/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2022 NKI/AVL, Netherlands Cancer Institute
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <cif++/v2/item.hpp>
#include <cif++/v2/condition.hpp>

namespace cif::v2
{

template <typename>
class row_handle;

namespace detail
{

	// some helper classes to help create tuple result types
	template <
		typename Category,
		typename... C>
	struct get_row_result
	{
		using category_type = Category;
		using row_type = category_type::row;
		using row_handle_type = row_handle<category_type>;
		using item_handle_type = item_handle<row_type>;

		static constexpr size_t N = sizeof...(C);

		get_row_result(const row_handle_type &r, std::array<size_t, N> &&columns)
			: m_row(r)
			, m_columns(std::move(columns))
		{
		}

		const item_handle_type operator[](size_t ix) const
		{
			return m_row[m_columns[ix]];
		}

		template <typename... Ts, std::enable_if_t<N == sizeof...(Ts), int> = 0>
		operator std::tuple<Ts...>() const
		{
			return get<Ts...>(std::index_sequence_for<Ts...>{});
		}

		template <typename... Ts, std::size_t... Is>
		std::tuple<Ts...> get(std::index_sequence<Is...>) const
		{
			return std::tuple<Ts...>{m_row[m_columns[Is]].template as<Ts>()...};
		}

		const row_handle_type &m_row;
		std::array<size_t, N> m_columns;
	};

	// we want to be able to tie some variables to a get_row_result, for this we use tiewraps
	template <typename... Ts>
	struct tie_wrap
	{
		tie_wrap(Ts... args)
			: m_value(args...)
		{
		}

		template <typename RR>
		void operator=(const RR &&rr)
		{
			// get_row_result will do the conversion, but only if the types
			// are compatible. That means the number of parameters to the get()
			// of the row should be equal to the number of items in the tuple
			// you are trying to tie.

			using RType = std::tuple<typename std::remove_reference<Ts>::type...>;

			m_value = static_cast<RType>(rr);
		}

		std::tuple<Ts...> m_value;
	};

} // namespace detail

template <typename... Ts>
auto tie(Ts &...v)
{
	return detail::tie_wrap<Ts &...>(std::forward<Ts &>(v)...);
}

// --------------------------------------------------------------------
/// \brief row_handle is the way to access data in rows

template <typename Category>
class row_handle
{
  public:
	using category_type = Category;
	using row_type = std::conditional_t<std::is_const_v<category_type>, const typename category_type::row, typename category_type::row>;

	using item_handle_type = item_handle<row_handle>;

	template <typename>
	friend class row_handle;

	template <typename>
	friend class item_handle;

	row_handle() = default;

	row_handle(const row_handle &) = default;
	row_handle(row_handle &&) = default;

	row_handle &operator=(const row_handle &) = default;
	row_handle &operator=(row_handle &&) = default;

	template <typename C2>
	row_handle(const row_handle<C2> &rhs)
		: m_cat(rhs.m_cat)
		, m_row(rhs.m_row)
	{
	}

	row_handle(category_type &cat, row_type &row)
		: m_cat(&cat)
		, m_row(&row)
	{
	}

	explicit operator bool() const
	{
		return m_cat != nullptr and m_row != nullptr;
	}

	item_handle_type operator[](uint32_t column_ix)
	{
		return item_handle_type(column_ix, *this);
	}

	const item_handle_type operator[](uint32_t column_ix) const
	{
		return item_handle_type(column_ix, const_cast<row_handle &>(*this));
	}

	item_handle_type operator[](std::string_view column_name)
	{
		return item_handle_type(add_column(column_name), *this);
	}

	const item_handle_type operator[](std::string_view column_name) const
	{
		return item_handle_type(get_column_ix(column_name), *this);
	}

	template <typename... Ts, size_t N>
	std::tuple<Ts...> get(char const *const (&columns)[N]) const
	{
		static_assert(sizeof...(Ts) == N, "Number of columns should be equal to number of types to return");

		std::array<size_t, N> cix;
		for (size_t i = 0; i < N; ++i)
			cix[i] = get_column_ix(columns[i]);
		return detail::get_row_result<category_type, Ts...>(*this, std::move(cix));
	}

	template <typename... C>
	auto get(C... columns) const
	{
		return detail::get_row_result<category_type, C...>(*this, {get_column_ix(columns)...});
	}

	void assign(const std::vector<item> &values)
	{
		// std::map<std::string, std::tuple<size_t, std::string, std::string>> changed;

		for (auto &value : values)
		{
			assign(value, true);

			// auto columnIx = cat->add_column(value.name());
			// auto &col = cat->m_columns[columnIx];
			// std::string tag = col.mValidator ? col.mValidator->mTag : std::to_string(columnIx);

			// changed[tag] = std::make_tuple(columnIx, operator[](columnIx).c_str(), value.value());

			// assign(columnIx, value.value(), true);
		}

		// // see if we need to update any child categories that depend on these values
		// // auto iv = col.mValidator;
		// if (mCascade)
		// {
		// 	for (auto &&[childCat, linked] : cat->mChildLinks)
		// 	{
		// 		Condition cond;
		// 		std::string childTag;

		// 		std::vector<Item> newValues;

		// 		for (size_t ix = 0; ix < linked->mParentKeys.size(); ++ix)
		// 		{
		// 			std::string pk = linked->mParentKeys[ix];
		// 			std::string ck = linked->mChildKeys[ix];

		// 			if (changed.count(pk) > 0)
		// 			{
		// 				childTag = ck;
		// 				cond = std::move(cond) && (Key(ck) == std::get<1>(changed[pk]));
		// 				newValues.emplace_back(ck, std::get<2>(changed[pk]));
		// 			}
		// 			else
		// 			{
		// 				const char *value = (*this)[pk].c_str();
		// 				cond = std::move(cond) && (Key(ck) == value);
		// 			}
		// 		}

		// 		auto rows = childCat->find(std::move(cond));
		// 		for (auto &cr : rows)
		// 			cr.assign(newValues);
		// 	}
		// }
	}

	void assign(std::string_view name, std::string_view value, bool updateLinked, bool validate = true)
	{
		assign(m_cat->add_column(name), value, updateLinked, validate);
	}

	void assign(size_t column, std::string_view value, bool updateLinked, bool validate = true)
	{
		m_cat->update_value(m_row, column, value, updateLinked, validate);	
	}

  private:
	uint16_t get_column_ix(std::string_view name) const
	{
		return m_cat->get_column_ix(name);
	}

	uint16_t add_column(std::string_view name)
	{
		return m_cat->add_column(name);
	}

	void assign(const item &i, bool updateLinked)
	{
		assign(i.name(), i.value(), updateLinked);
	}

	category_type *m_cat = nullptr;
	row_type *m_row = nullptr;
};

} // namespace cif::v2