#!/usr/bin/env php
<?php

set_error_handler(
    static function ($errno, $errstr, $errfile, $errline) {
        $msg = "Error {$errno}: {$errstr}\n";
        if ($errfile) {
            $msg .= "File: {$errfile}\n";
            if ($errline) {
                $msg .= "Line: {$errline}\n";
            }
        }

        throw new RuntimeException($msg);
    },
    -1
);

try {
    if (!isset($argv[1]) || isset($argv[2]) || !preg_match('/^\w+$/', $argv[1]) || in_array('-h', $argv, true) || in_array('--help', $argv, true)) {
        echo "Syntax: {$argv[0]} <extension>\n";
        exit(in_array('-h', $argv, true) || in_array('--help', $argv, true) ? 0 : 1);
    }
    echo 'Retrieving package versions... ';
    $versions = listPackageVersions($argv[1]);
    $numVersions = count($versions);
    echo "done.\n";
    $data = [];
    $lastData = null;
    $versionCount = 0;
    foreach ($versions as $version) {
        $versionCount++;
        echo "Inspecting version {$version} [{$versionCount}/{$numVersions}]... ";
        $versionData = inspectPackageVersion($argv[1], $version);
        if ($lastData !== null && $lastData->isCompatibleWith($versionData)) {
            $lastData->addVersion($versionData->getVersion());
        } else {
            $data[] = $lastData = new PackageVersionCombined($versionData);
        }
        echo "done.\n";
    }
    foreach ($data as $info) {
        echo '## Versions: ', implode(', ', $info->getVersions()), "\n";
        echo 'Min PHP version: ', $info->getMinPHPVersion(), "\n";
        echo 'Max PHP version: ', $info->getMaxPHPVersion(), "\n";
        foreach ($info->getConfigureOptions() as $configureOptionIndex => $configureOption) {
            echo 'Option ', $configureOptionIndex + 1, ': ', $configureOption->getName(), ' "', $configureOption->getPrompt(), '"';
            if ($configureOption->getDefault() !== null) {
                echo ' [', $configureOption->getDefault(), ']';
            }
            echo "\n";
        }
    }
} catch (RuntimeException $x) {
    echo $x->getMessage(), "\n";
    exit(1);
}

/**
 * @return string[]
 */
function listPackageVersions(string $package): array
{
    try {
        $xml = file_get_contents("https://pecl.php.net/rest/r/{$package}/allreleases.xml");
    } catch (RuntimeException $x) {
        if (strpos($x->getMessage(), '404 Not Found') !== false) {
            throw new RuntimeException("Invalid PECL package name or no versions available for {$package}");
        }

        throw $x;
    }
    $dom = new DOMDocument();
    if (!$dom->loadXML($xml)) {
        throw new RuntimeException('Failed to parse the downloaded XML data.');
    }
    $xpath = new DOMXPath($dom);
    $xpath->registerNamespace('v', 'http://pear.php.net/dtd/rest.allreleases');
    $versionNodes = $xpath->query('/v:a/v:r/v:v');
    if ($versionNodes->count() === 0) {
        throw new RuntimeException("No versions available for {$package}");
    }
    $versions = [];
    foreach ($versionNodes as $versionNode) {
        $versions[] = $versionNode->nodeValue;
    }
    usort($versions, 'version_compare');

    return $versions;
}

function inspectPackageVersion(string $package, string $version): PackageVersion
{
    $tgzFile = tempnam(sys_get_temp_dir(), 'dpx');

    try {
        file_put_contents($tgzFile, file_get_contents("https://pecl.php.net/get/{$package}-{$version}.tgz"));
        $archive = new PharData($tgzFile);
        $archive->decompress('tar');
        $tarFile = preg_replace('/\.\w+$/', '.tar', $tgzFile);

        try {
            $extractedDir = preg_replace('/\.tar$/', '.decompressed', $tarFile);
            mkdir($extractedDir);

            try {
                $archive->extractTo($extractedDir, 'package.xml');

                try {
                    $dom = new DOMDocument();
                    if (!$dom->loadXML(file_get_contents("{$extractedDir}/package.xml"))) {
                        throw new RuntimeException('Failed to parse the downloaded package.xml file.');
                    }
                    $xpath = new DOMXPath($dom);
                    $xpath->registerNamespace('v2', 'http://pear.php.net/dtd/package-2.0');
                    if ($xpath->query('/v2:package/v2:dependencies')->count() !== 1) {
                        throw new RuntimeException('Unsupported namespace');
                    }
                    $maxPHPVersionNodes = $xpath->query('/v2:package/v2:dependencies/v2:required/v2:php/v2:max');
                    $info = new PackageVersion(
                        $version,
                        $xpath->query('/v2:package/v2:dependencies/v2:required/v2:php/v2:min')[0]->nodeValue,
                        $maxPHPVersionNodes->count() === 0 ? '' : $maxPHPVersionNodes[0]->nodeValue
                    );
                    foreach ($xpath->query('/v2:package/v2:extsrcrelease/v2:configureoption') as $configureOptionNode) {
                        $info->addConfigureOption(new PackageConfigureOption(
                            $configureOptionNode->getAttribute('name'),
                            $configureOptionNode->getAttribute('prompt'),
                            $configureOptionNode->hasAttribute('default') ? $configureOptionNode->getAttribute('default') : null
                        ));
                    }
                } finally {
                    unlink("{$extractedDir}/package.xml");
                }
            } finally {
                rmdir($extractedDir);
            }
        } finally {
            unlink($tarFile);
        }
    } finally {
        unlink($tgzFile);
    }

    return $info;
}

abstract class PackageInfo
{
    private string $minPHPVersion;
    private string $maxPHPVersion;
    private array $configureOptions = [];

    protected function __construct(string $minPHPVersion, string $maxPHPVersion = '')
    {
        $this->minPHPVersion = $minPHPVersion;
        $this->maxPHPVersion = $maxPHPVersion;
    }

    public function getMinPHPVersion(): string
    {
        return $this->minPHPVersion;
    }

    public function getMaxPHPVersion(): string
    {
        return $this->maxPHPVersion;
    }

    /**
     * @return $this
     */
    public function addConfigureOption(PackageConfigureOption $value): self
    {
        $this->configureOptions[] = $value;

        return $this;
    }

    /**
     * @param PackageConfigureOption[] $value
     *
     * @return $this
     */
    public function setConfigureOptions(array $value): self
    {
        $this->configureOptions = $value;

        return $this;
    }

    /**
     * @return PackageConfigureOption[]
     */
    public function getConfigureOptions(): array
    {
        return $this->configureOptions;
    }
}

class PackageVersion extends PackageInfo
{
    private string $version;

    public function __construct(string $version, string $minPHPVersion, string $maxPHPVersion = '')
    {
        parent::__construct($minPHPVersion, $maxPHPVersion);
        $this->version = $version;
    }

    public function getVersion(): string
    {
        return $this->version;
    }
}

class PackageVersionCombined extends PackageInfo
{
    private array $versions = [];

    public function __construct(PackageInfo $info)
    {
        parent::__construct($info->getMinPHPVersion(), $info->getMaxPHPVersion());
        $this->setConfigureOptions($info->getConfigureOptions());
        $this->addVersion($info->getVersion());
    }

    /**
     * @return $this
     */
    public function addVersion(string $value): self
    {
        $this->versions[] = $value;

        return $this;
    }

    /**
     * @return string[]
     */
    public function getVersions(): array
    {
        return $this->versions;
    }

    public function isCompatibleWith(PackageInfo $info): bool
    {
        return $this->getMinPHPVersion() === $info->getMinPHPVersion()
            && $this->getMaxPHPVersion() === $info->getMaxPHPVersion()
            && $this->getConfigureOptions() == $info->getConfigureOptions()
        ;
    }
}

class PackageConfigureOption
{
    private string $name;
    private string $prompt;
    private ?string $default;

    public function __construct(string $name, string $prompt, ?string $default = null)
    {
        $this->name = $name;
        $this->prompt = $prompt;
        $this->default = $default;
    }

    public function getName(): string
    {
        return $this->name;
    }

    public function getPrompt(): string
    {
        return $this->prompt;
    }

    public function getDefault(): ?string
    {
        return $this->default;
    }
}