// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2022, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2022, Knut Reinert & MPI für molekulare Genetik
// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
// shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE.md
// -----------------------------------------------------------------------------------------------------

/*!\file
 * \author Marcel Ehrhardt <marcel.ehrhardt AT fu-berlin.de>
 * \brief Provides the declaration of seqan3::detail::trace_directions.
 */

#pragma once

#include <seqan3/core/add_enum_bitwise_operators.hpp>
#include <seqan3/core/debug_stream/debug_stream_type.hpp>

namespace seqan3::detail
{

/*!\brief The possible directions a trace can have. The values can be combined by the logical `|`-operator.
 * \ingroup alignment_matrix
 * \implements seqan3::enum_bitwise_operators
 * \implements seqan3::enum_bitwise_operators
 * \sa seqan3::enum_bitwise_operators enables combining enum values.
 * \sa seqan3::detail::alignment_trace_matrix implementations use this enum as matrix entry type.
 */
enum struct trace_directions : uint8_t
{
    //!\brief No trace
    none = 0b00000,
    //!\brief Trace comes from the diagonal entry.
    diagonal = 0b00001,
    //!\brief Trace comes from the above entry, while opening the gap.
    up_open = 0b00010,
    //!\brief Trace comes from the above entry.
    up = 0b00100,
    //!\brief Trace comes from the left entry, while opening the gap.
    left_open = 0b01000,
    //!\brief Trace comes from the left entry.
    left = 0b10000
};

} // namespace seqan3::detail

namespace seqan3
{
//!\cond DEV
//!\brief Enable bitwise operators for enum seqan3::detail::trace_directions.
//!\ingroup alignment_matrix
//!\sa seqan3::enum_bitwise_operators enables combining enum values.
template <>
constexpr bool add_enum_bitwise_operators<seqan3::detail::trace_directions> = true;
//!\endcond

/*!\brief All trace_directions can be printed as ascii or as utf8 to the seqan3::debug_stream.
 * \param s The seqan3::debug_stream.
 * \param trace The trace direction.
 * \relates seqan3::debug_stream_type
 *
 * \details
 *
 * The following table shows the printed symbol of a particular seqan3::detail::trace_directions:
 *
 * | trace direction                             | utf8 | ascii |
 * |:-------------------------------------------:|:----:|:-----:|
 * | seqan3::detail::trace_directions::none      | ↺    | N     |
 * | seqan3::detail::trace_directions::diagonal  | ↖    | D     |
 * | seqan3::detail::trace_directions::up_open   | ↑    | U     |
 * | seqan3::detail::trace_directions::up        | ⇡    | u     |
 * | seqan3::detail::trace_directions::left_open | ←    | L     |
 * | seqan3::detail::trace_directions::left      | ⇠    | l     |
 */
template <typename char_t>
inline debug_stream_type<char_t> & operator<<(debug_stream_type<char_t> & s, detail::trace_directions const trace)
{
    static char const * unicode[32]{"↺",   "↖",    "↑",   "↖↑",  "⇡",    "↖⇡",   "↑⇡",  "↖↑⇡",  "←",    "↖←",   "↑←",
                                    "↖↑←", "⇡←",   "↖⇡←", "↑⇡←", "↖↑⇡←", "⇠",    "↖⇠",  "↑⇠",   "↖↑⇠",  "⇡⇠",   "↖⇡⇠",
                                    "↑⇡⇠", "↖↑⇡⇠", "←⇠",  "↖←⇠", "↑←⇠",  "↖↑←⇠", "⇡←⇠", "↖⇡←⇠", "↑⇡←⇠", "↖↑⇡←⇠"};

    static char const * csv[32]{"N",   "D",    "U",   "DU",  "u",    "Du",   "Uu",  "DUu",  "L",    "DL",   "UL",
                                "DUL", "uL",   "DuL", "UuL", "DUuL", "l",    "Dl",  "Ul",   "DUl",  "ul",   "Dul",
                                "Uul", "DUul", "Ll",  "DLl", "ULl",  "DULl", "uLl", "DuLl", "UuLl", "DUuLl"};

    bool is_unicode = (s.flags2() & fmtflags2::utf8) == fmtflags2::utf8;
    auto const & trace_dir = is_unicode ? unicode : csv;

    s << trace_dir[static_cast<size_t>(trace)];
    return s;
}

} // namespace seqan3
