diff -r d71bc6db42ef -r 4258b9e010ae src/main/kotlin/de/uapcore/lightpit/servlet/FeedServlet.kt
--- a/src/main/kotlin/de/uapcore/lightpit/servlet/FeedServlet.kt	Sat Oct 09 17:46:12 2021 +0200
+++ b/src/main/kotlin/de/uapcore/lightpit/servlet/FeedServlet.kt	Sat Oct 09 20:05:39 2021 +0200
@@ -28,10 +28,12 @@
 import de.uapcore.lightpit.AbstractServlet
 import de.uapcore.lightpit.HttpRequest
 import de.uapcore.lightpit.dao.DataAccessObject
-import de.uapcore.lightpit.util.IssueFilter
-import de.uapcore.lightpit.util.IssueSorter
-import de.uapcore.lightpit.util.SpecificFilter
+import de.uapcore.lightpit.entities.IssueHistoryData
+import de.uapcore.lightpit.entities.IssueHistoryEntry
+import de.uapcore.lightpit.viewmodel.IssueDiff
 import de.uapcore.lightpit.viewmodel.IssueFeed
+import de.uapcore.lightpit.viewmodel.IssueFeedEntry
+import java.text.SimpleDateFormat
 import javax.servlet.annotation.WebServlet
 
 @WebServlet(urlPatterns = ["/feed/*"])
@@ -41,6 +43,43 @@
         get("/%project/issues.rss", this::issues)
     }
 
+    private fun String.convertLF() = replace("\r", "").replace("\n", "<br>")
+
+    private fun fullContent(issue: IssueHistoryData) = IssueDiff(
+        issue.id,
+        issue.subject,
+        issue.component,
+        issue.status.name,
+        issue.category.name,
+        issue.subject,
+        issue.description.convertLF(),
+        issue.assignee,
+        issue.eta?.let { SimpleDateFormat("dd.MM.yyyy").format(it) } ?: "",
+        issue.affected,
+        issue.resolved
+    )
+
+    private fun diffContent(cur: IssueHistoryData, next: IssueHistoryData): IssueDiff {
+        val prev = fullContent(next)
+        val diff = fullContent(cur)
+        // TODO: compute and apply diff
+        return diff
+    }
+
+    /**
+     * Generates the feed entries.
+     * Assumes that [historyEntry] is already sorted by timestamp (descending).
+     */
+    private fun generateFeedEntries(historyEntry: List<IssueHistoryEntry>) =
+        if (historyEntry.isEmpty()) emptyList()
+        else historyEntry.zipWithNext().map { (cur, next) ->
+            IssueFeedEntry(
+                cur.time, cur.type, diffContent(cur.data, next.data)
+            )
+        }.plus(
+            historyEntry.last().let { IssueFeedEntry(it.time, it.type, fullContent(it.data)) }
+        )
+
     private fun issues(http: HttpRequest, dao: DataAccessObject) {
         val project = http.pathParams["project"]?.let { dao.findProjectByNode(it) }
         if (project == null) {
@@ -48,10 +87,12 @@
             return
         }
 
-        // TODO: add a timestamp filter (e.g. last 30 days)
-        val issues = dao.listIssues(IssueFilter(SpecificFilter(project))).sortedWith(IssueSorter.DEFAULT_ISSUE_SORTER)
+        val days = http.param("days")?.toIntOrNull() ?: 30
 
-        http.view = IssueFeed(project, issues)
+        val issueHistory = dao.listIssueHistory(project.id, days)
+        // TODO: add comment history depending on parameter
+
+        http.view = IssueFeed(project, generateFeedEntries(issueHistory))
         http.renderFeed("issues-feed")
     }
 }
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