add subcommand for instance details

cmd/enbas/instance.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+
+	"codeflow.dananglin.me.uk/apollo/enbas/internal/client"
+)
+
+var instanceDetailsFormat = `INSTANCE:
+  %s - %s
+
+DOMAIN:
+  %s
+
+VERSION:
+  Running GoToSocial %s
+
+CONTACT:
+  name: %s
+  username: %s
+  email: %s
+`
+
+type instanceCommand struct {
+	*flag.FlagSet
+	summary string
+}
+
+func newInstanceCommand(name, summary string) *instanceCommand {
+	command := instanceCommand{
+		FlagSet: flag.NewFlagSet(name, flag.ExitOnError),
+		summary: summary,
+	}
+
+	command.Usage = commandUsageFunc(command.Name(), command.summary, command.FlagSet)
+
+	return &command
+}
+
+func (c *instanceCommand) Execute() error {
+	gtsClient, err := client.NewClientFromConfig()
+	if err != nil {
+		return fmt.Errorf("unable to create the GoToSocial client; %w", err)
+	}
+
+	instance, err := gtsClient.GetInstance()
+	if err != nil {
+		return fmt.Errorf("unable to retrieve the instance details; %w", err)
+	}
+
+	fmt.Printf(
+		instanceDetailsFormat,
+		instance.Title,
+		instance.Description,
+		instance.Domain,
+		instance.Version,
+		instance.Contact.Account.DisplayName,
+		instance.Contact.Account.Username,
+		instance.Contact.Email,
+	)
+
+	return nil
+}

cmd/enbas/main.go

@@ -11,6 +11,7 @@ import (
 const (
 	login    string = "login"
 	version  string = "version"
+	instance string = "instance"
 )
 
 type Executor interface {
@@ -23,6 +24,7 @@ func main() {
 	summaries := map[string]string{
 		login:    "login to an account on GoToSocial",
 		version:  "print the application's version and build information",
+		instance: "print the instance information",
 	}
 
 	flag.Usage = enbasUsageFunc(summaries)
@@ -44,6 +46,8 @@ func main() {
 		executor = newLoginCommand(login, summaries[login])
 	case version:
 		executor = newVersionCommand(version, summaries[version])
+	case instance:
+		executor = newInstanceCommand(instance, summaries[instance])
 	default:
 		fmt.Printf("ERROR: Unknown subcommand: %s\n", subcommand)
 		flag.Usage()

internal/client/client.go

@@ -19,6 +19,17 @@ type Client struct {
 	Timeout        time.Duration
 }
 
+func NewClientFromConfig() (*Client, error) {
+	config, err := config.NewAuthenticationConfigFromFile()
+	if err != nil {
+		return nil, fmt.Errorf("unable to get the authentication configuration; %w", err)
+	}
+
+	currentAuthentication := config.Authentications[config.CurrentAccount]
+
+	return NewClient(currentAuthentication), nil
+}
+
 func NewClient(authentication config.Authentication) *Client {
 	httpClient := http.Client{}
 
@@ -53,6 +64,27 @@ func (g *Client) VerifyCredentials() (model.Account, error) {
 	return account, nil
 }
 
+func (g *Client) GetInstance() (model.InstanceV2, error) {
+	path := "/api/v2/instance"
+	url := g.Authentication.Instance + path
+
+	ctx, cancel := context.WithTimeout(context.Background(), g.Timeout)
+	defer cancel()
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return model.InstanceV2{}, fmt.Errorf("unable to create the HTTP request, %w", err)
+	}
+
+	var instance model.InstanceV2
+
+	if err := g.sendRequest(request, &instance); err != nil {
+		return model.InstanceV2{}, fmt.Errorf("received an error after sending the request to get the instance details; %w", err)
+	}
+
+	return instance, nil
+}
+
 func (g *Client) sendRequest(request *http.Request, object any) error {
 	request.Header.Set("Content-Type", "application/json; charset=utf-8")
 	request.Header.Set("Accept", "application/json; charset=utf-8")

internal/config/config.go

@@ -39,7 +39,7 @@ func SaveAuthentication(username string, authentication Authentication) (string,
 
 		config.Authentications = make(map[string]Authentication)
 	} else {
-		config, err = newAuthenticationConfigFromFile()
+		config, err = NewAuthenticationConfigFromFile()
 		if err != nil {
 			return "", fmt.Errorf("unable to retrieve the existing authentication configuration; %w", err)
 		}
@@ -71,7 +71,7 @@ func SaveAuthentication(username string, authentication Authentication) (string,
 	return authenticationName, nil
 }
 
-func newAuthenticationConfigFromFile() (AuthenticationConfig, error) {
+func NewAuthenticationConfigFromFile() (AuthenticationConfig, error) {
 	path := authenticationConfigFile()
 
 	file, err := os.Open(path)

internal/model/instance_v2.go

@@ -0,0 +1,106 @@
+package model
+
+type InstanceV2 struct {
+	AccountDomain string                  `json:"account_domain"`
+	Configuration InstanceConfiguration   `json:"configuration"`
+	Contact       InstanceV2Contact       `json:"contact"`
+	Description   string                  `json:"description"`
+	Domain        string                  `json:"domain"`
+	Languages     []string                `json:"languages"`
+	Registrations InstanceV2Registrations `json:"registrations"`
+	Rules         []InstanceRule          `json:"rules"`
+	SourceURL     string                  `json:"source_url"`
+	Terms         string                  `json:"terms"`
+	Thumbnail     InstanceV2Thumbnail     `json:"thumbnail"`
+	Title         string                  `json:"title"`
+	Usage         InstanceV2Usage         `json:"usage"`
+	Version       string                  `json:"version"`
+}
+
+type InstanceConfiguration struct {
+	Accounts         InstanceConfigurationAccounts         `json:"accounts"`
+	Emojis           InstanceConfigurationEmojis           `json:"emojis"`
+	MediaAttachments InstanceConfigurationMediaAttachments `json:"media_attachments"`
+	Polls            InstanceConfigurationPolls            `json:"polls"`
+	Statuses         InstanceConfigurationStatuses         `json:"statuses"`
+	Translation      InstanceV2ConfigurationTranslation    `json:"translation"`
+	URLs             InstanceV2URLs                        `json:"urls"`
+}
+
+type InstanceConfigurationAccounts struct {
+	AllowCustomCSS   bool `json:"allow_custom_css"`
+	MaxFeaturedTags  int  `json:"max_featured_tags"`
+	MaxProfileFields int  `json:"max_profile_fields"`
+}
+
+type InstanceConfigurationEmojis struct {
+	EmojiSizeLimit int `json:"emoji_size_limit"`
+}
+
+type InstanceConfigurationMediaAttachments struct {
+	ImageMatrixLimit    int      `json:"image_matrix_limit"`
+	ImageSizeLimit      int      `json:"image_size_limit"`
+	SupportedMimeTypes  []string `json:"supported_mime_types"`
+	VideoFrameRateLimit int      `json:"video_frame_rate_limit"`
+	VideoMatrixLimit    int      `json:"video_matrix_limit"`
+	VideoSizeLimit      int      `json:"video_size_limit"`
+}
+
+type InstanceConfigurationPolls struct {
+	MaxCharactersPerOption int `json:"max_characters_per_option"`
+	MaxExpiration          int `json:"max_expiration"`
+	MaxOptions             int `json:"max_options"`
+	MinExpiration          int `json:"min_expiration"`
+}
+
+type InstanceConfigurationStatuses struct {
+	CharactersReservedPerURL int      `json:"characters_reserved_per_url"`
+	MaxCharacters            int      `json:"max_characters"`
+	MaxMediaAttachments      int      `json:"max_media_attachments"`
+	SupportedMimeTypes       []string `json:"supported_mime_types"`
+}
+
+type InstanceV2ConfigurationTranslation struct {
+	Enabled bool `json:"enabled"`
+}
+
+type InstanceV2URLs struct {
+	Streaming string `json:"streaming"`
+}
+
+type InstanceV2Contact struct {
+	Account Account `json:"account"`
+	Email   string  `json:"email"`
+}
+
+type InstanceV2Registrations struct {
+	ApprovalRequired bool   `json:"approval_required"`
+	Enabled          bool   `json:"enabled"`
+	Message          string `json:"message"`
+}
+
+type InstanceRule struct {
+	ID   string `json:"id"`
+	Text string `json:"text"`
+}
+
+type InstanceV2Thumbnail struct {
+	BlurHash             string                      `json:"blurhash"`
+	ThumbnailDescription string                      `json:"thumbnail_description"`
+	ThumbnailType        string                      `json:"thumbnail_type"`
+	URL                  string                      `json:"url"`
+	Version              InstanceV2ThumbnailVersions `json:"versions"`
+}
+
+type InstanceV2ThumbnailVersions struct {
+	Size1URL string `json:"@1x"`
+	Size2URL string `json:"@2x"`
+}
+
+type InstanceV2Usage struct {
+	Users InstanceV2Users `json:"users"`
+}
+
+type InstanceV2Users struct {
+	ActiveMonth int `json:"active_month"`
+}