<?php
/**
 * Settings: size limits, performance profile, schedule.
 *
 * @package Shiftbox
 */

defined( 'ABSPATH' ) || exit;

/**
 * Reads and sanitizes plugin settings.
 */
class Shiftbox_Settings {

	const OPTION = 'shiftbox_settings';

	/**
	 * Performance profiles: seconds of work per request, I/O chunk size, rows per query.
	 *
	 * @var array
	 */
	const PROFILES = array(
		'safe'     => array(
			'budget' => 8,
			'chunk'  => 2097152,
			'rows'   => 250,
		),
		'balanced' => array(
			'budget' => 20,
			'chunk'  => 8388608,
			'rows'   => 1000,
		),
		'turbo'    => array(
			'budget' => 40,
			'chunk'  => 33554432,
			'rows'   => 3000,
		),
	);

	/**
	 * Default values.
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			'max_import'     => 0,
			'max_backup'     => 0,
			'mode'           => 'balanced',
			'speed_cap'      => 0,
			'schedule'       => 'off',
			'keep'           => 5,
			'custom_exclude' => '',
			'remove_data'    => 0,
		);
	}

	/**
	 * All settings merged with defaults.
	 *
	 * @return array
	 */
	public static function all() {
		$saved = get_option( self::OPTION, array() );
		return wp_parse_args( is_array( $saved ) ? $saved : array(), self::defaults() );
	}

	/**
	 * One setting.
	 *
	 * @param string $key Key.
	 * @return mixed
	 */
	public static function get( $key ) {
		$all = self::all();
		return isset( $all[ $key ] ) ? $all[ $key ] : null;
	}

	/**
	 * Active performance profile, capped by the server's execution limit.
	 *
	 * @return array
	 */
	public static function profile() {
		$mode    = self::get( 'mode' );
		$profile = isset( self::PROFILES[ $mode ] ) ? self::PROFILES[ $mode ] : self::PROFILES['balanced'];
		$max     = (int) ini_get( 'max_execution_time' );
		if ( $max > 0 ) {
			$profile['budget'] = max( 3, min( $profile['budget'], $max - 5 ) );
		}
		/**
		 * Filters the performance profile.
		 *
		 * @param array $profile budget (seconds), chunk (bytes), rows (per query).
		 */
		return apply_filters( 'shiftbox_profile', $profile );
	}

	/**
	 * Largest upload chunk the server will accept for one request.
	 *
	 * @return int Bytes.
	 */
	public static function upload_chunk() {
		$server = (int) wp_max_upload_size();
		$cap    = $server > 0 ? (int) floor( $server * 0.9 ) - 65536 : 1048576;
		$chunk  = min( self::profile()['chunk'], $cap );
		return max( 262144, $chunk );
	}

	/**
	 * Converts a value and unit to bytes; 0 means unlimited.
	 *
	 * @param mixed  $value Number.
	 * @param string $unit  MB or GB.
	 * @return int
	 */
	public static function to_bytes( $value, $unit ) {
		$value = (float) $value;
		if ( $value <= 0 ) {
			return 0;
		}
		$mult = ( 'GB' === $unit ) ? 1073741824 : 1048576;
		return (int) round( $value * $mult );
	}

	/**
	 * Splits bytes into a value and unit for the settings form.
	 *
	 * @param int $bytes Bytes.
	 * @return array value, unit.
	 */
	public static function split( $bytes ) {
		$bytes = (int) $bytes;
		if ( $bytes <= 0 ) {
			return array( 10, 'GB' );
		}
		if ( 0 === $bytes % 1073741824 ) {
			return array( $bytes / 1073741824, 'GB' );
		}
		return array( round( $bytes / 1048576, 2 ), 'MB' );
	}

	/**
	 * Human size.
	 *
	 * @param int $bytes Bytes.
	 * @return string
	 */
	public static function human( $bytes ) {
		return $bytes > 0 ? size_format( $bytes, $bytes >= 1073741824 ? 2 : 1 ) : __( 'Unlimited', 'shiftbox' );
	}

	/**
	 * Sanitize callback for register_setting.
	 *
	 * @param array $input Raw input.
	 * @return array
	 */
	public static function sanitize( $input ) {
		$input = is_array( $input ) ? $input : array();
		$out   = self::defaults();

		foreach ( array( 'max_import', 'max_backup' ) as $key ) {
			// WordPress runs this callback twice on the very first save; the second pass
			// receives already-sanitized bytes, so keep them instead of resetting to 0.
			if ( ! isset( $input[ $key . '_value' ] ) && ! isset( $input[ $key . '_unlimited' ] ) && isset( $input[ $key ] ) ) {
				$out[ $key ] = max( 0, (int) $input[ $key ] );
				continue;
			}
			$unlimited   = ! empty( $input[ $key . '_unlimited' ] );
			$unit        = ( isset( $input[ $key . '_unit' ] ) && 'GB' === $input[ $key . '_unit' ] ) ? 'GB' : 'MB';
			$num         = isset( $input[ $key . '_value' ] ) ? (float) $input[ $key . '_value' ] : 0;
			$out[ $key ] = $unlimited ? 0 : self::to_bytes( $num, $unit );
		}

		$out['mode']      = ( isset( $input['mode'] ) && isset( self::PROFILES[ $input['mode'] ] ) ) ? $input['mode'] : 'balanced';
		$out['speed_cap'] = isset( $input['speed_cap'] ) ? max( 0, min( 10000, (float) $input['speed_cap'] ) ) : 0;
		$out['schedule']  = ( isset( $input['schedule'] ) && in_array( $input['schedule'], array( 'off', 'daily', 'weekly' ), true ) ) ? $input['schedule'] : 'off';
		$out['keep']      = isset( $input['keep'] ) ? max( 1, min( 100, (int) $input['keep'] ) ) : 5;

		$lines = isset( $input['custom_exclude'] ) ? preg_split( '/\R/', (string) $input['custom_exclude'] ) : array();
		$clean = array();
		foreach ( $lines as $line ) {
			$line = trim( str_replace( '\\', '/', sanitize_text_field( $line ) ), "/ \t" );
			if ( '' !== $line && false === strpos( $line, '..' ) ) {
				$clean[] = $line;
			}
		}
		$out['custom_exclude'] = implode( "\n", array_unique( $clean ) );
		$out['remove_data']    = empty( $input['remove_data'] ) ? 0 : 1;

		Shiftbox_Scheduler::reschedule( $out['schedule'] );
		return $out;
	}
}