#include "alloc.h"
#include "gc.h"
#include "matcher.h"

static bool
init_values_list(struct apfl_allocator allocator, struct apfl_value **list, size_t len)
{
    if (len == 0) {
        return true;
    }

    if ((*list = ALLOC_LIST(allocator, struct apfl_value, len)) == NULL) {
        return false;
    }

    for (size_t i = 0; i < len; i++) {
        (*list)[i] = (struct apfl_value) { .type = VALUE_NIL };
    }
    return true;
}

struct matcher *
apfl_matcher_new(struct gc *gc, struct matcher_instruction_list *milist)
{
    struct matcher matcher = {
        .instructions = milist,
        .value_count = 0,
        .capture_count = 0,
        .values = NULL,
        .captures = NULL,
        .result = false,
    };

    if (!init_values_list(gc->allocator, &matcher.values, milist->value_count)) {
        goto error;
    }
    matcher.value_count = milist->value_count;

    if (!init_values_list(gc->allocator, &matcher.captures, milist->capture_count)) {
        goto error;
    }
    matcher.capture_count = milist->capture_count;

    struct matcher *gc_matcher = apfl_gc_new_matcher(gc);
    if (gc_matcher == NULL) {
        goto error;
    }

    *gc_matcher = matcher;

    return gc_matcher;

error:
    apfl_matcher_deinit(gc->allocator, &matcher);
    return NULL;
}

void
apfl_matcher_deinit(struct apfl_allocator allocator, struct matcher *matcher)
{
    FREE_LIST(allocator, matcher->values, matcher->value_count);
    FREE_LIST(allocator, matcher->captures, matcher->capture_count);
}

void
apfl_gc_matcher_traverse(struct matcher *matcher, gc_visitor visitor, void *opaque)
{
    visitor(opaque, GC_OBJECT_FROM(matcher->instructions, GC_TYPE_MATCHER_INSTRUCTIONS));

    for (size_t i = 0; i < matcher->instructions->value_count; i++) {
        struct gc_object *object = apfl_value_get_gc_object(matcher->values[i]);
        if (object != NULL) {
            visitor(opaque, object);
        }
    }

    for (size_t i = 0; i < matcher->instructions->capture_count; i++) {
        struct gc_object *object = apfl_value_get_gc_object(matcher->captures[i]);
        if (object != NULL) {
            visitor(opaque, object);
        }
    }
}