<?php

namespace runcommand\Profile;

use WP_CLI;
use WP_CLI\Utils;

class Command {

	private $loggers = array();
	private $focus_stage = null;
	private $stage_hooks = array();
	private $focus_hook = null;
	private $previous_filter = null;
	private $previous_filter_callbacks = null;
	private $filter_depth = 0;
	private $focus_query_offset = 0;

	private static $exception_message = "Need to bail, because can't restore the hooks";

	/**
	 * Profile each stage of the WordPress load process (bootstrap, main_query, template).
	 *
	 * ## OPTIONS
	 *
	 * [<stage>]
	 * : Drill down into a specific stage.
	 *
	 * [--all]
	 * : Expand upon all stages.
	 *
	 * [--url=<url>]
	 * : Execute a request against a specified URL. Defaults to the home URL.
	 *
	 * [--fields=<fields>]
	 * : Display one or more fields.
	 *
	 * [--format=<format>]
	 * : Render output in a particular format.
	 * ---
	 * default: table
	 * options:
	 *   - table
	 *   - json
	 *   - yaml
	 *   - csv
	 * ---
	 *
	 * @when before_wp_load
	 */
	public function stage( $args, $assoc_args ) {
		global $wpdb;

		$this->focus_stage = Utils\get_flag_value( $assoc_args, 'all', isset( $args[0] ) ? $args[0] : null );

		$valid_stages = array( 'bootstrap', 'main_query', 'template' );
		if ( $this->focus_stage && ( true !== $this->focus_stage && ! in_array( $this->focus_stage, $valid_stages, true ) ) ) {
			WP_CLI::error( 'Invalid stage. Must be one of ' . implode( ', ', $valid_stages ) . ', or use --all.' );
		}

		$this->run_profiler();

		if ( $this->focus_stage ) {
			$fields = array(
				'hook',
				'callback_count',
				'time',
				'query_time',
				'query_count',
				'cache_ratio',
				'cache_hits',
				'cache_misses',
				'request_time',
				'request_count',
			);
		} else {
			$fields = array(
				'stage',
				'time',
				'query_time',
				'query_count',
				'cache_ratio',
				'cache_hits',
				'cache_misses',
				'hook_time',
				'hook_count',
				'request_time',
				'request_count',
			);
		}
		$formatter = new Formatter( $assoc_args, $fields );
		$formatter->display_items( $this->loggers );
	}

	/**
	 * Profile key metrics for a WordPress hook (action or filter).
	 *
	 * ## OPTIONS
	 *
	 * <hook>
	 * : WordPress hook (action or filter) to profile.
	 *
	 * [--url=<url>]
	 * : Execute a request against a specified URL. Defaults to the home URL.
	 *
	 * [--fields=<fields>]
	 * : Display one or more fields.
	 *
	 * [--format=<format>]
	 * : Render output in a particular format.
	 * ---
	 * default: table
	 * options:
	 *   - table
	 *   - json
	 *   - yaml
	 *   - csv
	 * ---
	 *
	 * @when before_wp_load
	 */
	public function hook( $args, $assoc_args ) {

		$this->focus_hook = $args[0];
		$this->run_profiler();

		// 'shutdown' won't actually fire until script completion
		// but we can mock it
		if ( 'shutdown' === $this->focus_hook ) {
			do_action( 'shutdown' );
			remove_all_actions( 'shutdown' );
		}

		$fields = array(
			'callback',
			'location',
			'time',
			'query_time',
			'query_count',
			'cache_ratio',
			'cache_hits',
			'cache_misses',
			'request_time',
			'request_count',
		);
		$formatter = new Formatter( $assoc_args, $fields );
		$formatter->display_items( $this->loggers );
	}

	/**
	 * Profile arbitrary code execution.
	 *
	 * Code execution happens after WordPress has loaded entirely, which means
	 * you can use any utilities defined in WordPress, active plugins, or the
	 * current theme.
	 *
	 * ## OPTIONS
	 *
	 * <php-code>
	 * : The code to execute, as a string.
	 *
	 * [--fields=<fields>]
	 * : Display one or more fields.
	 *
	 * [--format=<format>]
	 * : Render output in a particular format.
	 * ---
	 * default: table
	 * options:
	 *   - table
	 *   - json
	 *   - yaml
	 *   - csv
	 * ---
	 *
	 * @when before_wp_load
	 * @subcommand eval
	 */
	public function eval_( $args, $assoc_args ) {

		$this->run_profiler();

		$logger = new Logger();
		$logger->start();
		eval( $args[0] );
		$logger->stop();

		$fields = array(
			'time',
			'query_time',
			'query_count',
			'cache_ratio',
			'cache_hits',
			'cache_misses',
			'request_time',
			'request_count',
		);
		$formatter = new Formatter( $assoc_args, $fields );
		$formatter->display_items( array( $logger ) );
	}

	/**
	 * Profile execution of an arbitrary file.
	 *
	 * File execution happens after WordPress has loaded entirely, which means
	 * you can use any utilities defined in WordPress, active plugins, or the
	 * current theme.
	 *
	 * ## OPTIONS
	 *
	 * <file>
	 * : The path to the PHP file to execute and profile.
	 *
	 * [--fields=<fields>]
	 * : Display one or more fields.
	 *
	 * [--format=<format>]
	 * : Render output in a particular format.
	 * ---
	 * default: table
	 * options:
	 *   - table
	 *   - json
	 *   - yaml
	 *   - csv
	 * ---
	 *
	 * @when before_wp_load
	 * @subcommand eval-file
	 */
	public function eval_file( $args, $assoc_args ) {

		$file = $args[0];
		if ( ! file_exists( $file ) ) {
			WP_CLI::error( "'$file' does not exist." );
		}

		$this->run_profiler();

		$logger = new Logger();
		$logger->start();
		self::include_file( $file );
		$logger->stop();

		$fields = array(
			'time',
			'query_time',
			'query_count',
			'cache_ratio',
			'cache_hits',
			'cache_misses',
			'request_time',
			'request_count',
		);
		$formatter = new Formatter( $assoc_args, $fields );
		$formatter->display_items( array( $logger ) );
	}

	/**
	 * Profiling verbosity at the beginning of every action and filter
	 */
	public function wp_hook_begin() {
		global $wpdb, $wp_filter;

		foreach( Logger::$active_loggers as $logger ) {
			$logger->start_hook_timer();
		}

		$current_filter = current_filter();
		if ( in_array( $current_filter, $this->stage_hooks ) ) {
			$pseudo_hook = "before {$current_filter}";
			if ( isset( $this->loggers[ $pseudo_hook ] ) ) {
				$this->loggers[ $pseudo_hook ]->stop();
			}
			$callback_count = 0;
			if ( isset( $wp_filter[ $current_filter ] ) && is_a( $wp_filter[ $current_filter ], 'WP_Hook' ) ) {
				if ( is_array( $wp_filter[ $current_filter ]->callbacks ) ) {
					foreach( $wp_filter[ $current_filter ]->callbacks as $priority => $callbacks ) {
						$callback_count += count( $callbacks );
					}
				}
			} else {
				if ( isset( $wp_filter[ $current_filter ] ) && is_array( $wp_filter[ $current_filter ] ) ) {
					foreach( $wp_filter[ $current_filter ] as $priority => $callbacks ) {
						$callback_count += count( $callbacks );
					}
				}
			}
			$this->loggers[ $current_filter ] = new Logger( array( 'hook' => $current_filter, 'callback_count' => $callback_count ) );
			$this->loggers[ $current_filter ]->start();
		}

		if ( ! is_null( $this->previous_filter_callbacks ) && 0 === $this->filter_depth ) {
			if ( is_a( $wp_filter[ $this->previous_filter ], 'WP_Hook' ) ) {
				$wp_filter[ $this->previous_filter ]->callbacks = $this->previous_filter_callbacks;
			} else {
				$wp_filter[ $this->previous_filter ] = $this->previous_filter_callbacks;
			}
			$this->previous_filter_callbacks = null;
		}

		if ( $this->focus_hook && $current_filter === $this->focus_hook && 0 === $this->filter_depth ) {
			$this->wrap_current_filter_callbacks( $current_filter );
			$this->filter_depth = 1;
		}

		WP_CLI::add_wp_hook( $current_filter, array( $this, 'wp_hook_end' ), 9999 );
	}

	/**
	 * Wrap current filter callbacks with a timer
	 */
	private function wrap_current_filter_callbacks( $current_filter ) {
		global $wp_filter;

		if ( ! isset( $wp_filter[ $current_filter ] ) ) {
			return;
		}

		$this->previous_filter = $current_filter;
		if ( is_a( $wp_filter[ $current_filter ], 'WP_Hook' ) ) {
			$callbacks = $this->previous_filter_callbacks = $wp_filter[ $current_filter ]->callbacks;
		} else {
			$callbacks = $this->previous_filter_callbacks = $wp_filter[ $current_filter ];
		}

		if ( ! is_array( $callbacks ) ) {
			return;
		}

		foreach( $callbacks as $priority => $priority_callbacks ) {
			foreach( $priority_callbacks as $i => $the_ ) {
				$callbacks[ $priority ][ $i ] = array(
					'function'       => function() use( $the_, $i ) {
						if ( ! isset( $this->loggers[ $i ] ) ) {
							list( $callback, $location ) = self::get_name_location_from_callback( $the_['function'] );
							$definition = array(
								'callback'     => $callback,
								'location'     => $location,
							);
							$this->loggers[ $i ] = new Logger( $definition );
						}
						$this->loggers[ $i ]->start();
						$value = call_user_func_array( $the_['function'], func_get_args() );
						$this->loggers[ $i ]->stop();
						return $value;
					},
					'accepted_args'  => $the_['accepted_args'],
				);
			}
		}

		if ( is_a( $wp_filter[ $current_filter ], 'WP_Hook' ) ) {
			$wp_filter[ $current_filter ]->callbacks = $callbacks;
		} else {
			$wp_filter[ $current_filter ] = $callbacks;
		}
	}

	/**
	 * Profiling verbosity at the end of every action and filter
	 */
	public function wp_hook_end( $filter_value = null ) {
		global $wpdb, $wp_filter;

		foreach( Logger::$active_loggers as $logger ) {
			$logger->stop_hook_timer();
		}

		$current_filter = current_filter();
		if ( $this->focus_hook && $current_filter === $this->focus_hook ) {
			$this->filter_depth = 0;
		}

		if ( in_array( $current_filter, $this->stage_hooks ) ) {
			$this->loggers[ $current_filter ]->stop();
			$key = array_search( $current_filter, $this->stage_hooks );
			if ( false !== $key && isset( $this->stage_hooks[$key+1] ) ) {
				$pseudo_hook = "before {$this->stage_hooks[$key+1]}";
				$this->loggers[ $pseudo_hook ] = new Logger( array( 'hook' => '' ) );
				$this->loggers[ $pseudo_hook ]->start();
			} else {
				$pseudo_hook = 'wp_profile_last_hook';
				$this->loggers[ $pseudo_hook ] = new Logger( array( 'hook' => '' ) );
				$this->loggers[ $pseudo_hook ]->start();
			}
		}

		return $filter_value;
	}

	/**
	 * Profiling request time for any active Loggers
	 */
	public function wp_request_begin( $filter_value = null ) {
		foreach( Logger::$active_loggers as $logger ) {
			$logger->start_request_timer();
		}
		return $filter_value;
	}

	/**
	 * Profiling request time for any active Loggers
	 */
	public function wp_request_end( $filter_value = null ) {
		foreach( Logger::$active_loggers as $logger ) {
			$logger->stop_request_timer();
		}
		return $filter_value;
	}

	/**
	 * Run the profiler against WordPress
	 */
	private function run_profiler() {
		WP_CLI::add_wp_hook( 'muplugins_loaded', function(){
			if ( $url = WP_CLI::get_runner()->config['url'] ) {
				WP_CLI::set_url( trailingslashit( $url ) );
			} else {
				WP_CLI::set_url( home_url( '/' ) );
			}
		});
		WP_CLI::add_hook( 'after_wp_config_load', function() {
			if ( defined( 'SAVEQUERIES' ) && ! SAVEQUERIES ) {
				WP_CLI::error( "'SAVEQUERIES' is defined as false, and must be true. Please check your wp-config.php" );
			}
			if ( ! defined( 'SAVEQUERIES' ) ) {
				define( 'SAVEQUERIES', true );
			}
		});
		WP_CLI::add_wp_hook( 'all', array( $this, 'wp_hook_begin' ) );
		WP_CLI::add_wp_hook( 'pre_http_request', array( $this, 'wp_request_begin' ) );
		WP_CLI::add_wp_hook( 'http_api_debug', array( $this, 'wp_request_end' ) );
		$this->load_wordpress_with_template();
	}

	/**
	 * Runs through the entirety of the WP bootstrap process
	 */
	private function load_wordpress_with_template() {
		global $wp_query;

		$stage_hooks = array(
			'bootstrap'    => array(
				'muplugins_loaded',
				'plugins_loaded',
				'setup_theme',
				'after_setup_theme',
				'init',
				'wp_loaded',
			),
			'main_query'   => array(
				'parse_request',
				'send_headers',
				'pre_get_posts',
				'the_posts',
				'wp',
			),
			'template'     => array(
				'template_redirect',
				'template_include',
				'wp_head',
				'loop_start',
				'loop_end',
				'wp_footer',
			),
		);
		if ( true === $this->focus_stage ) {
			$hooks = array();
			foreach( $stage_hooks as $stage_hook ) {
				$hooks = array_merge( $hooks, $stage_hook );
			}
			$this->set_stage_hooks( $hooks );
		}

		if ( 'bootstrap' === $this->focus_stage ) {
			$this->set_stage_hooks( $stage_hooks['bootstrap'] );
		} else if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger = new Logger( array( 'stage' => 'bootstrap' ) );
			$logger->start();
		}
		WP_CLI::get_runner()->load_wordpress();
		if ( isset( $this->loggers['wp_profile_last_hook'] ) && $this->loggers['wp_profile_last_hook']->running() ) {
			$this->loggers['wp_profile_last_hook']->stop();
		}
		if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger->stop();
			$this->loggers[] = $logger;
		}

		// Set up main_query main WordPress query.
		if ( 'main_query' === $this->focus_stage ) {
			$this->set_stage_hooks( $stage_hooks['main_query'] );
		} else if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger = new Logger( array( 'stage' => 'main_query' ) );
			$logger->start();
		}
		wp();
		if ( isset( $this->loggers['wp_profile_last_hook'] ) && $this->loggers['wp_profile_last_hook']->running() ) {
			$this->loggers['wp_profile_last_hook']->stop();
		}
		if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger->stop();
			$this->loggers[] = $logger;
		}

		define( 'WP_USE_THEMES', true );

		// Template is normally loaded in global stage, so we need to replicate
		foreach( $GLOBALS as $key => $value ) {
			global $$key;
		}

		// Load the theme template.
		if ( 'template' === $this->focus_stage ) {
			$this->set_stage_hooks( $stage_hooks['template'] );
		} else if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger = new Logger( array( 'stage' => 'template' ) );
			$logger->start();
		}
		ob_start();
		require_once( ABSPATH . WPINC . '/template-loader.php' );
		ob_get_clean();
		if ( isset( $this->loggers['wp_profile_last_hook'] ) && $this->loggers['wp_profile_last_hook']->running() ) {
			$this->loggers['wp_profile_last_hook']->stop();
		}
		if ( ! $this->focus_stage && ! $this->focus_hook ) {
			$logger->stop();
			$this->loggers[] = $logger;
		}

	}

	/**
	 * Get a human-readable name from a callback
	 */
	private static function get_name_location_from_callback( $callback ) {
		$name = $location = '';
		$reflection = false;
		if ( is_array( $callback ) && is_object( $callback[0] ) ) {
			$reflection = new \ReflectionMethod( $callback[0], $callback[1] );
			$name = get_class( $callback[0] ) . '->' . $callback[1] . '()';
		} elseif ( is_array( $callback ) && method_exists( $callback[0], $callback[1] ) ) {
			$reflection = new \ReflectionMethod( $callback[0], $callback[1] );
			$name = $callback[0] . '::' . $callback[1] . '()';
		} elseif ( is_object( $callback ) && is_a( $callback, 'Closure' ) ) {
			$reflection = new \ReflectionFunction( $callback );
			$name = 'function(){}';
		} else if ( is_string( $callback ) ) {
			$reflection = new \ReflectionFunction( $callback );
			$name = $callback . '()';
		}
		if ( $reflection ) {
			$location = $reflection->getFileName() . ':' . $reflection->getStartLine();
			if ( 0 === stripos( $location, WP_PLUGIN_DIR ) ) {
				$location = str_replace( trailingslashit( WP_PLUGIN_DIR ), '', $location );
			} else if ( 0 === stripos( $location, WPMU_PLUGIN_DIR ) ) {
				$location = str_replace( trailingslashit( dirname( WPMU_PLUGIN_DIR ) ), '', $location );
			} else if ( 0 === stripos( $location, get_theme_root() ) ) {
				$location = str_replace( trailingslashit( get_theme_root() ), '', $location );
			} else if ( 0 === stripos( $location, ABSPATH . 'wp-admin/' ) ) {
				$location = str_replace( ABSPATH, '', $location );
			} else if ( 0 === stripos( $location, ABSPATH . 'wp-includes/' ) ) {
				$location = str_replace( ABSPATH, '', $location );
			}
		}
		return array( $name, $location );
	}

	/**
	 * Set the hooks for the current stage
	 */
	private function set_stage_hooks( $hooks ) {
		$this->stage_hooks = $hooks;
		$pseudo_hook = "before {$hooks[0]}";
		$this->loggers[ $pseudo_hook ] = new Logger( array( 'hook' => '' ) );
		$this->loggers[ $pseudo_hook ]->start();
	}

	/**
	 * Include a file without exposing it to current scope
	 *
	 * @param string $file
	 */
	private static function include_file( $file ) {
		include( $file );
	}

}