// 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.

#include "src/inspector/test_inspector_builder.h"

#include <memory>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "gtest/gtest.h"

namespace tint {
namespace inspector {

InspectorBuilder::InspectorBuilder() = default;
InspectorBuilder::~InspectorBuilder() = default;

void InspectorBuilder::MakeEmptyBodyFunction(std::string name,
                                             ast::DecorationList decorations) {
  Func(name, ast::VariableList(), ty.void_(), ast::StatementList{Return()},
       decorations);
}

void InspectorBuilder::MakeCallerBodyFunction(std::string caller,
                                              std::vector<std::string> callees,
                                              ast::DecorationList decorations) {
  ast::StatementList body;
  body.reserve(callees.size() + 1);
  for (auto callee : callees) {
    body.push_back(CallStmt(Call(callee)));
  }
  body.push_back(Return());

  Func(caller, ast::VariableList(), ty.void_(), body, decorations);
}

const ast::Struct* InspectorBuilder::MakeInOutStruct(
    std::string name,
    std::vector<std::tuple<std::string, uint32_t>> inout_vars) {
  ast::StructMemberList members;
  for (auto var : inout_vars) {
    std::string member_name;
    uint32_t location;
    std::tie(member_name, location) = var;
    members.push_back(
        Member(member_name, ty.u32(), {Location(location), Flat()}));
  }
  return Structure(name, members);
}

const ast::Function* InspectorBuilder::MakePlainGlobalReferenceBodyFunction(
    std::string func,
    std::string var,
    const ast::Type* type,
    ast::DecorationList decorations) {
  ast::StatementList stmts;
  stmts.emplace_back(Decl(Var("local_" + var, type)));
  stmts.emplace_back(Assign("local_" + var, var));
  stmts.emplace_back(Return());

  return Func(func, ast::VariableList(), ty.void_(), stmts, decorations);
}

bool InspectorBuilder::ContainsName(const std::vector<StageVariable>& vec,
                                    const std::string& name) {
  for (auto& s : vec) {
    if (s.name == name) {
      return true;
    }
  }
  return false;
}

std::string InspectorBuilder::StructMemberName(size_t idx,
                                               const ast::Type* type) {
  return std::to_string(idx) + type->FriendlyName(Symbols());
}

const ast::Struct* InspectorBuilder::MakeStructType(
    const std::string& name,
    std::vector<const ast::Type*> member_types,
    bool is_block) {
  ast::StructMemberList members;
  for (auto* type : member_types) {
    members.push_back(MakeStructMember(members.size(), type, {}));
  }
  return MakeStructTypeFromMembers(name, std::move(members), is_block);
}

const ast::Struct* InspectorBuilder::MakeStructTypeFromMembers(
    const std::string& name,
    ast::StructMemberList members,
    bool is_block) {
  ast::DecorationList decos;
  if (is_block) {
    decos.push_back(create<ast::StructBlockDecoration>());
  }
  return Structure(name, std::move(members), decos);
}

const ast::StructMember* InspectorBuilder::MakeStructMember(
    size_t index,
    const ast::Type* type,
    ast::DecorationList decorations) {
  return Member(StructMemberName(index, type), type, std::move(decorations));
}

const ast::Struct* InspectorBuilder::MakeUniformBufferType(
    const std::string& name,
    std::vector<const ast::Type*> member_types) {
  return MakeStructType(name, member_types, true);
}

std::function<const ast::TypeName*()> InspectorBuilder::MakeStorageBufferTypes(
    const std::string& name,
    std::vector<const ast::Type*> member_types) {
  MakeStructType(name, member_types, true);
  return [this, name] { return ty.type_name(name); };
}

void InspectorBuilder::AddUniformBuffer(const std::string& name,
                                        const ast::Type* type,
                                        uint32_t group,
                                        uint32_t binding) {
  Global(name, type, ast::StorageClass::kUniform,
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

void InspectorBuilder::AddWorkgroupStorage(const std::string& name,
                                           const ast::Type* type) {
  Global(name, type, ast::StorageClass::kWorkgroup);
}

void InspectorBuilder::AddStorageBuffer(const std::string& name,
                                        const ast::Type* type,
                                        ast::Access access,
                                        uint32_t group,
                                        uint32_t binding) {
  Global(name, type, ast::StorageClass::kStorage, access,
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

void InspectorBuilder::MakeStructVariableReferenceBodyFunction(
    std::string func_name,
    std::string struct_name,
    std::vector<std::tuple<size_t, const ast::Type*>> members) {
  ast::StatementList stmts;
  for (auto member : members) {
    size_t member_idx;
    const ast::Type* member_type;
    std::tie(member_idx, member_type) = member;
    std::string member_name = StructMemberName(member_idx, member_type);

    stmts.emplace_back(Decl(Var("local" + member_name, member_type)));
  }

  for (auto member : members) {
    size_t member_idx;
    const ast::Type* member_type;
    std::tie(member_idx, member_type) = member;
    std::string member_name = StructMemberName(member_idx, member_type);

    stmts.emplace_back(Assign("local" + member_name,
                              MemberAccessor(struct_name, member_name)));
  }

  stmts.emplace_back(Return());

  Func(func_name, ast::VariableList(), ty.void_(), stmts,
       ast::DecorationList{});
}

void InspectorBuilder::AddSampler(const std::string& name,
                                  uint32_t group,
                                  uint32_t binding) {
  Global(name, sampler_type(),
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

void InspectorBuilder::AddComparisonSampler(const std::string& name,
                                            uint32_t group,
                                            uint32_t binding) {
  Global(name, comparison_sampler_type(),
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

void InspectorBuilder::AddResource(const std::string& name,
                                   const ast::Type* type,
                                   uint32_t group,
                                   uint32_t binding) {
  Global(name, type,
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

void InspectorBuilder::AddGlobalVariable(const std::string& name,
                                         const ast::Type* type) {
  Global(name, type, ast::StorageClass::kPrivate);
}

const ast::Function* InspectorBuilder::MakeSamplerReferenceBodyFunction(
    const std::string& func_name,
    const std::string& texture_name,
    const std::string& sampler_name,
    const std::string& coords_name,
    const ast::Type* base_type,
    ast::DecorationList decorations) {
  std::string result_name = "sampler_result";

  ast::StatementList stmts;
  stmts.emplace_back(Decl(Var(result_name, ty.vec(base_type, 4))));

  stmts.emplace_back(Assign(result_name, Call("textureSample", texture_name,
                                              sampler_name, coords_name)));
  stmts.emplace_back(Return());

  return Func(func_name, ast::VariableList(), ty.void_(), stmts, decorations);
}

const ast::Function* InspectorBuilder::MakeSamplerReferenceBodyFunction(
    const std::string& func_name,
    const std::string& texture_name,
    const std::string& sampler_name,
    const std::string& coords_name,
    const std::string& array_index,
    const ast::Type* base_type,
    ast::DecorationList decorations) {
  std::string result_name = "sampler_result";

  ast::StatementList stmts;

  stmts.emplace_back(Decl(Var("sampler_result", ty.vec(base_type, 4))));

  stmts.emplace_back(
      Assign("sampler_result", Call("textureSample", texture_name, sampler_name,
                                    coords_name, array_index)));
  stmts.emplace_back(Return());

  return Func(func_name, ast::VariableList(), ty.void_(), stmts, decorations);
}

const ast::Function*
InspectorBuilder::MakeComparisonSamplerReferenceBodyFunction(
    const std::string& func_name,
    const std::string& texture_name,
    const std::string& sampler_name,
    const std::string& coords_name,
    const std::string& depth_name,
    const ast::Type* base_type,
    ast::DecorationList decorations) {
  std::string result_name = "sampler_result";

  ast::StatementList stmts;

  stmts.emplace_back(Decl(Var("sampler_result", base_type)));
  stmts.emplace_back(
      Assign("sampler_result", Call("textureSampleCompare", texture_name,
                                    sampler_name, coords_name, depth_name)));
  stmts.emplace_back(Return());

  return Func(func_name, ast::VariableList(), ty.void_(), stmts, decorations);
}

const ast::Type* InspectorBuilder::GetBaseType(
    ResourceBinding::SampledKind sampled_kind) {
  switch (sampled_kind) {
    case ResourceBinding::SampledKind::kFloat:
      return ty.f32();
    case ResourceBinding::SampledKind::kSInt:
      return ty.i32();
    case ResourceBinding::SampledKind::kUInt:
      return ty.u32();
    default:
      return nullptr;
  }
}

const ast::Type* InspectorBuilder::GetCoordsType(ast::TextureDimension dim,
                                                 const ast::Type* scalar) {
  switch (dim) {
    case ast::TextureDimension::k1d:
      return scalar;
    case ast::TextureDimension::k2d:
    case ast::TextureDimension::k2dArray:
      return create<ast::Vector>(scalar, 2);
    case ast::TextureDimension::k3d:
    case ast::TextureDimension::kCube:
    case ast::TextureDimension::kCubeArray:
      return create<ast::Vector>(scalar, 3);
    default:
      [=]() { FAIL() << "Unsupported texture dimension: " << dim; }();
  }
  return nullptr;
}

const ast::Type* InspectorBuilder::MakeStorageTextureTypes(
    ast::TextureDimension dim,
    ast::TexelFormat format) {
  return ty.storage_texture(dim, format, ast::Access::kWrite);
}

void InspectorBuilder::AddStorageTexture(const std::string& name,
                                         const ast::Type* type,
                                         uint32_t group,
                                         uint32_t binding) {
  Global(name, type,
         ast::DecorationList{
             create<ast::BindingDecoration>(binding),
             create<ast::GroupDecoration>(group),
         });
}

const ast::Function* InspectorBuilder::MakeStorageTextureBodyFunction(
    const std::string& func_name,
    const std::string& st_name,
    const ast::Type* dim_type,
    ast::DecorationList decorations) {
  ast::StatementList stmts;

  stmts.emplace_back(Decl(Var("dim", dim_type)));
  stmts.emplace_back(Assign("dim", Call("textureDimensions", st_name)));
  stmts.emplace_back(Return());

  return Func(func_name, ast::VariableList(), ty.void_(), stmts, decorations);
}

std::function<const ast::Type*()> InspectorBuilder::GetTypeFunction(
    ComponentType component,
    CompositionType composition) {
  std::function<const ast::Type*()> func;
  switch (component) {
    case ComponentType::kFloat:
      func = [this]() -> const ast::Type* { return ty.f32(); };
      break;
    case ComponentType::kSInt:
      func = [this]() -> const ast::Type* { return ty.i32(); };
      break;
    case ComponentType::kUInt:
      func = [this]() -> const ast::Type* { return ty.u32(); };
      break;
    case ComponentType::kUnknown:
      return []() -> const ast::Type* { return nullptr; };
  }

  uint32_t n;
  switch (composition) {
    case CompositionType::kScalar:
      return func;
    case CompositionType::kVec2:
      n = 2;
      break;
    case CompositionType::kVec3:
      n = 3;
      break;
    case CompositionType::kVec4:
      n = 4;
      break;
    default:
      return []() -> ast::Type* { return nullptr; };
  }

  return [this, func, n]() -> const ast::Type* { return ty.vec(func(), n); };
}

Inspector& InspectorBuilder::Build() {
  if (inspector_) {
    return *inspector_;
  }
  program_ = std::make_unique<Program>(std::move(*this));
  [&]() {
    ASSERT_TRUE(program_->IsValid())
        << diag::Formatter().format(program_->Diagnostics());
  }();
  inspector_ = std::make_unique<Inspector>(program_.get());
  return *inspector_;
}

}  // namespace inspector
}  // namespace tint