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

FILE *hex;

char *buffer;

char * decToHex(int num) {
    char hex[100];
    sprintf(hex, "%x", num);
    char *cpy = malloc(3);
    cpy[2] = 0;
    int diff = 'A' - 'a';
    if (num < 0) {
        cpy[0] = hex[6] > 58 ? hex[6] + diff : hex[6];
        cpy[1] = hex[7] > 58 ? hex[7] + diff : hex[7];
    } else if (num == 0) {
        cpy[0] = '0';
        cpy[1] = '0';
    } else if (hex[1] == 0) {
        cpy[0] = '0';
        cpy[1] = hex[0] > 58 ? hex[0] + diff : hex[0];
    } else {
        cpy[0] = hex[0] > 58 ? hex[0] + diff : hex[0];
        cpy[1] = hex[1] > 58 ? hex[1] + diff : hex[1];
    }
    return cpy;
}

void clearWhiteSpace(char **str) {
    while (**str <= 32 || **str == ',') {
        if (**str == 0)
            return;
        (*str)++;
    }
}

char *getNextLine() {
    clearWhiteSpace(&buffer);
    char *res = buffer;
    if (*buffer == 0)
        return 0;
    while (*buffer != 10) {
        buffer++;
    }
 // *buffer = 0;
    buffer++;
    return res;
}

void nextNum(int *res, int *error, char **str) {
    *res = 0;
    *error = 0;
    clearWhiteSpace(str);
    if (!((**str >= '0' && **str <= '9') || **str == '-')) {
        *error = 1;
        return;
    }
    int neg = 1;
    if (**str == '-') {
        neg = -1;
        (*str)++;
    }
    while (**str >= '0' && **str <= '9') {
        *res = (*res) * 10 + (**str - '0');
        (*str)++;
    }
    *res = (*res) * neg;
}

char readReg(char **str) {
    clearWhiteSpace(str);
    (*str) += 1; //r
    int num;
    int error;
    nextNum(&num, &error, str);
    return *(decToHex(num) + 1);
}

char * readImm(char **str) {
    clearWhiteSpace(str);
    int num;
    int error;
    nextNum(&num, &error, str);
    return decToHex(num);
}

void processText() {
    char *str = getNextLine();
    while (str) {
        if (str[0] == 'm' && str[1] == 'o' && str[2] == 'v') { //movh and movl
            if (str[3] == 'l') {
                fprintf(hex, "8");
                printf("8");
                str += 4;
            } else {
                fprintf(hex, "9");
                printf("9");
                str += 4;
            }
            char reg = readReg(&str);
            char * imm = readImm(&str);
            fprintf(hex, "%c\n%c%c\n", imm[0], imm[1], reg);
            printf("%c\n%c%c\n", imm[0], imm[1], reg);
        } else if (str[0] == 'l' && str[1] == 'd') {        //ld
            str += 2;
            char target = readReg(&str);
            char regA = readReg(&str);
            fprintf(hex, "F%c\n0%c\n", regA, target);
            printf("F%c\n0%c\n", regA, target);
        } else if (str[0] == 's' && str[1] == 't') {        //st
            str += 2;
            char target = readReg(&str);
            char regA = readReg(&str);
            fprintf(hex, "F%c\n1%c\n", regA, target);
            printf("F%c\n1%c\n", regA, target);
        } else if (str[0] == 'j') {                         //jz, jnz, js, jns
            char op;
            if (str[1] == 'z') {
                str += 2;
                op = '0';
            } else if (str[1] == 's') {
                str += 2;
                op = '2';
            } else {
                if (str[2] == 'z') {
                    op = '1';
                } else {
                    op = '3';
                }
                str += 3;
            }
            char target = readReg(&str);
            char regA = readReg(&str);
            fprintf(hex, "E%c\n%c%c\n", regA, op, target);
            printf("E%c\n%c%c\n", regA, op, target);

        } else {
            str += 3;
            char target = readReg(&str);
            char regA = readReg(&str);
            char regB = readReg(&str);
            fprintf(hex, "0%c\n%c%c\n", regA, regB, target);
            printf("0%c\n%c%c\n", regA, regB, target);
        }


        str = getNextLine();
    }

}

int main(int argc, char **argv) {
    if (argc != 2) {
        fprintf(stderr,"usage: %s <name>\n",argv[0]);
        exit(1);
    }

    char* name = argv[1];
    size_t len = strlen(name);

    size_t hexLen = len+5;  // ".hex" + 0
    char* hexName = (char*) malloc(hexLen);
    if (hexName == 0) {
        perror("malloc");
        exit(1);
    } else {
        strncpy(hexName,name,hexLen);
        strncat(hexName,".hex",hexLen);
    }

    size_t srcLen = len+3; // ".s" + 0
    char* srcName = (char*) malloc(srcLen);
    if (hexName == 0) {
        perror("malloc");
        exit(1);
    }
    strncpy(srcName,name,srcLen);
    strncat(srcName,".s",srcLen);

    FILE * src = fopen (srcName, "rb");

    if (src) {
        fseek (src, 0, SEEK_END);
        long length = ftell (src);
        fseek (src, 0, SEEK_SET);
        buffer = malloc (length + 1);

        if (buffer) {
            buffer[length] = '\0';
            fread (buffer, 1, length, src);
        }
        fclose (src);
    }
    char * bufferfree = buffer;

    hex = fopen(hexName,"w");
    if (hex == 0) {
        perror(hexName);
        exit(1);
    }

    fprintf(hex, "@0\n");
    printf("@0\n");
    processText();

    fclose(hex);

    free(bufferfree);
    free(srcName);
    free(hexName);
}