<?php
/**
 * Activity log and operation history.
 *
 * @package Spinix_Migration
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Spinix_Log {

	const MAX_BYTES = 2097152;

	/**
	 * Append a line to the log file.
	 *
	 * @param string $message Message.
	 * @param string $level   info|warning|error.
	 * @param string $job     Job id.
	 */
	public static function add( $message, $level = 'info', $job = '' ) {
		$dir = Spinix_Storage::logs_dir();
		if ( ! is_dir( $dir ) ) {
			return;
		}
		$file = $dir . '/spinix.log';
		if ( is_file( $file ) && filesize( $file ) > self::MAX_BYTES ) {
			@rename( $file, $dir . '/spinix.old.log' ); // phpcs:ignore
		}
		$line = '[' . gmdate( 'Y-m-d H:i:s' ) . ' UTC] ' . strtoupper( $level ) . ( $job ? ' [' . $job . ']' : '' ) . ' ' . str_replace( array( "\r", "\n" ), ' ', $message ) . "\n";
		@file_put_contents( $file, $line, FILE_APPEND | LOCK_EX ); // phpcs:ignore
	}

	/**
	 * Last N lines of the log.
	 *
	 * @param int $lines Lines.
	 * @return string
	 */
	public static function tail( $lines = 200 ) {
		$file = Spinix_Storage::logs_dir() . '/spinix.log';
		if ( ! is_file( $file ) ) {
			return '';
		}
		$size = filesize( $file );
		$h    = fopen( $file, 'rb' ); // phpcs:ignore
		$read = min( $size, 262144 );
		fseek( $h, -$read, SEEK_END );
		$data = fread( $h, $read ); // phpcs:ignore
		Spinix_Env::close( $h );
		$arr = explode( "\n", trim( (string) $data ) );
		return implode( "\n", array_slice( $arr, -$lines ) );
	}

	/**
	 * Record a finished operation in the history list.
	 *
	 * @param array $entry Entry.
	 */
	public static function history_add( $entry ) {
		$file = Spinix_Storage::logs_dir() . '/history.json';
		$list = self::history();
		array_unshift( $list, $entry + array( 'time' => time() ) );
		$list = array_slice( $list, 0, 50 );
		@file_put_contents( $file, wp_json_encode( $list ), LOCK_EX ); // phpcs:ignore
	}

	/**
	 * History list.
	 *
	 * @return array
	 */
	public static function history() {
		$file = Spinix_Storage::logs_dir() . '/history.json';
		if ( ! is_file( $file ) ) {
			return array();
		}
		$list = Spinix_Env::read_json( $file );
		return is_array( $list ) ? $list : array();
	}
}