#include <luna/Alloc.h>
#include <luna/CString.h>
#include <luna/OwnedStringView.h>

OwnedStringView::OwnedStringView()
{
}

OwnedStringView::OwnedStringView(OwnedStringView&& other)
{
    m_string = other.m_string;
    m_length = other.m_length;

    other.m_string = nullptr;
}

OwnedStringView::OwnedStringView(char* c_str)
{
    m_string = c_str;

    if (m_string) { m_length = strlen(m_string); }
}

OwnedStringView::OwnedStringView(char* c_str, usize length)
{
    m_string = c_str;
    m_length = length;
}

OwnedStringView::~OwnedStringView()
{
    if (m_string) free_impl(m_string);
}

Result<OwnedStringView> OwnedStringView::clone() const
{
    return from_string_literal(m_string);
}

Result<OwnedStringView> OwnedStringView::substring(usize begin, usize size) const
{
    if (begin + size >= size) return err(EINVAL);
    char* const dup = strndup(m_string + begin, size);
    if (!dup) return err(ENOMEM);
    return OwnedStringView { dup, size };
}

const char& OwnedStringView::operator[](usize index) const
{
    expect(index < m_length, "index out of range");
    return m_string[index];
}

Result<OwnedStringView> OwnedStringView::from_string_literal(const char* str)
{
    char* const dup = strdup(str);
    if (!dup) return err(ENOMEM);
    return OwnedStringView { dup };
}