From ffe0f9d2a9ddfdc9a4aa7a65c8777f9b302a25fe Mon Sep 17 00:00:00 2001
From: Kelly Norton <kellegous@gmail.com>
Date: Tue, 22 Oct 2024 10:08:42 -0400
Subject: [PATCH] Added DotRenderer for debugging of AutomataMatcher

---
 bin/render-state-machine            | 21 +++++++++++++++
 src/AutomataMatcher.php             | 30 +++++++++++++++++++--
 src/AutomataMatcher/DotRenderer.php | 41 +++++++++++++++++++++++++++++
 src/AutomataMatcher/State.php       | 35 +++++++++++++++++++++++-
 4 files changed, 124 insertions(+), 3 deletions(-)
 create mode 100755 bin/render-state-machine
 create mode 100644 src/AutomataMatcher/DotRenderer.php

diff --git a/bin/render-state-machine b/bin/render-state-machine
new file mode 100755
index 0000000..ab398dd
--- /dev/null
+++ b/bin/render-state-machine
@@ -0,0 +1,21 @@
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+use Kellegous\CodeOwners\AutomataMatcher;
+use Kellegous\CodeOwners\AutomataMatcher\DotRenderer;
+use Kellegous\CodeOwners\Owners;
+
+require __DIR__ . '/../vendor/autoload.php';
+
+if ($argc !== 2) {
+    fprintf(STDERR, "Usage: %s <filename>\n", $argv[0]);
+    exit(1);
+}
+
+$matcher = AutomataMatcher::build(
+    Owners::fromFile($argv[1])->getRules()
+);
+
+printf("%s\n", DotRenderer::render($matcher));
\ No newline at end of file
diff --git a/src/AutomataMatcher.php b/src/AutomataMatcher.php
index 3d185f0..66a7066 100644
--- a/src/AutomataMatcher.php
+++ b/src/AutomataMatcher.php
@@ -51,8 +51,6 @@ private static function parsePattern(Pattern $pattern): array
         $tokens = [];
         $pattern = $pattern->toString();
 
-        $original = $pattern;
-
         if (!str_starts_with($pattern, '/')) {
             $pattern = '**/' . $pattern;
         }
@@ -131,4 +129,32 @@ public function asJson(): array
     {
         return $this->start->jsonSerialize();
     }
+
+    /**
+     * @return array{nodes: array<string, int>, edges: array{from: string, to: string, label: string}[]}
+     */
+    public function getDebugInfo(): array
+    {
+        $patterns = [];
+        foreach ($this->rules as $rule) {
+            foreach (self::parsePattern($rule->getPattern()) as $token) {
+                $patterns[$token->getRegex()] = $token->getPattern();
+            }
+        }
+
+        $nodes = [];
+        $edges = [];
+        $this->start->getDebugInfo($nodes, $edges);
+        $edges = array_map(
+            function (array $edge) use ($patterns): array {
+                ['from' => $from, 'to' => $to, 'label' => $label] = $edge;
+                if ($label !== '**') {
+                    $label = $patterns[$label] ?? '??';
+                }
+                return ['from' => $from, 'to' => $to, 'label' => $label];
+            },
+            $edges
+        );
+        return ['nodes' => $nodes, 'edges' => $edges];
+    }
 }
\ No newline at end of file
diff --git a/src/AutomataMatcher/DotRenderer.php b/src/AutomataMatcher/DotRenderer.php
new file mode 100644
index 0000000..9570810
--- /dev/null
+++ b/src/AutomataMatcher/DotRenderer.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Kellegous\CodeOwners\AutomataMatcher;
+
+use Kellegous\CodeOwners\AutomataMatcher;
+
+final class DotRenderer
+{
+    /**
+     * @param AutomataMatcher $matcher
+     * @return string
+     */
+    public static function render(AutomataMatcher $matcher): string
+    {
+        ['nodes' => $nodes, 'edges' => $edges] = $matcher->getDebugInfo();
+
+        $start = array_key_first($nodes);
+
+        $lines = [
+            'node [shape = circle; label = "";];',
+            "{$start} [peripheries = 2;];",
+        ];
+        foreach ($nodes as $id => $priority) {
+            $label = $priority === -1 ? '' : $priority;
+            $lines[] = "{$id} [label=\"{$label}\";];";
+        }
+
+        foreach ($edges as ['from' => $from, 'to' => $to, 'label' => $label]) {
+            $lines[] = "{$from} -> {$to} [label=\"{$label}\"];";
+        }
+
+        return implode(
+            PHP_EOL,
+            [
+                'digraph G {',
+                ...$lines,
+                '}',
+            ]
+        );
+    }
+}
\ No newline at end of file
diff --git a/src/AutomataMatcher/State.php b/src/AutomataMatcher/State.php
index c95339c..0c9c8a7 100644
--- a/src/AutomataMatcher/State.php
+++ b/src/AutomataMatcher/State.php
@@ -2,11 +2,14 @@
 
 namespace Kellegous\CodeOwners\AutomataMatcher;
 
-use http\Exception\InvalidArgumentException;
+use InvalidArgumentException;
 use JsonSerializable;
 
 final class State implements JsonSerializable
 {
+    /**
+     * @var int
+     */
     private int $priority = -1;
 
     /**
@@ -19,6 +22,9 @@ final class State implements JsonSerializable
      */
     private bool $isRecursive;
 
+    /**
+     * @param bool $isRecursive
+     */
     public function __construct(bool $isRecursive = false)
     {
         $this->isRecursive = $isRecursive;
@@ -99,4 +105,31 @@ public function jsonSerialize(): array
             '**' => $this->isRecursive,
         ];
     }
+
+    /**
+     * @param array<string, int> $nodes
+     * @param array{from:int, to: int, label:string}[] $edges
+     * @return void
+     */
+    public function getDebugInfo(
+        array &$nodes,
+        array &$edges
+    ): void {
+        $nodes[spl_object_id($this)] = $this->priority;
+        foreach ($this->edges as $regex => $state) {
+            $edges[] = [
+                'from' => spl_object_id($this),
+                'to' => spl_object_id($state),
+                'label' => $regex,
+            ];
+            $state->getDebugInfo($nodes, $edges);
+        }
+        if ($this->isRecursive) {
+            $edges[] = [
+                'from' => spl_object_id($this),
+                'to' => spl_object_id($this),
+                'label' => '**',
+            ];
+        }
+    }
 }
\ No newline at end of file