api: Begin implementing an API

internal/config/config.yml

@@ -39,6 +39,10 @@ http:
   # This email address can be configured here. 
   certbot_email: null
 
+  # Enable or Disable the HTTP API.
+  # In the future, it will be enabled by default, but at this point it is not.
+  api: null
+
 # Configuration for the (public) homepage of the distillery.
 home:
   # the title of the distillery to be set

internal/config/http.go

@@ -2,9 +2,12 @@ package config
 
 import (
 	"fmt"
+	"net/http"
 	"net/url"
 	"strings"
 
+	"github.com/FAU-CDI/wisski-distillery/internal/config/validators"
+	"github.com/tkw1536/pkglib/httpx"
 	"golang.org/x/net/idna"
 )
 
@@ -22,6 +25,30 @@ type HTTPConfig struct {
 	// It can be enabled by setting an email for certbot certificates.
 	// This email address can be configured here.
 	CertbotEmail string `yaml:"certbot_email" validate:"email"`
+
+	// API determines if the API is enabled.
+	// In a future version of the distillery, it will be enabled by default.
+	API validators.NullableBool `yaml:"api" validate:"bool" default:"false"`
+}
+
+var apiNotEnabled = httpx.Response{
+	StatusCode: http.StatusForbidden,
+	Body:       []byte(`{"message":"API is not enabled"}`),
+}
+
+func (hcfg HTTPConfig) APIDecorator(methods ...string) func(http.Handler) http.Handler {
+	methods = append(methods, "OPTIONS") // always permit the options method!
+
+	if !hcfg.API.Value {
+		return func(http.Handler) http.Handler {
+			return httpx.PermitMethods(apiNotEnabled, methods...)
+		}
+	}
+
+	// permit only the specified methods
+	return func(h http.Handler) http.Handler {
+		return httpx.PermitMethods(h, methods...)
+	}
 }
 
 // JoinPath returns the root public url joined with the provided parts.

internal/config/validators/bool.go

@@ -8,13 +8,13 @@ import (
 
 // NullableBool represents a bool that can be null
 type NullableBool struct {
-	Null, Value bool
+	Set, Value bool
 }
 
 func (nb *NullableBool) UnmarshalYAML(value *yaml.Node) error {
-	nb.Null = false
+	nb.Set = true
 	if err := value.Decode(&nb.Value); err != nil {
-		nb.Null = true
+		nb.Set = false
 		nb.Value = false
 	}
 
@@ -22,19 +22,19 @@ func (nb *NullableBool) UnmarshalYAML(value *yaml.Node) error {
 }
 
 func (nb NullableBool) MarshalYAML() (interface{}, error) {
-	if nb.Null {
+	if !nb.Set {
 		return nil, nil
 	}
 	return nb.Value, nil
 }
 
 func ValidateBool(value *NullableBool, dflt string) (err error) {
-	if value.Null {
+	if !value.Set {
 		res, err := strconv.ParseBool(dflt)
 		if err != nil {
 			return err
 		}
-		value.Null = false
+		value.Set = true
 		value.Value = res
 	}
 	return err

internal/dis/component/server/home/api.go

@@ -0,0 +1,64 @@
+package home
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/status"
+	"github.com/tkw1536/pkglib/httpx"
+)
+
+type API struct {
+	component.Base
+
+	Dependencies struct {
+		Home *Home
+	}
+}
+
+var (
+	_ component.Routeable = (*API)(nil)
+)
+
+func (api *API) Routes() component.Routes {
+	return component.Routes{
+		Prefix:    "/api/v1/systems",
+		Exact:     true,
+		Decorator: api.Config.HTTP.APIDecorator("GET"),
+	}
+}
+
+type APISystemInfo struct {
+	Slug    string
+	URL     string
+	Tagline string
+
+	EntityCount int
+	BundleCount int
+	LastEdit    time.Time
+}
+
+func (api *API) HandleRoute(ctx context.Context, path string) (http.Handler, error) {
+	return httpx.JSON(func(r *http.Request) ([]APISystemInfo, error) {
+		var statuses []status.WissKI
+		if api.Dependencies.Home.ShouldShowList(r) {
+			statuses = api.Dependencies.Home.homeInstances.Get(nil)
+		}
+
+		if len(statuses) == 0 {
+			return []APISystemInfo{}, nil
+		}
+
+		infos := make([]APISystemInfo, len(statuses))
+		for i, status := range statuses {
+			infos[i].Slug = status.Slug
+			infos[i].URL = status.URL
+			infos[i].EntityCount = status.Statistics.Bundles.TotalCount()
+			infos[i].BundleCount = status.Statistics.Bundles.TotalBundles
+			infos[i].LastEdit = status.Statistics.Bundles.LastEdit().Time
+		}
+		return infos, nil
+	}), nil
+}

internal/dis/component/server/home/public.go

@@ -29,7 +29,6 @@ var aboutTemplate = template.Must(template.New("about.html").Parse(aboutHTML))
 // aboutContext is passed to about.html
 type aboutContext struct {
 	Instances    []status.WissKI // list of WissKI Instancaes
-	SignedIn     bool            // is there a signed in user?
 	Logo         template.HTML
 	SelfRedirect string
 }
@@ -48,6 +47,23 @@ type publicContext struct {
 
 const logoHTML = template.HTML(`<img src="/logo.svg" alt="WissKI Distillery Logo" class="biglogo">`)
 
+// ShouldShowList determines if the given request should show a WissKI list
+func (home *Home) ShouldShowList(r *http.Request) bool {
+	allowPrivate := home.Config.Home.List.Private.Value
+	allowPublic := home.Config.Home.List.Public.Value
+
+	if allowPrivate == allowPublic {
+		return allowPrivate
+	}
+
+	user, _ := home.Dependencies.Auth.UserOf(r)
+	if user == nil {
+		return allowPublic
+	} else {
+		return allowPrivate
+	}
+}
+
 func (home *Home) publicHandler(ctx context.Context) http.Handler {
 	title := home.Config.Home.Title
 
@@ -75,10 +91,6 @@ func (home *Home) publicHandler(ctx context.Context) http.Handler {
 		pc.aboutContext.Logo = logoHTML
 		pc.aboutContext.Instances = home.homeInstances.Get(nil)
 		pc.aboutContext.SelfRedirect = home.Config.Home.SelfRedirect.String()
-		{
-			user, _ := home.Dependencies.Auth.UserOf(r)
-			pc.aboutContext.SignedIn = user != nil
-		}
 
 		// render the about template
 
@@ -89,13 +101,8 @@ func (home *Home) publicHandler(ctx context.Context) http.Handler {
 		// and return about!
 		pc.About = template.HTML(builder.String())
 
-		// user is not signed in!
-
-		if pc.aboutContext.SignedIn {
-			pc.ListEnabled = home.Config.Home.List.Private.Value
-		} else {
-			pc.ListEnabled = home.Config.Home.List.Public.Value
-		}
+		// check if we should show the list of WissKIs
+		pc.ListEnabled = home.ShouldShowList(r)
 
 		// title of the list
 		pc.ListTitle = home.Config.Home.List.Title

internal/dis/component/server/news/api.go

@@ -0,0 +1,43 @@
+package news
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/tkw1536/pkglib/httpx"
+)
+
+type API struct {
+	component.Base
+}
+
+var (
+	_ component.Routeable = (*API)(nil)
+)
+
+func (api *API) Routes() component.Routes {
+	return component.Routes{
+		Prefix:    "/api/v1/news/",
+		Exact:     true,
+		Decorator: api.Config.HTTP.APIDecorator("GET"),
+	}
+}
+
+func (api *API) HandleRoute(ctx context.Context, path string) (http.Handler, error) {
+	items, err := Items()
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := json.Marshal(items)
+	if err != nil {
+		return nil, err
+	}
+
+	return httpx.Response{
+		ContentType: "application/json",
+		Body:        data,
+	}, nil
+}

internal/dis/distillery.go

@@ -187,5 +187,9 @@ func (dis *Distillery) allComponents() []initFunc {
 		auto[*cron.Cron],
 		auto[*home.UpdateHome],
 		auto[*home.UpdateInstanceList],
+
+		// API
+		auto[*home.API],
+		auto[*news.API],
 	}
 }

internal/status/wisski.go

@@ -79,6 +79,13 @@ type BundleStatistics struct {
 	TotalMainBundles int `json:"totalMainBundles"`
 }
 
+func (bs BundleStatistics) TotalCount() (total int) {
+	for _, bundle := range bs.Bundles {
+		total += bundle.Count
+	}
+	return
+}
+
 type LastEdit struct {
 	Time  time.Time
 	Valid bool
@@ -101,10 +108,7 @@ func (bs BundleStatistics) LastEdit() (le LastEdit) {
 }
 
 func (bs BundleStatistics) Summary() string {
-	var totalCount int
-	for _, bundle := range bs.Bundles {
-		totalCount += bundle.Count
-	}
+	totalCount := bs.TotalCount()
 	if totalCount == 0 {
 		return ""
 	}