<?php

/*
 * Copyright (C) 2014, NoccyLabs
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

namespace NoccyLabs\Gpio\GpioMapper;

use NoccyLabs\Gpio\GpioMapperInterface;
use NoccyLabs\Gpio\Exception\GpioException;

class WiringPiMapper implements GpioMapperInterface
{
    const REV_A = 1;
    const REV_B = 2;
    const REV_BPLUS = 3;

    protected $version;

    public function __construct($version=1)
    {
        $this->version = $version;
    }

    /** {@inheritdoc} */
    public function mapGpioToLogicalPin($gpio)
    {
        switch ($gpio) {
            case 17:    return 0;
            case 18:    return 1;
            case 22:    return 3;
            case 23:    return 4;
            case 24:    return 5;
            case 25:    return 6;
            case 11:    return 7;
            case 8:     return 10;
            case 7:     return 11;
            case 10:    return 12;
            case 9:     return 13;
            case 11:    return 14;
            case 14:    return 15;
            case 15:    return 16;
            case 28:    return 17;
            case 29:    return 18;
            case 30:    return 19;
            case 31:    return 20;
        }
        if ($this->version == self::REV_B) {
            switch ($gpio) {
                case 27:    return 2;
                case 2:     return 8;
                case 3:     return 9;
            }
        } elseif ($this->version == self::REV_BPLUS) {
            switch ($gpio) {
                case 27:    return 2;
                case 2:     return 8;
                case 3:     return 9;
            }
        } elseif ($this->version == self::REV_A) {
            switch ($gpio) {
                case 21:    return 2;
                case 9:     return 8;
                case 1:     return 9;
            }
        }
        throw new GpioException("Unable to map GPIO{$gpio} to logical pin");
    }
    
    /** {@inheritdoc} */
    public function mapLogicalToGpioPin($logical)
    {
        switch ($logical) {
            case 0:     return 17;
            case 1:     return 18;
            case 2:     
                if (($this->version == self::REV_B)
                    ||($this->version == self::REV_BPLUS)) {
                    return 27;
                }
                return 21; 
            case 3:     return 22;
            case 4:     return 23;
            case 5:     return 24;
            case 6:     return 25;
            case 7:     return 11;
            case 8:     
                if (($this->version == self::REV_B)
                    ||($this->version == self::REV_BPLUS)) {
                    return 2;
                }
                return 0; 
            case 9:     
                if (($this->version == self::REV_B)
                    ||($this->version == self::REV_BPLUS)) {
                    return 3;
                }
                return 1; 
            case 10:    return 8;
            case 11:    return 7;
            case 12:    return 10;
            case 13:    return 9;
            case 14:    return 11;
            case 15:    return 14;
            case 16:    return 15;
            case 17:    return 28;
            case 18:    return 29;
            case 19:    return 30;
            case 20:    return 31;
        }
        throw new GpioException("Unable to map logical pin {$logical} to GPIO pin");
    }

}