/*
 * Copyright 2020, Jérôme Duval, jerome.duval@gmail.com.
 * Distributed under the terms of the MIT license.
 */


#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <Drivers.h>

#include <AutoDeleter.h>

#include "i2c.h"


static struct option const kLongOptions[] = {
        {"help", no_argument, 0, 'h'},
        {NULL}
};


extern const char *__progname;
static const char *kProgramName = __progname;


void
usage(int returnValue)
{
        fprintf(stderr, "Usage: %s <path-to-i2c-bus-device>\n", kProgramName);
        exit(returnValue);
}


static int
scan_bus(const char *path)
{
        int err = EXIT_SUCCESS;
        FileDescriptorCloser fd(open(path, O_RDONLY));
        if (!fd.IsSet()) {
                fprintf(stderr, "%s: Could not access path: %s\n", kProgramName,
                        strerror(errno));
                return EXIT_FAILURE;
        }

        setbuf(stdout, NULL);
        printf("Scanning I2C bus: %s\n", path);

        printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f\n");
        for (int i = 0; i < 128; i+=16) {
                printf("%02x: ", i);
                for (int j = 0; j < 16; j++) {
                        uint16 addr = i + j;
                        uint8 cmd = 0;
                        uint8 data = 0;
                        i2c_ioctl_exec exec;
                        exec.addr = addr;
                        exec.op = I2C_OP_READ_STOP;
                        exec.cmdBuffer = &cmd;
                        exec.cmdLength = sizeof(cmd);
                        exec.buffer = &data;
                        exec.bufferLength = sizeof(data);
                        if (ioctl(fd.Get(), I2CEXEC, &exec, sizeof(exec)) == 0)
                                printf("%02x ", addr);
                        else
                                printf("-- ");
                }
                printf("\n");
        }

        return err;
}


int
main(int argc, char** argv)
{
        int c;
        while ((c = getopt_long(argc, argv, "h", kLongOptions, NULL)) != -1) {
                switch (c) {
                        case 0:
                                break;
                        case 'h':
                                usage(0);
                                break;
                        default:
                                usage(1);
                                break;
                }
        }

        if (argc - optind < 1)
                usage(1);
        const char* path = argv[optind++];

        exit(scan_bus(path));
}