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

#include "datum.h"

datum* cons(datum *e, datum *xs) {
    e->next = xs;
    return e;
}

datum* const_i32(int32_t value) {
    datum* r = malloc(sizeof(datum));
    if (!r) exit(-1);
    r->type = datum_type_i32;
    r->value = value;
    return r;
}

datum* const_bool(int32_t value) {
    datum* r = malloc(sizeof(datum));
    if (!r) exit(-1);
    r->type = datum_type_bool;
    r->value = value;
    return r;
}

datum* const_primitive_proc(datum* (*primitive_procedure) (datum*)) {
    datum* r = malloc(sizeof(datum));
    if (!r) exit(-1);
    r->type = datum_type_primitive_proc;
    r->primitive_procedure = primitive_procedure;
    return r;
}

int primitive_procedure(datum* d) {
    if (d->type == datum_type_primitive_proc) {
        return 1;
    }
    return 0;
}

int is_false(datum *d) {
    if (d->type == datum_type_i32) {
        return 0;
    } else if (d->type == datum_type_bool) {
        return !d->value;
    } else if (d->next) {
        return 0;
    } else {
        return 1;
    }
}

int datum_eq(datum *a, datum *b) {
    if ((a->type == datum_type_i32) && (b->type == datum_type_i32)) {
        return a->value == b->value;
    }
    return 0;
}

int datum_lt(datum *a, datum *b) {
    if ((a->type == datum_type_i32) && (b->type == datum_type_i32)) {
        return a->value < b->value;
    }
    return 0;
}

void print_datum(datum* d) {
    if (!d) {
        printf("ERROR - DATUM is null");
        exit(-1);
    }

    switch (d->type) {
        case datum_type_i32:
            printf("%i", d->value);
            break;
        default:
            printf("Cannot print type %u", d->type);
            break;
    }
}

void* compiled_procedure_entry(datum* d) {
    return d->compiled_procedure_entry;
}