#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>


#include "lm75.h"
#include "deftypes.h"



extern uint16 devicef;
extern void bus_err(int ern);
extern void print_help(void);
uchar buf[32];

  

void lm75_print_all(void)
{
    printf(
        "00: Temperature data  [°C]     (reg: 0x00)\n"
        "01: Configuration     [hex]    (reg: 0x01)\n"
        "02: Tos (Overtemp)    [°C]     (reg: 0x03)\n"
        "03: Thys (Hysteresis) [°C]     (reg: 0x04)\n"
        "\n");
} 

 
uchar *read_data( uchar *buf ){                     //# [buf] = 32 byte         

	if(write(devicef, buf, 1) != 1){                //# write one byte to device
        bus_err(errno);
    }
    usleep(10*1000);                                //# Wait 10ms for reading

    if(read(devicef, buf, 2) != 2) {                //# read the result
        bus_err(errno);
    }
    return buf; 
}



float calculate_temp(float offset){             // Calculate temperature 
    int16 rawtemp = 0;                              //# Signed by default
    float temp;

    buf[0] = 0x00;                                  //# Measurement in the REG[0]
    read_data(buf);                                 //# [buf] = 32 byte
     
    rawtemp = (buf[0]*256 + buf[1]) >> 5;           // (buf[0] << 8), and (>> 5), Device with 11bit data, is also supported

	if((rawtemp & 0x400) == 0x400){                 //# check if the msb(bit11) is 1 (1024 = 0x400),  2'complement negative number
	    rawtemp = rawtemp - 2048;                   //# 2^11 = 2048 
	}

	temp = rawtemp * 0.125 ;                        //# 11bit -> 0.125°C  or  9bit -> 0.5°C	
    return (temp + offset);    
}



float read_tos(void){                           // Over-Temperature Shutdown register                                           
    int16 rawtemp = 0;                              //# Int16 default signed                                                  
    buf[0] = 0x02;                                  //# Tos = REG[2]                        
    read_data(buf);                                                                                                                    

    rawtemp = buf[0]*256 + buf[1];                           
    rawtemp = (rawtemp) >> 7;                       //# 9bit data

    if((rawtemp & 256) == 256){                     //# check MSB if it's a 2'complement number
        rawtemp = rawtemp - 512 ;                   //# 2^9 = 512;
    }
    return (rawtemp * 0.5);                         //# 9bit -> 0.5 celsius                                                                                                                 
}                       



float read_thys(void){                          // Over-Temp Hysteresis Register                                           
    int16 rawtemp = 0;                              //# signed 
    buf[0] = 0x03;                                                      
    read_data(buf);                                 //# read from REG[3]                     
                                                           
    rawtemp = buf[0]*256 + buf[1];                           
    rawtemp = (rawtemp) >> 7;                       //# 9bit data 
    if((rawtemp & 256) == 256){
        rawtemp = rawtemp - 512 ;                   //# 2^9 = 512;
    }
    return (rawtemp * 0.5);                         //# 9bit -> 0.5 celsius                                                                                                                 
}                       
     

uchar read_conf(void){                          //Configuration register
    buf[0] = 0x01;                                                                                                                  
    read_data(buf);
    return buf[0];                                                                                                                                   
}



void lm75_read_all(const uchar *opts){          // Print out whole device's data
    // if(opts != NULL)
    // {
    //     printf("00:%f\n", calculate_temp(strtof(opts, NULL)));
    // }
    // else
    // {
    printf("00:%f\n",   calculate_temp(0.0));
    // }     
    printf("01:0x%x\n", read_conf()); 
    printf("02:%f\n",   read_tos()); 
    printf("03:%f\n",   read_thys()); 
}



void lm75_read_one(const uchar *opts){                  // Prints the selected register's data
    uint16 id,i;
    uchar temp[256];

    if(opts != NULL){
        for(i = 0; i < strlen((char*)opts); i++){
            if (*(opts+i) == ','){
                break;
            }
            temp[i] = *(opts+i);
            temp[i+1] = '\0';
        }

        id = atoi((char*)temp);
        strncpy((char*)temp, (char*)opts+i+1, 255);
        // id = strtol (opts,&ptr,0); //all format allowed
        // ptr++;      //one separator allowed

        switch (id)
        {
            case 0x00:
                printf("%f\n", calculate_temp(atof((char*)temp)));
                break;
            case 0x01:
                printf("0x%x\n", read_conf());
                break;
            case 0x02:
                printf("%f\n", read_tos());
                break;
            case 0x03:
                printf("%f\n", read_thys()); 
                break;
            default:
                print_help();
        } 
    }
}


void lm75_conf_set(const uchar *opts){
    // printf("");
}