1 files changed, 99 insertions, 0 deletions
diff --git a/src/Gemtext.php b/src/Gemtext.php
new file mode 100644
index 0000000..d382c45
--- /dev/null
+++ b/src/Gemtext.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace GeminiFoundation;
+
+class Gemtext
+{
+  protected string $input;
+  protected array $output;
+
+  protected string $preformattedMode = 'off';
+
+  public function __construct(string $input)
+  {
+    $this->input = $input;
+  }
+
+  public function parse(): array
+  {
+    $input = fopen('php://temp', 'r+');
+    fputs($input, $this->input);
+    rewind($input);
+
+    $output = [];
+    while ($line = fgets($input)) {
+      $output[] = $this->parseLine($line);
+    }
+
+    fclose($input);
+
+    return $this->output = $output;
+  }
+
+  private function parseLine(string $input)
+  {
+    $line = [
+      'raw' => $input,
+    ];
+
+    $input = ltrim($input);
+
+    if (str_starts_with($input, '```')) {
+      $this->preformattedMode = $this->preformattedMode === 'on' ? 'off' : 'on';
+
+      $line['type'] = $this->preformattedMode === 'on' ? 'preformatted_on' : 'preformatted_off';
+      $line['text'] = $line['alt'] = trim(substr($input, 3));
+    }
+    else if ($this->preformattedMode === 'on') {
+      $line['type'] = 'preformatted';
+      $line['text'] = $line['raw'];
+    }
+
+    else if (str_starts_with($input, '#')) {
+      $firstWhitespacePosition = $this->findWhitespace($input);
+
+      $line['type'] = 'heading';
+      $line['size'] = substr_count(
+        haystack: $input,
+        needle: '#',
+        length: min($firstWhitespacePosition, 3)
+      );
+      $line['text'] = trim(substr(
+        string: $input,
+        offset: min($firstWhitespacePosition, 3)
+      ));
+    }
+    else if (str_starts_with($input, '*')) {
+      $line['type'] = 'listitem';
+      $line['text'] = trim(substr($input, 1));
+    }
+    else if (str_starts_with($input, '>')) {
+      $line['type'] = 'quote';
+      $line['text'] = trim(substr($input, 1));
+    }
+    else if (str_starts_with($input, '=>')) {
+      $whitespacePosition = $this->findWhitespace($input, 3);
+
+      $link = substr(string: $input, offset: 2, length: $whitespacePosition - 2);
+      $text = substr(string: $input, offset: $whitespacePosition);
+
+      $line['type'] = 'link';
+      $line['link'] = trim($link);
+      $line['text'] = trim($text);
+    }
+    else {
+      $line['type'] = 'text';
+      $line['text'] = rtrim($input);
+    }
+
+    return $line;
+  }
+
+  private function findWhitespace(string $input, int $offset = 0): int
+  {
+    $space = strpos($input, ' ', $offset);
+    $tab = strpos($input, "\t", $offset);
+
+    return $space === false ? ($tab === false ? PHP_INT_MAX : $tab) : $space;
+  }
+}