feat: add 1px transparent image in RSS item descriptions for telemetry content views

api/src/main/java/run/halo/feed/TelemetryEventInfo.java

@@ -0,0 +1,45 @@
+package run.halo.feed;
+
+import java.util.Objects;
+import lombok.Data;
+import lombok.Getter;
+import lombok.experimental.Accessors;
+import org.springframework.http.HttpHeaders;
+import org.springframework.lang.NonNull;
+
+@Data
+@Accessors(chain = true)
+public class TelemetryEventInfo {
+    private String pageUrl;
+    private String screen;
+    private String language;
+    private String languageRegion;
+    private String title;
+    private String referrer;
+    private String ip;
+    private String userAgent;
+    private String browser;
+    private String os;
+
+    @Getter(onMethod_ = @NonNull)
+    private HttpHeaders headers;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        TelemetryEventInfo that = (TelemetryEventInfo) o;
+        return Objects.equals(pageUrl, that.pageUrl) && Objects.equals(title, that.title)
+            && Objects.equals(referrer, that.referrer) && Objects.equals(ip, that.ip)
+            && Objects.equals(userAgent, that.userAgent);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(pageUrl, title, referrer, ip, userAgent);
+    }
+}

api/src/main/java/run/halo/feed/TelemetryRecorder.java

@@ -0,0 +1,8 @@
+package run.halo.feed;
+
+import org.pf4j.ExtensionPoint;
+
+public interface TelemetryRecorder extends ExtensionPoint {
+
+    void record(TelemetryEventInfo eventInfo);
+}

app/src/main/java/run/halo/feed/RssCacheManager.java

@@ -35,22 +35,23 @@ public Mono<String> get(String key, Mono<RSS2> loader) {
     }
 
     private Mono<String> generateRssXml(Mono<RSS2> loader) {
-        var builder = new RssXmlBuilder();
+        var builder = new RssXmlBuilder()
+            .withGenerator("Halo v2.0");
+
         var rssMono = loader.doOnNext(builder::withRss2);
-        var generatorMono = getRssGenerator()
-            .doOnNext(builder::withGenerator);
+
+        var generatorMono = systemInfoGetter.get()
+            .doOnNext(info -> builder.withExternalUrl(info.getUrl().toString())
+                .withGenerator("Halo v" + info.getVersion().toStableVersion().toString())
+            );
+
         var extractTagsMono = BasicProp.getBasicProp(settingFetcher)
             .doOnNext(prop -> builder.withExtractRssTags(prop.getRssExtraTags()));
+
         return Mono.when(rssMono, generatorMono, extractTagsMono)
             .then(Mono.fromSupplier(builder::toXmlString));
     }
 
-    private Mono<String> getRssGenerator() {
-        return systemInfoGetter.get()
-            .map(info -> "Halo v" + info.getVersion().toStableVersion().toString())
-            .defaultIfEmpty("Halo v2.0");
-    }
-
     @EventListener(PluginConfigUpdatedEvent.class)
     public void onPluginConfigUpdated() {
         cache.invalidateAll();

app/src/main/java/run/halo/feed/RssXmlBuilder.java

@@ -2,6 +2,7 @@
 
 import com.google.common.base.Throwables;
 import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
 import java.time.Instant;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
@@ -14,13 +15,17 @@
 import org.dom4j.Element;
 import org.dom4j.io.SAXReader;
 import org.springframework.util.CollectionUtils;
+import org.springframework.web.util.UriComponentsBuilder;
+import org.springframework.web.util.UriUtils;
+import run.halo.feed.telemetry.TelemetryEndpoint;
 
 @Slf4j
 public class RssXmlBuilder {
     private RSS2 rss2;
     private String generator = "Halo v2.0";
     private String extractRssTags;
     private Instant lastBuildDate = Instant.now();
+    private String externalUrl;
 
     public RssXmlBuilder withRss2(RSS2 rss2) {
         this.rss2 = rss2;
@@ -48,6 +53,11 @@ RssXmlBuilder withLastBuildDate(Instant lastBuildDate) {
         return this;
     }
 
+    RssXmlBuilder withExternalUrl(String externalUrl) {
+        this.externalUrl = externalUrl;
+        return this;
+    }
+
     public String toXmlString() {
         Document document = DocumentHelper.createDocument();
 
@@ -127,18 +137,19 @@ private Element parseXmlString(String xml) throws DocumentException {
         }
     }
 
-    private static void createItemElementsToChannel(Element channel, List<RSS2.Item> items) {
+    private void createItemElementsToChannel(Element channel, List<RSS2.Item> items) {
         if (CollectionUtils.isEmpty(items)) {
             return;
         }
         items.forEach(item -> createItemElementToChannel(channel, item));
     }
 
-    private static void createItemElementToChannel(Element channel, RSS2.Item item) {
+    private void createItemElementToChannel(Element channel, RSS2.Item item) {
         Element itemElement = channel.addElement("item");
         itemElement.addElement("title").addCDATA(item.getTitle());
         itemElement.addElement("link").addText(item.getLink());
-        itemElement.addElement("description").addCDATA(item.getDescription());
+        var description = getDescriptionWithTelemetry(item);
+        itemElement.addElement("description").addCDATA(description);
         itemElement.addElement("guid")
             .addAttribute("isPermaLink", "false")
             .addText(item.getGuid());
@@ -201,6 +212,29 @@ private static void createItemElementToChannel(Element channel, RSS2.Item item)
         });
     }
 
+    private String getDescriptionWithTelemetry(RSS2.Item item) {
+        if (StringUtils.isBlank(externalUrl)) {
+            return item.getDescription();
+        }
+        var uri = UriComponentsBuilder.fromUriString(item.getLink())
+            .build();
+        var telemetryBaseUri = externalUrl + TelemetryEndpoint.TELEMETRY_PATH;
+        var telemetryUri = UriComponentsBuilder.fromUriString(telemetryBaseUri)
+            .queryParam("title", UriUtils.encode(item.getTitle(), StandardCharsets.UTF_8))
+            .queryParam("url", uri.getPath())
+            .build(true)
+            .toUriString();
+
+        // Build the telemetry image HTML
+        var telemetryImageHtml = String.format(
+            "<img src=\"%s\" width=\"1\" height=\"1\" alt=\"\" style=\"opacity:0;\" />",
+            telemetryUri
+        );
+
+        // Append telemetry image to description
+        return telemetryImageHtml + item.getDescription();
+    }
+
     static <T> List<T> nullSafeList(List<T> list) {
         return list == null ? List.of() : list;
     }

app/src/main/java/run/halo/feed/telemetry/AcceptLanguageParser.java

@@ -0,0 +1,72 @@
+package run.halo.feed.telemetry;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Objects;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import lombok.experimental.UtilityClass;
+import org.springframework.lang.NonNull;
+
+@UtilityClass
+public class AcceptLanguageParser {
+
+    public record Language(String code, String script, String region, double quality) {
+        @Override
+        public String toString() {
+            return "Language{" +
+                "code='" + code + '\'' +
+                ", script='" + script + '\'' +
+                ", region='" + region + '\'' +
+                ", quality=" + quality +
+                '}';
+        }
+    }
+
+    private static final Pattern REGEX = Pattern.compile(
+        "((([a-zA-Z]+(-[a-zA-Z0-9]+){0,2})|\\*)(;q=[0-1](\\.[0-9]+)?)?)*");
+
+    @NonNull
+    public static List<Language> parseAcceptLanguage(String acceptLanguage) {
+        if (acceptLanguage == null || acceptLanguage.isEmpty()) {
+            return Collections.emptyList();
+        }
+
+        List<Language> languages = new ArrayList<>();
+        Matcher matcher = REGEX.matcher(acceptLanguage);
+
+        while (matcher.find()) {
+            String match = matcher.group();
+            if (match == null || match.isEmpty()) {
+                continue;
+            }
+
+            String[] parts = match.split(";");
+            String ietfTag = parts[0];
+            String[] ietfComponents = ietfTag.split("-");
+            String code = ietfComponents[0];
+            String script = ietfComponents.length == 3 ? ietfComponents[1] : null;
+            String region = ietfComponents.length == 3 ? ietfComponents[2]
+                : ietfComponents.length == 2 ? ietfComponents[1] : null;
+
+            double quality = 1.0;
+            if (parts.length > 1 && parts[1].startsWith("q=")) {
+                try {
+                    quality = Double.parseDouble(parts[1].substring(2));
+                } catch (NumberFormatException e) {
+                    // ignore
+                }
+            }
+
+            languages.add(new Language(code, script, region, quality));
+        }
+
+        return languages.stream()
+            .filter(Objects::nonNull)
+            .sorted(Comparator.comparingDouble((Language l) -> l.quality).reversed())
+            .collect(Collectors.toList());
+    }
+}