/// @file dpf/eval_peel.hpp
/// @brief Eval overloads that accept a wrapper and evaluate its `dpf_key`.
/// @details Include this after the eval headers. A call passes through while
///          the argument has a public `dpf_key` member and is not itself a
///          DPF key. `dpf3` / `dpf3_cmp` / `dpf3_ic` keep their key-first
///          protocol overloads; `eval_*(cmp, …)` and `eval_*(out<I>, …)` still
///          peel those wrappers down to the inner DPF key.
/// @copyright Copyright (c) 2019-2026 Ryan Henry and [others](@ref authors)
/// @license Released under a GNU General Public v2.0 (GPLv2) license.

#ifndef LIBDPF_INCLUDE_DPF_EVAL_PEEL_HPP__
#define LIBDPF_INCLUDE_DPF_EVAL_PEEL_HPP__

#include <type_traits>
#include <utility>

#include "dpf/eval_target.hpp"

namespace dpf
{

template <typename T>
inline constexpr bool peel_key_v =
    has_embedded_dpf_key_v<std::decay_t<T>>
    && !owns_protocol_eval_v<std::decay_t<T>>;

template <typename T>
inline constexpr bool peel_tag_key_v =
    has_embedded_dpf_key_v<std::decay_t<T>>;

#define LIBDPF_PEEL_KEY_FIRST(fn)                                             \
    template <std::size_t I = 0,                                              \
              typename KeyT,                                                  \
              typename... Args,                                                \
              std::enable_if_t<peel_key_v<KeyT>, int> = 0>                    \
    decltype(auto) fn(const KeyT & key, Args &&... args)                      \
    {                                                                         \
        return fn<I>(key.dpf_key, std::forward<Args>(args)...);              \
    }

#define LIBDPF_PEEL_TAG_FIRST(fn)                                             \
    template <typename Tag,                                                   \
              typename KeyT,                                                  \
              typename... Args,                                                \
              std::enable_if_t<peel_tag_key_v<KeyT>                           \
                  && is_eval_channel_tag_v<std::decay_t<Tag>>, int> = 0>      \
    decltype(auto) fn(Tag tag, const KeyT & key, Args &&... args)             \
    {                                                                         \
        return fn(tag, key.dpf_key, std::forward<Args>(args)...);            \
    }

LIBDPF_PEEL_KEY_FIRST(eval_point)
LIBDPF_PEEL_KEY_FIRST(eval_interval)
LIBDPF_PEEL_KEY_FIRST(eval_full)
LIBDPF_PEEL_KEY_FIRST(eval_sequence)
LIBDPF_PEEL_KEY_FIRST(eval_inner_product)
LIBDPF_PEEL_KEY_FIRST(eval_full_inner_product)
LIBDPF_PEEL_KEY_FIRST(eval_sequence_inner_product)

LIBDPF_PEEL_TAG_FIRST(eval_point)
LIBDPF_PEEL_TAG_FIRST(eval_interval)
LIBDPF_PEEL_TAG_FIRST(eval_full)
LIBDPF_PEEL_TAG_FIRST(eval_sequence)
LIBDPF_PEEL_TAG_FIRST(eval_sequence_breadth_first)
LIBDPF_PEEL_TAG_FIRST(eval_inner_product)
LIBDPF_PEEL_TAG_FIRST(eval_full_inner_product)
LIBDPF_PEEL_TAG_FIRST(make_output_buffer)
LIBDPF_PEEL_TAG_FIRST(make_sequence_recipe)
LIBDPF_PEEL_TAG_FIRST(eval_prefixes)
LIBDPF_PEEL_TAG_FIRST(eval_prefix_inner_product)

#undef LIBDPF_PEEL_KEY_FIRST
#undef LIBDPF_PEEL_TAG_FIRST

template <typename KeyT,
          typename... Args,
          std::enable_if_t<peel_key_v<KeyT>, int> = 0>
decltype(auto) eval_sequence_xor(const KeyT & key, Args &&... args)
{
    return eval_sequence_xor(key.dpf_key, std::forward<Args>(args)...);
}

template <typename KeyT,
          typename... Args,
          std::enable_if_t<peel_key_v<KeyT>, int> = 0>
decltype(auto) prove_cmp_interval(const KeyT & key, Args &&... args)
{
    return prove_cmp_interval(key.dpf_key, std::forward<Args>(args)...);
}

template <typename KeyT,
          typename... Args,
          std::enable_if_t<peel_key_v<KeyT>, int> = 0>
decltype(auto) prove_cmp_full(const KeyT & key, Args &&... args)
{
    return prove_cmp_full(key.dpf_key, std::forward<Args>(args)...);
}

template <typename KeyT,
          typename... Args,
          std::enable_if_t<peel_key_v<KeyT>, int> = 0>
decltype(auto) prove_cmp_sequence(const KeyT & key, Args &&... args)
{
    return prove_cmp_sequence(key.dpf_key, std::forward<Args>(args)...);
}

template <std::size_t I = 0,
          typename Buffer,
          typename KeyT,
          typename... Args,
          std::enable_if_t<peel_key_v<KeyT>, int> = 0>
void eval_full_add_into(Buffer & buf, const KeyT & key, Args &&... args)
{
    eval_full_add_into<I>(buf, key.dpf_key, std::forward<Args>(args)...);
}

/// @brief Row-wise and column inner products keep the tag in front of the key.
template <typename Tag,
          typename KeyT,
          typename... Args,
          std::enable_if_t<peel_tag_key_v<KeyT>
              && (std::is_same_v<std::decay_t<Tag>, paired_t>
                  || std::is_same_v<std::decay_t<Tag>, columns_t>), int> = 0>
decltype(auto) eval_inner_product(Tag tag, const KeyT & key, Args &&... args)
{
    return eval_inner_product(tag, key.dpf_key, std::forward<Args>(args)...);
}

template <typename Tag,
          typename KeyT,
          typename... Args,
          std::enable_if_t<peel_tag_key_v<KeyT>
              && (std::is_same_v<std::decay_t<Tag>, paired_t>
                  || std::is_same_v<std::decay_t<Tag>, columns_t>), int> = 0>
decltype(auto) eval_full_inner_product(Tag tag, const KeyT & key, Args &&... args)
{
    return eval_full_inner_product(tag, key.dpf_key, std::forward<Args>(args)...);
}

template <typename Tag,
          typename KeyT,
          typename... Args,
          std::enable_if_t<peel_tag_key_v<KeyT>
              && (std::is_same_v<std::decay_t<Tag>, paired_t>
                  || std::is_same_v<std::decay_t<Tag>, columns_t>), int> = 0>
decltype(auto) eval_sequence_inner_product(Tag tag, const KeyT & key,
    Args &&... args)
{
    return eval_sequence_inner_product(tag, key.dpf_key,
        std::forward<Args>(args)...);
}

}  // namespace dpf

#endif  // LIBDPF_INCLUDE_DPF_EVAL_PEEL_HPP__