Add avatar to AccountMeta (#779)

smol change. couple of new rules need avatar cids. currently have to
fetch from public api before the rule processes in a separate request
which is meh, since we have the info here already.

automod/engine/account_meta.go

@@ -32,6 +32,8 @@ type AccountMeta struct {
 
 type ProfileSummary struct {
 	HasAvatar   bool
+	AvatarCid   *string
+	BannerCid   *string
 	Description *string
 	DisplayName *string
 }

automod/engine/cid_from_cdn_test.go

@@ -0,0 +1,42 @@
+package engine
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestCidFromCdnUrl(t *testing.T) {
+	assert := assert.New(t)
+
+	fixCid := "abcdefghijk"
+
+	fixtures := []struct {
+		url string
+		cid *string
+	}{
+		{
+			url: "https://cdn.bsky.app/img/avatar/plain/did:plc:abc123/abcdefghijk@jpeg",
+			cid: &fixCid,
+		},
+		{
+			url: "https://cdn.bsky.app/img/feed_fullsize/plain/did:plc:abc123/abcdefghijk@jpeg",
+			cid: &fixCid,
+		},
+		{
+			url: "https://cdn.bsky.app/img/feed_fullsize",
+			cid: nil,
+		},
+		{
+			url: "https://cdn.bsky.app/img/feed_fullsize/plain/did:plc:abc123/abcdefghijk",
+			cid: &fixCid,
+		},
+		{
+			url: "https://cdn.asky.app/img/feed_fullsize/plain/did:plc:abc123/abcdefghijk@jpeg",
+			cid: nil,
+		},
+	}
+
+	for _, fix := range fixtures {
+		assert.Equal(fix.cid, cidFromCdnUrl(&fix.url))
+	}
+}

automod/engine/fetch_account_meta.go

@@ -75,6 +75,8 @@ func (e *Engine) GetAccountMeta(ctx context.Context, ident *identity.Identity) (
 
 	am.Profile = ProfileSummary{
 		HasAvatar:   pv.Avatar != nil,
+		AvatarCid:   cidFromCdnUrl(pv.Avatar),
+		BannerCid:   cidFromCdnUrl(pv.Banner),
 		Description: pv.Description,
 		DisplayName: pv.DisplayName,
 	}

automod/engine/util.go

@@ -1,5 +1,10 @@
 package engine
 
+import (
+	"net/url"
+	"strings"
+)
+
 func dedupeStrings(in []string) []string {
 	var out []string
 	seen := make(map[string]bool)
@@ -11,3 +16,22 @@ func dedupeStrings(in []string) []string {
 	}
 	return out
 }
+
+// get the cid from a bluesky cdn url
+func cidFromCdnUrl(str *string) *string {
+	if str == nil {
+		return nil
+	}
+
+	u, err := url.Parse(*str)
+	if err != nil || u.Host != "cdn.bsky.app" {
+		return nil
+	}
+
+	parts := strings.Split(u.Path, "/")
+	if len(parts) != 6 {
+		return nil
+	}
+
+	return &strings.Split(parts[5], "@")[0]
+}