// 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_LANG_WGSL_AST_TRANSFORM_RENAMER_H_
#define SRC_TINT_LANG_WGSL_AST_TRANSFORM_RENAMER_H_

#include <string>
#include <unordered_map>

#include "src/tint/lang/wgsl/ast/transform/transform.h"

namespace tint::ast::transform {

/// Renamer is a Transform that renames all the symbols in a program.
class Renamer final : public Castable<Renamer, Transform> {
  public:
    /// Data is outputted by the Renamer transform.
    /// Data holds information about shader usage and constant buffer offsets.
    struct Data final : public Castable<Data, transform::Data> {
        /// Remappings is a map of old symbol name to new symbol name
        using Remappings = std::unordered_map<std::string, std::string>;

        /// Constructor
        /// @param remappings the symbol remappings
        explicit Data(Remappings&& remappings);

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

        /// Destructor
        ~Data() override;

        /// A map of old symbol name to new symbol name
        const Remappings remappings;
    };

    /// Target is an enumerator of rename targets that can be used
    enum class Target {
        /// Rename every symbol.
        kAll,
        /// Only rename symbols that are reserved keywords in GLSL.
        kGlslKeywords,
        /// Only rename symbols that are reserved keywords in HLSL.
        kHlslKeywords,
        /// Only rename symbols that are reserved keywords in MSL.
        kMslKeywords,
    };

    /// Optional configuration options for the transform.
    /// If omitted, then the renamer will use Target::kAll.
    struct Config final : public Castable<Config, transform::Data> {
        /// Constructor
        /// @param tgt the targets to rename
        /// @param keep_unicode if false, symbols with non-ascii code-points are
        /// renamed
        explicit Config(Target tgt, bool keep_unicode = false);

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

        /// Destructor
        ~Config() override;

        /// The targets to rename
        Target const target = Target::kAll;

        /// If false, symbols with non-ascii code-points are renamed.
        bool preserve_unicode = false;
    };

    /// Constructor using a the configuration provided in the input Data
    Renamer();

    /// Destructor
    ~Renamer() override;

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

}  // namespace tint::ast::transform

#endif  // SRC_TINT_LANG_WGSL_AST_TRANSFORM_RENAMER_H_