#include <stdio.h>
#include <sys/epoll.h>
#include <unistd.h>

#include <lua.h>

#include "plop.h"

/// Prints program usage to standard error.
/// \param name Name of the executable from argv
static void usage(const char * const name)
{
	dprintf(2,
		"Usage: %s [-p PORT] [-h] [HANDLER]\n"
		"Starts plop server listening on PORT and serving HANDLER.\n"
		"HANDLER defaults to '" PLOP_DEFAULT_HANDLER "'.\n\n"
		"  -p\tstart listening on PORT (default: 8080)\n"
		"  -h\tprints this help message\n",
		name);
}

/// Standard entry point for the program.
/// \param argc Argument count
/// \param argv Argument array
/// \return Error code
int main(int argc, char ** argv)
{
	const char * service = "8080";
	int opt;

	while (-1 != (opt = getopt(argc, argv, "p:h")))
	{
		switch (opt)
		{
			case 'p':
			{
				service = optarg;
				break;
			}
			case 'h':
			{
				usage(argv[0]);
				return 0;
			}
			default:
			{
				usage(argv[0]);
				return 1; // TODO: Extend error handling in main().
			}
		}
	}

	const char * handler_path = PLOP_DEFAULT_HANDLER;

	if (optind < argc)
	{
		handler_path = argv[optind];
	}

	lua_State * L = plop_initialize_lua();

	if (NULL == L)
	{
		return 9;
	}

	if (LUA_OK != plop_load_handler(L, handler_path))
	{
		return 2;
	}

	const int efd = epoll_create1(0);

	if (-1 == efd)
	{
		return 3;
	}

	struct epoll_event e;
	e.events = EPOLLIN;
	e.data.ptr = NULL; // TODO: Consider putting server's Lua state in here?
	const int server = plop_make_server(NULL, service); // TODO: Check server's fd before ctl?

	if (-1 == epoll_ctl(efd, EPOLL_CTL_ADD, server, &e))
	{
		return 4;
	}

	static const int MAX_EVENTS = 20;
	struct epoll_event events[MAX_EVENTS];

	while (1)
	{
		int evc = epoll_wait(efd, events, MAX_EVENTS, -1);

		if (-1 == evc)
		{
			return 5;
		}

		for (int i = 0; i < evc; ++i)
		{
			if (NULL == events[i].data.ptr)
			{
				if (-1 == plop_handle_server(L, efd, server))
				{
					return 6;
				}
			}
			else
			{
				if (-1 == plop_handle_client(L, &events[i]))
				{
					return 7;
				}
			}
		}
	}
}