<?php

// D++ changelog generator, saves 15 minutes for each release :-)

// Pattern list
$categories = [
    'break' => '💣 Breaking Changes',
    'breaking' => '💣 Breaking Changes',
    'feat' => '✨ New Features',
    'feature' => '✨ New Features',
    'add' => '✨ New Features',
    'added' => '✨ New Features',
    'fix' => '🐞 Bug Fixes',
    'bug' => '🐞 Bug Fixes',
    'bugfix' => '🐞 Bug Fixes',
    'fixed' => '🐞 Bug Fixes',
    'fixes' => '🐞 Bug Fixes',
    'perf' => '🚀 Performance Improvements',
    'performance' => '🚀 Performance Improvements',
    'impro' => '♻️ Refactoring',
    'improved' => '♻️ Refactoring',
    'improvement' => '♻️ Refactoring',
    'refactor' => '♻️ Refactoring',
    'refactored' => '♻️ Refactoring',
    'refactoring' => '♻️ Refactoring',
    'deprecated' => '♻️ Refactoring',
    'deprecate' => '♻️ Refactoring',
    'remove' => '♻️ Refactoring',
    'change' => '♻️ Refactoring',
    'changed' => '♻️ Refactoring',
    'test' => '🚨 Testing',
    'tests' => '🚨 Testing',
    'testing' => '🚨 Testing',
    'ci' => '👷 Build/CI',
    'build' => '👷 Build/CI',
    'docs' => '📚 Documentation',
    'documentation' => '📚 Documentation',
    'style' => '💎 Style Changes',
    'chore' => '🔧 Chore',
    'misc' => '📜 Miscellaneous Changes',
    'update' => '📜 Miscellaneous Changes',
    'updated' => '📜 Miscellaneous Changes',
];

$catgroup = [];
$changelog = [];
$githubstyle = true;
if (count($argv) > 2 && $argv[1] == '--discord') {
    $githubstyle = false;
}

// Magic sauce
exec("git log --format=\"%s\" $(git log --no-walk --tags | head -n1 | cut -d ' ' -f 2)..HEAD | grep -v '^Merge '", $changelog);

// Leadin
if ($githubstyle) {
    echo "The changelog is listed below:\n\nRelease Changelog\n===========\n";
} else {
    echo "The changelog is listed below:\n\n__**Release Changelog**__\n";
}

// Case insensitive removal of duplicates
$changelog = array_intersect_key($changelog, array_unique(array_map("strtolower", $changelog)));

// remove duplicates where two entries are the same but one ends with a GitHub pull request link
foreach ($changelog as $item) {
    $entryWithoutPrLink = preg_replace('/( \(#\d+\))$/', '', $item);
    if ($entryWithoutPrLink === $item) {
        continue;
    }

    // if $item ends with (#123)
    foreach ($changelog as $key => $change) {
        if ($entryWithoutPrLink === $change) {
            unset($changelog[$key]);
            break;
        }
    }
}

foreach ($changelog as $change) {

    // Wrap anything that looks like a symbol name in backticks
    $change = preg_replace('/([a-zA-Z][\w_\/\-]+\.\w+|\S+\(\)|\w+::\w+|dpp::\w+|utility::\w+|(\w+_\w+)+)/', '`$1`', $change);
    $change = preg_replace("/vs(\d+)/", "Visual Studio $1", $change);
    $change = preg_replace("/\bfaq\b/", "FAQ", $change);
    $change = preg_replace("/\bdiscord\b/", "Discord", $change);
    $change = preg_replace("/\bmicrosoft\b/", "Microsoft", $change);
    $change = preg_replace("/\bwindows\b/", "Windows", $change);
    $change = preg_replace("/\blinux\b/", "Linux", $change);
    $change = preg_replace("/\sarm(\d+)\s/i", ' ARM$1 ', $change);
    $change = preg_replace("/\b(was|is|wo)nt\b/i", '$1n\'t', $change);
    $change = preg_replace("/\bfreebsd\b/", 'FreeBSD', $change);
    $change = preg_replace("/``/", "`", $change);

    // Match keywords against categories
    $matched = false;
    foreach ($categories as $cat => $header) {
        // Purposefully ignored: comments that are one word, merge commits, and version bumps
        if (strpos($change, ' ') === false || preg_match("/^Merge (branch|pull request|remote-tracking branch) /", $change) || preg_match("/version bump/i", $change)) {
            $matched = true;
            continue;
        }
        // Groupings
        if ((preg_match("/^" . $cat . ":/i", $change)) || (preg_match("/^\[" . $cat . "\//i", $change)) || (preg_match("/^\[" . $cat . "\]/i", $change)) || (preg_match("/^\[" . $cat . ":/i", $change)) || (preg_match("/^" . $cat . "\//i", $change)) || (preg_match("/^" . $cat . ":/i", $change))) {
            if (!isset($catgroup[$header])) {
                $catgroup[$header] = [];
            }
            $matched = true;
            $catgroup[$header][] = preg_replace("/^\S+\s+/", "", $change);
            break;
        } else if (preg_match("/^" . $cat . " /i", $change)) {
            if (!isset($catgroup[$header])) {
                $catgroup[$header] = [];
            }
            $matched = true;
            $catgroup[$header][] = $change;
            break;
        }
    }
}

// Output tidy formatting
foreach ($catgroup as $cat => $list) {
    echo "\n" . ($githubstyle ? '## ' : '__**') . $cat . ($githubstyle ? '' : '**__') . "\n";
    foreach ($list as $item) {
        // Exclude bad commit messages like 'typo fix', 'test push' etc by pattern
        if (!preg_match("/^(typo|test|fix)\s\w+$/", $item) && strpos($item, ' ') !== false) {
            echo ($githubstyle ? '-' : '•') . ' ' . ucfirst(str_replace('@', '', $item)) . "\n";
        }
    }
}

// Leadout
echo "\n\n**Thank you for using D++!**\n\n";
if (!$githubstyle) {
    $version = $argv[2];
    echo 'The ' . $version . ' download can be found here: <https://dl.dpp.dev/' . $version . '>';
    echo "\n";
}