From 6ec88b36b9e4aabfc4c6c79ffcd23ad75b8101c5 Mon Sep 17 00:00:00 2001
From: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Date: Thu, 6 Apr 2023 23:30:02 +0300
Subject: [PATCH] LibWeb: Implement "get the target history entry" for
 navigables

---
 Userland/Libraries/LibWeb/HTML/Navigable.cpp | 20 ++++++++++++++++++++
 Userland/Libraries/LibWeb/HTML/Navigable.h   |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/Userland/Libraries/LibWeb/HTML/Navigable.cpp b/Userland/Libraries/LibWeb/HTML/Navigable.cpp
index 60702bd5183..18a7a0286fb 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigable.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Navigable.cpp
@@ -77,6 +77,26 @@ ErrorOr<void> Navigable::initialize_navigable(JS::NonnullGCPtr<DocumentState> do
     return {};
 }
 
+// https://html.spec.whatwg.org/multipage/browsing-the-web.html#getting-the-target-history-entry
+JS::GCPtr<SessionHistoryEntry> Navigable::get_the_target_history_entry(int target_step) const
+{
+    // 1. Let entries be the result of getting session history entries for navigable.
+    auto& entries = get_session_history_entries();
+
+    // 2. Return the item in entries that has the greatest step less than or equal to step.
+    JS::GCPtr<SessionHistoryEntry> result = nullptr;
+    for (auto& entry : entries) {
+        auto entry_step = entry->step.get<int>();
+        if (entry_step <= target_step) {
+            if (!result || result->step.get<int>() < entry_step) {
+                result = entry;
+            }
+        }
+    }
+
+    return result;
+}
+
 // https://html.spec.whatwg.org/multipage/document-sequences.html#nav-document
 JS::GCPtr<DOM::Document> Navigable::active_document()
 {
diff --git a/Userland/Libraries/LibWeb/HTML/Navigable.h b/Userland/Libraries/LibWeb/HTML/Navigable.h
index 61c1d9d7f8a..6340f18acfa 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigable.h
+++ b/Userland/Libraries/LibWeb/HTML/Navigable.h
@@ -42,6 +42,8 @@ public:
     JS::GCPtr<WindowProxy> active_window_proxy();
     JS::GCPtr<Window> active_window();
 
+    JS::GCPtr<SessionHistoryEntry> get_the_target_history_entry(int target_step) const;
+
     String target_name() const;
 
     JS::GCPtr<NavigableContainer> container() const;