defer

Author: takev

src/utility/defer.hpp

@@ -0,0 +1,32 @@
+
+
+#pragma once
+
+#include <concepts>
+#include <functional>
+
+namespace hk {
+
+class defer {
+public:
+    ~defer()
+    {
+        if (_f) {
+            _f();
+        }
+    }
+
+    [[nodiscard]] defer(std::function<void()> && arg) : _f(std::move(arg)) {}
+    [[nodiscard]] defer(std::function<void()> const& arg) : _f(arg) {}
+
+    void cancel()
+    {
+        _f = nullptr;
+    }
+
+private:
+    std::function<void()> _f;
+};
+
+
+}

src/utility/git.cpp

@@ -1,5 +1,6 @@
 
 #include "git.hpp"
+#include "defer.hpp"
 #include <git2.h>
 #include <mutex>
 #include <format>
@@ -159,13 +160,84 @@ class git_lib {
     return r;
 }
 
-//[[nodiscard]] std::expected<git_oid, git_error> git_hash(std::string const& url, std::string const& branch)
-//{
-//
-//}
+/** Check if one of the remote has the correct branch checked out.
+ * 
+ * @param repository The repository to check all the remotes
+ * @param branch The branch to compare.
+ * @retval true The correct branch was checked out.
+ * @retval false Another branch was checked out.
+ * @retval error An error during query.
+ */
+[[nodiscard]] std::expected<bool, git_error> repository_matches_branch(::git_repository *repository, std::string const& branch)
+{
+
+}
+
+/** Check if one of the remote has a url that matches the given url.
+ * 
+ * @param repository The repository to check all the remotes
+ * @param url The url to compare.
+ * @retval true The url is a remote of the @a repository.
+ * @retval false None of the remotes match.
+ * @retval error An error during query.
+ */
+[[nodiscard]] std::expected<bool, git_error> repository_matches_url(::git_repository *repository, std::string const& url)
+{
+    assert(repository != nullptr);
+
+    auto remote_names = ::git_strarray{};
+    if (auto const result = ::git_remote_list(&remote_names, repository); result != GIT_OK) {
+        return std::unexpected{make_git_error(result)};
+    }
+    auto const _ = defer{[&]{ ::git_strarray_dispose(&remote_names); }};
+
+    for (auto i = 0uz; i != remote_names.count; ++i) {
+        ::git_remote *remote = nullptr;
+        if (auto const result = ::git_remote_lookup(&remote, repository, remote_names.strings[i]); result != GIT_OK) {
+            return std::unexpected{make_git_error(result)};
+        }
+        auto const _ = defer{[&]{ ::git_remote_free(remote); }};
+
+        auto const remote_url = ::git_remote_url(remote);
+        if (remote_url and url == remote_url) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+[[nodiscard]] git_error git_fetch_and_update(std::string const& url, std::string const& branch, std::filesystem::path path, git_checkout_flags flags)
+{
+    auto const& _ = git_lib_initialize();
+
+    auto r = git_error::ok;
+
+    ::git_repository *repository = nullptr;
+    if (auto const result = ::git_repository_open(&repository, url.c_str()); result != GIT_OK) {
+        return make_git_error(result);
+    }
+    auto const d1 = defer{[&]{ ::git_repository_free(repository); }};
+
+    if (auto result = repository_matches_url(repository, url)) {
+        if (not *result) {
+            std::print("The repository at {}, does not have a remote with the url {}", path.string(), url);
+            return git_error::remote_url_mismatch;
+        }
+    } else {
+        return result.error();
+    }
+
+    if (auto result = repository_matches_branch(repository, branch)) {
+
+    }
+}
 
 [[nodiscard]] git_error git_clone(std::string const& url, std::string const& branch, std::filesystem::path path)
 {
+    auto const& _ = git_lib_initialize();
+
+
     auto force_checkout = false;
 
     auto ref_list = git_references{};

src/utility/git.hpp

@@ -50,6 +50,10 @@ enum class git_error {
     unchanged,
     not_supported,
     read_only,
+
+    /** The repository does have a remote that matches the expected URL. 
+     */
+    remote_url_mismatch,
 };
 
 enum class git_checkout_flags {
@@ -85,6 +89,16 @@ struct git_reference {
     {
         return lhs.name <=> rhs.name;
     }
+
+    [[nodiscard]] constexpr bool is_branch() const noexcept
+    {
+        return name.starts_with("refs/heads/");
+    }
+
+    [[nodiscard]] constexpr bool is_tag() const noexcept
+    {
+        return name.starts_with("ref/tags/");
+    }
 };
 
 class git_references : public std::vector<git_reference> {
@@ -121,7 +135,16 @@ class git_references : public std::vector<git_reference> {
 
 [[nodiscard]] git_error git_clone(std::string const& url, std::string const& branch, std::filesystem::path path);
 
-[[nodiscard]] git_error git_checkout(std::filesystem::path path);
+/** This function will open the repository and update to the latest version.
+ * 
+ * @param url The remote url, used to check if the repository at the path
+ *            has the same remote url.
+ * @param branch The branch to checkout. If the repository is of a different
+ *               branch this branch is checked out, and the repository is cleaned.
+ * @param path The path where the repository is located.
+ * @param flags Flags for the way the repository should be checked out.
+ */
+[[nodiscard]] git_error git_fetch_and_update(std::string const& url, std::string const& branch, std::filesystem::path path, git_checkout_flags flags);
 
 /** Checkout or clone the repository.
  *