/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2016-2017 Danny Robson <danny@nerdcruft.net>
 */

#include "term.hpp"

#include "string.hpp"

#include <filesystem>
#include <cstdlib>
#include <stdexcept>

using cruft::term::csi::graphics;

const graphics graphics::RESET (0);


///////////////////////////////////////////////////////////////////////////////
// find the terminfo path within a directory, for a key
//
// throws an exception if not found
static
std::filesystem::path
find_terminfo_path (const std::filesystem::path &dir,
                    const std::string &key)
{
    const char letter[2] = { key[0], '\0' };
    auto candidate = dir / letter / key;

    if (!std::filesystem::is_directory (candidate))
        throw std::runtime_error ("path not found");

    return candidate;
}


//-----------------------------------------------------------------------------
// find the terminfo path for a given key.
//
// throws an exception if not found
static
std::filesystem::path
find_terminfo_path [[gnu::unused]] (const std::string &key)
{
    static const std::filesystem::path DEFAULT_SEARCH_DIR = "/usr/share/terminfo";

    // check if the path is explicitly listed. must not fall through.
    if (const char *dir = getenv ("TERMINFO")) {
        return find_terminfo_path (dir, key);
    }

    // check if we have a path at $HOME. falls through.
    if (const char *home = getenv ("HOME")) {
        std::filesystem::path HOME (home);
        try {
            return find_terminfo_path (HOME / ".terminfo", key);
        } catch (...) { }
    }

    // check colon seperated list in TERMINFO_DIRS
    if (const char *dirs = getenv ("TERMINFO_DIRS")) {
        auto tok = cruft::tokeniser (dirs, ':');

        for (auto i: tok) {
            try {
                return find_terminfo_path (
                    i.empty () ?
                    DEFAULT_SEARCH_DIR :
                    std::filesystem::path (i.cbegin (), i.cend ()), key
                );
            } catch (...) { }
        }
    }

    return find_terminfo_path ("/usr/share/terminfo", key);
}


///////////////////////////////////////////////////////////////////////////////
bool
cruft::term::has_csi_support (void)
{
    // HACK: this will do until we get a terminfo/termcap reader
    return getenv ("TERM") == std::string ("XTERM");
}


///////////////////////////////////////////////////////////////////////////////
graphics::graphics (layer _layer, hue _hue):
    m_value (_layer + int (_hue))
{ ; }


//-----------------------------------------------------------------------------
graphics::graphics (char _value):
    m_value (_value)
{ ; }


///////////////////////////////////////////////////////////////////////////////
char
graphics::value (void) const
{
    return m_value;
}


//-----------------------------------------------------------------------------
char
graphics::value (char _value)
{
    return m_value = _value;
}


///////////////////////////////////////////////////////////////////////////////
std::ostream&
cruft::term::csi::operator<< (std::ostream &os, graphics g)
{
    return os << code::CSI << '[' << +g.value () << decltype(g)::terminator;
}