#include "lib.h"

#define DBG 0

static
unsigned char input[] = {
#embed "day3_input.txt"
};

static
unsigned char test[] = {
#embed "day3_test.txt"
};


static
unsigned long do_part1(size_t file_len, unsigned char file[file_len]) {
    unsigned long result = 0;
    unsigned char *s = file;

    do {
        unsigned char n0 = 0, n1 = 0;
        unsigned char *n0p = NULL;
        do {
            if (s[0] > n0) {
                n0 = s[0];
                n0p = s;
            }
            s++;
        } while (s[1] != '\n');
        s = n0p+1;
        do {
            if (s[0] > n1) {
                n1 = s[0];
            }
            s++;
        } while (s[0] != '\n');
        s++;
        unsigned n = (n0 - '0') * 10 + (n1 - '0');
        result += n;
    } while(s < &file[file_len]);

    return result;
}

static
unsigned long do_part2(size_t file_len, unsigned char file[file_len]) {
    unsigned long result = 0;
    unsigned char *s = file;

    do {
        // for some reason this crashes
        // but works fine under blink so.
        // whatever
        unsigned char n[12] = { };
        unsigned char *np[12] = { };
        for (int i = 0; i < 12; i++) {
            do {
                if (s[0] > n[i]) {
                    n[i] = s[0];
                    np[i] = s;
                }
                s++;
            } while (s[11-i] != '\n');
            s = np[i]+1;
        }
        unsigned long v = 0;
        for (int i = 0; i < 12; i++) {
            v = v * 10 + (n[i] - '0');
        }
#if DBG
        print("got ");
        printd(v);
        print("\n");
#endif
        result += v;
        while (*s != '\n') s++;
        s++;
    } while(s < &file[file_len]);

    return result;
}

#define RUN_TEST1 1
#define RUN_PART1 1
#define RUN_TEST2 1
#define RUN_PART2 1

#define TEST1_EXPECT 357
#define TEST2_EXPECT 3121910778619

void _start() {
#if RUN_TEST1
    print("PART 1 TEST: ");
    if (unsigned long v = do_part1(countof(test), test); v != TEST1_EXPECT) {
        print("FAILED (got ");
        printd(v);
        print(", expected " xstr(TEST1_EXPECT) ")\n");
    } else {
        print("PASSED\n");
    }
#endif

#if RUN_PART1
    print("PART 1 RESULT: ");
    printd(do_part1(countof(input), input));
    print("\n");
#endif

#if RUN_TEST2
    print("PART 2 TEST: ");
    if (unsigned long v = do_part2(countof(test), test); v != TEST2_EXPECT) {
        print("FAILED (got ");
        printd(v);
        print(", expected " xstr(TEST2_EXPECT) ")\n");
    } else {
        print("PASSED\n");
    }
#endif

#if RUN_PART2
    print("PART 2 RESULT: ");
    printd(do_part2(countof(input), input));
    print("\n");
#endif

    syscall(SYS_exit_group, 0);
}