Initial commit

1 files changed, 285 insertions, 0 deletions

diff --git a/service/service.go b/service/service.go
new file mode 100644
index 0000000..7088a9b
--- /dev/null
+++ b/service/service.go
@@ -0,0 +1,285 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+
+	"mastodon"
+	"web/model"
+	"web/renderer"
+	"web/util"
+)
+
+var (
+	ErrInvalidArgument = errors.New("invalid argument")
+	ErrInvalidToken    = errors.New("invalid token")
+	ErrInvalidClient   = errors.New("invalid client")
+)
+
+type Service interface {
+	ServeHomePage(ctx context.Context, client io.Writer) (err error)
+	GetAuthUrl(ctx context.Context, instance string) (url string, sessionID string, err error)
+	GetUserToken(ctx context.Context, sessionID string, c *mastodon.Client, token string) (accessToken string, err error)
+	ServeErrorPage(ctx context.Context, client io.Writer, err error)
+	ServeSigninPage(ctx context.Context, client io.Writer) (err error)
+	ServeTimelinePage(ctx context.Context, client io.Writer, c *mastodon.Client, maxID string, sinceID string, minID string) (err error)
+	ServeThreadPage(ctx context.Context, client io.Writer, c *mastodon.Client, id string, reply bool) (err error)
+	Like(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error)
+	UnLike(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error)
+	Retweet(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error)
+	UnRetweet(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error)
+	PostTweet(ctx context.Context, client io.Writer, c *mastodon.Client, content string, replyToID string) (err error)
+}
+
+type service struct {
+	clientName    string
+	clientScope   string
+	clientWebsite string
+	renderer      renderer.Renderer
+	sessionRepo   model.SessionRepository
+	appRepo       model.AppRepository
+}
+
+func NewService(clientName string, clientScope string, clientWebsite string,
+	renderer renderer.Renderer, sessionRepo model.SessionRepository,
+	appRepo model.AppRepository) Service {
+	return &service{
+		clientName:    clientName,
+		clientScope:   clientScope,
+		clientWebsite: clientWebsite,
+		renderer:      renderer,
+		sessionRepo:   sessionRepo,
+		appRepo:       appRepo,
+	}
+}
+
+func (svc *service) GetAuthUrl(ctx context.Context, instance string) (
+	redirectUrl string, sessionID string, err error) {
+	if !strings.HasPrefix(instance, "https://") {
+		instance = "https://" + instance
+	}
+
+	sessionID = util.NewSessionId()
+	err = svc.sessionRepo.Add(model.Session{
+		ID:          sessionID,
+		InstanceURL: instance,
+	})
+	if err != nil {
+		return
+	}
+
+	app, err := svc.appRepo.Get(instance)
+	if err != nil {
+		if err != model.ErrAppNotFound {
+			return
+		}
+
+		var mastoApp *mastodon.Application
+		mastoApp, err = mastodon.RegisterApp(ctx, &mastodon.AppConfig{
+			Server:       instance,
+			ClientName:   svc.clientName,
+			Scopes:       svc.clientScope,
+			Website:      svc.clientWebsite,
+			RedirectURIs: svc.clientWebsite + "/oauth_callback",
+		})
+		if err != nil {
+			return
+		}
+
+		app = model.App{
+			InstanceURL:  instance,
+			ClientID:     mastoApp.ClientID,
+			ClientSecret: mastoApp.ClientSecret,
+		}
+
+		err = svc.appRepo.Add(app)
+		if err != nil {
+			return
+		}
+	}
+
+	u, err := url.Parse(path.Join(instance, "/oauth/authorize"))
+	if err != nil {
+		return
+	}
+
+	q := make(url.Values)
+	q.Set("scope", "read write follow")
+	q.Set("client_id", app.ClientID)
+	q.Set("response_type", "code")
+	q.Set("redirect_uri", svc.clientWebsite+"/oauth_callback")
+	u.RawQuery = q.Encode()
+
+	redirectUrl = u.String()
+
+	return
+}
+
+func (svc *service) GetUserToken(ctx context.Context, sessionID string, c *mastodon.Client,
+	code string) (token string, err error) {
+	if len(code) < 1 {
+		err = ErrInvalidArgument
+		return
+	}
+
+	session, err := svc.sessionRepo.Get(sessionID)
+	if err != nil {
+		return
+	}
+
+	app, err := svc.appRepo.Get(session.InstanceURL)
+	if err != nil {
+		return
+	}
+
+	data := &bytes.Buffer{}
+	err = json.NewEncoder(data).Encode(map[string]string{
+		"client_id":     app.ClientID,
+		"client_secret": app.ClientSecret,
+		"grant_type":    "authorization_code",
+		"code":          code,
+		"redirect_uri":  svc.clientWebsite + "/oauth_callback",
+	})
+	if err != nil {
+		return
+	}
+
+	resp, err := http.Post(app.InstanceURL+"/oauth/token", "application/json", data)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+
+	var res struct {
+		AccessToken string `json:"access_token"`
+	}
+
+	err = json.NewDecoder(resp.Body).Decode(&res)
+	if err != nil {
+		return
+	}
+	/*
+		err = c.AuthenticateToken(ctx, code, svc.clientWebsite+"/oauth_callback")
+		if err != nil {
+			return
+		}
+		err = svc.sessionRepo.Update(sessionID, c.GetAccessToken(ctx))
+	*/
+
+	return res.AccessToken, nil
+}
+
+func (svc *service) ServeHomePage(ctx context.Context, client io.Writer) (err error) {
+	err = svc.renderer.RenderHomePage(ctx, client)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (svc *service) ServeErrorPage(ctx context.Context, client io.Writer, err error) {
+	svc.renderer.RenderErrorPage(ctx, client, err)
+}
+
+func (svc *service) ServeSigninPage(ctx context.Context, client io.Writer) (err error) {
+	err = svc.renderer.RenderSigninPage(ctx, client)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (svc *service) ServeTimelinePage(ctx context.Context, client io.Writer,
+	c *mastodon.Client, maxID string, sinceID string, minID string) (err error) {
+
+	var hasNext, hasPrev bool
+	var nextLink, prevLink string
+
+	var pg = mastodon.Pagination{
+		MaxID:   maxID,
+		SinceID: sinceID,
+		MinID:   minID,
+		Limit:   20,
+	}
+
+	statuses, err := c.GetTimelineHome(ctx, &pg)
+	if err != nil {
+		return err
+	}
+
+	if len(pg.MaxID) > 0 {
+		hasNext = true
+		nextLink = fmt.Sprintf("/timeline?max_id=%s", pg.MaxID)
+	}
+	if len(pg.SinceID) > 0 {
+		hasPrev = true
+		prevLink = fmt.Sprintf("/timeline?since_id=%s", pg.SinceID)
+	}
+
+	data := renderer.NewTimelinePageTemplateData(statuses, hasNext, nextLink, hasPrev, prevLink)
+	err = svc.renderer.RenderTimelinePage(ctx, client, data)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (svc *service) ServeThreadPage(ctx context.Context, client io.Writer, c *mastodon.Client, id string, reply bool) (err error) {
+	status, err := c.GetStatus(ctx, id)
+	if err != nil {
+		return
+	}
+
+	context, err := c.GetStatusContext(ctx, id)
+	if err != nil {
+		return
+	}
+
+	data := renderer.NewThreadPageTemplateData(status, context, reply, id)
+	err = svc.renderer.RenderThreadPage(ctx, client, data)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (svc *service) Like(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error) {
+	_, err = c.Favourite(ctx, id)
+	return
+}
+
+func (svc *service) UnLike(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error) {
+	_, err = c.Unfavourite(ctx, id)
+	return
+}
+
+func (svc *service) Retweet(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error) {
+	_, err = c.Reblog(ctx, id)
+	return
+}
+
+func (svc *service) UnRetweet(ctx context.Context, client io.Writer, c *mastodon.Client, id string) (err error) {
+	_, err = c.Unreblog(ctx, id)
+	return
+}
+
+func (svc *service) PostTweet(ctx context.Context, client io.Writer, c *mastodon.Client, content string, replyToID string) (err error) {
+	tweet := &mastodon.Toot{
+		Status:      content,
+		InReplyToID: replyToID,
+	}
+	_, err = c.PostStatus(ctx, tweet)
+	return
+}