#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>

#include <tabby/link.h>

static void usage(int argc, char **argv, char *message, ...) {
    if (message) {
        va_list args;

        va_start(args, message);
        vfprintf(stderr, message, args);
         fprintf(stderr, "\n");
        va_end(args);
    }

    fprintf(stderr, "usage: %s device\n", argv[0]);

    exit(1);
}

int main(int argc, char **argv) {
    int fd;
    ssize_t len;

    uint8_t state           =   0,
            value           =   0,
            compression     =   0,
            dataLengthLSB   =   0,
            dataLengthMSB   =   0,
            acknowledgeCode = 129,
            statusCode      =   0;

    uint16_t dataPosition = 0;

    if (argc != 2) {
        usage(argc, argv, "No device specified");
    }

    if ((fd = tabby_link_open(argv[1])) < 0) {
        fprintf(stderr, "%s: %s: %s: %s\n", argv[0], "tabby_link_open()",
            argv[1], strerror(errno));

        goto error_link_open;
    }

    while ((len = tabby_link_recv(fd, &value, 1)) >= 0) {
        uint8_t response = 0;

        fprintf(stderr, "state %d recv 0x%02x\n", state, value);

        switch (state) {
            case 0: {
                if (value == 136) {
                    state = 1;
                }

                response = 0;

                break;
            }

            case 1: {
                if (value == 51) {
                    state    = 2;
                    response = 0;
                } else {
                    state    = 0;
                    response = 0;
                }

                break;
            }

            case 2: {
                if (value == 1) {
                    state         = 3;
                    response      = 0;
                    compression   = 0;
                    dataLengthLSB = 0;
                    dataLengthMSB = 0;
                } else if (value == 2) {
                    state    = 50;
                    response =  0;
                } else if (value == 4) {
                    state    = 20;
                    response =  0;
                } else if (value == 15) {
                    state    = 90;
                    response =  0;
                } else {
                    state    = 0;
                    response = 5;
                }

                break;
            }

            case 3: {
                compression = value;
                response    = 0;
                state       = 4;

                break;
            }

            case 4: {
                dataLengthLSB = value;
                response      = 0;
                state         = 5;

                break;
            }

            case 5: {
                dataLengthMSB = value;
                response      = 0;
                state         = 6;

                break;
            }

            case 6: {
                response = 0;
                state    = 7;

                break;
            }

            case 7: {
                response = 129;
                state    = 8;

                break;
            }

            case 8: {
                response = 129;
                state    = 20;

                break;
            }

            case 20: {
                compression = value;
                response    = 0;
                state       = 21;

                break;
            }

            case 21: {
                dataLengthLSB = value;
                response      =  0;
                state         = 22;

                break;
            }

            case 22: {
                dataLengthMSB = value;
                response      = 0;
                state         = 23;
                dataPosition  = 256 * dataLengthMSB + dataLengthLSB;

                break;
            }

            case 23: {
                dataPosition--;

                if (dataPosition == 0 || dataPosition == 65535) {
                    state = 24;
                } else {
                    state = 23;
                }

                response = 0;

                break;
            }

            case 24: {
                response = 0;
                state    = 25;

                break;
            }

            case 26: {
                response = acknowledgeCode;
                state    = 27;

                break;
            }

            case 27: {
                response = statusCode;
                state    = 0;

                break;
            }

            case 50: {
                response =  0;
                state    = 51;

                break;
            }

            case 51: {
                response = 0;
                state    = 52;

                break;
            }

            case 52: {
                response = 0;
                state    = 53;

                break;
            }

            case 53: {
                response = 0;
                state    = 54;

                break;
            }

            case 54: {
                response =  0;
                state    = 55;

                break;
            }

            case 55: {
                response =  0;
                state    = 56;

                break;
            }

            case 56: {
                response =  0;
                state    = 57;

                break;
            }

            case 57: {
                response =  0;
                state    = 58;

                break;
            }

            case 58: {
                response = acknowledgeCode;
                state    = 59;

                break;
            }

            case 59: {
                response = statusCode;
                state    = 0;

                break;
            }

            case 90: {
                response =  0;
                state    = 91;

                break;
            }

            case 91: {
                response = 0;
                state    = 92;

                break;
            }

            case 92: {
                response =  0;
                state    = 93;

                break;
            }

            case 93: {
                response =  0;
                state    = 94;

                break;
            }

            case 94: {
                response = 129;
                state    =  95;

                break;
            }

            case 95: {
                response = statusCode;
                state    = 0;

                break;
            }

            default: {
                response = 0;
                state    = 0;

                break;
            }
        }

        fprintf(stderr, "send 0x%02x\n", response);

        if (tabby_link_send(fd, &response, 1) < 0) {
            fprintf(stderr, "%s: %s: %s: %s\n", argv[0], "tabby_link_send()",
                argv[1], strerror(errno));

            goto error_link_send;
        }
    }

    tabby_link_close(fd);

    return 0;

error_link_send:
    tabby_link_close(fd);

error_link_open:
    return 1;
}