// Copyright 2023 Huawei Cloud Computing Technology Co., Ltd.
//
// 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 INCLUDED_SRC_BUILDTOOL_SERVE_API_REMOTE_SERVE_API_HPP
#define INCLUDED_SRC_BUILDTOOL_SERVE_API_REMOTE_SERVE_API_HPP

#ifdef BOOTSTRAP_BUILD_TOOL
class ServeApi final {};
#else

#include <filesystem>
#include <memory>
#include <optional>
#include <string>
#include <unordered_map>
#include <utility>
#include <variant>
#include <vector>

#include "gsl/gsl"
#include "src/buildtool/common/artifact_digest.hpp"
#include "src/buildtool/common/remote/remote_common.hpp"
#include "src/buildtool/crypto/hash_function.hpp"
#include "src/buildtool/execution_api/common/api_bundle.hpp"
#include "src/buildtool/execution_api/local/context.hpp"
#include "src/buildtool/execution_api/remote/context.hpp"
#include "src/buildtool/file_system/git_types.hpp"
#include "src/buildtool/file_system/symlinks/pragma_special.hpp"
#include "src/buildtool/serve_api/remote/config.hpp"
#include "src/buildtool/serve_api/remote/configuration_client.hpp"
#include "src/buildtool/serve_api/remote/source_tree_client.hpp"
#include "src/buildtool/serve_api/remote/target_client.hpp"
#include "src/buildtool/storage/config.hpp"
#include "src/buildtool/storage/target_cache_key.hpp"
#include "src/utils/cpp/expected.hpp"

class ServeApi final {
  public:
    explicit ServeApi(ServerAddress const& address,
                      gsl::not_null<LocalContext const*> const& local_context,
                      gsl::not_null<RemoteContext const*> const& remote_context,
                      gsl::not_null<ApiBundle const*> const& apis) noexcept
        : stc_{address,
               local_context->storage_config->hash_function,
               remote_context},
          tc_{address, local_context->storage, remote_context, apis},
          cc_{address, remote_context},
          storage_config_{*local_context->storage_config},
          apis_{*apis} {}

    ~ServeApi() noexcept = default;
    ServeApi(ServeApi const&) = delete;
    ServeApi(ServeApi&&) = delete;
    auto operator=(ServeApi const&) -> ServeApi& = delete;
    auto operator=(ServeApi&&) -> ServeApi& = delete;

    [[nodiscard]] static auto Create(
        RemoteServeConfig const& serve_config,
        gsl::not_null<LocalContext const*> const& local_context,
        gsl::not_null<RemoteContext const*> const& remote_context,
        gsl::not_null<ApiBundle const*> const& apis) noexcept
        -> std::optional<ServeApi> {
        if (serve_config.remote_address) {
            return std::make_optional<ServeApi>(*serve_config.remote_address,
                                                local_context,
                                                remote_context,
                                                apis);
        }
        return std::nullopt;
    }

    [[nodiscard]] auto RetrieveTreeFromCommit(
        std::string const& commit,
        std::string const& subdir = ".",
        bool sync_tree = false) const noexcept -> SourceTreeClient::result_t {
        return stc_.ServeCommitTree(commit, subdir, sync_tree);
    }

    [[nodiscard]] auto RetrieveTreeFromArchive(
        std::string const& content,
        std::string const& archive_type = "archive",
        std::string const& subdir = ".",
        std::optional<PragmaSpecial> const& resolve_symlinks = std::nullopt,
        bool sync_tree = false) const noexcept -> SourceTreeClient::result_t {
        return stc_.ServeArchiveTree(
            content, archive_type, subdir, resolve_symlinks, sync_tree);
    }

    [[nodiscard]] auto RetrieveTreeFromDistdir(
        std::shared_ptr<std::unordered_map<std::string, std::string>> const&
            distfiles,
        bool sync_tree = false) const noexcept -> SourceTreeClient::result_t {
        return stc_.ServeDistdirTree(distfiles, sync_tree);
    }

    [[nodiscard]] auto RetrieveTreeFromForeignFile(
        const std::string& content,
        const std::string& name,
        bool executable) const noexcept -> SourceTreeClient::result_t {
        return stc_.ServeForeignFileTree(content, name, executable);
    }

    [[nodiscard]] auto ContentInRemoteCAS(std::string const& content)
        const noexcept -> expected<ArtifactDigest, GitLookupError> {
        return stc_.ServeContent(content);
    }

    [[nodiscard]] auto TreeInRemoteCAS(std::string const& tree_id)
        const noexcept -> expected<ArtifactDigest, GitLookupError> {
        return stc_.ServeTree(tree_id);
    }

    [[nodiscard]] auto CheckRootTree(std::string const& tree_id) const noexcept
        -> std::optional<bool> {
        return stc_.CheckRootTree(tree_id);
    }

    [[nodiscard]] auto GetTreeFromRemote(
        ArtifactDigest const& digest) const noexcept -> bool {
        return stc_.GetRemoteTree(digest);
    }

    [[nodiscard]] auto ComputeTreeStructure(ArtifactDigest const& digest)
        const noexcept -> expected<ArtifactDigest, GitLookupError> {
        return stc_.ComputeTreeStructure(digest);
    }

    [[nodiscard]] auto ServeTargetVariables(std::string const& target_root_id,
                                            std::string const& target_file,
                                            std::string const& target)
        const noexcept -> std::optional<std::vector<std::string>> {
        return tc_.ServeTargetVariables(target_root_id, target_file, target);
    }

    [[nodiscard]] auto ServeTargetDescription(std::string const& target_root_id,
                                              std::string const& target_file,
                                              std::string const& target)
        const noexcept -> std::optional<ArtifactDigest> {
        return tc_.ServeTargetDescription(target_root_id, target_file, target);
    }

    [[nodiscard]] auto ServeTarget(const TargetCacheKey& key,
                                   const ArtifactDigest& repo_key,
                                   bool keep_artifact_root = false)
        const noexcept -> std::optional<serve_target_result_t> {
        return tc_.ServeTarget(key, repo_key, keep_artifact_root);
    }

    [[nodiscard]] auto CheckServeRemoteExecution() const noexcept -> bool {
        return cc_.CheckServeRemoteExecution();
    }

    [[nodiscard]] auto IsCompatible() const noexcept -> std::optional<bool> {
        return cc_.IsCompatible();
    }

    class UploadError;
    /// \brief Upload a git tree from git repo to serve.
    /// \param tree         Tree to upload.
    /// \param git_repo     Git repository where the tree can be found.
    /// \return std::monostate if the tree is available for this serve
    /// instance after the call, or an unexpected UploadError on failure.
    [[nodiscard]] auto UploadTree(ArtifactDigest const& tree,
                                  std::filesystem::path const& git_repo)
        const noexcept -> expected<std::monostate, UploadError>;

    /// \brief Download a git tree from serve.
    /// \param tree         Tree to download.
    /// \return std::monostate if after the call the requested tree can be found
    /// in the native CAS to which this serve instance is bound to, or an
    /// unexpected error message on failure.
    [[nodiscard]] auto DownloadTree(ArtifactDigest const& tree) const noexcept
        -> expected<std::monostate, std::string>;

  private:
    // source tree service client
    SourceTreeClient const stc_;
    // target service client
    TargetClient const tc_;
    // configuration service client
    ConfigurationClient const cc_;

    StorageConfig const& storage_config_;
    ApiBundle const& apis_;
};

class ServeApi::UploadError final {
  public:
    [[nodiscard]] auto Message() const& noexcept -> std::string const& {
        return message_;
    }

    [[nodiscard]] auto Message() && noexcept -> std::string {
        return std::move(message_);
    }

    [[nodiscard]] auto IsSyncError() const noexcept -> bool {
        return is_sync_error_;
    }

  private:
    friend ServeApi;
    explicit UploadError(std::string message, bool is_sync_error) noexcept
        : message_{std::move(message)}, is_sync_error_{is_sync_error} {}

    std::string message_;
    bool is_sync_error_;
};

#endif  // BOOTSTRAP_BUILD_TOOL

#endif  // INCLUDED_SRC_BUILDTOOL_SERVE_API_REMOTE_SERVE_API_HPP