonclient"
+)
+
+// apiPostMessage is the Slack API endpoint for sending messages.
+const (
+	apiPostMessage     = "https://slack.com/api/chat.postMessage"
+	defaultHTTPTimeout = 10 * time.Second // defaultHTTPTimeout is the default timeout for HTTP requests.
+)
+
+// Service sends notifications to a pre-configured Slack channel or user.
+type Service struct {
+	standard.Standard
+	Config *Config
+	pkr    format.PropKeyResolver
+	client *http.Client
+}
+
+// Send delivers a notification message to Slack.
+func (service *Service) Send(message string, params *types.Params) error {
+	config := service.Config
+
+	if err := service.pkr.UpdateConfigFromParams(config, params); err != nil {
+		return fmt.Errorf("updating config from params: %w", err)
+	}
+
+	payload := CreateJSONPayload(config, message)
+
+	var err error
+	if config.Token.IsAPIToken() {
+		err = service.sendAPI(config, payload)
+	} else {
+		err = service.sendWebhook(config, payload)
+	}
+
+	if err != nil {
+		return fmt.Errorf("failed to send slack notification: %w", err)
+	}
+
+	return nil
+}
+
+// Initialize configures the service with a URL and logger.
+func (service *Service) Initialize(configURL *url.URL, logger types.StdLogger) error {
+	service.SetLogger(logger)
+	service.Config = &Config{}
+	service.pkr = format.NewPropKeyResolver(service.Config)
+	service.client = &http.Client{
+		Timeout: defaultHTTPTimeout,
+	}
+
+	return service.Config.setURL(&service.pkr, configURL)
+}
+
+// GetID returns the service identifier.
+func (service *Service) GetID() string {
+	return Scheme
+}
+
+// sendAPI sends a notification using the Slack API.
+func (service *Service) sendAPI(config *Config, payload any) error {
+	response := APIResponse{}
+	jsonClient := jsonclient.NewClient()
+	jsonClient.Headers().Set("Authorization", config.Token.Authorization())
+
+	if err := jsonClient.Post(apiPostMessage, payload, &response); err != nil {
+		return fmt.Errorf("posting to Slack API: %w", err)
+	}
+
+	if !response.Ok {
+		if response.Error != "" {
+			return fmt.Errorf("%w: %v", ErrAPIResponseFailure, response.Error)
+		}
+
+		return ErrUnknownAPIError
+	}
+
+	if response.Warning != "" {
+		service.Logf("Slack API warning: %q", response.Warning)
+	}
+
+	return nil
+}
+
+// sendWebhook sends a notification using a Slack webhook.
+func (service *Service) sendWebhook(config *Config, payload any) error {
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("failed to marshal payload: %w", err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultHTTPTimeout)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(
+		ctx,
+		http.MethodPost,
+		config.Token.WebhookURL(),
+		bytes.NewBuffer(payloadBytes),
+	)
+	if err != nil {
+		return fmt.Errorf("failed to create webhook request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", jsonclient.ContentType)
+
+	res, err := service.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to invoke webhook: %w", err)
+	}
+
+	defer res.Body.Close()
+	resBytes, _ := io.ReadAll(res.Body)
+	response := string(resBytes)
+
+	switch response {
+	case "":
+		if res.StatusCode != http.StatusOK {
+			return fmt.Errorf("%w: %v", ErrWebhookStatusFailure, res.Status)
+		}
+
+		fallthrough
+	case "ok":
+		return nil
+	default:
+		return fmt.Errorf("%w: %v", ErrWebhookResponseFailure, response)
+	}
+}