/******************************************************************************
 *
 * Copyright (c) 2017, the Perspective Authors.
 *
 * This file is part of the Perspective library, distributed under the terms of
 * the Apache License 2.0.  The full license can be found in the LICENSE file.
 *
 */

#include <perspective/first.h>
#include <perspective/base.h>
#include <perspective/sym_table.h>
#include <perspective/column.h>
#include <unordered_map>
#include <functional>
#include <mutex>

namespace perspective
{

std::mutex sym_table_mutex;

t_symtable::t_symtable() {}

t_symtable::~t_symtable()
{
    for (auto& kv : m_mapping)
    {
        free(const_cast<char*>(kv.second));
    }
}

const t_char*
t_symtable::get_interned_cstr(const t_char* s)
{
    auto iter = m_mapping.find(s);

    if (iter != m_mapping.end())
    {
        return iter->second;
    }

    auto scopy = strdup(s);
    m_mapping[scopy] = scopy;
    return scopy;
}

t_tscalar
t_symtable::get_interned_tscalar(const t_char* s)
{
    if (t_tscalar::can_store_inplace(s))
    {
        t_tscalar rval;
        rval.set(s);
        return rval;
    }

    t_tscalar rval;
    rval.set(get_interned_cstr(s));
    return rval;
}

t_tscalar
t_symtable::get_interned_tscalar(const t_tscalar& s)
{
    if (!s.is_str() || s.is_inplace())
        return s;

    t_tscalar rval;
    rval.set(get_interned_cstr(s.get_char_ptr()));
    return rval;
}

t_uindex
t_symtable::size() const
{
    return m_mapping.size();
}

static t_symtable*
get_symtable()
{
    static t_symtable* sym = 0;

    if (!sym)
    {
        sym = new t_symtable;
    }
    return sym;
}

const t_char*
get_interned_cstr(const t_char* s)
{
    std::lock_guard<std::mutex> guard(sym_table_mutex);
    auto sym = get_symtable();
    return sym->get_interned_cstr(s);
}

t_tscalar
get_interned_tscalar(const t_char* s)
{
    if (t_tscalar::can_store_inplace(s))
    {
        t_tscalar rval;
        rval.set(s);
        return rval;
    }
    t_tscalar rval;
    rval.set(get_interned_cstr(s));
    return rval;
}

t_tscalar
get_interned_tscalar(const t_tscalar& s)
{
    if (!s.is_str() || s.is_inplace())
        return s;

    t_tscalar rval;
    rval.set(get_interned_cstr(s.get_char_ptr()));
    return rval;
}

} // end namespace perspective