Add an utility to list all installed packages

1 files changed, 76 insertions, 0 deletions

diff --git a/src/package.cpp b/src/package.cpp
new file mode 100644
index 0000000..0734a5e
--- /dev/null
+++ b/src/package.cpp
@@ -0,0 +1,76 @@
+#include "package.h"
+#include <filesystem>
+
+namespace katja
+{
+    package::package(const std::string& name, const std::string& version,
+        const std::string& architecture, const std::string& tag)
+        : m_name(name), m_version(version), m_architecture(architecture), m_tag(tag)
+    {
+    }
+
+    const std::string& package::name() const noexcept
+    {
+        return m_name;
+    }
+
+    const std::string& package::version() const noexcept
+    {
+        return m_version;
+    }
+
+    const std::string& package::architecture() const noexcept
+    {
+        return m_architecture;
+    }
+
+    const std::string& package::tag() const noexcept
+    {
+        return m_tag;
+    }
+
+    std::optional<package> package::parse(const std::string& full_name) noexcept
+    {
+        std::size_t tag_separator = full_name.find_last_of('-');
+
+        if (tag_separator == std::string::npos || tag_separator == 0)
+        {
+            return std::nullopt;
+        }
+        std::size_t architecture_separator = full_name.find_last_of('-', tag_separator - 1);
+
+        if (architecture_separator == std::string::npos || architecture_separator == 0)
+        {
+            return std::nullopt;
+        }
+        std::size_t version_separator = full_name.find_last_of('-', architecture_separator - 1);
+
+        if (version_separator == std::string::npos || version_separator == 0)
+        {
+            return std::nullopt;
+        }
+        package parsed_package{
+            full_name.substr(0, version_separator),
+            full_name.substr(version_separator + 1, architecture_separator - version_separator - 1),
+            full_name.substr(architecture_separator + 1, tag_separator - architecture_separator - 1),
+            full_name.substr(tag_separator + 1)
+        };
+        return std::make_optional(parsed_package);
+    }
+
+    std::unordered_map<std::string, package> read_package_database()
+    {
+        std::unordered_map<std::string, package> packages;
+
+        for (const auto& entry : std::filesystem::directory_iterator("/var/lib/pkgtools/packages"))
+        {
+            std::optional<package> maybe_package = package::parse(entry.path().filename());
+
+            if (maybe_package.has_value())
+            {
+                packages.insert_or_assign(maybe_package.value().name(), maybe_package.value());
+            }
+        }
+        return packages;
+    }
+}