Config command

cli/BUILD.bazel

@@ -10,6 +10,7 @@ cc_binary(
     deps = [
         "//cli/commands:codegen",
         "//cli/commands:command",
+        "//cli/commands:config",
     ],
 )
 

cli/cli.cc

@@ -5,6 +5,7 @@
 
 #include "./commands/command.hh"
 #include "./commands/codegen.hh"
+#include "./commands/config.hh"
 
 namespace fs = std::filesystem;
 
@@ -24,6 +25,7 @@ int main(int argc, char* argv[]) {
 
 	const std::unordered_map<std::string, command_fn_t> commands{
 		{"codegen", &ecsact::cli::detail::codegen_command},
+		{"config", &ecsact::cli::detail::config_command},
 	};
 
 	for(int i=1; argc > i; ++i) {

cli/commands/BUILD.bazel

@@ -26,3 +26,15 @@ cc_library(
         "@ecsact_runtime//:meta",
     ],
 )
+
+cc_library(
+    name = "config",
+    srcs = ["config.cc"],
+    hdrs = ["config.hh"],
+    copts = copts,
+    deps = [
+        ":command",
+        "//executable_path",
+        "@bazelregistry_docopt_cpp//:docopt",
+    ],
+)

cli/commands/config.cc

@@ -0,0 +1,124 @@
+#include "./config.hh"
+
+#include <iostream>
+#include <filesystem>
+#include <map>
+#include <string>
+#include "docopt.h"
+
+#include "executable_path/executable_path.hh"
+
+namespace fs = std::filesystem;
+
+constexpr auto USAGE = R"(Ecsact Config Command
+
+Usage:
+	ecsact config [--include_dir] [--plugin_dir] [--builtin_plugins]
+
+Options:
+	--include_dir
+		Prints the include directory containing Ecsact headers.
+	--plugin_dir
+		Prints the directory containing all built-in Ecsact codegen plugins.
+	--builtin_plugins
+		Prints a list of built-in Ecsact codegen plugins available.
+)";
+
+constexpr auto CANNOT_FIND_INCLUDE_DIR = R"(
+[ERROR] Cannot find Ecsact include directory.
+	Expected include directory next to bin directory. Make sure you're using a
+	standard Ecsact SDK installation.
+	If you believe this is a mistake please file an issue at
+	https://github.com/ecsact-dev/ecsact_sdk/issues
+)";
+
+constexpr auto CANNOT_FIND_PLUGIN_DIR = R"(
+[ERROR] Cannot find Ecsact built-in plugin directory.
+	Make sure you're using a standard Ecsact SDK installation.
+	If you believe this is a mistake please file an issue at
+	https://github.com/ecsact-dev/ecsact_sdk/issues
+)";
+
+int ecsact::cli::detail::config_command(int argc, char* argv[]) {
+	using namespace std::string_literals;
+	using executable_path::executable_path;
+
+	auto args = docopt::docopt(USAGE, {argv + 1, argv + argc});
+	auto exec_path = executable_path();
+	if(exec_path.empty()) {
+		exec_path = fs::path{argv[0]};
+		std::error_code ec;
+		exec_path = fs::canonical(exec_path, ec);
+		if(ec) {
+			exec_path = fs::weakly_canonical(fs::path{argv[0]});
+		}
+	}
+
+	auto install_prefix = exec_path.parent_path().parent_path();
+	auto plugin_dir = install_prefix / "share" / "ecsact" / "plugins";
+	std::map<std::string, std::string> output;
+
+	if(args.at("--include_dir").asBool()) {
+		auto includedir = install_prefix / "include";
+		auto core_hdr = includedir / "ecsact" / "runtime" / "core.h";
+
+		if(fs::exists(core_hdr)) {
+			output["include_dir"] = includedir.string();
+		} else {
+			std::cerr << CANNOT_FIND_INCLUDE_DIR;
+			return 1;
+		}
+	}
+
+	if(args.at("--plugin_dir").asBool()) {
+		if(fs::exists(plugin_dir)) {
+			output["plugin_dir"] = plugin_dir.string();
+		} else {
+			std::cerr << CANNOT_FIND_PLUGIN_DIR;
+			return 1;
+		}
+	}
+
+	if(args.at("--builtin_plugins").asBool()) {
+		if(fs::exists(plugin_dir)) {
+			auto& builtin_plugins_str = output["builtin_plugins"];
+			std::vector<std::string> builtin_plugins;
+			for(auto& entry : fs::directory_iterator(plugin_dir)) {
+				auto filename = entry.path().filename().replace_extension("").string();
+				const auto prefix = "ecsact_"s;
+				const auto suffix = "_codegen"s;
+				if(filename.starts_with(prefix) && filename.ends_with(suffix)) {
+					builtin_plugins.emplace_back() = filename.substr(
+						prefix.size(),
+						filename.size() - prefix.size() - suffix.size()
+					);
+				}
+			}
+
+			if(!builtin_plugins.empty()) {
+				auto& builtin_plugins_str = output["builtin_plugins"];
+				for(auto i=0; builtin_plugins.size() - 1 > i; ++i) {
+					builtin_plugins_str += builtin_plugins[i] + "\n";
+				}
+				builtin_plugins_str += builtin_plugins.back();
+			}
+		} else {
+			std::cerr << CANNOT_FIND_PLUGIN_DIR;
+			return 1;
+		}
+	}
+
+	if(output.empty()) {
+		return 1;
+	}
+
+	if(output.size() == 1) {
+		std::cout << output.begin()->second << "\n";
+	} else {
+		for(auto&& [key, value] : output) {
+			std::cout << key << ": " << value << "\n";
+		}
+	}
+
+	return 0;
+}

cli/commands/config.hh

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <type_traits>
+
+#include "./command.hh"
+
+namespace ecsact::cli::detail {
+	int config_command(int argc, char* argv[]);
+	static_assert(std::is_same_v<command_fn_t, decltype(&config_command)>);
+}