script to convert local git commit log into JSON

git-log-to-json.php

<?php

// script to convert local git commit log history into JSON format
// usage: cd git-repository && php git-log-to-json.php > commits.json
// script might take a while to execute 

$tags = [ ];
$lines = shell_exec('git show-ref --tags');
foreach (array_filter(explode("\n", $lines)) as $line) {
  list($commit, $ref) = explode(" ", $line, 2);
  $tags[$commit] = preg_replace("/^refs\/tags\//", "", $ref);
}

$ids = [ ];
$lines = shell_exec('git log --full-history --pretty="format:%H"');
foreach (explode("\n", $lines) as $line) {
  $ids[] = $line;
}

$commits = [ ];
foreach ($ids as $id) {
  $output = shell_exec('git log -1 --name-only --pretty="format:%H xxxxPARENTSxxxx %P xxxxDATExxxx %ai xxxxAUTHOR-NAMExxxx %an xxxxAUTHOR-EMAILxxxx %ae xxxxMSGxxxx %s xxxxFILESxxxx" ' . $id);

  if (! preg_match("/^([a-f0-9]+)\sxxxxPARENTSxxxx\s(([a-f0-9]+\s)*\s?)xxxxDATExxxx\s(\d+-\d+-\d+\s\d+:\d+:\d+\s[^\s]+)\sxxxxAUTHOR-NAMExxxx\s(.*)?\sxxxxAUTHOR-EMAILxxxx\s(.*?)\sxxxxMSGxxxx\s(.*?)\sxxxxFILESxxxx\s*/", $output, $matches)) {
    die("oops, unexpected input: " . $output . PHP_EOL);
  }

  $commits[$id] = [
    "_key" => $id,
    "date" => $matches[4], 
    "author" => [ 
      "name" => $matches[5], 
      "email" => str_replace("@", " (at) ", $matches[6]) . ".nospam", 
    ], 
    "message" => $matches[7] 
  ];

  if ($matches[2] !== "") {
    $commits[$id]["parents"] = explode(" ", trim($matches[2]));
  }

  $files = trim(substr($output, strlen($matches[0])));

  if ($files !== "") {
    $commits[$id]["files"] = explode("\n", $files);
  }

  if (isset($tags[$id])) {
    $commits[$id]["tag"] = $tags[$id];
  }
}

echo json_encode(array_values($commits), false) . PHP_EOL;