<?php

namespace WP_CLI\Doctor;

use Mustangostang\Spyc;
use WP_CLI;
use WP_CLI\Utils;

class Checks {

    private static $instance;

    private $checks         = array();
    private $skipped_checks = array();

    public static function get_instance() {
        if ( ! isset( self::$instance ) ) {
            self::$instance = new Checks();
        }
        return self::$instance;
    }

    /**
     * Register checks from a config file
     *
     * @param string $file
     */
    public static function register_config( $file ) {
        if ( ! is_file( $file ) ) {
            WP_CLI::error( 'Invalid configuration file.' );
        }

        $check_data = Spyc::YAMLLoad( file_get_contents( $file ) );

        if ( ! empty( $check_data['_']['inherit'] ) ) {
            $inherited = $check_data['_']['inherit'];
            if ( 'default' === $inherited ) {
                $inherited = dirname( __DIR__ ) . '/doctor.yml';
            }
            $inherited = self::absolutize( $inherited, dirname( $file ) );
            if ( isset( $check_data['_']['skipped_checks'] ) ) {
                self::get_instance()->skipped_checks[ $inherited ] = $check_data['_']['skipped_checks'];
            }
            self::register_config( $inherited );
        }

        unset( $check_data['_'] );

        $skipped_checks = isset( self::get_instance()->skipped_checks[ $file ] ) ? self::get_instance()->skipped_checks[ $file ] : array();
        foreach ( $check_data as $check_name => $check_args ) {
            if ( ! empty( $check_args['require'] ) ) {
                $required_file = self::absolutize( $check_args['require'], dirname( $file ) );
                if ( ! file_exists( $required_file ) ) {
                    $required_file = basename( $required_file );
                    WP_CLI::error( "Required file '{$required_file}' doesn't exist (from '{$check_name}')." );
                }
                require_once $required_file;
            }

            if ( empty( $check_args['class'] ) && empty( $check_args['check'] ) ) {
                WP_CLI::error( "Check '{$check_name}' is missing 'class' or 'check'. Verify check registration." );
            }

            $class = ! empty( $check_args['check'] ) ? 'WP_CLI\\Doctor\\Check\\' . $check_args['check'] : $check_args['class'];
            if ( ! class_exists( $class ) ) {
                WP_CLI::error( "Class '{$class}' for check '{$check_name}' doesn't exist. Verify check registration." );
            }
            if ( $skipped_checks && in_array( $check_name, $skipped_checks, true ) ) {
                continue;
            }
            $options = ! empty( $check_args['options'] ) ? $check_args['options'] : array();
            $obj     = new $class( $options );
            self::add_check( $check_name, $obj );
        }
    }

    /**
     * Register a check with the Doctor
     *
     * @param string $name Name for the check.
     * @param string $class Check class name.
     */
    public static function add_check( $name, $check ) {

        if ( ! preg_match( '#^[A-Za-z0-9-]+$#', $name ) ) {
            WP_CLI::error( "Check name '{$name}' is invalid. Verify check registration." );
        }

        if ( ! is_object( $check ) ) {
            if ( ! class_exists( $check ) ) {
                WP_CLI::error( "Class '{$check}' for check '{$name}' doesn't exist. Verify check registration." );
            }
            $check = new $check();
        }
        if ( ! is_subclass_of( $check, 'WP_CLI\\Doctor\\Check' ) ) {
            $class = get_class( $check );
            WP_CLI::error( "Class '{$class}' for check '{$name}' needs to extend Check base class. Verify check registration." );
        }
        self::$instance->checks[ $name ] = $check;
    }

    /**
     * Get checks registred with the Doctor.
     *
     * @param array $args Filter checks based on some attribute.
     */
    public static function get_checks( $args = array() ) {
        if ( ! empty( $args['name'] ) ) {
            $checks = array();
            $names  = is_array( $args['name'] ) ? $args['name'] : array( $args['name'] );
            foreach ( $names as $name ) {
                if ( isset( self::$instance->checks[ $name ] ) ) {
                    $checks[ $name ] = self::$instance->checks[ $name ];
                }
            }
            return $checks;
        }
        return self::get_instance()->checks;
    }

    /**
     * Make a path absolute.
     *
     * @param string $path Path to file.
     * @param string $base Base path to prepend.
     */
    private static function absolutize( $path, $base ) {
        if ( ! empty( $path ) && ! Utils\is_path_absolute( $path ) ) {
            $path = $base . DIRECTORY_SEPARATOR . $path;
        }
        return $path;
    }
}