<?php

namespace dokuwiki\plugin\extension;

use dokuwiki\Extension\PluginController;
use dokuwiki\Utf8\PhpString;
use RuntimeException;

class Extension
{
    const TYPE_PLUGIN = 'plugin';
    const TYPE_TEMPLATE = 'template';

    /** @var string "plugin"|"template" */
    protected string $type = self::TYPE_PLUGIN;

    /** @var string The base name of this extension */
    protected string $base;

    /** @var string|null The current location of this extension */
    protected ?string $currentDir;

    /** @var array The local info array of the extension */
    protected array $localInfo = [];

    /** @var array The remote info array of the extension */
    protected array $remoteInfo = [];

    /** @var array The manager info array of the extension */
    protected array $managerInfo = [];

    // region Constructors

    /**
     * The main constructor is private to force the use of the factory methods
     */
    protected function __construct()
    {
    }

    /**
     * Initializes an extension from a directory
     *
     * The given directory might be the one where the extension has already been installed to
     * or it might be the extracted source in some temporary directory.
     *
     * @param string $dir Where the extension code is currently located
     * @param string|null $type TYPE_PLUGIN|TYPE_TEMPLATE, null for auto-detection
     * @param string $base The base name of the extension, null for auto-detection
     * @return Extension
     */
    public static function createFromDirectory($dir, $type = null, $base = null)
    {
        $extension = new self();
        $extension->initFromDirectory($dir, $type, $base);
        return $extension;
    }

    protected function initFromDirectory($dir, $type = null, $base = null)
    {
        if (!is_dir($dir)) throw new RuntimeException('Directory not found: ' . $dir);
        $this->currentDir = realpath($dir);

        if ($type === null || $type === self::TYPE_TEMPLATE) {
            if (
                file_exists($dir . '/template.info.php') ||
                file_exists($dir . '/style.ini') ||
                file_exists($dir . '/main.php') ||
                file_exists($dir . '/detail.php') ||
                file_exists($dir . '/mediamanager.php')
            ) {
                $this->type = self::TYPE_TEMPLATE;
            }
        } else {
            $this->type = self::TYPE_PLUGIN;
        }

        $this->readLocalInfo();

        if ($base !== null) {
            $this->base = $base;
        } elseif (isset($this->localInfo['base'])) {
            $this->base = $this->localInfo['base'];
        } else {
            $this->base = basename($dir);
        }
    }

    /**
     * Initializes an extension from remote data
     *
     * @param array $data The data as returned by the repository api
     * @return Extension
     */
    public static function createFromRemoteData($data)
    {
        $extension = new self();
        $extension->initFromRemoteData($data);
        return $extension;
    }

    protected function initFromRemoteData($data)
    {
        if (!isset($data['plugin'])) throw new RuntimeException('Invalid remote data');

        [$type, $base] = sexplode(':', $data['plugin'], 2);
        if ($base === null) {
            $base = $type;
            $type = self::TYPE_PLUGIN;
        } else {
            $type = self::TYPE_TEMPLATE;
        }

        $this->remoteInfo = $data;
        $this->type = $type;
        $this->base = $base;

        if ($this->isInstalled()) {
            $this->currentDir = $this->getInstallDir();
            $this->readLocalInfo();
        }
    }

    // endregion

    // region Getters

    /**
     * @return string The extension id (same as base but prefixed with "template:" for templates)
     */
    public function getId()
    {
        if ($this->type === self::TYPE_TEMPLATE) {
            return self::TYPE_TEMPLATE . ':' . $this->base;
        }
        return $this->base;
    }

    /**
     * Get the base name of this extension
     *
     * @return string
     */
    public function getBase()
    {
        return $this->base;
    }

    /**
     * Get the type of the extension
     *
     * @return string "plugin"|"template"
     */
    public function getType()
    {
        return $this->type;
    }

    /**
     * The current directory of the extension
     *
     * @return string|null
     */
    public function getCurrentDir()
    {
        // recheck that the current currentDir is still valid
        if ($this->currentDir && !is_dir($this->currentDir)) {
            $this->currentDir = null;
        }

        // if the extension is installed, then the currentDir is the install dir!
        if (!$this->currentDir && $this->isInstalled()) {
            $this->currentDir = $this->getInstallDir();
        }

        return $this->currentDir;
    }

    /**
     * Get the directory where this extension should be installed in
     *
     * Note: this does not mean that the extension is actually installed there
     *
     * @return string
     */
    public function getInstallDir()
    {
        if ($this->isTemplate()) {
            $dir = dirname(tpl_incdir()) . $this->base;
        } else {
            $dir = DOKU_PLUGIN . $this->base;
        }

        return realpath($dir);
    }


    /**
     * Get the display name of the extension
     *
     * @return string
     */
    public function getDisplayName()
    {
        return $this->getTag('name', PhpString::ucwords($this->getBase() . ' ' . $this->getType()));
    }

    /**
     * Get the author name of the extension
     *
     * @return string Returns an empty string if the author info is missing
     */
    public function getAuthor()
    {
        return $this->getTag('author');
    }

    /**
     * Get the email of the author of the extension if there is any
     *
     * @return string Returns an empty string if the email info is missing
     */
    public function getEmail()
    {
        // email is only in the local data
        return $this->localInfo['email'] ?? '';
    }

    /**
     * Get the email id, i.e. the md5sum of the email
     *
     * @return string Empty string if no email is available
     */
    public function getEmailID()
    {
        if (!empty($this->remoteInfo['emailid'])) return $this->remoteInfo['emailid'];
        if (!empty($this->localInfo['email'])) return md5($this->localInfo['email']);
        return '';
    }

    /**
     * Get the description of the extension
     *
     * @return string Empty string if no description is available
     */
    public function getDescription()
    {
        return $this->getTag(['desc', 'description']);
    }

    /**
     * Get the URL of the extension, usually a page on dokuwiki.org
     *
     * @return string
     */
    public function getURL()
    {
        return $this->getTag(
            'url',
            'https://www.dokuwiki.org/' .
            ($this->isTemplate() ? 'template' : 'plugin') . ':' . $this->getBase()
        );
    }

    /**
     * Is this extension a template?
     *
     * @return bool false if it is a plugin
     */
    public function isTemplate()
    {
        return $this->type === self::TYPE_TEMPLATE;
    }

    /**
     * Is the extension installed locally?
     *
     * @return bool
     */
    public function isInstalled()
    {
        return is_dir($this->getInstallDir());
    }

    /**
     * Is the extension under git control?
     *
     * @return bool
     */
    public function isGitControlled()
    {
        if (!$this->isInstalled()) return false;
        return file_exists($this->getInstallDir() . '/.git');
    }

    /**
     * If the extension is bundled
     *
     * @return bool If the extension is bundled
     */
    public function isBundled()
    {
        $this->loadRemoteInfo();
        return $this->remoteInfo['bundled'] ?? in_array(
            $this->getId(),
            [
                'authad',
                'authldap',
                'authpdo',
                'authplain',
                'acl',
                'config',
                'extension',
                'info',
                'popularity',
                'revert',
                'safefnrecode',
                'styling',
                'testing',
                'usermanager',
                'logviewer',
                'template:dokuwiki'
            ]
        );
    }

    /**
     * Is the extension protected against any modification (disable/uninstall)
     *
     * @return bool if the extension is protected
     */
    public function isProtected()
    {
        // never allow deinstalling the current auth plugin:
        global $conf;
        if ($this->getId() == $conf['authtype']) return true;

        // FIXME disallow current template to be uninstalled

        /** @var PluginController $plugin_controller */
        global $plugin_controller;
        $cascade = $plugin_controller->getCascade();
        return ($cascade['protected'][$this->getId()] ?? false);
    }

    /**
     * Is the extension installed in the correct directory?
     *
     * @return bool
     */
    public function isInWrongFolder()
    {
        return $this->getInstallDir() != $this->currentDir;
    }

    /**
     * Is the extension enabled?
     *
     * @return bool
     */
    public function isEnabled()
    {
        global $conf;
        if ($this->isTemplate()) {
            return ($conf['template'] == $this->getBase());
        }

        /* @var PluginController $plugin_controller */
        global $plugin_controller;
        return $plugin_controller->isEnabled($this->base);
    }

    // endregion

    // region Actions

    /**
     * Install or update the extension
     *
     * @throws Exception
     */
    public function installOrUpdate()
    {
        $installer = new Installer(true);
        $installer->installFromUrl(
            $this->getURL(),
            $this->getBase(),
        );
    }

    /**
     * Uninstall the extension
     * @throws Exception
     */
    public function uninstall()
    {
        $installer = new Installer(true);
        $installer->uninstall($this);
    }

    /**
     * Enable the extension
     * @todo I'm unsure if this code should be here or part of Installer
     * @throws Exception
     */
    public function enable()
    {
        if ($this->isTemplate()) throw new Exception('notimplemented');
        if (!$this->isInstalled()) throw new Exception('notinstalled');
        if ($this->isEnabled()) throw new Exception('alreadyenabled');

        /* @var PluginController $plugin_controller */
        global $plugin_controller;
        if (!$plugin_controller->enable($this->base)) {
            throw new Exception('pluginlistsaveerror');
        }
        Installer::purgeCache();
    }

    /**
     * Disable the extension
     * @todo I'm unsure if this code should be here or part of Installer
     * @throws Exception
     */
    public function disable()
    {
        if ($this->isTemplate()) throw new Exception('notimplemented');
        if (!$this->isInstalled()) throw new Exception('notinstalled');
        if (!$this->isEnabled()) throw new Exception('alreadydisabled');
        if ($this->isProtected()) throw new Exception('error_disable_protected');

        /* @var PluginController $plugin_controller */
        global $plugin_controller;
        if (!$plugin_controller->disable($this->base)) {
            throw new Exception('pluginlistsaveerror');
        }
        Installer::purgeCache();
    }

    // endregion

    // region Meta Data Management

    /**
     * This updates the timestamp and URL in the manager.dat file
     *
     * It is called by Installer when installing or updating an extension
     *
     * @param $url
     */
    public function updateManagerInfo($url)
    {
        $this->managerInfo['downloadurl'] = $url;
        if (isset($this->managerInfo['installed'])) {
            // it's an update
            $this->managerInfo['updated'] = date('r');
        } else {
            // it's a new install
            $this->managerInfo['installed'] = date('r');
        }

        $managerpath = $this->getInstallDir() . '/manager.dat';
        $data = '';
        foreach ($this->managerInfo as $k => $v) {
            $data .= $k . '=' . $v . DOKU_LF;
        }
        io_saveFile($managerpath, $data);
    }

    /**
     * Reads the manager.dat file and fills the managerInfo array
     */
    protected function readManagerInfo()
    {
        if ($this->managerInfo) return;

        $managerpath = $this->getInstallDir() . '/manager.dat';
        if (!is_readable($managerpath)) return;

        $file = (array)@file($managerpath);
        foreach ($file as $line) {
            [$key, $value] = sexplode('=', $line, 2, '');
            $key = trim($key);
            $value = trim($value);
            // backwards compatible with old plugin manager
            if ($key == 'url') $key = 'downloadurl';
            $this->managerInfo[$key] = $value;
        }
    }

    /**
     * Reads the info file of the extension if available and fills the localInfo array
     */
    protected function readLocalInfo()
    {
        if (!$this->currentDir) return;
        $file = $this->currentDir . '/' . $this->type . '.info.txt';
        if (!is_readable($file)) return;
        $this->localInfo = confToHash($file, true);
        $this->localInfo = array_filter($this->localInfo); // remove all falsy keys
    }

    /**
     * Fetches the remote info from the repository
     *
     * This ignores any errors coming from the repository and just sets the remoteInfo to an empty array in that case
     */
    protected function loadRemoteInfo()
    {
        if ($this->remoteInfo) return;
        $remote = Repository::getInstance();
        try {
            $this->remoteInfo = (array)$remote->getExtensionData($this->getId());
        } catch (Exception $e) {
            $this->remoteInfo = [];
        }
    }

    /**
     * Read information from either local or remote info
     *
     * Always prefers local info over remote info
     *
     * @param string|string[] $tag one or multiple keys to check
     * @param mixed $default
     * @return mixed
     */
    protected function getTag($tag, $default = '')
    {
        foreach ((array)$tag as $t) {
            if (isset($this->localInfo[$t])) return $this->localInfo[$t];
        }
        $this->loadRemoteInfo();
        foreach ((array)$tag as $t) {
            if (isset($this->remoteInfo[$t])) return $this->remoteInfo[$t];
        }

        return $default;
    }

    // endregion
}