// Copyright 2021 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_AST_TRANSFORM_BINDING_REMAPPER_H_
#define SRC_TINT_AST_TRANSFORM_BINDING_REMAPPER_H_

#include <unordered_map>

#include "src/tint/ast/transform/transform.h"
#include "src/tint/builtin/access.h"
#include "src/tint/sem/binding_point.h"

namespace tint::ast::transform {

/// BindingPoint is an alias to sem::BindingPoint
using BindingPoint = sem::BindingPoint;

/// BindingRemapper is a transform used to remap resource binding points and
/// access controls.
class BindingRemapper final : public utils::Castable<BindingRemapper, Transform> {
  public:
    /// BindingPoints is a map of old binding point to new binding point
    using BindingPoints = std::unordered_map<BindingPoint, BindingPoint>;

    /// AccessControls is a map of old binding point to new access control
    using AccessControls = std::unordered_map<BindingPoint, builtin::Access>;

    /// Remappings is consumed by the BindingRemapper transform.
    /// Data holds information about shader usage and constant buffer offsets.
    struct Remappings final : public utils::Castable<Remappings, Data> {
        /// Constructor
        /// @param bp a map of new binding points
        /// @param ac a map of new access controls
        /// @param may_collide If true, then validation will be disabled for
        /// binding point collisions generated by this transform
        Remappings(BindingPoints bp, AccessControls ac, bool may_collide = true);

        /// Copy constructor
        Remappings(const Remappings&);

        /// Destructor
        ~Remappings() override;

        /// A map of old binding point to new binding point
        const BindingPoints binding_points;

        /// A map of old binding point to new access controls
        const AccessControls access_controls;

        /// If true, then validation will be disabled for binding point collisions
        /// generated by this transform
        const bool allow_collisions;
    };

    /// Constructor
    BindingRemapper();
    ~BindingRemapper() override;

    /// @copydoc Transform::Apply
    ApplyResult Apply(const Program* program,
                      const DataMap& inputs,
                      DataMap& outputs) const override;
};

}  // namespace tint::ast::transform

#endif  // SRC_TINT_AST_TRANSFORM_BINDING_REMAPPER_H_