<?php

namespace Yipresser\AdminOptimizer\Modules;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Custom_Code_Filesystem class
 *
 * Handles creation and management of external CSS/JS files
 * in /wp-content/uploads/ao-custom-code/.
 */
class Custom_Code_Filesystem {

	/**
	 * Build the full file path for a given filetype/location pair.
	 *
	 * @param array $file Result of get_filepath().
	 * @return string
	 */
	private function build_full_path( array $file ): string {
		return $file['folder_path'] . DIRECTORY_SEPARATOR . $file['file_name'];
	}

	/**
	 * Check whether the target file/directory is writable.
	 *
	 * @param string $filetype 'css' or 'js'
	 * @param string $location
	 * @return bool
	 */
	public function can_write( string $filetype, string $location ): bool {
		$file = $this->get_filepath( $filetype, $location );

		if ( ! isset( $file['folder_path'], $file['file_name'] ) ) {
			return false;
		}

		if ( ! file_exists( $file['folder_path'] ) ) {
			return wp_mkdir_p( $file['folder_path'] );
		}

		$filesystem = $this->get_wp_filesystem();
		if ( ! $filesystem ) {
			return false;
		}

		$file_path = $this->build_full_path( $file );

		if (
			! $filesystem->is_writable( $file['folder_path'] ) &&
			( ! file_exists( $file_path ) || ! $filesystem->is_writable( $file_path ) )
		) {
			return false;
		}

		if (
			$filesystem->is_writable( $file['folder_path'] ) &&
			file_exists( $file_path ) && ! $filesystem->is_writable( $file_path )
		) {
			return false;
		}

		return true;
	}

	/**
	 * Write code to an external file and return its versioned URI.
	 *
	 * @param string $code
	 * @param string $filetype
	 * @param string $location
	 * @return string|false URI on success, false on failure.
	 */
	public function create_external_file( string $code, string $filetype, string $location ) {
		if ( ! $code || ! $this->can_write( $filetype, $location ) ) {
			return false;
		}

		$filesystem = $this->get_wp_filesystem();
		if ( ! $filesystem ) {
			return false;
		}

		$file      = $this->get_filepath( $filetype, $location );
		$file_path = $this->build_full_path( $file );

		if ( $filesystem->is_writable( $file_path ) || ( ! file_exists( $file_path ) && $filesystem->is_writable( dirname( $file_path ) ) ) ) {
			$chmod = defined( 'FS_CHMOD_FILE' ) ? FS_CHMOD_FILE : 0644;

			if ( ! $filesystem->put_contents( $file_path, $code, $chmod ) ) {
				return false;
			}

			if ( ! file_exists( $file_path ) ) {
				return false;
			}

			return $this->get_file_url( $filetype, $location ) . '?ver=' . filemtime( $file_path );
		}

		return false;
	}

	/**
	 * Return folder path and file name for a given filetype/location pair.
	 *
	 * @param string $filetype
	 * @param string $location
	 * @return array|false
	 */
	public function get_filepath( string $filetype, string $location ) {
		if ( ! in_array( $filetype, [ 'js', 'css' ], true ) ) {
			return false;
		}

		if ( ! array_key_exists( $location, Custom_Code::ALL_LOCATIONS ) ) {
			return false;
		}

		$upload_dir  = wp_get_upload_dir();
		$basename    = ( 'js' === $filetype ) ? 'script' : 'style';
		$folder_path = $upload_dir['basedir'] . DIRECTORY_SEPARATOR . 'ao-custom-code';
		if ( is_multisite() ) {
			$folder_path .= DIRECTORY_SEPARATOR . get_current_blog_id();
		}

		return [
			'folder_path' => $folder_path,
			'file_name'   => $basename . '-' . $location . '.' . $filetype,
		];
	}

	/**
	 * Return the public URL to a generated file.
	 *
	 * @param string $filetype
	 * @param string $location
	 * @return string
	 */
	public function get_file_url( string $filetype, string $location ): string {
		$upload_dir = wp_get_upload_dir();
		$basename   = ( 'js' === $filetype ) ? 'script' : 'style';
		$file_name  = $basename . '-' . $location . '.' . $filetype;

		return set_url_scheme( trailingslashit( $upload_dir['baseurl'] ) . 'ao-custom-code/' . $file_name );
	}

	/**
	 * Initialize and return the global WP_Filesystem object.
	 *
	 * @return \WP_Filesystem_Base|null
	 */
	public function get_wp_filesystem() {
		global $wp_filesystem;

		if ( ! $wp_filesystem ) {
			require_once ABSPATH . '/wp-admin/includes/file.php';

			$credentials = [];
			$constants   = [
				'hostname'    => 'FTP_HOST',
				'username'    => 'FTP_USER',
				'password'    => 'FTP_PASS',
				'public_key'  => 'FTP_PUBKEY',
				'private_key' => 'FTP_PRIKEY',
			];
			foreach ( $constants as $key => $constant ) {
				if ( defined( $constant ) ) {
					$credentials[ $key ] = constant( $constant );
				}
			}

			$success = WP_Filesystem( $credentials );
			if ( ! $success || $wp_filesystem->errors->has_errors() ) {
				return null;
			}
		}

		return $wp_filesystem;
	}

	/**
	 * Delete a generated external file.
	 *
	 * @param string $filetype
	 * @param string $location
	 * @return bool
	 */
	public function delete_file( string $filetype, string $location ): bool {
		$file = $this->get_filepath( $filetype, $location );
		if ( isset( $file['folder_path'], $file['file_name'] ) ) {
			$file_path = $this->build_full_path( $file );
			if ( file_exists( $file_path ) ) {
				return (bool) wp_delete_file( $file_path );
			}
		}
		return true;
	}
}