// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef SRC_TINT_TYPE_MANAGER_H_
#define SRC_TINT_TYPE_MANAGER_H_

#include <utility>

#include "src/tint/type/type.h"
#include "src/tint/type/unique_node.h"
#include "src/tint/utils/hash.h"
#include "src/tint/utils/unique_allocator.h"

// Forward declarations
namespace tint::type {
class AbstractFloat;
class AbstractInt;
class Bool;
class F16;
class F32;
class I32;
class Matrix;
class U32;
class Vector;
class Void;
}  // namespace tint::type

namespace tint::type {

/// The type manager holds all the pointers to the known types.
class Manager final {
  public:
    /// Iterator is the type returned by begin() and end()
    using TypeIterator = utils::BlockAllocator<Type>::ConstIterator;

    /// Constructor
    Manager();

    /// Move constructor
    Manager(Manager&&);

    /// Move assignment operator
    /// @param rhs the Manager to move
    /// @return this Manager
    Manager& operator=(Manager&& rhs);

    /// Destructor
    ~Manager();

    /// Wrap returns a new Manager created with the types of `inner`.
    /// The Manager returned by Wrap is intended to temporarily extend the types
    /// of an existing immutable Manager.
    /// As the copied types are owned by `inner`, `inner` must not be destructed
    /// or assigned while using the returned Manager.
    /// TODO(bclayton) - Evaluate whether there are safer alternatives to this
    /// function. See crbug.com/tint/460.
    /// @param inner the immutable Manager to extend
    /// @return the Manager that wraps `inner`
    static Manager Wrap(const Manager& inner) {
        Manager out;
        out.types_.Wrap(inner.types_);
        out.unique_nodes_.Wrap(inner.unique_nodes_);
        return out;
    }

    /// @param args the arguments used to construct the type, unique node or node.
    /// @return a pointer to an instance of `T` with the provided arguments.
    ///         If NODE derives from UniqueNode and an existing instance of `T` has been
    ///         constructed, then the same pointer is returned.
    template <typename NODE, typename... ARGS>
    NODE* Get(ARGS&&... args) {
        if constexpr (utils::traits::IsTypeOrDerived<NODE, Type>) {
            return types_.Get<NODE>(std::forward<ARGS>(args)...);
        } else if constexpr (utils::traits::IsTypeOrDerived<NODE, UniqueNode>) {
            return unique_nodes_.Get<NODE>(std::forward<ARGS>(args)...);
        } else {
            return nodes_.Create<NODE>(std::forward<ARGS>(args)...);
        }
    }

    /// @param args the arguments used to create the temporary used for the search.
    /// @return a pointer to an instance of `T` with the provided arguments, or nullptr if the item
    ///         was not found.
    template <typename TYPE,
              typename _ = std::enable_if<utils::traits::IsTypeOrDerived<TYPE, Type>>,
              typename... ARGS>
    TYPE* Find(ARGS&&... args) const {
        return types_.Find<TYPE>(std::forward<ARGS>(args)...);
    }

    /// @returns a void type
    const type::Void* void_();

    /// @returns a bool type
    const type::Bool* bool_();

    /// @returns an i32 type
    const type::I32* i32();

    /// @returns a u32 type
    const type::U32* u32();

    /// @returns an f32 type
    const type::F32* f32();

    /// @returns an f16 type
    const type::F16* f16();

    /// @returns a abstract-float type
    const type::AbstractFloat* AFloat();

    /// @returns a abstract-int type
    const type::AbstractInt* AInt();

    /// @param inner the inner type
    /// @param size the vector size
    /// @returns the vector type
    const type::Vector* vec(const type::Type* inner, uint32_t size);

    /// @param inner the inner type
    /// @returns the vector type
    const type::Vector* vec2(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the vector type
    const type::Vector* vec3(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the vector type
    const type::Vector* vec4(const type::Type* inner);

    /// @param inner the inner type
    /// @param cols the number of columns
    /// @param rows the number of rows
    /// @returns the matrix type
    const type::Matrix* mat(const type::Type* inner, uint32_t cols, uint32_t rows);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat2x2(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat2x3(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat2x4(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat3x2(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat3x3(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat3x4(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat4x2(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat4x3(const type::Type* inner);

    /// @param inner the inner type
    /// @returns the matrix type
    const type::Matrix* mat4x4(const type::Type* inner);

    /// @returns an iterator to the beginning of the types
    TypeIterator begin() const { return types_.begin(); }
    /// @returns an iterator to the end of the types
    TypeIterator end() const { return types_.end(); }

  private:
    /// Unique types owned by the manager
    utils::UniqueAllocator<Type> types_;
    /// Unique nodes (excluding types) owned by the manager
    utils::UniqueAllocator<UniqueNode> unique_nodes_;
    /// Non-unique nodes owned by the manager
    utils::BlockAllocator<Node> nodes_;
};

}  // namespace tint::type

#endif  // SRC_TINT_TYPE_MANAGER_H_