#include <stdio.h>
#include "interference.h"
#include "puzzle.h"
#include "puzzle_io.h"

// run_puzzle solves a single puzzle and prints the output
void run_puzzle(char* puzzle_text);

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

    if (argc < 2) {
        filename = "sudoku_puzzles.txt";
    } else {
        filename = argv[1];
    }

    FILE *file = fopen(filename, "r");
    if (file == NULL) {
        perror("Failed to open file");
        return -1;
    }

    char line[N_CELLS + 2];
    // we expect a line of exactly N_CELLS+1 chars, where the last one is \n
    // we replace the \n with a \0 for compatibility with puzzle_init_string
    while (fgets(line, sizeof(line), file)) {
        bool too_short = strlen(line) != N_CELLS + 1;
        bool too_long = line[N_CELLS] != '\n';
        if (too_short || too_long) {
            crash("wrong number of characters in a puzzle");
        }
        line[N_CELLS] = '\0';
        run_puzzle(line);
    }
    return 0;
}

void run_puzzle(char* puzzle_text) {
    // this only needs to be done once
    // but it's harmless to do it more than once
    interference_init();

    // load and display info about the puzzle before and after solving
    puzzle_t puzzle;
    puzzle_init_string(&puzzle, puzzle_text);

    printf("Initial state:\n\n");
    puzzle_display(&puzzle);
    printf("\nSolving...\n\n");
    puzzle_solve(&puzzle);
    puzzle_display(&puzzle);
    printf("\n");
}