#!/usr/bin/php
<?php
/*
=head1 NAME

phpabtpl - generate phpab templates with dependency autoloading

=head1 SYNOPSIS

B<phpabtpl> [I<OPTION>...] [I<composer.json>]

=head1 DESCRIPTION

B<phpabtpl> is a command-line tool used to generate B<phpab> autoloader
templates. In addition to the regular autoloading of the package's own class
files, the generated template will also include automatic loading of
dependencies and statically loaded files, based on the specification read from
a I<composer.json> file.

=head1 OPTIONS

=over 4

=item B<-h, --help>

Print a help message and exit.

=item B<--basedir> I<directory>

Set the base directory for "files" autoloading.

This option can be used to adjust the paths for statically loaded files
(Composer's "files" section), to treat them as relative to the specified
directory rather than to the source's root. This would typical be used for
packages where the actual source files are kept in a sub-directory (commonly
"src").

Limitation: This directory must be somewhere above the to-be-loaded files in
the file hierarchy. It will not traverse upwards.

=item B<--require> I<composer_package>

Adds an additional required dependency to be loaded.

I<composer_package> is the name of a Composer package, e.g. "vendor/project".
It is treated as an extra entry in the composer.json "require" section.

This option can be repeated to add multiple dependencies.

=item B<--suggest> I<composer_package>

Adds an additional suggested dependency to be (optionally) loaded.

I<composer_package> is the name of a Composer package, e.g. "vendor/project".
It is treated as an extra entry in the composer.json "suggest" section.

This option can be repeated to add multiple dependencies.

=item B<--require-file> I<file>

Adds an additional file to be loaded.

The I<file> path will be adapted to B<--basedir>, if given.
It is treated as an extra entry in the composer.json "autoload.files" section.

This option can be repeated to add multiple files.

=back

=head1 EXAMPLES

=over 4

=item Generate a template with dependency autoloading:

phpabtpl composer.json >autoload.php.tpl

=item Generate a template for an autoloader to be placed in the "src" directory:

phpabtpl --basedir src composer.json >autoload.php.tpl

=item Generate a template with manually specified dependencies:

phpabtpl --require proj1/pack1 --require-file src/autoload.php

=back

=head1 FILES

=over 4

=item F<debian/pkg-php-tools-autoloaders>

Autoloaders that are not correctly identified by B<phpabtpl> by default can be
manually specified in this file.

The format is a set of lines, with each line having the following fields:

=over 6

=item I<vendor_name>

The Composer package's vendor name (e.g. "vendor" in "vendor/project").

=item I<project_name>

The Composer package's project name (e.g. "project" in "vendor/project").

=item I<autoloader_path>

The corresponding autoloader file (e.g. "Vendor/Project/autoload.php").

=back

It can be installed in B</usr/share/pkg-php-tools/autoloaders/>I<package>.

=back

=cut
*/

$usage = <<<USAGE
Usage: $argv[0] [OPTION...] [composer.json]

  -h, --help          Print a help message and exit.
  --basedir           Set the base directory for 'files' autoloading.
  --require           Load an additional required dependency (repeatable).
  --suggest           Load an additional suggested dependency (repeatable).
  --require-file      Load an additional required file (repeatable).

USAGE;

/*
Read user input.
*/

$options = getopt('h', [
	'basedir:',
	'help',
	'require:',
	'suggest:',
	'require-file:',
], $argi);

# -h, --help
$help = isset($options['h']) || isset($options['help']);
if ($help) {
	print $usage;
	exit;
}

# --basedir
$basedir = $options['basedir'] ?? null;
if ($basedir !== null)
	$basedir = rtrim($basedir, '/').'/';

# --require, --suggest, --require-file
$extra_requires = (array)($options['require'] ?? null);
$extra_suggests = (array)($options['suggest'] ?? null);
$extra_files = (array)($options['require-file'] ?? null);

# composer.json
$composer = $argv[$argi] ?? null;
if ($composer) {
	$composer = file_get_contents($composer);
	$composer = json_decode($composer, true, 512, JSON_THROW_ON_ERROR);
} else {
	fwrite(STDERR, 'Proceeding without a composer.json file.');
	$composer = [];
}

/*
Load known autoloaders from list files
1. /usr/share/pkg-php-tools/autoloaders/common
2. /usr/share/pkg-php-tools/autoloaders/*
3. debian/pkg-php-tools-autoloaders
*/

$autoloaders = [];

function load_list($file) {
	global $autoloaders;
	if (!file_exists($file))
		return;  # Ignore missing file
	if (($fh = fopen($file, 'r')) === false)
		throw new \RuntimeException("Unable to open '$file'");
	while (($line = fgets($fh)) !== false) {
		$line = trim($line);
		if (!$line)
			continue;  # Ignore empty line
		$fields = preg_split('/\s+/', $line, 3);
		if (count($fields) < 2) {  # 3rd field may be empty
			fwrite(STDERR, "Ignoring malformed line '$line' in $file\n");
			continue;
		}
		$dependency = $fields[0].'/'.$fields[1];
		$autoloader = ($fields[2] ?? 'none') !== 'none' ? $fields[2] : null;
		$autoloaders[$dependency] = $autoloader;
	}
	if (!feof($fh))
		throw new \RuntimeException("Unable to read '$file'");
	fclose($fh);
}

# Load list of common known autoloaders
$lists_dir = dirname(dirname(__FILE__)).'/share/pkg-php-tools/autoloaders';
load_list("$lists_dir/common");

# Load other installed lists of known autoloaders
if (($dh = opendir($lists_dir)) === false)
	throw new \RuntimeException("Unable to open '$lists_dir'");
while (($file = readdir($dh)) !== false) {
	if (!in_array($file, ['.', '..', 'common']))
		load_list("$lists_dir/$file");
}
closedir($dh);

# Load list from current package
load_list('debian/pkg-php-tools-autoloaders');

/*
Figure out autoloaders based on
1. Known autoloaders
2. Guessed namespaces
*/

function get_autoloader($dependency) {
	global $autoloaders;
	# Ignore php and extensions
	if (preg_match('/^(php(-cli)?$|ext-)/', $dependency))
		return null;
	# Known?
	if (array_key_exists($dependency, $autoloaders))
		return $autoloaders[$dependency];
	# Guess
	$ns = remove_repeated_parts($dependency);
	$ns = ucwords($ns, '/-_.');
	$ns = str_replace(['-', '_', '.'], '', $ns);
	return "$ns/autoload.php";
}

function remove_repeated_parts($dependency) {
	[$vendor, $project] = explode('/', $dependency, 2);
	$vendor_parts = preg_split('/[-_.]/', $vendor);
	$project_parts = preg_split('/[-_.]/', $project);
	$n = count($vendor_parts);
	# Remove vendor name from project name
	if ($vendor_parts === array_slice($project_parts, 0, $n))
		$project_parts = array_slice($project_parts, $n);
	# Drop first part of project name if equal to last part of vendor name
	else if ($vendor_parts[$n-1] === $project_parts[0])
		array_shift($project_parts);
	$project = implode('-', $project_parts);
	return trim("$vendor/$project", '/');
}

/*
Collect autoloaders for all dependencies
*/

# Required packages
$required = [];
$dependencies = array_merge(
	array_keys($composer['require'] ?? []),
	$extra_requires,
);
foreach ($dependencies as $dependency) {
	$path = get_autoloader($dependency);
	if ($path !== null)
		$required[] = "/usr/share/php/" . $path;
}

# Suggested packages
$suggested = [];
$dependencies = array_merge(
	array_keys($composer['suggest'] ?? []),
	$extra_suggests,
);
foreach ($dependencies as $dependency) {
	$path = get_autoloader($dependency);
	if ($path !== null)
		$suggested[] = "/usr/share/php/" . $path;
}

# Statically loaded files
$files = array_merge(
	$composer['autoload']['files'] ?? [],
	$extra_files,
);
foreach ($files as &$file) {
	if ($basedir !== null && strpos($file, $basedir) === 0)
		$file = substr($file, strlen($basedir));
}

# Output autoloader template
sort($required);
sort($suggested);
sort($files);
################################################################################
echo "<?php\n"; ?>

// Require
<?php foreach ($required as $path) { ?>
require_once '<?=$path?>';
<?php } ?>

// Suggest
<?php foreach ($suggested as $path) { ?>
if (stream_resolve_include_path('<?=$path?>')) { include_once '<?=$path?>'; }
<?php } ?>

// @codingStandardsIgnoreFile
// @codeCoverageIgnoreStart
// this is an autogenerated file - do not edit
spl_autoload_register(
    function($class) {
        static $classes = null;
        if ($classes === null) {
            $classes = array(
                ___CLASSLIST___
            );
        }
        $cn = strtolower($class);
        if (isset($classes[$cn])) {
            require ___BASEDIR___$classes[$cn];
        }
    },
    ___EXCEPTION___,
    ___PREPEND___
);
// @codeCoverageIgnoreEnd

// Files
<?php foreach ($files as $path) { ?>
<?php if (str_starts_with($path, '/')) { ?>
require_once realpath('<?=$path?>');
<?php } else { ?>
require_once __DIR__.'/<?=$path?>';
<?php } ?>
<?php } ?>