Merge pull request #296 from appwrite/feat-go-discord-command-bot

Feat: Go discord command bot

go/discord-command-bot/.gitignore

@@ -0,0 +1,2 @@
+# Directory used by Appwrite CLI for local development
+.appwrite

go/discord-command-bot/README.md

@@ -0,0 +1,81 @@
+# 🤖 Go Discord Command Bot Function
+
+Simple command using Discord Interactions.
+
+## 🧰 Usage
+
+### POST /interactions
+
+Webhook to receive Discord command events. To receive events, you must register your application as a [Discord bot](https://discord.com/developers/applications).
+
+**Parameters**
+
+| Name                  | Description                      | Location | Type   | Sample Value                                                                                  |
+| --------------------- | -------------------------------- | -------- | ------ | --------------------------------------------------------------------------------------------- |
+| x-signature-ed25519   | Signature of the request payload | Header   | string | `d1efb...aec35`                                                                               |
+| x-signature-timestamp | Timestamp of the request payload | Header   | string | `1629837700`                                                                                  |
+| JSON Body             | GitHub webhook payload           | Body     | Object | See [Discord docs](https://discord.com/developers/docs/interactions/receiving-and-responding) |
+
+**Response**
+
+Sample `200` Response:
+
+Returns a Discord message object.
+
+```json
+{
+  "type": 4,
+  "data": {
+    "content": "Hello from Appwrite 👋"
+  }
+}
+```
+
+Sample `401` Response:
+
+```json
+{
+  "error": "Invalid request signature"
+}
+```
+
+## ⚙️ Configuration
+
+| Setting           | Value         |
+| ----------------- | ------------- |
+| Runtime           | Go (1.22)     |
+| Entrypoint        | `main.go`     |
+| Permissions       | `any`         |
+| Timeout (Seconds) | 15            |
+
+## 🔒 Environment Variables
+
+### DISCORD_PUBLIC_KEY
+
+Public Key of your application in Discord Developer Portal.
+
+| Question      | Answer                                                                                                                 |
+| ------------- | ---------------------------------------------------------------------------------------------------------------------- |
+| Required      | Yes                                                                                                                    |
+| Sample Value  | `db9...980`                                                                                                            |
+| Documentation | [Discord Docs](https://discord.com/developers/docs/tutorials/hosting-on-cloudflare-workers#creating-an-app-on-discord) |
+
+### DISCORD_APPLICATION_ID
+
+ID of your application in Discord Developer Portal.
+
+| Question      | Answer                                                                                                                 |
+| ------------- | ---------------------------------------------------------------------------------------------------------------------- |
+| Required      | Yes                                                                                                                    |
+| Sample Value  | `427...169`                                                                                                            |
+| Documentation | [Discord Docs](https://discord.com/developers/docs/tutorials/hosting-on-cloudflare-workers#creating-an-app-on-discord) |
+
+### DISCORD_TOKEN
+
+Bot token of your application in Discord Developer Portal.
+
+| Question      | Answer                                                                                                                 |
+| ------------- | ---------------------------------------------------------------------------------------------------------------------- |
+| Required      | Yes                                                                                                                    |
+| Sample Value  | `NDI...LUfg`                                                                                                           |
+| Documentation | [Discord Docs](https://discord.com/developers/docs/tutorials/hosting-on-cloudflare-workers#creating-an-app-on-discord) |

go/discord-command-bot/cli/setup.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+)
+
+func main() {
+	err := errorIfEnvMissing([]string{
+		"DISCORD_PUBLIC_KEY",
+		"DISCORD_APPLICATION_ID",
+		"DISCORD_TOKEN",
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	registerApi := "https://discord.com/api/v9/applications/" + os.Getenv("DISCORD_APPLICATION_ID") + "/commands"
+
+	bodyJson := map[string]string{"name": "hello", "description": "Hello World Command"}
+	bodyString, err := json.Marshal(bodyJson)
+	if err != nil {
+		panic(err)
+	}
+
+	req, err := http.NewRequest("POST", registerApi, bytes.NewBuffer(bodyString))
+	if err != nil {
+		panic(err)
+	}
+
+	req.Header.Set("Authorization", "Bot "+os.Getenv("DISCORD_TOKEN"))
+	req.Header.Set("Content-Type", "application/json")
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		panic(err)
+	}
+
+	defer resp.Body.Close()
+
+	fmt.Println("Command registered successfully")
+}
+
+func errorIfEnvMissing(keys []string) error {
+	missing := []string{}
+
+	for _, key := range keys {
+		if os.Getenv(key) == "" {
+			missing = append(missing, key)
+		}
+	}
+
+	if len(missing) > 0 {
+		return errors.New("Missing required fields: " + strings.Join(missing, ", "))
+	}
+
+	return nil
+}

go/discord-command-bot/discord.go

@@ -0,0 +1,76 @@
+package handler
+
+import (
+	"bytes"
+	"crypto/ed25519"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"io"
+	"strings"
+
+	"github.com/open-runtimes/types-for-go/v4"
+)
+
+type DiscordBodyData struct {
+	Name string `json:"name"`
+}
+
+type DiscordBody struct {
+	Type int             `json:"type"`
+	Data DiscordBodyData `json:"data"`
+}
+
+func discordParseBody(Context *types.Context) (DiscordBody, error) {
+	var body DiscordBody
+
+	err := json.Unmarshal(Context.Req.BodyBinary(), &body)
+	if err != nil {
+		return DiscordBody{}, err
+	}
+
+	return body, nil
+}
+
+func discordVerifyKey(body string, signature string, timestamp string, discordPublicKey string) error {
+	var msg bytes.Buffer
+
+	if signature == "" || timestamp == "" || discordPublicKey == "" {
+		return errors.New("payload or headers missing")
+	}
+
+	bytesKey, err := hex.DecodeString(discordPublicKey)
+	if err != nil {
+		return err
+	}
+
+	shaKey := ed25519.PublicKey(bytesKey)
+
+	bytesSignature, err := hex.DecodeString(signature)
+	if err != nil {
+		return err
+	}
+
+	if len(bytesSignature) != ed25519.SignatureSize || bytesSignature[63]&224 != 0 {
+		return errors.New("invalid signature key")
+	}
+
+	msg.WriteString(timestamp)
+
+	bodyReader := strings.NewReader(body)
+
+	var bodyBoffer bytes.Buffer
+
+	_, err = io.Copy(&msg, io.TeeReader(bodyReader, &bodyBoffer))
+	if err != nil {
+		return err
+	}
+
+	success := ed25519.Verify(shaKey, msg.Bytes(), bytesSignature)
+
+	if !success {
+		return errors.New("invalid body")
+	}
+
+	return nil
+}

go/discord-command-bot/go.mod

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+module openruntimes/handler
+
+go 1.22.5
+
+require github.com/open-runtimes/types-for-go/v4 v4.0.1

go/discord-command-bot/go.sum

@@ -0,0 +1,2 @@
+github.com/open-runtimes/types-for-go/v4 v4.0.1 h1:DRPNvUJl3yiiDFUxfs3AqToE78PTmr6KZxJdeCVZbdo=
+github.com/open-runtimes/types-for-go/v4 v4.0.1/go.mod h1:88UUMYovXGRbv5keL4uTKDYMWeNtIKV0BbxDRQ18/xY=

go/discord-command-bot/main.go

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+package handler
+
+import (
+	"os"
+
+	"github.com/open-runtimes/types-for-go/v4"
+)
+
+type any = map[string]interface{}
+
+func Main(Context *types.Context) types.ResponseOutput {
+	err := errorIfEnvMissing([]string{
+		"DISCORD_PUBLIC_KEY",
+		"DISCORD_APPLICATION_ID",
+		"DISCORD_TOKEN",
+	})
+	if err != nil {
+		Context.Error(err.Error())
+		return Context.Res.Text("", 500, nil)
+	}
+
+	err = discordVerifyKey(
+		Context.Req.BodyText(),
+		Context.Req.Headers["x-signature-ed25519"],
+		Context.Req.Headers["x-signature-timestamp"],
+		os.Getenv("DISCORD_PUBLIC_KEY"),
+	)
+	if err != nil {
+		Context.Error(err.Error())
+		return Context.Res.Json(any{
+			"error": "Invalid request signature.",
+		}, 401, nil)
+	}
+
+	Context.Log("Valid request")
+
+	discordBody, err := discordParseBody(Context)
+	if err != nil {
+		Context.Error(err.Error())
+		return Context.Res.Json(any{
+			"error": "Invalid body.",
+		}, 400, nil)
+	}
+
+	ApplicationCommandType := 2
+	if discordBody.Type == ApplicationCommandType && discordBody.Data.Name == "hello" {
+		Context.Log("Matched hello command - returning message")
+
+		channelMessageWithSource := 4
+		return Context.Res.Json(
+			any{
+				"type": channelMessageWithSource,
+				"data": any{
+					"content": "Hello, World!",
+				},
+			},
+			200,
+			nil,
+		)
+	}
+
+	Context.Log("Didn't match command - returning PONG")
+
+	return Context.Res.Json(any{"type": 1}, 200, nil)
+}

go/discord-command-bot/utils.go

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+package handler
+
+import (
+	"errors"
+	"os"
+	"strings"
+)
+
+func errorIfEnvMissing(keys []string) error {
+	missing := []string{}
+
+	for _, key := range keys {
+		if os.Getenv(key) == "" {
+			missing = append(missing, key)
+		}
+	}
+
+	if len(missing) > 0 {
+		return errors.New("Missing required fields: " + strings.Join(missing, ", "))
+	}
+
+	return nil
+}

go/starter/README.md

@@ -38,7 +38,7 @@ Sample `200` Response:
 | Setting           | Value         |
 | ----------------- | ------------- |
 | Runtime           | Go (1.22)     |
-| Entrypoint        | `src/main.go` |
+| Entrypoint        | `main.go`     |
 | Permissions       | `any`         |
 | Timeout (Seconds) | 15            |