<?php

namespace Adventurebook;

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

/**
 * Class Enemy_Spawn
 *
 * This class represents a spawn point for enemies in the game.
 * Spawn points can be defined for each page, allowing enemies to appear in specific locations.
 * Each spawn point is associated with an enemy definition and can have a respawn time.
 *
 * Upon character creation, a spawn point is instantiated for this character
 * if $character_id is 0, this spawn point is a template for all characters
 */
class Enemy_Spawn {

	public int $id;

	public string $code;            //  which enemy is spawned
	public int $page_id;       //  on which page is the enemy spawned
	public int $respawn_time; //  in seconds, how long until the enemy respawns; 0 = no respawn

	//  save the date/time when the enemy was last defeated
	//  this is used to calculate when the enemy should respawn
	//  format: 'Y-m-d H:i:s'
	//  if respawn_time is 0, this value is ignored
	public ?string $last_defeated = null;
	public int $character_id; // if set, the spawn point is an instance for this character
	public int $parent_id; // if set, the spawn point is an instance for this character, and this is the id of the root spawn point
	public string $alternate_page_ids; //  comma-separated list of page IDs where this enemy can also spawn

	public function __construct( $id, $code, $page_id, $last_defeated = null, $respawn_time = 0, $character_id = 0, $parent_id = 0, $alternate_page_ids = '' ) {
		$this->id           = intval( $id );
		$this->code         = $code;
		$this->page_id      = intval( $page_id );
		$this->respawn_time = intval( $respawn_time );
		$this->last_defeated = $last_defeated;
		$this->character_id = intval( $character_id );
		$this->parent_id = intval( $parent_id );
		$this->alternate_page_ids = (string) $alternate_page_ids;
	}

	public function get_enemy_definition(): ?Enemy_Definition {
		return Enemy_Definition::get_enemy_definition_by_id( $this->id );
	}
	public static function get_enemy_spawn_by_id( $id ): ?Enemy_Spawn {
		global $wpdb;
		$result     = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix."adventurebook_enemy_spawns WHERE id = %d", $id ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		if ( $result === null ) {
			return null;
		}
		return new Enemy_Spawn( $result['id'], $result['code'], $result['page_id'], null, $result['respawn_time'], $result['character_id'], $result['parent_id'], $result['alternate_page_ids'] );
	}

	public static function get_enemy_spawns_by_page_id( $page_id, $character_id = 0 ): array {
		global $wpdb;
		if ( $character_id > 0 ) {
			$results = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE page_id = %d AND character_id = %d", $page_id, $character_id ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		} else {
			$results = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE page_id = %d AND character_id = 0", $page_id ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		}
		$enemy_spawns = array();
		foreach ( $results as $result ) {
			$enemy_spawns[] = new Enemy_Spawn( $result['id'], $result['code'], $result['page_id'], $result['last_defeated'], $result['respawn_time'], $result['character_id'], $result['parent_id'], $result['alternate_page_ids'] );
		}

		return $enemy_spawns;
	}

	/**
	 * Create a new enemy spawn point template (character_id = 0) for the given page.
	 * This will also create an instance of this spawn point for each existing character in the same adventurebook.
	 *
	 * @param string $code The enemy code to spawn
	 * @param int $page_id The page ID where the enemy should spawn
	 * @param int $respawn_time The respawn time in seconds (0 = no respawn)
	 * @param string $alternate_page_ids Comma-separated list of additional page IDs where this enemy can also spawn
	 */
	public static function create_enemy_spawn(string $code, int $page_id, int $respawn_time = 0, string $alternate_page_ids = ''): void {
		self::create_enemy_spawn_point_root( $code, $page_id, $respawn_time, $alternate_page_ids );
	}

	/**
	 * Internal function to create the root spawn point and instances for existing characters.
	 *
	 * @param string $code The enemy code to spawn
	 * @param int $page_id The page ID where the enemy should spawn
	 * @param int $respawn_time The respawn time in seconds (0 = no respawn)
	 * @param string $alternate_page_ids Comma-separated list of additional page IDs where this enemy can also spawn
	 */
	public static function create_enemy_spawn_point_root(string $code, int $page_id, int $respawn_time = 0, string $alternate_page_ids = ''): void {
		global $wpdb;
		$table_name = $wpdb->prefix . 'adventurebook_enemy_spawns';
		$wpdb->insert( $table_name, array(// phpcs:ignore WordPress.DB.DirectDatabaseQuery
			'code'      => $code,
			'page_id'       => $page_id,
			'respawn_time' => $respawn_time,
			'last_defeated' => null,
			'character_id' => 0,
			'parent_id' => 0,
			'alternate_page_ids' => $alternate_page_ids,
		) );
		//  now create an instance of this spawn point for each existing character in the same adventurebook, with parent_id set to the id of the root spawn point
		//  first, get the id of the newly created spawn point
		$spawn_id = $wpdb->insert_id;
		//  get the adventurebook_id of the page (it's the parent id of the page)
		$adventurebook_id = wp_get_post_parent_id( $page_id );
		//  get all characters in this adventurebook
		$characters = Character::get_characters_by_adventurebook_id( $adventurebook_id );
		foreach ( $characters as $character ) {
			self::create_enemy_spawn_point( $character->id, $spawn_id );
		}
	}

	public static function create_enemy_spawn_point( $character_id, $parent_spawn_point_id): void {
		global $wpdb;
		//  get the parent spawn point
		$parent_spawn_point = self::get_enemy_spawn_by_id( $parent_spawn_point_id );
		if ( ! $parent_spawn_point ) {
			return;
		}
		$table_name = $wpdb->prefix . 'adventurebook_enemy_spawns';
		//  set the last_defeated to null so the enemy can spawn immediately
		$wpdb->insert( $table_name, array(// phpcs:ignore WordPress.DB.DirectDatabaseQuery
			'code'      => $parent_spawn_point->code,
			'page_id'       => $parent_spawn_point->page_id,
			'respawn_time' => $parent_spawn_point->respawn_time,
			'last_defeated' => null,
			'character_id' => $character_id,
			'parent_id' => $parent_spawn_point_id,
			'alternate_page_ids' => $parent_spawn_point->alternate_page_ids,
		) );
	}

	public static function delete_enemy_spawn_points_by_code( $code ): void {
		global $wpdb;

		//  first, get all spawn points with this code
		$spawns = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE code = %s", $code ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		foreach ( $spawns as $spawn ) {
			//  delete each enemy for this spawn point
			Enemy::delete_enemies_for_spawn_id( $spawn['id'] );
			self::delete_enemy_spawn_point( $spawn['id'] );
		}
	}

	public static function delete_enemy_spawn_point( $id ): void {
		global $wpdb;

		//  first, get all child spawn points (instances for characters) and delete their enemies
		$child_spawns = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE parent_id = %d", $id ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		//  remove all enemy instances associated with these spawn points
		foreach ( $child_spawns as $child_spawn ) {
			Enemy::delete_enemies_for_spawn_id( $child_spawn['id'] );
		}
		//  then remove all enemies associated with this spawn point
		Enemy::delete_enemies_for_spawn_id( $id );
		$table_name = $wpdb->prefix . 'adventurebook_enemy_spawns';
		//  delete all adventurebook_enemy_spawns with parent_id = $id (child spawn points)
		$wpdb->delete( $table_name, array( 'parent_id' => $id ) );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		//  then delete the spawn point itself
		$wpdb->delete( $table_name, array( 'id' => $id ) );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
	}

	public static function delete_enemy_spawn_points_by_character_id( $character_id ): void {
		global $wpdb;

		//  remove all enemy instances associated with these spawn points
		$enemy_spawns = Enemy_Spawn::get_all_enemy_spawn_points( $character_id );
		foreach ( $enemy_spawns as $enemy_spawn ) {
			Enemy::delete_enemies_for_spawn_id( $enemy_spawn->id );
		}

		$table_name = $wpdb->prefix . 'adventurebook_enemy_spawns';
		$wpdb->delete( $table_name, array( 'character_id' => $character_id ) );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
	}

	/**
	 * Delete all enemy spawn points that have no valid parent_id or character_id
	 *
	 * @return int Number of deleted spawn points
	 */
	public static function delete_orphaned_enemy_spawn_points(): int {
		global $wpdb;
		//  get all enemy spawn points where parent_id does not exist in the table or where character_id is set but has no entry in the characters table
		$results = $wpdb->get_results( "SELECT es.id FROM ".$wpdb->prefix . "adventurebook_enemy_spawns es LEFT JOIN ".$wpdb->prefix . "adventurebook_characters c ON es.character_id = c.id WHERE (es.parent_id != 0 AND es.parent_id NOT IN (SELECT id FROM ".$wpdb->prefix . "adventurebook_enemy_spawns)) OR (es.character_id != 0 AND c.id IS NULL)", ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		foreach ( $results as $result ) {
			//  delete each enemy for this spawn point
			Enemy::delete_enemies_for_spawn_id( $result['id'] );
			Enemy_Spawn::delete_enemy_spawn_point( $result['id'] );
		}
		return count( $results );
	}

	public static function get_all_enemy_spawn_points( $character_id = 0 ): array {
		global $wpdb;
		if ( $character_id > 0 ) {
			$results = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE character_id = %d", $character_id ), ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		} else {
			$results = $wpdb->get_results(  "SELECT * FROM ".$wpdb->prefix . "adventurebook_enemy_spawns WHERE character_id = 0", ARRAY_A );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		}
		$enemy_spawns = array();
		foreach ( $results as $result ) {
			$enemy_spawns[] = new Enemy_Spawn( $result['id'], $result['code'], $result['page_id'], $result['last_defeated'], $result['respawn_time'], $result['character_id'], $result['parent_id'], $result['alternate_page_ids'] );
		}

		return $enemy_spawns;
	}

	/**
	 * Check if any enemies need to be respawned for the given character.
	 * This function should be called whenever a page is loaded or an action is taken.
	 *
	 * @param int $character_id The ID of the character to check for respawns.
	 */
	public static function check_for_respawns( int $character_id ): void {
		global $wpdb;
		//  get all enemy spawns for this character and his current location reset them if respawn_time has passed
		$character = Character::get_character_by_id( $character_id );
		if ( ! $character ) {
			return;
		}

		$enemy_spawns = Enemy_Spawn::get_enemy_spawns_by_page_id($character->location_id, $character_id);
		foreach ( $enemy_spawns as $enemy_spawn ) {
			/* @var $enemy_spawn Enemy_Spawn */
			//  check if enemy instance already exists for this spawn point
			//  if it does, skip to the next spawn point
			if ( $enemy_spawn->is_enemy_spawned() ) {
				continue;
			}

			//  if respawn_time is 0 and last_defeated is not NULL, the enemy was defeated and should not respawn
			if ( $enemy_spawn->respawn_time === 0 && ! empty( $enemy_spawn->last_defeated ) ) {
				continue;
			}

			$last_defeated = !empty($enemy_spawn->last_defeated)
				? strtotime($enemy_spawn->last_defeated)
				: time() - $enemy_spawn->respawn_time - 1; //  if last_defeated is NULL, set it to a time in the past so the enemy can respawn immediately

			$respawn_time  = $enemy_spawn->respawn_time;

			if ($last_defeated + $respawn_time <= time()) {
				//  respawn the enemy now, set last_defeated NULL
				$wpdb->update( $wpdb->prefix . "adventurebook_enemy_spawns", array( 'last_defeated' => null ), array( 'id' => $enemy_spawn->id ) );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
				//  spawn a new enemy instance for this character in the possible locations
				$possible_page_ids = $enemy_spawn->get_possible_spawn_locations_page_ids();
				//  choose one of the possible page IDs at random
				$spawn_page_id = $possible_page_ids[array_rand($possible_page_ids)];
				//  create the enemy instance
				$enemy_definition = Enemy_Definition::get_enemy_definition_by_code( $enemy_spawn->code );
				Enemy::create_enemy( $enemy_definition->code, $enemy_definition->stats, $enemy_definition->is_hostile, $enemy_spawn->id , $spawn_page_id );
			}
		}

	}

	public function is_enemy_spawned(): bool {
		$existing_enemies = Enemy::get_enemies_for_spawn_id( $this->id );
		//  if there is at least one enemy for this spawn point, return true
		if ( count( $existing_enemies ) > 0 ) {
			return true;
		}
		//  otherwise return false
		return false;
	}

	public function update_last_defeated(): void {
		global $wpdb;
		$now = gmdate( 'Y-m-d H:i:s' );
		$wpdb->update( $wpdb->prefix . "adventurebook_enemy_spawns", array( 'last_defeated' => $now ), array( 'id' => $this->id ) );// phpcs:ignore WordPress.DB.DirectDatabaseQuery
	}

	public function get_possible_spawn_locations_page_ids(): array {
		$possible_page_ids = array( $this->page_id );
		if ( ! empty( $this->alternate_page_ids ) ) {
			$additional_page_ids = explode( ',', $this->alternate_page_ids );
			foreach ( $additional_page_ids as $additional_page_id ) {
				$additional_page_id = intval( trim( $additional_page_id ) );
				if ( $additional_page_id > 0 && ! in_array( $additional_page_id, $possible_page_ids, true ) ) {
					$possible_page_ids[] = $additional_page_id;
				}
			}
		}
		return $possible_page_ids;
	}

	/**
	 * Get all pages where an enemy with the given code is spawned
	 *
	 * @param string $code
	 * @return array<int> Array of pages
	 */
	public static function get_all_pages_for_enemy_spawn_code(string $code): array
	{
		global $wpdb;
		$results = $wpdb->get_results($wpdb->prepare("SELECT page_id FROM ".$wpdb->prefix."adventurebook_enemy_spawns WHERE code = %s AND parent_id = 0", $code), ARRAY_A);// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		$pages = array();
		foreach ($results as $result) {
			//  chedk if the page exists
			$page_id = intval($result['page_id']);
			//  check if a page with this ID exists
			if (get_post_status( $page_id ) === false) {
				continue;
			}
			//  check if the page is already in the list
			//  check if the page is already in the array
			$found = false;
			foreach ($pages as $page) {
				if ($page->ID === $page_id) {
					$found = true;
					break;
				}
			}
			if ($found) {
				continue;
			}
			//  get the page
			$pages[] = get_post( $page_id );
		}
		return $pages;
	}

	/**
	 * convert the given result to a list of enemy spawns
	 *
	 * @param array<array<string,mixed>> $results

	 * @return array<Enemy_Spawn>
	 */
	public static function get_enemy_spawns_by_result($results): array
	{
		$enemy_spawns = array();
		foreach ($results as $result) {
			$enemy_spawns[] = new Enemy_Spawn($result['id'], $result['code'], $result['page_id'], $result['last_defeated'], $result['respawn_time'], $result['character_id'], $result['parent_id'], $result['alternate_page_ids']);
		}
		return $enemy_spawns;
	}

}