/*
 * API.xs file for WiringPi::API Perl distribution
 *
 * Copyright (c) 2017 by Steve Bertrand
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the same terms as Perl itself, either Perl version 5.18.2 or, at your option,
 * any later version of Perl 5 you may have available.
 *
 */
#include <stdlib.h>
#include <stdint.h>
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
#include "INLINE.h"
#include "API.h"
#include <wiringPi.h>
#include <wiringPiSPI.h>
#include <lcd.h>
#include <sys/mman.h>
#include <softPwm.h>
#include <sr595.h>
#define PERL_NO_GET_CONTEXT
char* serialGets(int fd, char* buf, int nbytes){
    int bytes_read = 0;
    while (bytes_read < nbytes){
        int result = read(fd, buf + bytes_read, nbytes - bytes_read);
         
        if (0 >= result){
            if (0 > result){
                exit(-1);
            }
            break;
        }
        bytes_read += result;
    }
    return buf;
}
void spiDataRW(int channel, SV* byte_ref, int len){
     /*
      * Custom wrapper for wiringPiSPIDataRW() as we
      * need to translate an aref into an unsigned char *,
      * and then send back an array containing the bytes
      * read from the device
      */ 
    if (channel != 0 && channel != 1){
        croak("channel param must be 0 or 1\n");
    }
    if (! SvROK(byte_ref) || SvTYPE(SvRV(byte_ref)) != SVt_PVAV){
        croak("data param must be an array reference\n");
    }
    AV* bytes = (AV*)SvRV(byte_ref);
    int num_bytes = av_len(bytes) + 1;
    if (len != num_bytes){
        croak("len param doesn't match element count in data\n");
    }
    unsigned char buf[num_bytes];
    int i;
    for (i=0; i<len; i++){
        SV** elem = av_fetch(bytes, i, 0);
        int elem_int = (int)SvNV(*elem);
         
        if (elem_int < 0 || elem_int > 255){
            printf("byte %d in data param out of range: (%d)\n", i, elem_int);
            exit(1);
        }
        buf[i] = (unsigned char)SvNV(*elem);
    }
     
    if (wiringPiSPIDataRW(channel, buf, len) < 0){
        croak("failed to write to the SPI bus\n");
    }
    inline_stack_vars;
    inline_stack_reset;
    int x;
    for (x=0; x<len; x++){
        inline_stack_push(sv_2mortal(newSViv(buf[x])));
    } 
    inline_stack_done;
}
char * perl_callback; // dynamically set perl callback for interrupt handler
PerlInterpreter * mine;
void interruptHandler(){
    PERL_SET_CONTEXT(mine);
    dSP;
    ENTER;
    SAVETMPS;
    PUSHMARK(SP);
    PUTBACK;
    call_pv(perl_callback, G_DISCARD|G_NOARGS);
    FREETMPS;
    LEAVE;
}
int setInterrupt(int pin, int edge, char * callback){
    mine = Perl_get_context();
    perl_callback = callback;
    int interrupt = wiringPiISR(pin, edge, &interruptHandler);
    return interrupt;
}
int initThread(char * callback){
    mine = Perl_get_context();
    PI_THREAD (myThread){
        dSP;
        ENTER;
        SAVETMPS;
        PUSHMARK(SP);
        PUTBACK;
        call_pv(callback, G_DISCARD|G_NOARGS);
        FREETMPS;
        LEAVE;
    }
    return piThreadCreate(myThread);
}
int physPinToWpi(int wpi_pin){
    return phys_wpi_map[wpi_pin];
}
int bmp180Pressure(int pin){
    return analogRead(pin);
}
int bmp180Temp(int pin){
    return analogRead(pin);
}
/*
    not yet implemented
    extern          void setPadDrive         (int group, int value) ;
    extern          void pwmToneWrite        (int pin, int freq) ;
    extern          void gpioClockSet        (int pin, int freq) ;
*/
MODULE = WiringPi::API  PACKAGE = WiringPi::API PREFIX = XS_
PROTOTYPES: DISABLE
#
# core
#
int
wiringPiSetup()
int
wiringPiSetupSys()
int
wiringPiSetupGpio()
int wiringPiSetupPhys()
void
pinMode(pin, mode)
    int pin
    int mode
void
pullUpDnControl(pin, pud)
    int pin
    int pud
int
digitalRead(pin)
    int pin
void
digitalWrite(pin, value)
    int pin
    int value
void
pwmWrite(pin, value)
    int pin
    int value
int
getAlt(pin)
    int pin
int
analogRead(pin)
    int pin
void
analogWrite(pin, value)
    int pin
    int value
#
# board
#
int
piGpioLayout()
int 
wpiPinToGpio(wpiPin)
    int wpiPin
int 
physPinToGpio(physPin)
    int physPin
void
pwmSetRange(range)
    unsigned int range
void
pwmSetClock(divisor)
    int divisor
void pwmSetMode(mode)
    int mode
#
# lcd
#
int
lcdInit(rows, cols, bits, rs, strb, d0, d1, d2, d3, d4, d5, d6, d7)
    int rows
    int cols
    int bits
    int rs
    int strb
    int d0
    int d1
    int d2
    int d3
    int d4
    int d5
    int d6
    int d7
void
lcdHome(fd)
    int fd
void
lcdClear(fd)
    int fd
void
lcdDisplay(fd, state)
    int fd
    int state
void
lcdCursor(fd, state)
    int fd
    int state
void
lcdCursorBlink(fd, state)
    int fd
    int state
void
lcdSendCommand(fd, command)
    int fd
    char command
void
lcdPosition(fd, x, y)
    int fd
    int x
    int y
void
lcdCharDef(fd, index, data)
    int fd
    int index
    unsigned char * data
void
lcdPutchar(fd, data)
    int fd
    unsigned char data
void
lcdPuts(fd, string)
    int fd
    char * string
# soft pwm
int
softPwmCreate(pin, value, range)
    int pin
    int value
    int range
void
softPwmWrite(pin, value)
    int pin
    int value
void softPwmStop(pin)
    int pin
# SR74HC595 shift register
int
sr595Setup(pin_base, num_pins, data_pin, clock_pin, latch_pin)
    int pin_base
    int num_pins
    int data_pin
    int clock_pin
    int latch_pin
void
piLock(keyNum)
    int keyNum
void piUnlock(keyNum)
    int keyNum
# bmp180 pressure sensor
int
bmp180Setup(pin_base)
    int pin_base
int
bmp180Pressure(pin)
    int pin
int
bmp180Temp(pin)
    int pin
# custom
int
setInterrupt(pin, edge, callback)
    int pin
    int edge
    char * callback
void
interruptHandler()
int
initThread(callback)
    char * callback
int
physPinToWpi(wpi_pin)
    int wpi_pin
int
ads1115Setup(pin_base, addr)
    int pin_base
    int addr
int
pseudoPinsSetup(pin_base)
    int pin_base
void
pinModeAlt(pin, mode)
    int pin
    int mode
int
digitalReadByte()
unsigned int
digitalReadByte2()
void
digitalWriteByte(value)
    int value
void
digitalWriteByte2(value)
    int value
# SPI
int
wiringPiSPISetup(channel, speed)
    int channel
    int speed
void
spiDataRW (channel, byte_ref, len)
        int     channel
        SV *    byte_ref
        int     len
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        spiDataRW(channel, byte_ref, len);
        if (PL_markstack_ptr != temp) {
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY;
        }
        return;
# I2C
int wiringPiI2CSetup (devId)
    int devId
int wiringPiI2CSetupInterface (device, devId)
    char* device
    int devId
int wiringPiI2CRead (fd)
    int fd
int wiringPiI2CReadReg8 (fd, reg)
    int fd
    int reg
int wiringPiI2CReadReg16 (fd, reg)
    int fd
    int reg
int wiringPiI2CWrite (fd, data)
    int fd
    int data
int wiringPiI2CWriteReg8 (fd, reg, data)
     int fd
     int reg
     int data
int wiringPiI2CWriteReg16 (fd, reg, data)
    int fd
    int reg
    int data
# serial interface
int serialOpen (device, baud)
    char* device
    int baud
void serialClose (fd)
    int fd
void serialFlush (fd)
    int fd
void serialPutchar (fd, c)
    int fd
    unsigned char c
void serialPuts (fd, s)
    int fd
    char* s
int serialDataAvail (fd)
    int fd
int serialGetchar (fd)
    int fd
char* serialGets(fd, buf, nbytes)
    int fd
    char* buf
    int nbytes