<?php

namespace Adventurebook;

require_once __DIR__ . '/interfaces/ICombattant.php';

abstract class AbstractCombattant implements ICombattant {

	// Common properties for all combattants
	public int $id;
	public string $name;
	public string $description;
	public int $location_id;        //  in which zone does this creature exist
	public array $stats; // e.g., CurHealth, Health, Attack, Defense, Initiative, etc.
	public array $inventory = []; // items the combattant has (array of item_ids)
	public ?string $next_action = null;

	public function __construct( string $name, string $description, array $stats ) {
		$this->name        = $name;
		$this->description = $description;
		$this->stats       = $stats;
		//  upon creation, the "CurHealth" stat is set to the "Health" stat if it exists
		if ( isset( $this->stats['Health'] ) && ! isset( $this->stats['CurHealth'] ) ) {
			$this->stats['CurHealth'] = $this->stats['Health'];
		}
	}

	public function get_name(): string {
		return $this->name;
	}

	public function set_name( string $name ): void {
		$this->name = $name;
		$this->save_to_db();
	}

	public function get_description(): string {
		return $this->description;
	}

	public function get_stats(): array {
		return $this->stats;
	}

	/** Get a specific stat by name.
	 * Returns null if the stat does not exist.
	 *
	 * a Stat MUST start with a capital letter!
	 * e.g. "CurHealth", "Health", "Attack", "Defense", "Initiative", etc.)
	 *
	 * @param string $stat_name The name of the stat to retrieve.
	 *
	 * @return string The value of the stat, or null if it does not exist
	 * TODO: some stats count as -3 if they do not exist (e.g. Initiative)
	 */
	public function get_stat( string $stat_name ): ?string {
		return $this->stats[ $stat_name ] ?? null;
	}

	public function get_slots(): array {
		return $this->stats['SLOTS'] ?? [];
	}

	/** Set a specific stat by name.
	 * If the stat does not exist, it will be created.
	 *
	 * a Stat MUST start with a capital letter!
	 *
	 * @param string $stat_name The name of the stat to set.
	 * @param int $value The value to set the stat to.
	 *
	 * @return void
	 */
	public function set_stat( string $stat_name, $value ): void {
		$this->stats[ $stat_name ] = $value;
		$this->save_to_db();
	}

	public function isAlive(): bool {
		//  if Health is not set or 0, the combattant is always alive
		if ( ! isset( $this->stats['Health'] ) || $this->stats['Health'] <= 0 ) {
			return true;
		}

		return ( $this->stats['CurHealth'] ?? 0 ) > 0;
	}

	public function take_damage( int $amount ): void {
		if ( isset( $this->stats['CurHealth'] ) ) {
			$this->stats['CurHealth'] -= $amount;
			if ( $this->stats['CurHealth'] < 0 ) {
				$this->stats['CurHealth'] = 0;
			}
			//  save the combattant to the database if applicable
			if ( method_exists( $this, 'save_to_db' ) ) {
				$this->save_to_db();
			}
		}
	}

	public function heal( int $amount ): int {
		if ( $amount == - 1 ) {
			//  full heal
			$amount = $this->stats['Health'] - ( $this->stats['CurHealth'] ?? 0 );
		}
		$healed_amount = 0;
		if ( isset( $this->stats['CurHealth'] ) && isset( $this->stats['Health'] ) ) {
			$healed_amount            = $amount;
			$this->stats['CurHealth'] += $amount;
			if ( $this->stats['CurHealth'] > $this->stats['Health'] ) {
				//  get the correct amount healed
				$healed_amount            = $this->stats['Health'] - ( $this->stats['CurHealth'] - $amount );
				$this->stats['CurHealth'] = $this->stats['Health'];
			}
			//  save the combattant to the database if applicable
			if ( method_exists( $this, 'save_to_db' ) ) {
				$this->save_to_db();
			}
		}

		return $healed_amount;
	}

	public function get_next_action(): ?string {
		return $this->next_action;
	}

	public function set_next_action( string $action ): void {
		$this->next_action = $action;
		$this->save_to_db();
	}

	/**
	 * Get the total value of a stat including bonuses from equipped items.
	 * If the stat does not exist, it is considered to be 0.
	 *
	 * @param string $stat_name The name of the stat to retrieve.
	 *
	 * @return int The total value of the stat including item bonuses.
	 */
	public function get_total_stat_including_items( string $stat_name ): int {
		$base_stat  = intval( $this->stats[ $stat_name ] ?? 0 );
		$item_bonus = $this->get_stat_bonus_from_equipped_items( $stat_name );

		return $base_stat + $item_bonus;
	}

	public function get_stat_bonus_from_equipped_items( string $stat_name ): int {
		$bonus          = 0;
		$equipped_items = $this->get_equipped_items();
		foreach ( $equipped_items as $item ) {
			$item_definition = Item_Definition::get_item_definition_by_code( $item->code );
			if ( $item_definition ) {
				$item_stats = $item_definition->get_stats();
				$bonus      += intval( $item_stats[ $stat_name ] ?? 0 );
			}
		}

		return $bonus;
	}

	/**
	 * Check if the combattant has a specific slot for equipping items.
	 * The slots are defined in the combattandt's stats under 'SLOTS'.
	 * The value is a an associative array with slot names as keys and item_id as values
	 * e.g. ['Weapon' => '1', 'Armor' => '2']
	 * item_id = 0 means the slot is empty
	 *
	 * @param string $slot_name The name of the slot to check.
	 *
	 * @return bool True if the combattant has the slot, false otherwise.
	 */
	public function has_slot( string $slot_name ): bool {
		$slots = $this->get_slots();
		//  search for the array key with the slot name
		return array_key_exists( $slot_name, $slots );
	}

	public function get_slot_value( string $slot_name ): ?int {
		$slots = $this->get_slots();
		if ( array_key_exists( $slot_name, $slots ) ) {
			return intval( $slots[ $slot_name ] );
		}
		return null; // slot does not exist
	}

	/** Set the value of a specific slot.
	 * The value is the item_id of the item equipped in this slot.
	 * If the slot does not exist, it will be created.
	 *
	 * @param string $slot_name The name of the slot to set.
	 * @param int $item_id The item_id to set the slot to (0 = empty).
	 *
	 * @return void
	 */
	public function set_slot_value( string $slot_name, int $item_id ): void {
		$slots = $this->get_slots();
		$slots[ $slot_name ] = $item_id;
		$this->stats['SLOTS'] = $slots;
		//  save the combattant to the database if applicable
		if ( method_exists( $this, 'save_to_db' ) ) {
			$this->save_to_db();
		}

	}

	/**
	 * Determine if the combattant can equip a given item.
	 * This is possible if the combattant has the required slot for the item.
	 * The slots are defined in the combattandt's stats under 'SLOTS'.
	 * There has to be a slot with the same name as the item's slot stat.
	 * For example, if the item has a stat 'Slot' with value 'Weapon',
	 * the combattant must have 'Weapon' in its 'SLOTS' stat to equip it
	 *
	 * @param string $item_code the code of the item to check.
	 *
	 * @return bool True if the item can be equipped, false otherwise.
	 */
	public function can_equip_item( string $item_code ): bool {
		//  get the item's slot and check if the combattant has this slot
		$item_definition = Item_Definition::get_item_definition_by_code( $item_code );
		$item_stats      = $item_definition->get_stats();
		$item_slot       = $item_stats['Slot'] ?? null;
		if ( $item_slot === null ) {
			return false; // item has no slot defined
		}
		if ( ! $this->has_slot( $item_slot ) ) {
			return false; // combattant does not have the required slot
		}

		return true;
	}

	/**
	 * Equip an item to the combattant
	 * This removes one instance of the item from the inventory
	 * and adds it to the character's stats in the Slots stat
	 * e.g. if the item has a Slot stat with value "Weapon",
	 * the character's Slots stat will be updated to "Weapon:short_sword"
	 *
	 * @param int $item_id The code of the item to equip.
	 *
	 * @return bool True if the item was successfully equipped, false otherwise.
	 */
	public function equip_item( int $item_id ): bool {
		$item = Item::get_item_by_id( $item_id );
		if ( ! $this->can_equip_item( $item->code ) ) {
			return false; // cannot equip the item
		}
		//  check if the item is in the inventory
		if ( ! $this->has_item_with_id( $item_id ) ) {
			return false; // item not in inventory
		}
		//  get the item's slot
		$item_slot = $item->get_item_slot();
		//  unequip any item currently in this slot and add it to the inventory again
		$this->unequip_slot( $item_slot );
		//  set the slot to the new item_id
		$this->set_slot_value( $item_slot, $item_id );
		return true;
	}

	/**
	 * Get all equipped items as an associative array
	 * with slot names as keys and item ids as values
	 *
	 * @return array An associative array of equipped items.
	 *               e.g. ['Weapon' => (item sword), 'Armor' => (item leather_armor)]
	 */
	public function get_equipped_items(): array {
		$equipped_items   = [];
		foreach ( $this->get_slots() as $slot_name => $item_id ) {
			$item = Item::get_item_by_id( $item_id );
			if( $item ) $equipped_items[ $slot_name ] = $item;
		}
		return $equipped_items;
	}

	public function get_equipped_item_ids(): array {
		$equipped_item_ids = [];
		foreach ( $this->get_slots() as $slot_name => $item_id ) {
			if ( $item_id > 0 ) {
				$equipped_item_ids[] = $item_id;
			}
		}
		return $equipped_item_ids;
	}

	/**
	 * Unequip the item in a given slot
	 * this sets the value of the slot with the key $slot_name to 0
	 *
	 * @param string $slot_name The name of the slot to unequip.
	 *
	 * @return void
	 */
	public function unequip_slot( string $slot_name ): void {
		//  check if the combattant has this slot
		if ( ! $this->has_slot( $slot_name ) ) {
			return; // combattant does not have the slot
		}
		//  set the given slot to 0
		$this->set_slot_value( $slot_name, 0 );

		//  save the combattant to the database if applicable
		if ( method_exists( $this, 'save_to_db' ) ) {
			$this->save_to_db();
		}

	}


	//  region Inventory Management

	public function add_item_to_inventory( string $item_code ): void {
		//  create a new item in the Item table with location_id = 0 (inventory)
		Item::create_item( $this->id, $item_code, 0 );
	}


	/**
	 * Delete an item from the inventory by its item code.
	 * If multiple items with the same code exist, only one will be deleted.
	 * First, all unequipped items in the inventory are searched.
	 * If no item is found there, equipped items are searched as well.
	 *
	 * @param string $item_code The code of the item to delete.
	 *
	 * @return bool True if the item was found and deleted, false otherwise.
	 */
	public function delete_itemcode_from_inventory( string $item_code ): bool {
		//  find an item with this code in the inventory and delete it from the db

		$inventory_items = $this->get_inventory();
		foreach ( $inventory_items as $item ) {
			/** @var Item $item */
			if ( $item->code === $item_code ) {
				Item::delete_item( $item->id );
				return true; // item deleted
			}
		}
		//  not found, we search for equipped items as well
		$equipped_items = $this->get_equipped_items();
		foreach ( $equipped_items as $slot => $item ) {
			/** @var Item $item */
			if ( $item->code === $item_code ) {
				$this->unequip_slot( $slot );
				Item::delete_item( $item->id );
				return true; // item deleted
			}
		}
		return false; // item not found
	}

	/**
	 * Remove an item from the inventory and place it in the current location (zone)
	 *
	 * @param int $item_id The ID of the item to remove from the inventory.
	 *
	 * @return bool True if the item was successfully removed, false otherwise.
	 */
	public function remove_item_from_inventory( $item_id ): bool {
		//  if the item is equipped, unequip it first
		$equipped_items = $this->get_equipped_items();
		foreach ( $equipped_items as $slot => $item ) {
			/** @var Item $item */
			if ( $item->id === $item_id ) {
				$this->unequip_slot( $slot );
				break;
			}
		}
		//  update this item_id in the Item table and set the location to the current character's zone
		$item = Item::get_item_by_id( $item_id );
		if ( $item === null ) {
			return false; // item not found
		}
		$item->set_location( $this->location_id );

		return true;
	}

	public function has_item_with_id( int $item_id ): bool {
		return in_array( $item_id, $this->inventory );
	}

	public function get_item_count_by_code( string $code ): int {
		/** @var Item $inventory_item */
		$count = 0;
		foreach ( $this->get_inventory() as $inventory_item ) {
			if ( $inventory_item->code == $code ) {
				$count ++;
				//  continue to count all items with the same code
			}
		}

		return $count;
	}

	/**
	 * Get all items in the inventory as an array of Item objects
	 * these are entries in the adventurebook_items table with character_id = this character's id and location_id = 0
	 *
	 * @return array An array of Item objects in the inventory
	 */
	public function get_inventory( $exclude_equipped = true ): array {

		$all_items_in_inventory = get_items_for_page( 0, $this->id );
		//  get all item_ids in the inventory
		$all_item_ids_in_inventory = array_map( function ( $item ) {
			return $item->id;
		}, $all_items_in_inventory );

		if ( $exclude_equipped ) {
			$equipped_item_ids   = $this->get_equipped_item_ids();
			//  filter out equipped items from the inventory
			$inventory_items = array_filter( $all_item_ids_in_inventory, function ( $item_id ) use ( $equipped_item_ids ) {
				return ! in_array( $item_id, $equipped_item_ids );
			} );

			//  convert item ids to Item objects
			return array_map( function ( $item_id ) {
				return Item::get_item_by_id( $item_id );
			}, $inventory_items );
		}

		return $all_items_in_inventory;
	}

	// endregion Inventory Management

	public function addXP( int $xp ): string {
		//  if the character has no "XP" stat, we cannot add XP
		if ( ! isset( $this->stats['XP'] ) || $xp <= 0 ) {
			return '';
		}
		$this->stats['XP'] += $xp;
		$this->save_to_db();

		/* translators: %d is the amount of XP gained */

		return esc_html( sprintf( __( 'You gain %d XP!', 'adventurebook' ), $xp ) );
	}

	/** Adds wealth to the creature's inventory
	 * Usage: addWealth amount
	 * e.g. addWealth 10 gold
	 */
	public function addWealth( int $amount, string $unit = '' ): string {
		//  if the character has no "Wealth" stat, we cannot add wealth
		if ( ! isset( $this->stats['Wealth'] ) || $amount <= 0 ) {
			return '';
		}
		$this->stats['Wealth'] += $amount;
		$this->save_to_db();

		/* translators: %1$d is the amount of wealth gained, %2$s is the unit (e.g. gold) */

		return esc_html( sprintf( __( 'You gain %1$d %2$s!', 'adventurebook' ), $amount, $unit ) );
	}

	/** Removes wealth from the creature's inventory
	 * Usage: removeWealth amount [unit]
	 * e.g. removeWealth 10 gold
	 */
	public function removeWealth( int $amount, string $unit = '' ): string {
		//  if the character has no "Wealth" stat, we cannot remove wealth
		if ( ! isset( $this->stats['Wealth'] ) || $amount <= 0 ) {
			return '';
		}
		$this->stats['Wealth'] -= $amount;
		if ( $this->stats['Wealth'] < 0 ) {
			$this->stats['Wealth'] = 0;
		}
		$this->save_to_db();

		/* translators: %1$d is the amount of wealth lost, %2$s is the unit (e.g. gold) */

		return esc_html( sprintf( __( 'You lose %1$d %2$s!', 'adventurebook' ), $amount, $unit ) );
	}

	/** Get a game variable by its name
	 * Game variables are stored in the stats array under the key "VARS" as an associative array
	 * If the variable does not exist, an empty string is returned
	 *
	 * @param string $var_name The name of the variable to get
	 *
	 * @return mixed The value of the variable, or an empty string if it does not exist
	 */
	public function get_game_var( string $var_name ) {
		$vars = $this->stats['VARS'] ?? [];
		if ( is_array( $vars ) && array_key_exists( $var_name, $vars ) ) {
			return $vars[ $var_name ];
		}
		return '';
	}

	/** Set a game variable by its name
	 * Game variables are stored in the stats array under the key "VARS" as an associative array
	 *
	 * @param string $var_name The name of the variable to set
	 * @param mixed $value The value to set the variable to
	 *
	 * @return void
	 */
	public function set_game_var( string $var_name, $value ): void {
		$vars = $this->stats['VARS'] ?? [];
		if ( ! is_array( $vars ) ) {
			$vars = [];
		}
		$vars[ $var_name ] = $value;
		$this->stats['VARS'] = $vars;
		$this->save_to_db();
	}

	#region Skills Management

	/** Get a specific skill by name.
	 * Returns 0 if the skill does not exist.
	 *
	 * Skills are saved in as an array value in stats with the key "SKILLS"
	 *
	 * @param string $skill_name The name of the skill to retrieve.
	 *
	 * @return int The value of the skill, or 0 if it does not exist
	 */
	public function get_skill( string $skill_name ): int {
		$skills = $this->stats['SKILLS'] ?? [];
		if ( is_array( $skills ) && array_key_exists( $skill_name, $skills ) ) {
			return intval( $skills[ $skill_name ] );
		}
		return 0;
	}

	/** Set a specific skill by name.
	 * If the skill does not exist, it will be created.
	 *
	 * Skills are saved in as an array value in stats with the key "SKILLS"
	 *
	 * @param string $skill_name The name of the skill to set.
	 * @param int $amount The value to set the skill to.
	 *
	 * @return void
	 */
	public function set_skill( string $skill_name, int $amount ): void {
		$skills = $this->stats['SKILLS'] ?? [];
		if ( ! is_array( $skills ) ) {
			$skills = [];
		}
		$skills[ $skill_name ] = $amount;
		$this->stats['SKILLS'] = $skills;
		$this->save_to_db();
	}

	/** Check if a skill can be raised.
	 *
	 * The combat system sets the rules for raising skills.
	 *
	 * @param string $skill_name The name of the skill to check.
	 * @return bool True if the skill can be raised, false otherwise.
	 */
	public function can_raise_skill( string $skill_name ) : bool {
		//  we will ask the Combat System if the skill can be raised
		$combat_system = get_combat_system_for_character_id( $this->id );
		return $combat_system->combattant_can_raise_skill( $this, $skill_name );
	}


	#endregion Skills Management

}