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

#if 0
#define PART_1
#else
#define PART_2
#endif

#if 0
#define FILE_PATH "example-valid.txt"
#else
#define FILE_PATH "input.txt"
#endif

char fields[8][4] = {"byr", "iyr", "eyr", "hgt", "hcl", "ecl", "pid", "cid"};

size_t valid = 0;

void parse()
{
    FILE *fp = fopen(FILE_PATH, "r");
    if(!fp) {
        fprintf(stderr, "ERROR: Could not open file: %s", FILE_PATH);
        exit(EXIT_FAILURE);
    }

    char line[2048] = {0};
    int field_valid[8] = {0};
    while(fgets(line, sizeof(line), fp) != NULL)
    {
        if(line[0] == '\n' || strncmp(line, "EOF", 3) == 0)
        {
            int result = 1;
            for(int i = 0; i < 7; i++)
                result *= field_valid[i];

            valid += result;
            memset(field_valid, 0 , sizeof(field_valid));
            continue;
        }

        char *tok = strtok(line, " ");
        while(tok != NULL)
        {
            for(int i = 0; i < 8; i++)
            {
                if(strncmp(tok, fields[i], 3) == 0)
                {
                    #ifdef PART_1
                    field_valid[i] = 1;
                    #endif

                    #ifdef PART_2

                    char *saveptr;
                    (void)strtok_r(tok, ":", &saveptr);
                    char *val = strtok_r(NULL, ":", &saveptr);
                    assert(val != NULL);
                    assert(strtok_r(NULL, ":", &saveptr) == NULL);

                    if(val[strlen(val)-1] == '\n') val[strlen(val)-1] = '\0';

                    int ival;
                    switch(i)
                    {
                    case 0: ival = atoi(val);
                        if(ival >= 1920 && ival <= 2002) field_valid[i] = 1;
                        break;
                    case 1: ival = atoi(val);
                        if(ival >= 2010 && ival <= 2020) field_valid[i] = 1;
                        break;
                    case 2: ival = atoi(val);
                        if(ival >= 2020 && ival <= 2030) field_valid[i] = 1;
                        break;
                    case 3:
                        if(strlen(val) == 5)
                        {
                            if(!(val[3] == 'c' && val[4] == 'm')) break;
                            char _val[4] = {0}; _val[0] = val[0];
                            _val[1] = val[1]; _val[2] = val[2];
                            ival = atoi(_val);
                            if(ival >= 150 && ival <= 193) field_valid[i] = 1;
                        }
                        if(strlen(val) == 4)
                        {
                            if(!(val[2] == 'i' && val[3] == 'n')) break;
                            char _val[3] = {0}; _val[0] = val[0]; _val[1] = val[1];
                            ival = atoi(_val);

                            if(ival >= 59 && ival <= 76) field_valid[i] = 1;
                        }

                        break;
                    case 4:
                        int num = 0;
                        char valid_vals[16] = "0123456789abcdef";
                        for(int k = 1; k <= strlen(val); k++)
                            for(int j = 0; j < 16; j++)
                                if(val[k] == valid_vals[j]) num++;

                        if(val[0] == '#' && num == 6) field_valid[i] = 1;
                        break;
                    case 5:
                        int valid_ecl = 0;
                        char valid_cols[7][4] = {"amb", "blu", "brn", "gry", "grn", "hzl", "oth"};
                        for(int k = 0; k < 7; k++)
                            if(strncmp(val, valid_cols[k], 3) == 0) valid_ecl++;

                        if(valid_ecl == 1) field_valid[i] = 1;
                        break;
                    case 6:
                        int valid_pid = 0;
                        if(strlen(val) != 9) break;
                        char valid_nums[10] = "0123456789";
                        for(int k = 0; k < strlen(val); k++)
                            for(int j = 0; j < 10; j++)
                                if(val[k] == valid_nums[j]) valid_pid++;

                        if(valid_pid == 9) field_valid[i] = 1;
                        break;
                    }
                    #endif
                }
            }
            tok = strtok(NULL, " ");
        }
    }

    fclose(fp);
}

int main(void)
{
    parse();
    printf("%ld passports are valid\n", valid);
    return 0;
}