<?php

namespace WP_CLI\Bootstrap;

use Exception;
use WP_CLI;

/**
 * Abstract class AutoloaderStep.
 *
 * Abstract base class for steps that include an autoloader.
 *
 * @package WP_CLI\Bootstrap
 */
abstract class AutoloaderStep implements BootstrapStep {

    /**
     * Store state for subclasses to have access.
     *
     * @var BootstrapState
     */
    protected $state;

    /**
     * Process this single bootstrapping step.
     *
     * @param BootstrapState $state Contextual state to pass into the step.
     *
     * @return BootstrapState Modified state to pass to the next step.
     */
    public function process( BootstrapState $state ) {
        $this->state = $state;

        $found_autoloader = false;
        $autoloader_paths = $this->get_autoloader_paths();

        if ( false === $autoloader_paths ) {
            // Skip this autoload step.
            return $state;
        }

        foreach ( $autoloader_paths as $autoloader_path ) {
            if ( is_readable( $autoloader_path ) ) {
                try {
                    WP_CLI::debug(
                        sprintf(
                            'Loading detected autoloader: %s',
                            $autoloader_path
                        ),
                        'bootstrap'
                    );
                    require $autoloader_path;
                    $found_autoloader = true;
                } catch ( Exception $exception ) {
                    WP_CLI::warning(
                        "Failed to load autoloader '{$autoloader_path}'. Reason: "
                        . $exception->getMessage()
                    );
                }
            }
        }

        if ( ! $found_autoloader ) {
            $this->handle_failure();
        }

        return $this->state;
    }

    /**
     * Get the name of the custom vendor folder as set in `composer.json`.
     *
     * @return string|false Name of the custom vendor folder or false if none.
     */
    protected function get_custom_vendor_folder() {
        $maybe_composer_json = WP_CLI_ROOT . '/../../../composer.json';
        if ( ! is_readable( $maybe_composer_json ) ) {
            return false;
        }

        $composer = json_decode( file_get_contents( $maybe_composer_json ) );

        if ( ! empty( $composer->config )
            && ! empty( $composer->config->{'vendor-dir'} )
        ) {
            return $composer->config->{'vendor-dir'};
        }

        return false;
    }

    /**
     * Handle the failure to find an autoloader.
     *
     * @return void
     */
    protected function handle_failure() { }

    /**
     * Get the autoloader paths to scan for an autoloader.
     *
     * @return string[]|false Array of strings with autoloader paths, or false
     *                        to skip.
     */
    abstract protected function get_autoloader_paths();
}