1 files changed, 146 insertions, 0 deletions
diff --git a/src/lua_state.c b/src/lua_state.c
new file mode 100644
index 0000000..7e9dd18
--- /dev/null
+++ b/src/lua_state.c
@@ -0,0 +1,146 @@
+#include <lua.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "lua_state.h"
+#include "state.h"
+#include "str.h"
+
+lua_State *L = NULL;
+bool L_is_loaded = false;
+
+static void lua_path_push(const char *new_path) {
+	lua_getglobal(L, "package");
+	lua_getfield(L, -1, "path");
+
+	const char *current_path = lua_tostring(L, -1);
+	if (!current_path)
+		current_path = "";
+	lua_pop(L, 1);
+
+	lua_pushfstring(L, "%s;%s", current_path, new_path);
+	lua_setfield(L, -2, "path");
+
+	lua_pop(L, 1);
+}
+
+bool init_lua_state(void) {
+	if (L_is_loaded)
+		return true;
+
+	L = luaL_newstate();
+	luaL_openlibs(L);
+
+	str lua_path = str_format("%.*s/?.lua", str_fmt(&config.dir));
+	lua_path_push(lua_path.data);
+
+	if (luaL_loadfile(L, config.init_path.data) || lua_pcall(L, 0, 1, 0)) {
+		log_error("cannot run configuration script: %s", lua_tostring(L, -1));
+		log_pkgit("to generate a configuration file, head into the");
+		log_pkgit(
+			"root directory of the pkgit source and run `make defconfig`");
+		lua_close(L);
+		return false;
+	}
+
+	if (!lua_istable(L, -1)) {
+		log_error("top-level configuration is not a table");
+		lua_pop(L, 1);
+		lua_close(L);
+		return false;
+	}
+
+	str_free(&lua_path);
+	L_is_loaded = true;
+	return true;
+}
+
+static void setup_base_dirs(void) {
+	int uid = getuid(), euid = geteuid();
+
+	config.is_root = false;
+
+	if (uid < 0 || uid != euid) {
+		config.is_root = true;
+		config.dir = mstr("/etc/pkgit");
+	} else {
+		char *tmp = getenv("XDG_CONFIG_HOME");
+		if (tmp) {
+			config.dir = str_format("%s/pkgit", tmp);
+		} else {
+			config.dir = str_format("%s/.config/pkgit", getenv("HOME"));
+		}
+	}
+
+	config.init_path = str_concat_cstr(&config.dir, "/init.lua");
+	config.autogenerated_path =
+		str_concat_cstr(&config.dir, "/autogenerated.lua");
+}
+
+#define HANDLE_LUA_ERROR                                                       \
+	do {                                                                       \
+		log_error("lua: %s", lua_tostring(L, -1));                             \
+		lua_pop(L, 1);                                                         \
+		return false;                                                          \
+	} while (0)
+
+#define lua_get_field_type(name, type, file)                                   \
+	do {                                                                       \
+		lua_getfield(L, -1, name);                                             \
+		if (!lua_is##type(L, -1)) {                                            \
+			log_error("lua: expected type " #type " for " name " in %.*s",     \
+					  str_fmt(file));                                          \
+			lua_pop(L, 1);                                                     \
+			return false;                                                      \
+		}                                                                      \
+	} while (0)
+
+static bool load_init_lua(void) {
+	if (luaL_loadfile(L, config.init_path.data))
+		HANDLE_LUA_ERROR;
+
+	lua_setglobal(L, "__PkgitUserConfig");
+
+	lua_getglobal(L, "__PkgitUserConfig");
+	lua_get_field_type("dirs", table, &config.init_path);
+
+#define X(field)                                                               \
+	do {                                                                       \
+		lua_get_field_type(#field, string, &config.init_path);                 \
+		config.inst_dirs.field = str_adopt((char *)lua_tostring(L, -1));       \
+		lua_pop(L, -1);                                                        \
+	} while (0)
+
+	X(prefix);
+	X(bin);
+	X(include);
+	X(lib);
+	X(src);
+
+#undef X
+
+	lua_getfield(L, -1, "prefix");
+
+	return true;
+}
+
+bool init_lua_config(void) {
+	if (!init_lua_state())
+		return false;
+
+	setup_base_dirs();
+
+	if (!load_init_lua())
+		return false;
+
+	return true;
+}
+
+void free_lua_state(void) {
+	if (L != NULL) {
+		lua_close(L);
+		L = NULL;
+	}
+	L_is_loaded = false;
+}