Add slack integration

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

pkg/connector/slack.go

@@ -0,0 +1,134 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package connector
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/getprobo/probo/pkg/gid"
+)
+
+type (
+	SlackConnection struct {
+		OAuth2Connection
+		Settings SlackSettings `json:"settings"`
+	}
+
+	SlackSettings struct {
+		WebhookURL string `json:"webhook_url,omitempty"` // Encrypted
+		Channel    string `json:"channel,omitempty"`
+		ChannelID  string `json:"channel_id,omitempty"`
+	}
+
+	IncomingWebhook struct {
+		URL       string `json:"url"`
+		Channel   string `json:"channel"`
+		ChannelID string `json:"channel_id"`
+	}
+
+	SlackTokenResponse struct {
+		IncomingWebhook *IncomingWebhook `json:"incoming_webhook,omitempty"`
+	}
+)
+
+const (
+	SlackProvider = "SLACK"
+)
+
+var _ Connection = (*SlackConnection)(nil)
+
+func (c *SlackConnection) Type() ProtocolType {
+	return ProtocolOAuth2
+}
+
+func (c *SlackConnection) Client(ctx context.Context) (*http.Client, error) {
+	return c.OAuth2Connection.Client(ctx)
+}
+
+func (c SlackConnection) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&struct {
+		Type         string    `json:"type"`
+		AccessToken  string    `json:"access_token"`
+		RefreshToken string    `json:"refresh_token,omitempty"`
+		ExpiresAt    time.Time `json:"expires_at"`
+		TokenType    string    `json:"token_type"`
+		Scope        string    `json:"scope,omitempty"`
+		WebhookURL   string    `json:"webhook_url,omitempty"`
+	}{
+		Type:         string(ProtocolOAuth2),
+		AccessToken:  c.OAuth2Connection.AccessToken,
+		RefreshToken: c.OAuth2Connection.RefreshToken,
+		ExpiresAt:    c.OAuth2Connection.ExpiresAt,
+		TokenType:    c.OAuth2Connection.TokenType,
+		Scope:        c.OAuth2Connection.Scope,
+		WebhookURL:   c.Settings.WebhookURL,
+	})
+}
+
+func (c *SlackConnection) UnmarshalJSON(data []byte) error {
+	aux := &struct {
+		Type         string    `json:"type"`
+		AccessToken  string    `json:"access_token"`
+		RefreshToken string    `json:"refresh_token,omitempty"`
+		ExpiresAt    time.Time `json:"expires_at"`
+		TokenType    string    `json:"token_type"`
+		Scope        string    `json:"scope,omitempty"`
+		WebhookURL   string    `json:"webhook_url,omitempty"`
+	}{}
+
+	if err := json.Unmarshal(data, aux); err != nil {
+		return err
+	}
+
+	c.OAuth2Connection = OAuth2Connection{
+		AccessToken:  aux.AccessToken,
+		RefreshToken: aux.RefreshToken,
+		ExpiresAt:    aux.ExpiresAt,
+		TokenType:    aux.TokenType,
+		Scope:        aux.Scope,
+	}
+	c.Settings.WebhookURL = aux.WebhookURL
+
+	return nil
+}
+
+func ParseSlackTokenResponse(body []byte, oauth2Conn OAuth2Connection, organizationID gid.GID) (*SlackConnection, *gid.GID, error) {
+	var slackResponse SlackTokenResponse
+	var buf bytes.Buffer
+	buf.Write(body)
+	if err := json.NewDecoder(&buf).Decode(&slackResponse); err != nil {
+		return nil, nil, fmt.Errorf("cannot decode Slack token response: %w", err)
+	}
+
+	if slackResponse.IncomingWebhook == nil {
+		return nil, nil, fmt.Errorf("incoming webhook is required for Slack")
+	}
+
+	settings := SlackSettings{
+		WebhookURL: slackResponse.IncomingWebhook.URL,
+		Channel:    slackResponse.IncomingWebhook.Channel,
+		ChannelID:  slackResponse.IncomingWebhook.ChannelID,
+	}
+
+	return &SlackConnection{
+		OAuth2Connection: oauth2Conn,
+		Settings:         settings,
+	}, &organizationID, nil
+}