Add configuration from toml file

src/config.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <chrono>
+#include <optional>
+#include <string>
+
+namespace weaseldb {
+
+struct ServerConfig {
+  std::string bind_address = "127.0.0.1";
+  int port = 8080;
+  size_t max_request_size_bytes =
+      1024 * 1024; // 1MB default for 413 Content Too Large
+};
+
+struct CommitConfig {
+  size_t min_request_id_length = 20; // Minimum length for request_id entropy
+  std::chrono::hours request_id_retention_time{
+      24}; // How long to keep request IDs
+  size_t request_id_retention_versions =
+      100000000; // Min versions to retain request IDs
+};
+
+struct SubscriptionConfig {
+  size_t max_buffer_size_bytes =
+      10 * 1024 * 1024; // 10MB buffer for unconsumed data
+  std::chrono::seconds keepalive_interval{30}; // Keepalive comment frequency
+};
+
+struct Config {
+  ServerConfig server;
+  CommitConfig commit;
+  SubscriptionConfig subscription;
+};
+
+class ConfigParser {
+public:
+  static std::optional<Config> load_from_file(const std::string &file_path);
+  static std::optional<Config>
+  parse_toml_string(const std::string &toml_content);
+
+private:
+  static void parse_server_config(const auto &toml_data, ServerConfig &config);
+  static void parse_commit_config(const auto &toml_data, CommitConfig &config);
+  static void parse_subscription_config(const auto &toml_data,
+                                        SubscriptionConfig &config);
+};
+
+} // namespace weaseldb