From 7fc6a70725d54cf767a250a4c6b3f3fcc9eff85a Mon Sep 17 00:00:00 2001
From: Aki <please@ignore.pl>
Date: Fri, 8 May 2020 16:37:19 +0200
Subject: Response body is now handled by Lua

---
 default.lua |  6 ++++++
 http.c      | 10 ++++++----
 http.h      |  2 +-
 plop.c      | 24 ++++++++++++++++++++----
 4 files changed, 33 insertions(+), 9 deletions(-)
 create mode 100644 default.lua

diff --git a/default.lua b/default.lua
new file mode 100644
index 0000000..0f9aaf4
--- /dev/null
+++ b/default.lua
@@ -0,0 +1,6 @@
+--- Default client request handler.
+--- @param request string Unparsed request from the client
+--- @return string Body of the response
+function Handler (request)
+	return [["Hello, from plop/Lua"]]
+end
diff --git a/http.c b/http.c
index 7e886b4..a966121 100644
--- a/http.c
+++ b/http.c
@@ -34,21 +34,23 @@ int respond_only_status(const int fd, const enum status status)
 /// \param fd File descriptor of the client socket
 /// \param status HTTP response status code
 /// \param body Content that will be sent
+/// \param size Size of the content in bytes
 /// \return Negative value if an error was encountered; numbers of bytes written otherwise
-int respond_with_body(const int fd, const enum status status, const char * body)
+int respond_with_body(const int fd, const enum status status, const char * body, const int size)
 {
 	static const char * pattern =
 		"HTTP/1.1 %s\r\n"
 		"Connection: close\r\n"
-		"Content-Type: text/plain\r\n"
+		"Content-Type: application/json\r\n"
+		"Content-Size: %d\r\n"
 		"\r\n";
 
-	if (0 > dprintf(fd, pattern, status_str[status]))
+	if (0 > dprintf(fd, pattern, status_str[status], size))
 	{
 		return -1; // TODO: Handle errors properly
 	}
 
-	return write(fd, body, strlen(body));
+	return write(fd, body, size);
 }
 
 /// Collects request between calls to `poll`.
diff --git a/http.h b/http.h
index 14a4769..e0d7891 100644
--- a/http.h
+++ b/http.h
@@ -15,7 +15,7 @@ enum status
 extern const char * status_str[];
 
 int respond_only_status(int, enum status);
-int respond_with_body(int, enum status, const char *);
+int respond_with_body(int, enum status, const char *, int);
 int collect_request(int, char **);
 
 #endif // HTTP_H
diff --git a/plop.c b/plop.c
index fb62b01..d676c4f 100644
--- a/plop.c
+++ b/plop.c
@@ -73,12 +73,13 @@ int make_server(const char * node, const char * service)
 
 /// Progresses the connection for a client and shifts it back in the array.
 /// `pfd` must be at least `shift_by + 1`-th element of the array.
+/// \param L Server's Lua state
 /// \param pfd Element in array processed by poll
 /// \param data Pointer to data associated with the client
 /// \param shift_by Element will be moved by in array this many indices
 /// \return Shift value for next handler
 /// \see poll(2)
-int handle_client(struct pollfd * pfd, char ** data, const int shift_by)
+int handle_client(lua_State * L, struct pollfd * pfd, char ** data, const int shift_by)
 {
 	if (0 == pfd->revents)
 	{
@@ -95,7 +96,17 @@ int handle_client(struct pollfd * pfd, char ** data, const int shift_by)
 		return -1; // TODO: Handle errors properly
 	}
 
-	respond_with_body(pfd->fd, STATUS_OK, *data);
+	lua_getglobal(L, "Handler");
+	lua_pushstring(L, *data);
+	lua_call(L, 1, 1);
+
+	size_t length;
+	const char * body = lua_tolstring(L, -1, &length);
+
+	if (NULL != body)
+	{
+		respond_with_body(pfd->fd, STATUS_OK, body, (int) length);
+	}
 
 	close(pfd->fd);
 	(pfd - shift_by)->fd = -1;
@@ -111,7 +122,7 @@ int handle_client(struct pollfd * pfd, char ** data, const int shift_by)
 /// \param fdv Array of descriptors for poll
 /// \param fdc Number of valid descriptors in the array including the server
 /// \param size Size limit for the array
-/// \param Number of valid descriptors in the array or -1 if an error occurred.
+/// \return Number of valid descriptors in the array or -1 if an error occurred.
 /// \see poll(2)
 int handle_server(struct pollfd * fdv, int fdc, const int size)
 {
@@ -143,6 +154,11 @@ int main(int argc, char ** argv)
 	lua_State * L = luaL_newstate();
 	luaL_openlibs(L);
 
+	if (LUA_OK != luaL_dofile(L, "default.lua"))
+	{
+		return 2; // TODO: Document error codes/print usage information
+	}
+
 	if (2 != argc)
 	{
 		return 1; // TODO: Document error codes/print usage information
@@ -167,7 +183,7 @@ int main(int argc, char ** argv)
 
 		for (int i = 1; i < fdc; ++i)
 		{
-			shift_by = handle_client(&fdv[i], &data[i], shift_by);
+			shift_by = handle_client(L, &fdv[i], &data[i], shift_by);
 		}
 
 		fdc = handle_server(fdv, fdc - shift_by, max_clients);
-- 
cgit v1.1