// Metamethods for enums

#include <stdint.h>
#include <stdio.h>
#include <sys/param.h>

#include "integers.h"
#include "metamethods.h"
#include "siphash.h"
#include "text.h"
#include "util.h"

CONSTFUNC static ptrdiff_t value_offset(const TypeInfo_t *type) {
    ptrdiff_t offset = sizeof(int32_t);
    for (int i = 0; i < type->EnumInfo.num_tags; i++) {
        if (type->EnumInfo.tags[i].type) offset = MAX(offset, type->EnumInfo.tags[i].type->align);
    }
    return offset;
}

PUREFUNC public uint64_t Enum$hash(const void *obj, const TypeInfo_t *type) {
    int32_t tag = *(int32_t *)obj;
    uint32_t components[2] = {(uint32_t)tag, 0};

    const TypeInfo_t *value = type->EnumInfo.tags[tag - 1].type;
    if (value && value->size > 0) {
        components[1] = generic_hash(obj + value_offset(type), value);
    }
    return siphash24((void *)components, sizeof(components));
}

PUREFUNC public int32_t Enum$compare(const void *x, const void *y, const TypeInfo_t *type) {
    if (x == y) return 0;

    int32_t x_tag = *(int32_t *)x;
    int32_t y_tag = *(int32_t *)y;
    if (x_tag != y_tag) return x_tag > y_tag ? 1 : -1;

    const TypeInfo_t *value = type->EnumInfo.tags[x_tag - 1].type;
    if (value && value->size > 0) {
        ptrdiff_t byte_offset = value_offset(type);
        return generic_compare(x + byte_offset, y + byte_offset, value);
    }
    return 0;
}

PUREFUNC public bool Enum$equal(const void *x, const void *y, const TypeInfo_t *type) {
    if (x == y) return true;

    int32_t x_tag = *(int32_t *)x;
    int32_t y_tag = *(int32_t *)y;
    if (x_tag != y_tag) return false;

    const TypeInfo_t *value = type->EnumInfo.tags[x_tag - 1].type;
    if (value && value->size > 0) {
        ptrdiff_t byte_offset = value_offset(type);
        return generic_equal(x + byte_offset, y + byte_offset, value);
    }
    return true;
}

public
Text_t Enum$as_text(const void *obj, bool colorize, const TypeInfo_t *type) {
    if (!obj) return Text$from_str(type->EnumInfo.name);

    int32_t tag = *(int32_t *)obj;
    NamedType_t value = type->EnumInfo.tags[tag - 1];
    if (!value.type || value.type->size == 0) {
        Text_t text = Text$from_str(value.name);
        return colorize ? Text$concat(Text("\x1b[1m"), text, Text("\x1b[m")) : text;
    }

    return generic_as_text(obj + value_offset(type), colorize, value.type);
}

PUREFUNC public bool Enum$is_none(const void *x, const TypeInfo_t *info) {
    (void)info;
    return *(int32_t *)x == 0;
}

public
void Enum$serialize(const void *obj, FILE *out, Table_t *pointers, const TypeInfo_t *type) {
    int32_t tag = *(int32_t *)obj;
    Int32$serialize(&tag, out, pointers, &Int32$info);

    NamedType_t value = type->EnumInfo.tags[tag - 1];
    if (value.type && value.type->size > 0) {
        _serialize(obj + value_offset(type), out, pointers, value.type);
    }
}

public
void Enum$deserialize(FILE *in, void *outval, List_t *pointers, const TypeInfo_t *type) {
    int32_t tag = 0;
    Int32$deserialize(in, &tag, pointers, &Int32$info);
    if (tag < 1 || tag > type->EnumInfo.num_tags) deserialization_failed();
    *(int32_t *)outval = tag;

    NamedType_t value = type->EnumInfo.tags[tag - 1];
    if (value.type && value.type->size > 0) {
        _deserialize(in, outval + value_offset(type), pointers, value.type);
    }
}