From c53ff0da7c53539fb58621c0915d8382c8ab642e Mon Sep 17 00:00:00 2001
From: Josh Bruce <josh@8fold.pro>
Date: Fri, 15 Oct 2021 18:43:50 -0500
Subject: [PATCH] book end build

---
 src/PageComponents/PageTitle.php              | 68 ++++++++++---------
 .../PageComponents/PageTitleBaselineTest.php  | 45 +++++++++++-
 2 files changed, 80 insertions(+), 33 deletions(-)

diff --git a/src/PageComponents/PageTitle.php b/src/PageComponents/PageTitle.php
index 4e86fee..a11fcb2 100644
--- a/src/PageComponents/PageTitle.php
+++ b/src/PageComponents/PageTitle.php
@@ -15,7 +15,7 @@ class PageTitle implements Buildable
      */
     private $store;
 
-    private string $titleStyle = 'page';
+    private $titles = [];
 
     private bool $isReversed = false;
 
@@ -29,12 +29,6 @@ public function __construct(Store $store)
         $this->store = $store;
     }
 
-    public function bookEnd(): PageTitle
-    {
-        $this->titleStyle = 'book-end';
-        return $this;
-    }
-
     public function reversed(): PageTitle
     {
         $this->isReversed = true;
@@ -44,14 +38,18 @@ public function reversed(): PageTitle
     public function build(): string
     {
         $titles = $this->titles();
-        if ($this->titleStyle === 'book-end' and count($titles) > 2) {
-            $t = [];
-            $t[] = array_shift($titles);
-            $t[] = array_pop($titles);
+        return $this->combineTitles($titles);
+    }
 
-            $titles = $t;
-        }
-        return implode(' | ', $titles);
+    public function buildBookEnd(): string
+    {
+        $titles = $this->titles();
+
+        $t = [];
+        $t[] = array_shift($titles);
+        $t[] = array_pop($titles);
+
+        return $this->combineTitles($t);
     }
 
     public function __toString(): string
@@ -59,33 +57,41 @@ public function __toString(): string
         return $this->build();
     }
 
+    private function combineTitles(array $titles): string
+    {
+        if ($this->isReversed()) {
+            $titles = array_reverse($titles);
+        }
+        return implode(' | ', $titles);
+    }
+
     /**
      * @return array<string> [description]
      */
     private function titles(): array
     {
-        $titles = [];
-        $s = $this->store();
-        while (! $s->isRoot()) {
-            $m = $s->markdown();
-            if (is_object($m)) {
-                $titles[] = $m->title();
+        if (count($this->titles) === 0) {
+            $titles = [];
+            $s = $this->store();
+            while (! $s->isRoot()) {
+                $m = $s->markdown();
+                if (is_object($m)) {
+                    $titles[] = $m->title();
+                }
+
+                $s = $s->up();
             }
 
-            $s = $s->up();
-        }
-
-        if ($s->isRoot()) {
-            $m = $s->markdown();
-            if (is_object($m)) {
-                $titles[] = $m->title();
+            if ($s->isRoot()) {
+                $m = $s->markdown();
+                if (is_object($m)) {
+                    $titles[] = $m->title();
+                }
             }
-        }
 
-        if ($this->isReversed()) {
-            return array_reverse($titles);
+            $this->titles = $titles;
         }
-        return $titles;
+        return $this->titles;
     }
 
     private function isReversed(): bool
diff --git a/tests/PageComponents/PageTitleBaselineTest.php b/tests/PageComponents/PageTitleBaselineTest.php
index 6882c10..c4a2dc0 100644
--- a/tests/PageComponents/PageTitleBaselineTest.php
+++ b/tests/PageComponents/PageTitleBaselineTest.php
@@ -33,11 +33,11 @@
     )->toBe('Sub | Subfolder content title | Index page');
 });
 
-test('Book-end page title style', function() {
+test('Book end page title style', function() {
     $store = Store::create($this->root, '/subfolder/sub');
 
     expect(
-        PageTitle::create($store)->bookEnd()->build()
+        PageTitle::create($store)->buildBookEnd()
     )->toBe(
         'Sub | Index page'
     );
@@ -50,3 +50,44 @@
         PageTitle::create($store)->reversed()->build()
     )->toBe('Index page | Subfolder content title | Sub');
 });
+
+$ms = function($start, $end) {
+    $time = $end - $start;
+    $ms   = $time/1e+6;
+    return $ms;
+};
+
+test('Performant and cached', function() use ($ms) {
+    $store = Store::create($this->root, '/subfolder/sub');
+
+    $start = hrtime(true);
+
+    $pageTitle = PageTitle::create($store);
+
+    $start1 = hrtime(true);
+
+    $build1 = $pageTitle->build();
+
+    $end1 = hrtime(true);
+
+    $start2 = hrtime(true);
+
+    $build2 = $pageTitle->buildBookend();
+
+    $end2 = hrtime(true);
+
+    // Total elapsed time
+    $leadTime = $ms($start, $end2);
+
+    expect($leadTime)->toBeLessThan(0.5);
+
+    // build call
+    $cycleTime1 = $ms($start1, $end1);
+
+    expect($cycleTime1)->toBeLessThan(0.4);
+
+    // build book end call
+    $cycleTime2 = $ms($start2, $end2);
+
+    expect($cycleTime2)->toBeLessThan(0.002);
+});