package ClosureKeyPresses
import HashMap

/*  
    This package is a comfort wrapper around wc3 key presses events introduced in 1.31,
	for easy event listening via closures.

    Example usage:
        onKeyPress(OSKEY_A) -> 
            print("A player pressed on the A key.")

        onKeyPress(OSKEY_B, OSKEY_META.SHIFT) -> 
            print("A player pressed on the B key while holding a SHIFT key.")

        onKeyRelease(OSKEY_C) -> 
            print("A player released the C key.")

        onKeyPress(players[0], OSKEY_D, OSKEY_META.ALT, false) -> 
            print("Player 0 released the D key while holding an ALT key.")

    Important:
        * When the metakey NONE is passed or when no metaKey is given like in `onKeyPress(OSKEY_A, () -> print("A"))`,
          pressing or releasing the key will not fire an event while holding a metakey.
*/


/* CONSTANTS */

constant KEY_TRIGGER = CreateTrigger()..addAction(function onEvent)
constant KEY_MAP = new HashMap<int, KeyPressListener>
    

/* CLOSURES */

public function onKeyPress(oskeytype key, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(key, OSKEY_META.NONE, true, listener)

public function onKeyPress(oskeytype key, OSKEY_META metaKey, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(key, metaKey, true, listener)

public function onKeyRelease(oskeytype key, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(key, OSKEY_META.NONE, false, listener)

public function onKeyPress(oskeytype key, OSKEY_META metaKey, bool onKeyDown, KeyPressListener listener) returns KeyPressListener
    for i = 0 to bj_MAX_PLAYERS
        if players[i].isIngame()
            KEY_TRIGGER.registerPlayerKeyPress(players[i], key, metaKey, onKeyDown)
    return registerListener(listener, key, metaKey, onKeyDown)

public function onKeyPress(player whichPlayer, oskeytype key, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(whichPlayer, key, OSKEY_META.NONE, true, listener)

public function onKeyPress(player whichPlayer, oskeytype key, OSKEY_META metaKey, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(whichPlayer, key, metaKey, true, listener)
        
public function onKeyRelease(player whichPlayer, oskeytype key, KeyPressListener listener) returns KeyPressListener
    return onKeyPress(whichPlayer, key, OSKEY_META.NONE, false, listener)

public function onKeyPress(player whichPlayer, oskeytype key, OSKEY_META metaKey, bool onKeyDown, KeyPressListener listener) returns KeyPressListener
    KEY_TRIGGER.registerPlayerKeyPress(whichPlayer, key, metaKey, onKeyDown)
    return registerListener(listener, key, metaKey, onKeyDown)

function registerListener(KeyPressListener listener, oskeytype key, OSKEY_META metaKey, bool onKeyDown) returns KeyPressListener
    listener.key = key
    listener.metaKey = metaKey.toInt()
    listener.onKeyDown = onKeyDown
    let id = key.getHandleId()
    let first = KEY_MAP.get(id)
    if first != null 
        first.prev = listener 
        listener.next = first 
    KEY_MAP.put(id, listener)
    return listener 


/* ON EVENT */

function onEvent() 
    var listener = KEY_MAP.get(BlzGetTriggerPlayerKey().getHandleId())
    let metaKey = BlzGetTriggerPlayerMetaKey()
    let onKeyDown = BlzGetTriggerPlayerIsKeyDown()
    while listener != null 
        if listener.metaKey == metaKey and listener.onKeyDown == onKeyDown
            listener.onEvent()
        listener = listener.next 


/* KEY PRESSES LISTENER */

abstract class KeyPressListener
    oskeytype key 
    int metaKey
    bool onKeyDown
    thistype next = null 
    thistype prev = null 

    abstract function onEvent()

    ondestroy
        let id = key.getHandleId() 
        let first = KEY_MAP.get(id)
        if first == this 
            if next == null 
                KEY_MAP.remove(id)
            else 
                KEY_MAP.put(id, next)
        else if prev != null
            prev.next = next
        next.prev = prev