<?php

class ConfigTgz
{
	
	private $configId = 0;
	private $configTitle = '';
	private $file = '';
	private $modules = array();

	private function __construct()
	{
	}

	public function id(): int
	{
		return $this->configId;
	}
	
	public function title(): string
	{
		return $this->configTitle;
	}
	
	public function areAllModulesUpToDate(): bool
	{
		if (!$this->configId > 0)
			ErrorHandler::traceError('ConfigTgz::areAllModulesUpToDate called on un-inserted config.tgz!');
		foreach ($this->modules as $module) {
			if (!empty($module['filepath']) && file_exists($module['filepath'])) {
				if ($module['status'] !== 'OK')
					return false;
			} else {
				return false;
			}
		}
		return true;
	}
	
	public function isActive(): bool
	{
		return readlink(CONFIG_HTTP_DIR . '/default/config.tgz') === $this->file;
	}

	/**
	 * @return int[]
	 */
	public function getModuleIds(): array
	{
		$ret = [];
		foreach ($this->modules as $module) {
			$ret[] = (int)$module['moduleid'];
		}
		return $ret;
	}

	/**
	 * @param string $title New title for module
	 * @param int[] $moduleIds List of modules to include in this config
	 */
	public function update(string $title, array $moduleIds): void
	{
		if (!empty($title)) {
			$this->configTitle = $title;
		}
		$this->modules = array();
		// Get all modules to put in config
		$idstr = '0'; // Passed directly in query. Make sure no SQL injection is possible
		foreach ($moduleIds as $module) {
			$idstr .= ',' . (int)$module; // Casting to int should make it safe
		}
		$res = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_module WHERE moduleid IN ($idstr)");
		// Delete old connections
		Database::exec("DELETE FROM configtgz_x_module WHERE configid = :configid", array('configid' => $this->configId));
		// Make connection
		foreach ($res as $row) {
			Database::exec("INSERT INTO configtgz_x_module (configid, moduleid) VALUES (:configid, :moduleid)", array(
				'configid' => $this->configId,
				'moduleid' => $row['moduleid']
			));
			$this->modules[] = $row;
		}
		// Update name
		Database::exec("UPDATE configtgz SET title = :title, status = :status, dateline = :now WHERE configid = :configid LIMIT 1", array(
			'configid' => $this->configId,
			'title' => $this->configTitle,
			'status' => 'OUTDATED',
			'now' => time(),
		));
	}
	
	/**
	 * 
	 * @param bool $deleteOnError Delete this config in case of error?
	 * @param int $timeoutMs max time to wait for completion
	 * @param string|null $parentTask parent task to order this (re)build after
	 * @return string|bool true=success, false=error, string=taskid, still running
	 */
	public function generate(bool $deleteOnError = false, int $timeoutMs = 0, ?string $parentTask = null)
	{
		if (!($this->configId > 0) || empty($this->file))
			ErrorHandler::traceError('configId <= 0 or no file in ConfigTgz::rebuild()');
		$files = array();
		// Get all config modules for system config
		foreach ($this->modules as $module) {
			if (!empty($module['filepath']) && file_exists($module['filepath'])) {
				// Dupcheck only for custom modules for now
				$files[$module['filepath']] = ($module['moduletype'] === 'CustomModule');
			}
		}

		$task = self::recompress($files, $this->file, $parentTask);

		// Wait for completion
		if ($timeoutMs > 0 && !Taskmanager::isFailed($task) && !Taskmanager::isFinished($task)) {
			$task = Taskmanager::waitComplete($task, $timeoutMs);
		}
		if (Taskmanager::isFinished($task)) {
			// Success!
			$this->markUpdated($task);
			return true;
		}
		if (!is_array($task) || !isset($task['id']) || Taskmanager::isFailed($task)) {
			// Failed...
			Taskmanager::addErrorMessage($task);
			if (!$deleteOnError)
				$this->markFailed();
			else
				$this->delete();
			return false;
		}
		// Still running, add callback
		TaskmanagerCallback::addCallback($task, 'cbConfTgzCreated', array(
			'configid' => $this->configId,
			'deleteOnError' => $deleteOnError
		));
		return $task['id'];
	}

	public function delete(): bool
	{
		if ($this->configId === 0)
			ErrorHandler::traceError('ConfigTgz::delete called with invalid config id!');
		$ret = Database::exec("DELETE FROM configtgz WHERE configid = :configid LIMIT 1",
				['configid' => $this->configId], true);
		if ($ret !== false) {
			if (!empty($this->file)) {
				Taskmanager::submit('DeleteFile', array('file' => $this->file), true);
			}
			$this->configId = 0;
			$this->modules = [];
			$this->file = '';
		}
		return $ret !== false;
	}
	
	public function markOutdated(): void
	{
		if ($this->configId === 0)
			ErrorHandler::traceError('ConfigTgz::markOutdated called with invalid config id!');
		$this->mark('OUTDATED');
	}
	
	private function markUpdated(array $task): void
	{
		if ($this->configId === 0)
			ErrorHandler::traceError('ConfigTgz::markUpdated called with invalid config id!');
		if ($this->areAllModulesUpToDate()) {
			if (empty($task['data']['warnings'])) {
				$warnings = '';
			} else {
				// There have been warnings while generating the combined archive
				// Most likely duplicate file entries.
				// Get mapping of moduleid to module name for prettier log display
				$res = Database::simpleQuery('SELECT moduleid, title FROM configtgz_module');
				$mods = [];
				foreach ($res as $row) {
					$mods[$row['moduleid']] = $row['title'];
				}
				// Now extract module id from filename and if applicable, replace filename by module name
				$warnings = preg_replace_callback('#/opt/openslx/configs/modules/(\w+)_id-(\d+)__.*$#m', function ($m) use ($mods) {
					if (!isset($mods[$m[2]]))
						return $m[0];
					return $mods[$m[2]] . ' (' . $m[1] . '#' . $m[2] . ')';
				}, $task['data']['warnings']);
			}
			Database::exec("UPDATE configtgz SET status = :status, warnings = :warnings
					WHERE configid = :configid LIMIT 1", [
				'configid' => $this->configId,
				'status' => 'OK',
				'warnings' => $warnings,
			]);
			return;
		}
		$this->mark('OUTDATED');
	}
	
	private function markFailed(): void
	{
		if ($this->configId === 0)
			ErrorHandler::traceError('ConfigTgz::markFailed called with invalid config id!');
		if (empty($this->file) || !file_exists($this->file)) {
			$this->mark('MISSING');
		} else {
			$this->mark('OUTDATED');
		}
	}
	
	private function mark($status): void
	{
		Database::exec("UPDATE configtgz SET status = :status WHERE configid = :configid LIMIT 1", [
			'configid' => $this->configId,
			'status' => $status,
		]);
	}

	/*
	 * Static part
	 */

	/**
	 * @param bool[] $files source files to include key = file, value = dupCheck
	 * @param string $destFile where to store final result
	 * @return false|array taskmanager task
	 */
	private static function recompress(array $files, string $destFile, $parentTask = null)
	{
		// Get stuff other modules want to inject
		$handler = function($hook) {
			include $hook->file;
			return $file ?? false;
		};
		foreach (Hook::load('config-tgz') as $hook) {
			$file = $handler($hook);
			if ($file !== false) {
				$files[$file] = true;
			}
		}

		// Hand over to tm
		return Taskmanager::submit('RecompressArchive', array(
			'inputFiles' => $files,
			'outputFile' =>$destFile,
			'parentTask' => $parentTask,
			'failOnParentFail' => false,
		));
	}

	/**
	 * Marks all modules as outdated and triggers generate()
	 * on each one. This mostly makes sense to call if a global module
	 * that is injected via a hook has changed.
	 */
	public static function rebuildAllConfigs(): void
	{
		Database::exec("UPDATE configtgz SET status = :status", array(
			'status' => 'OUTDATED'
		));
		$res = Database::simpleQuery("SELECT configid FROM configtgz");
		foreach ($res as $row) {
			$configTgz = self::get($row['configid']);
			if ($configTgz !== null) {
				$configTgz->generate();
			}
		}
	}

	/**
	 * @param string $title Title of config
	 * @param int[] $moduleIds Modules to include in config
	 * @return ConfigTgz The module instance
	 */
	public static function insert(string $title, array $moduleIds): ConfigTgz
	{
		$instance = new ConfigTgz;
		$instance->configTitle = $title;
		// Create output file name (config.tgz)
		do {
			$instance->file = CONFIG_TGZ_LIST_DIR . '/config-' . Util::sanitizeFilename($instance->configTitle) . '-' . mt_rand() . '-' . time() . '.tgz';
		} while (file_exists($instance->file));
		Database::exec("INSERT INTO configtgz (title, filepath, status, dateline) VALUES (:title, :filepath, :status, :now)", array(
			'title' => $instance->configTitle,
			'filepath' => $instance->file,
			'status' => 'MISSING',
			'now' => time(),
		));
		$instance->configId = Database::lastInsertId();
		$instance->modules = array();
		// Get all modules to put in config
		$idstr = '0'; // Passed directly in query. Make sure no SQL injection is possible
		foreach ($moduleIds as $module) {
			$idstr .= ',' . (int)$module; // Casting to int should make it safe
		}
		$res = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_module WHERE moduleid IN ($idstr)");
		// Make connection
		foreach ($res as $row) {
			Database::exec("INSERT INTO configtgz_x_module (configid, moduleid) VALUES (:configid, :moduleid)", array(
				'configid' => $instance->configId,
				'moduleid' => $row['moduleid']
			));
			$instance->modules[] = $row;
		}
		return $instance;
	}

	/**
	 * @param array{configid: int, title:  string, filepath: string} $row Input data, fields mandatory
	 */
	private static function instanceFromRow(array $row): ConfigTgz
	{
		$instance = new ConfigTgz;
		$instance->configId = $row['configid'];
		$instance->configTitle = $row['title'];
		$instance->file = $row['filepath'];
		$innerRes = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_x_module "
			. " INNER JOIN configtgz_module USING (moduleid) "
			. " WHERE configid = :configid", array('configid' => $instance->configId));
		$instance->modules = array();
		foreach ($innerRes as $innerRow) {
			$instance->modules[] = $innerRow;
		}
		return $instance;
	}

	public static function get(int $configId): ?ConfigTgz
	{
		$ret = Database::queryFirst("SELECT configid, title, filepath FROM configtgz WHERE configid = :configid", array(
			'configid' => $configId
		));
		if ($ret === false)
			return null;
		return self::instanceFromRow($ret);
	}

	/**
	 * @param int $moduleId ID of config module
	 * @return ConfigTgz[]
	 */
	public static function getAllForModule(int $moduleId): array
	{
		$res = Database::simpleQuery("SELECT configid, title, filepath FROM configtgz_x_module "
			. " INNER JOIN configtgz USING (configid) "
			. " WHERE moduleid = :moduleid", array(
			'moduleid' => $moduleId
		));
		if ($res === false) {
			EventLog::warning('ConfigTgz::getAllForModule failed: ' . Database::lastError());
			return [];
		}
		$list = array();
		foreach ($res as $row) {
			$instance = self::instanceFromRow($row);
			$list[] = $instance;
		}
		return $list;
	}

	/**
	 * Called when (re)generating a config tgz failed, so we can
	 * update the status in the DB and add a server log entry.
	 *
	 * @param array $args contains 'configid' and optionally 'deleteOnError'
	 */
	public static function generateFailed(array $task, array $args): void
	{
		if (!isset($args['configid']) || !is_numeric($args['configid'])) {
			EventLog::warning('Ignoring generateFailed event as it has no configid assigned.');
			return;
		}
		$config = self::get($args['configid']);
		if ($config === null) {
			EventLog::warning('generateFailed callback for config id ' . $args['configid'] . ', but no instance could be generated.');
			return;
		}
		if (isset($task['data']['error'])) {
			$error = $task['data']['error'];
		} elseif (isset($task['data']['messages'])) {
			$error = $task['data']['messages'];
		} else {
			$error = '';
		}
		EventLog::failure("Generating config.tgz '" . $config->configTitle . "' failed.", $error);
		if ($args['deleteOnError']) {
			$config->delete();
		} else {
			$config->markFailed();
		}
	}

	/**
	 * (Re)generating a config tgz succeeded. Update db entry.
	 *
	 * @param array $task the task object
	 * @param array $args contains 'configid' and optionally 'deleteOnError'
	 */
	public static function generateSucceeded(array $task, array $args): void
	{
		if (!isset($args['configid']) || !is_numeric($args['configid'])) {
			EventLog::warning('Ignoring generateSucceeded event as it has no configid assigned.');
			return;
		}
		$config = self::get($args['configid']);
		if ($config === null) {
			EventLog::warning('generateSucceeded callback for config id ' . $args['configid'] . ', but no instance could be generated.');
			return;
		}
		$config->markUpdated($task);
	}

}