feat(ntfy): add the HTTP client, stream manager, and account discovery

Speak the ntfy JSON API directly: subscribe, publish, group topics that share a server and credentials, reconnect with backoff and a since cursor, and list account subscriptions, reservations, and ACL grants.

internal/ntfy/account.go

@@ -0,0 +1,151 @@
+package ntfy
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"lazyntfy/internal/config"
+)
+
+type accountBody struct {
+	SyncTopic     string `json:"sync_topic"`
+	Subscriptions []struct {
+		BaseURL     string  `json:"base_url"`
+		Topic       string  `json:"topic"`
+		DisplayName *string `json:"display_name"`
+	} `json:"subscriptions"`
+	Reservations []struct {
+		Topic string `json:"topic"`
+	} `json:"reservations"`
+}
+
+type grantBody struct {
+	Topic      string `json:"topic"`
+	Permission string `json:"permission"`
+}
+
+type userBody struct {
+	Grants []grantBody `json:"grants"`
+}
+
+// AccountTopics lists topics visible to this login: account subscriptions,
+// reserved topics, and ACL grants when the token can read /v1/users.
+// Wildcard patterns are skipped. Credentials are not included in errors.
+func (c *Client) AccountTopics(ctx context.Context, host string, auth config.Auth) ([]config.Sub, error) {
+	host = strings.TrimRight(strings.TrimSpace(host), "/")
+	if host == "" || (auth.Token == "" && auth.User == "") {
+		return nil, nil
+	}
+	body, status, err := c.get(ctx, host+"/v1/account", auth)
+	if err != nil {
+		return nil, err
+	}
+	if status == http.StatusUnauthorized || status == http.StatusForbidden {
+		return nil, fmt.Errorf("HTTP %d: not authorized to list topics", status)
+	}
+	if status < 200 || status >= 300 {
+		return nil, fmt.Errorf("HTTP %d from /v1/account", status)
+	}
+	var account accountBody
+	if err := json.Unmarshal(body, &account); err != nil {
+		return nil, fmt.Errorf("account response: %w", err)
+	}
+
+	var subs []config.Sub
+	seen := map[string]bool{}
+	add := func(base, topic, display string) {
+		topic = strings.TrimSpace(topic)
+		if topic == "" || strings.Contains(topic, "*") || topic == account.SyncTopic {
+			return
+		}
+		originHost := host
+		if strings.TrimSpace(base) != "" {
+			originHost = strings.TrimRight(base, "/")
+		}
+		origin, name, err := config.Resolve(topic, originHost)
+		if err != nil {
+			return
+		}
+		key := origin + "\n" + name
+		if seen[key] {
+			return
+		}
+		seen[key] = true
+		subs = append(subs, config.Sub{
+			Origin:  origin,
+			Name:    name,
+			Display: strings.TrimSpace(display),
+			Auth:    auth,
+		})
+	}
+
+	for _, sub := range account.Subscriptions {
+		display := ""
+		if sub.DisplayName != nil {
+			display = *sub.DisplayName
+		}
+		add(sub.BaseURL, sub.Topic, display)
+	}
+	for _, res := range account.Reservations {
+		add("", res.Topic, "")
+	}
+
+	usersBody, usersStatus, err := c.get(ctx, host+"/v1/users", auth)
+	if err != nil || usersStatus < 200 || usersStatus >= 300 {
+		return subs, nil
+	}
+	for _, grant := range parseGrants(usersBody) {
+		perm := strings.ToLower(grant.Permission)
+		if perm == "deny-all" || perm == "deny" || perm == "none" {
+			continue
+		}
+		add("", grant.Topic, "")
+	}
+	return subs, nil
+}
+
+func parseGrants(body []byte) []grantBody {
+	var wrapped struct {
+		Users []userBody `json:"users"`
+	}
+	if err := json.Unmarshal(body, &wrapped); err == nil && wrapped.Users != nil {
+		return flattenGrants(wrapped.Users)
+	}
+	var list []userBody
+	if err := json.Unmarshal(body, &list); err != nil {
+		return nil
+	}
+	return flattenGrants(list)
+}
+
+func flattenGrants(users []userBody) []grantBody {
+	var out []grantBody
+	for _, user := range users {
+		out = append(out, user.Grants...)
+	}
+	return out
+}
+
+func (c *Client) get(ctx context.Context, endpoint string, auth config.Auth) ([]byte, int, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+	if err != nil {
+		return nil, 0, err
+	}
+	req.Header.Set("User-Agent", userAgent)
+	req.Header.Set("Accept", "application/json")
+	auth.Apply(req)
+	resp, err := c.http().Do(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer resp.Body.Close()
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, resp.StatusCode, err
+	}
+	return body, resp.StatusCode, nil
+}