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

enum action {TUK, INK, DEK, BREK, GLEK, PUK, KUK, op, cl, FUK};


void run_tukafuk(const char* code);
int convert_code(enum action* commands, const char* code);
void run_code(enum action*  commands, int size);

int main(int argc, char* argv[]){

    if(argc < 2){
        printf("Please provide file with source code\n");
        return 0;
    }

    char commands[999999];

    FILE* file = fopen(argv[1], "r");
    fread(commands, 1, 999999, file);

    run_tukafuk(commands);
}

void run_tukafuk(const char* code){
    enum action *commands = calloc(999999, sizeof(enum action));
    int pos = 0;

    int size = convert_code(commands, code);

    run_code(commands, size);
}

void run_code(enum action*  commands, int size){
    char memory[1000] = {0};
    int pos = 0;

    int ended = 0;

    for(int i = 0; i < size; i++){
        if(commands[i] == INK){
            memory[pos] += 1;
        }
        else if(commands[i] == DEK){
            memory[pos] -= 1;
        }
        else if(commands[i] == BREK){
            pos++;
        }
        else if(commands[i] == GLEK){
            pos--;
        }
        else if(commands[i] == PUK){
            putchar(memory[pos]);
        }
        else if(commands[i] == KUK){
            memory[pos] = getchar();
        }
        else if(commands[i] == op && memory[pos] == 0){
            int closed = 1;
            while(closed > 0){
                i++;
                if(commands[i] == op){
                    closed++;
                }
                else if(commands[i] == cl){
                    closed--;
                }
                if(i > size){
                    printf("Error with opening bracket!\n");
                    exit(1);
                }
            }
        }
        else if(commands[i] == cl && memory[pos] != 0){
            int opened = 1;
            while(opened > 0){
                i--;
                if(commands[i] == cl){
                    opened++;
                }
                else if(commands[i] == op){
                    opened--;
                }
                if(i < 0){
                    printf("Error with opening bracket!\n");
                    exit(1);
                }
            }
        }
        else if(commands[i] == FUK){
            ended = 1;
            break;
        }
    }

    if(!ended){
        printf("No FUK at the end :(\n");
    }
}

int convert_code(enum action* commands, const char* code){
    int pos = 0;
    int offset = 0;
    int add_offset = 0;
    char buff[100];

    int size = strlen(code);

    while(1){
        int res = sscanf(code + offset ,"%s%n", buff, &add_offset);
        if(res == 0 || strcmp(buff, "TUK") == 0){
            break;
        }
    }

    while (1){
        if(offset >= size){
            break;
        }
        int res = sscanf(code + offset ,"%s%n", buff, &add_offset);

        if(res == 0){
            break;
        }
        offset += add_offset;

        if(strcmp(buff, "TUK") == 0){
            commands[pos] = TUK;
        }
        else if(strcmp(buff, "INK") == 0){
            commands[pos] = INK;
        }
        else if(strcmp(buff, "DEK") == 0){
            commands[pos] = DEK;
        }
        else if(strcmp(buff, "BREK") == 0){
            commands[pos] = BREK;
        }
        else if(strcmp(buff, "GLEK") == 0){
            commands[pos] = GLEK;
        }
        else if(strcmp(buff, "PUK") == 0){
            commands[pos] = PUK;
        }
        else if(strcmp(buff, "KUK") == 0){
            commands[pos] = KUK;
        }
        else if(strcmp(buff, "[") == 0){
            commands[pos] = op;
        }
        else if(strcmp(buff, "]") == 0){
            commands[pos] = cl;
        }
        else if(strcmp(buff, "FUK") == 0){
            commands[pos] = FUK;
        }
        else if(strcmp(buff, "[") == 0){
            commands[pos] = op;
        }
        else if(strcmp(buff, "]") == 0){
            commands[pos] = cl;
        }
        else{
            pos--;
        }
        pos++;
    }
    return pos;
}