/* *******************************************************************
 *  Includes
 * ******************************************************************/

#include "HumanPlayer.h"
#include "System.h"
#include "Cursor.h"
#include <Buttons.h>
#include <Gamebuino.h>
#include <stdint.h>
#include <string.h>
#include <limits.h>

/* *******************************************************************
 *  Defines
 * ******************************************************************/

/* *******************************************************************
 *  Types definition
 * ******************************************************************/

/* *******************************************************************
 *  Global variables definition
 * ******************************************************************/

/* *******************************************************************
 *  Local variables definition
 * ******************************************************************/

/* *******************************************************************
 *  Local prototypes declaration
 * ******************************************************************/

/* *******************************************************************
 *  Functions definition
 * ******************************************************************/

/*****************************************************************//**
 *
 * \brief   Event handler executed when human player presses
 *          left arrow button.
 *
 *********************************************************************/
void HumanPlayer::buttonHandler(void)
{
    for (size_t szBtn = 0; szBtn < NUM_BTN; szBtn++)
    {
        if (gb.buttons.timeHeld(static_cast<uint8_t>(szBtn)) > 0)
        {
            /* Update player attributes
             * according to pressed button. */
            playerButtonPressedHandler(szBtn);

            /* Update camera attributes
             * according to pressed button. */
            cameraButtonPressedHandler(szBtn);
        }
        else if (gb.buttons.released(static_cast<uint8_t>(szBtn)))
        {
            /* Key has not been pressed. */

            /* Update player attributes
             * according to released button. */
            playerButtonReleasedHandler(szBtn);
        }
    }
}

/*****************************************************************//**
 *
 * \brief   This function executes button pressed handler events
 *          used on a \ref HumanPlayer object.
 *
 * \param   szBtn
 *              Pressed button ID.
 *
 *********************************************************************/
void HumanPlayer::playerButtonPressedHandler(const size_t szBtn)
{
    /* This array of member functions lists
     * button pressed event handlers for each button. */
    static void (HumanPlayer::*const apBtnHandlerTable[NUM_BTN])(void) =
    {
        [BTN_LEFT]  = NULL,
        [BTN_UP]    = NULL,
        [BTN_RIGHT] = NULL,
        [BTN_DOWN]  = NULL,
        [BTN_A]     = &HumanPlayer::onABtnPressed,
        [BTN_B]     = &HumanPlayer::onBBtnPressed
    };

    /* Key has been pressed. Execute both
     * HumanPlayer and Camera handlers, if available. */

    /* Get pointer to HumanPlayer member function for selected button. */
    void (HumanPlayer::*const pBtnHandler)(void) = apBtnHandlerTable[szBtn];

    if (pBtnHandler != NULL)
    {
        /* HumanPlayer member function
         * pointer is available. Execute. */
        (this->*pBtnHandler)();
    }
    else
    {
        /* Undefined callback for selected button. */
    }
}

/*****************************************************************//**
 *
 * \brief   This function executes button pressed handler events
 *          used on a \ref Camera object.
 *
 * \param   szBtn
 *              Pressed button ID.
 *
 *********************************************************************/
void HumanPlayer::cameraButtonPressedHandler(const size_t szBtn)
{
   if (not _cam.isLocked())
    {
        static void (Camera::*const apBtnCameraHandlerTable[NUM_BTN])(Cursor&) =
        {
            [BTN_LEFT]  = &Camera::onLeftBtnPressed,
            [BTN_UP]    = &Camera::onUpBtnPressed,
            [BTN_RIGHT] = &Camera::onRightBtnPressed,
            [BTN_DOWN]  = &Camera::onDownBtnPressed
        };

        /* Get pointer to Camera member function for selected button. */
        void (Camera::*const pCameraBtnHandler)(Cursor&) = apBtnCameraHandlerTable[szBtn];

        if (pCameraBtnHandler != NULL)
        {
            /* Camera member function pointer
             * is available.
             * Note: "const" qualifier must be
             * removed since camera button event
             * handler modifies Camera class members. */
            ((Camera&)_cam.*pCameraBtnHandler)(_cursor);
        }
        else
        {
            /* Undefined callback for selected button. */
        }
    }
}

/*****************************************************************//**
 *
 * \brief   This function executes button released handler events
 *          used on a \ref HumanPlayer object.
 *
 * \param   szBtn
 *              Released button ID.
 *
 *********************************************************************/
void HumanPlayer::playerButtonReleasedHandler(const size_t szBtn)
{
    /* This array of member functions lists
     * button pressed event handlers for each button. */
    static void (HumanPlayer::*const apBtnHandlerTable[NUM_BTN])(void) =
    {
        [BTN_LEFT]  = NULL,
        [BTN_UP]    = NULL,
        [BTN_RIGHT] = NULL,
        [BTN_DOWN]  = NULL,
        [BTN_A]     = &HumanPlayer::onABtnReleased,
        [BTN_B]     = &HumanPlayer::onBBtnReleased
    };

    /* Key has been pressed. Execute both
     * HumanPlayer and Camera handlers, if available. */

    /* Get pointer to HumanPlayer member function for selected button. */
    void (HumanPlayer::*const pBtnHandler)(void) = apBtnHandlerTable[szBtn];

    if (pBtnHandler != NULL)
    {
        /* HumanPlayer member function
         * pointer is available. Execute. */
        (this->*pBtnHandler)();
    }
    else
    {
        /* Undefined callback for selected button. */
    }
}

/*****************************************************************//**
 *
 * \brief   Event handler executed when human player presses
 *          A button.
 *
 *********************************************************************/
void HumanPlayer::onABtnPressed(void)
{
    switch (_eState)
    {
        case PLAYER_STATE_IDLE:

            /* Select nearest unit, if possible. */
            _eState = selectUnit();
        break;

        case PLAYER_STATE_UNIT_SELECTED:

            if (_ABtnFrames < UCHAR_MAX)
            {
                /* Increase number of frames
                 * A button has been pressed. */
                _ABtnFrames++;
            }

        break;

        default:
            /* Undefined player state. Exit. */
        break;
    }
}

/*****************************************************************//**
 *
 * \brief   Event handler executed when human player presses
 *          B button.
 *
 *********************************************************************/
void HumanPlayer::onBBtnPressed(void)
{
    enum
    {
        /* Number of frames that B button must
         * be pressed in order to cancel unit selection. */
        CANCEL_SELECTION_FRAMES = 10
    };

    if (++_BBtnFrames >= CANCEL_SELECTION_FRAMES)
    {
        switch (_eState)
        {
            case PLAYER_STATE_UNIT_SELECTED:
            {
                /* Iterator that will be used
                 * to move along _unitsMap. */
                size_t i;

                for (i = 0; i < (sizeof (_unitsMap) / sizeof (_unitsMap[0])); i++)
                {
                    Unit& u = _unitsMap[i];

                    /* Reset selected flags. */
                    u.setSelected(false);
                }

                /* Reset to default state. */
                _eState = PLAYER_STATE_IDLE;
            }
                /* Fall through. */
            case PLAYER_STATE_IDLE:
                /* Fall through. */
            default:
                /* Reset pressed B button frames counter. */
                _BBtnFrames = 0;

                /* Undefined player state. Exit. */
            break;
        }
    }
}

/*****************************************************************//**
 *
 * \brief   Event handler executed when human player releases
 *          A button.
 *
 *********************************************************************/
void HumanPlayer::onABtnReleased(void)
{
    switch (_eState)
    {
        case PLAYER_STATE_UNIT_SELECTED:
        {
            enum
            {
                /* Number of frames where A button
                 * must be pressed in order to enter
                 * unit menu. */
                ENTER_MENU_FRAMES = 5
            };

            if (_ABtnFrames >= ENTER_MENU_FRAMES)
            {
                /* Enable unit menu. */
                _eState = PLAYER_STATE_UNIT_MENU;
            }
            else
            {
                /* Short button press. Exit. */
            }
        }
            /* Fall through. */
        case PLAYER_STATE_IDLE:
            /* Fall through. */
        default:
            /* Undefined player state. Exit. */

            /* Reset pressed A button frames counter. */
            _ABtnFrames = 0;
        break;
    }
}

/*****************************************************************//**
 *
 * \brief   Event handler executed when human player releases
 *          B button.
 *
 *********************************************************************/
void HumanPlayer::onBBtnReleased(void)
{
    switch (_eState)
    {
        case PLAYER_STATE_UNIT_SELECTED:
        {
            /* Iterator that will be used
             * to move along _unitsMap. */
            size_t i;

            for (i = 0; i < (sizeof (_unitsMap) / sizeof (_unitsMap[0])); i++)
            {
                Unit& u = _unitsMap[i];

                if (u.isSelected())
                {
                    /* Get cursor coordinates. */
                    const uint16_t x = _cursor.getX();
                    const uint16_t y = _cursor.getY();

                    /* Move unit to cursor position. */
                    u.moveTo(x, y);
                }
                else
                {
                    /* Unit is not selected by the player. Continue. */
                }
            }
        }
            /* Fall through.*/
        case PLAYER_STATE_IDLE:
            /* Fall through. */
        default:
            /* Undefined player state. Exit. */
            /* Reset pressed B button frames counter. */
            _BBtnFrames = 0;
        break;
    }
}