#include "libabacus.h"
#include "util.h"
#include "value.h"
#include <stdio.h>

#define TRY(expression)                                                        \
    if (result == LIBAB_SUCCESS)                                               \
        result = expression;
#define INTERACTIONS 5

void* impl_parse(const char* string) {
    double* data = malloc(sizeof(*data));
    if (data) {
        *data = strtod(string, NULL);
    }
    return data;
}

void impl_free(void* data) { free(data); }

libab_result function_atan(libab* ab, libab_ref_vec* params, libab_ref* into) {
    printf("atan called\n");
    libab_ref_null(into);
    return LIBAB_SUCCESS;
}

libab_result function_atan2(libab* ab, libab_ref_vec* params, libab_ref* into) {
    printf("atan2 called\n");
    libab_ref_null(into);
    return LIBAB_SUCCESS;
}

libab_result function_operator(libab* ab, libab_ref_vec* params, libab_ref* into) {
    libab_result result = LIBAB_SUCCESS;
    libab_ref left_ref;
    libab_value* left_value;
    double right;
    double left;
    double* return_value;

    printf("operator called\n");

    libab_ref_vec_index(params, 0, &left_ref);
    left_value = libab_ref_get(&left_ref);
    left = *((double*)libab_unwrap_param(params, 0));
    right = *((double*)libab_unwrap_param(params, 1));

    return_value = malloc(sizeof(*return_value));
    if (return_value == NULL) {
        result = LIBAB_MALLOC;
        libab_ref_null(into);
    } else {
        *return_value = left + right;
        result = libab_create_value_raw(into, return_value, &left_value->type);
    }

    libab_ref_free(&left_ref);

    return result;
}

libab_result register_functions(libab* ab) {
    libab_result result = LIBAB_SUCCESS;
    libab_ref trig_type;
    libab_ref atan2_type;
    libab_ref difficult_type;

    result = libab_create_type(ab, &trig_type, "(num)->num");
    TRY(libab_create_type(ab, &atan2_type, "(num, num)->num"));
    TRY(libab_create_type(ab, &difficult_type, "((num)->num)->num"));

    TRY(libab_register_function(ab, "atan", &trig_type, function_atan));
    TRY(libab_register_function(ab, "atan2", &atan2_type, function_atan2));
    TRY(libab_register_operator_infix(ab, "+", 0, -1, &atan2_type,
                                      function_operator));
    TRY(libab_register_operator_infix(ab, "-", 0, -1, &atan2_type,
                                      function_operator));
    TRY(libab_register_operator_infix(ab, "*", 1, -1, &atan2_type,
                                      function_operator));
    TRY(libab_register_operator_infix(ab, "/", 1, -1, &atan2_type,
                                      function_operator));

    libab_ref_free(&trig_type);
    libab_ref_free(&atan2_type);
    libab_ref_free(&difficult_type);

    return result;
}

int main() {
    char input_buffer[2048];
    int interaction_count = INTERACTIONS;
    libab_ref eval_into;
    libab_result result;
    libab_result eval_result;
    libab ab;

    if (libab_init(&ab, impl_parse, impl_free) != LIBAB_SUCCESS) {
        fprintf(stderr, "Failed to initialize libab.\n");
        exit(1);
    }

    result = register_functions(&ab);
    while (interaction_count-- && result == LIBAB_SUCCESS) {
        printf("(%d) > ", INTERACTIONS - interaction_count);
        fgets(input_buffer, 2048, stdin);
        eval_result = libab_run(&ab, input_buffer, &eval_into);

        if (eval_result != LIBAB_SUCCESS) {
            printf("Invalid input.\n");
        }
        libab_ref_free(&eval_into);
    }

    libab_free(&ab);
}