basic mastodon client implemented, will do more later

Signed-off-by: Xe <me@christine.website>

1 files changed, 107 insertions, 0 deletions

diff --git a/web/mastodon/client.go b/web/mastodon/client.go
new file mode 100644
index 0000000..bdcd8ec
--- /dev/null
+++ b/web/mastodon/client.go
@@ -0,0 +1,107 @@
+package mastodon
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+
+	"within.website/x/web"
+	"within.website/x/web/useragent"
+)
+
+// Client is the client for Mastodon
+type Client struct {
+	cli    *http.Client
+	server *url.URL
+	token  string
+}
+
+// Unauthenticated makes a new unauthenticated Mastodon client.
+func Unauthenticated(botName, botURL, instanceURL string) (*Client, error) {
+	u, err := url.Parse(instanceURL)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Client{
+		cli:    &http.Client{Transport: useragent.Transport(botName, botURL, http.DefaultTransport)},
+		server: u,
+	}, nil
+}
+
+// Authenticated makes a new authenticated Mastodon client.
+func Authenticated(botName, botURL, instanceURL, token string) (*Client, error) {
+	u, err := url.Parse(instanceURL)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Client{
+		cli: &http.Client{
+			Transport: useragent.Transport(botName, botURL, authTransport{token, http.DefaultTransport}),
+		},
+		server: u,
+		token:  token,
+	}, nil
+}
+
+type authTransport struct {
+	bearerToken string
+	next        http.RoundTripper
+}
+
+var (
+	_ http.RoundTripper = &authTransport{}
+)
+
+func (at authTransport) RoundTrip(r *http.Request) (*http.Response, error) {
+	r.Header.Set("Authorization", fmt.Sprintf("Bearer %s", at.bearerToken))
+
+	return at.next.RoundTrip(r)
+}
+
+func (c *Client) doJSONPost(ctx context.Context, path string, wantCode int, data any) (*http.Response, error) {
+	h := http.Header{}
+	h.Set("Content-Type", "application/json")
+	h.Set("Accept", "application/json")
+
+	var buf bytes.Buffer
+	if err := json.NewEncoder(&buf).Encode(data); err != nil {
+		return nil, err
+	}
+
+	return c.doRequest(ctx, http.MethodPost, "/api/v1/apps", h, http.StatusOK, &buf)
+}
+
+func (c *Client) doRequest(ctx context.Context, method, path string, headers http.Header, wantCode int, body io.Reader) (*http.Response, error) {
+	u, err := c.server.Parse(path)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest(method, u.String(), body)
+	if err != nil {
+		return nil, fmt.Errorf("mastodon: can't make request: %w", err)
+	}
+
+	for key, hn := range headers {
+		for _, hv := range hn {
+			req.Header.Set(key, hv)
+		}
+	}
+
+	resp, err := c.cli.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("mastodon: HTTP response error: %w", err)
+	}
+
+	if resp.StatusCode != wantCode {
+		return nil, web.NewError(wantCode, resp)
+	}
+
+	return resp, nil
+}