1 files changed, 133 insertions, 0 deletions
diff --git a/src/buildtool/common/repository_config.hpp b/src/buildtool/common/repository_config.hpp
new file mode 100644
index 00000000..62c2c4ff
--- /dev/null
+++ b/src/buildtool/common/repository_config.hpp
@@ -0,0 +1,133 @@
+#ifndef INCLUDED_SRC_BUILDTOOL_COMMON_REPOSITORY_CONFIG_HPP
+#define INCLUDED_SRC_BUILDTOOL_COMMON_REPOSITORY_CONFIG_HPP
+
+#include <filesystem>
+#include <string>
+#include <unordered_map>
+
+#include "src/buildtool/file_system/file_root.hpp"
+#include "src/buildtool/file_system/git_cas.hpp"
+
+class RepositoryConfig {
+  public:
+    struct RepositoryInfo {
+        FileRoot workspace_root;
+        FileRoot target_root{workspace_root};
+        FileRoot rule_root{target_root};
+        FileRoot expression_root{rule_root};
+        std::unordered_map<std::string, std::string> name_mapping{};
+        std::string target_file_name{"TARGETS"};
+        std::string rule_file_name{"RULES"};
+        std::string expression_file_name{"EXPRESSIONS"};
+    };
+
+    [[nodiscard]] static auto Instance() noexcept -> RepositoryConfig& {
+        static RepositoryConfig instance{};
+        return instance;
+    }
+
+    void SetInfo(std::string const& repo, RepositoryInfo&& info) {
+        infos_.emplace(repo, std::move(info));
+    }
+
+    [[nodiscard]] auto SetGitCAS(
+        std::filesystem::path const& repo_path) noexcept {
+        git_cas_ = GitCAS::Open(repo_path);
+        return static_cast<bool>(git_cas_);
+    }
+
+    [[nodiscard]] auto Info(std::string const& repo) const noexcept
+        -> RepositoryInfo const* {
+        auto it = infos_.find(repo);
+        if (it != infos_.end()) {
+            return &it->second;
+        }
+        return nullptr;
+    }
+
+    [[nodiscard]] auto ReadBlobFromGitCAS(std::string const& hex_id)
+        const noexcept -> std::optional<std::string> {
+        return git_cas_ ? git_cas_->ReadObject(hex_id, /*is_hex_id=*/true)
+                        : std::nullopt;
+    }
+
+    [[nodiscard]] auto WorkspaceRoot(std::string const& repo) const noexcept
+        -> FileRoot const* {
+        return Get<FileRoot>(
+            repo, [](auto const& info) { return &info.workspace_root; });
+    }
+
+    [[nodiscard]] auto TargetRoot(std::string const& repo) const noexcept
+        -> FileRoot const* {
+        return Get<FileRoot>(
+            repo, [](auto const& info) { return &info.target_root; });
+    }
+
+    [[nodiscard]] auto RuleRoot(std::string const& repo) const
+        -> FileRoot const* {
+        return Get<FileRoot>(repo,
+                             [](auto const& info) { return &info.rule_root; });
+    }
+
+    [[nodiscard]] auto ExpressionRoot(std::string const& repo) const noexcept
+        -> FileRoot const* {
+        return Get<FileRoot>(
+            repo, [](auto const& info) { return &info.expression_root; });
+    }
+
+    [[nodiscard]] auto GlobalName(std::string const& repo,
+                                  std::string const& local_name) const noexcept
+        -> std::string const* {
+        return Get<std::string>(
+            repo, [&local_name](auto const& info) -> std::string const* {
+                auto it = info.name_mapping.find(local_name);
+                if (it != info.name_mapping.end()) {
+                    return &it->second;
+                }
+                return nullptr;
+            });
+    }
+
+    [[nodiscard]] auto TargetFileName(std::string const& repo) const noexcept
+        -> std::string const* {
+        return Get<std::string>(
+            repo, [](auto const& info) { return &info.target_file_name; });
+    }
+
+    [[nodiscard]] auto RuleFileName(std::string const& repo) const noexcept
+        -> std::string const* {
+        return Get<std::string>(
+            repo, [](auto const& info) { return &info.rule_file_name; });
+    }
+
+    [[nodiscard]] auto ExpressionFileName(
+        std::string const& repo) const noexcept -> std::string const* {
+        return Get<std::string>(
+            repo, [](auto const& info) { return &info.expression_file_name; });
+    }
+
+    // used for testing
+    void Reset() {
+        infos_.clear();
+        git_cas_.reset();
+    }
+
+  private:
+    std::unordered_map<std::string, RepositoryInfo> infos_;
+    GitCASPtr git_cas_;
+
+    template <class T>
+    [[nodiscard]] auto Get(std::string const& repo,
+                           std::function<T const*(RepositoryInfo const&)> const&
+                               getter) const noexcept -> T const* {
+        if (auto const* info = Info(repo)) {
+            try {  // satisfy clang-tidy's bugprone-exception-escape
+                return getter(*info);
+            } catch (...) {
+            }
+        }
+        return nullptr;
+    }
+};
+
+#endif  // INCLUDED_SRC_BUILDTOOL_COMMON_REPOSITORY_CONFIG_HPP