#include <assert.h>

#include "apfl.h"
#include "internal.h"

/**
 * Decrease a refererence count. Returns true, if the object should be freed.
 */
static bool
dec_refcount(unsigned *rc)
{
    if (rc == 0) {
        return false;
    }
    return --(*rc) == 0;
}

static void
print(unsigned indent, FILE *out, struct apfl_value value)
{
    switch (value.type) {
    case APFL_VALUE_NIL:
        apfl_print_indented(indent, out, "nil\n");
        return;
    case APFL_VALUE_BOOLEAN:
        apfl_print_indented(indent, out, value.boolean ? "true\n" : "false\n");
        return;
    case APFL_VALUE_NUMBER:
        apfl_print_indented(indent, out, "%f\n", value.number);
        return;
    case APFL_VALUE_STRING:
        apfl_print_indented(indent, out, "\"" APFL_STR_FMT "\"\n", APFL_STR_FMT_ARGS(value.string));
        return;
    case APFL_VALUE_LIST:
        apfl_print_indented(indent, out, "[\n");
        for (size_t i = 0; i < value.list->len; i++) {
            print(indent+1, out, value.list->items[i]);
        }
        apfl_print_indented(indent, out, "]\n");
        return;
    }

    fprintf(out, "Unknown value? (%d)\n", (int)value.type);
}

bool
apfl_value_copy(struct apfl_value *dst, struct apfl_value src)
{
    struct apfl_string string;

    *dst = src;

    switch (src.type) {
    case APFL_VALUE_NIL:
    case APFL_VALUE_BOOLEAN:
    case APFL_VALUE_NUMBER:
        // Nothing to do
        goto ok;
    case APFL_VALUE_STRING:
        string = apfl_string_blank();
        if (!apfl_string_copy(&string, apfl_string_view_from(src.string))) {
            return false;
        }
        dst->string = string;
        goto ok;
    case APFL_VALUE_LIST:
        assert(src.list != NULL);
        assert(dst->list == src.list);
        src.list->refcount++;
        goto ok;
    }

    assert(false);

ok:
    return true;
}

void
apfl_value_print(struct apfl_value value, FILE *out)
{
    print(0, out, value);
}

struct apfl_list *
apfl_list_new(void)
{
    struct apfl_list *list = ALLOC(struct apfl_list);
    if (list == NULL) {
        return NULL;
    }

    *list = (struct apfl_list) {
        .refcount = 1,
        .items = NULL,
        .len = 0,
        .cap = 0,
    };

    return list;
}

void
apfl_list_deinit(struct apfl_list *list)
{
    DEINIT_LIST(list->items, list->len, apfl_value_deinit);
    list->refcount = 0;
    list->cap = 0;
}

void
apfl_value_deinit(struct apfl_value *value)
{
    switch (value->type) {
    case APFL_VALUE_NIL:
    case APFL_VALUE_BOOLEAN:
    case APFL_VALUE_NUMBER:
        goto ok;
    case APFL_VALUE_STRING:
        apfl_string_deinit(&value->string);
        goto ok;
    case APFL_VALUE_LIST:
        if (dec_refcount(&value->list->refcount)) {
            DESTROY(value->list, apfl_list_deinit);
        }
        goto ok;
    }

    assert(false);

ok:
    value->type = APFL_VALUE_NIL;
}