//###########################################################################
// btl4lobby -- the Steam lobby (BT_STEAM only; compiled only when the gate
// is on -- see CMakeLists.txt).  Design: btl4lobby.hpp.
//###########################################################################

#include "btl4lobby.hpp"

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#pragma pack(push, 8)
#include "steam/steam_api.h"
#include "steam/isteammatchmaking.h"
#pragma pack(pop)

//
// The engine-side transport surface (munga_engine).
//
extern int BTSteamNet_Install();
extern int BTSteamNet_Active();
extern unsigned long long BTSteamNet_MySteamID();

static FILE *lobbyLogFile = NULL;
static void
	LobbyLog(const char *format, ...)
{
	if (lobbyLogFile == NULL)
	{
		lobbyLogFile = fopen("marshal.log", "at");	// shares the marshal's file
		if (lobbyLogFile == NULL)
		{
			return;
		}
	}
	va_list arguments;
	va_start(arguments, format);
	fprintf(lobbyLogFile, "[lobby] ");
	vfprintf(lobbyLogFile, format, arguments);
	fprintf(lobbyLogFile, "\n");
	fflush(lobbyLogFile);
	va_end(arguments);
}
#include <stdarg.h>

//###########################################################################
// Synchronous Steam call-result helper (manual polling -- no callback
// template machinery in this C-style TU).
//###########################################################################

static int
	WaitApiCall(SteamAPICall_t call, void *result, int result_size,
		int expected_callback_id, int timeout_ms)
{
	ISteamUtils *utils = SteamUtils();
	for (int waited = 0; waited < timeout_ms; waited += 50)
	{
		SteamAPI_RunCallbacks();
		bool failed = false;
		if (utils->IsAPICallCompleted(call, &failed))
		{
			if (failed)
			{
				return -1;
			}
			return utils->GetAPICallResult(call, result, result_size,
				expected_callback_id, &failed) && !failed ? 0 : -1;
		}
		Sleep(50);
	}
	return -1;
}

//###########################################################################
// Member data
//###########################################################################

static CSteamID currentLobby;

static void
	PublishSelf(const char *pilot_name, const char *vehicle, const char *color)
{
	//
	// Identity is implicit (the member's SteamID); the roster TOKENS are
	// minted by the host at GO time -- only the pilot identity publishes.
	//
	ISteamMatchmaking *matchmaking = SteamMatchmaking();
	matchmaking->SetLobbyMemberData(currentLobby, "nm", pilot_name);
	matchmaking->SetLobbyMemberData(currentLobby, "vh", vehicle);
	matchmaking->SetLobbyMemberData(currentLobby, "cl", color);
}

static int
	ReadMember(CSteamID lobby, int index, BTLobbyMember *out)
{
	ISteamMatchmaking *matchmaking = SteamMatchmaking();
	CSteamID member = matchmaking->GetLobbyMemberByIndex(lobby, index);
	const char *published_name = matchmaking->GetLobbyMemberData(lobby, member, "nm");
	if (published_name == NULL || published_name[0] == 0)
	{
		return -1;					// not published yet
	}
	memset(out, 0, sizeof(*out));
	out->steamID = member.ConvertToUint64();
	out->consolePort = 1501;		// token ports (see L4STEAMNET token table)
	out->gamePort    = 1502;
	strncpy(out->name,
		matchmaking->GetLobbyMemberData(lobby, member, "nm"),
		sizeof(out->name) - 1);
	strncpy(out->vehicle,
		matchmaking->GetLobbyMemberData(lobby, member, "vh"),
		sizeof(out->vehicle) - 1);
	strncpy(out->color,
		matchmaking->GetLobbyMemberData(lobby, member, "cl"),
		sizeof(out->color) - 1);
	out->isSelf = (member == SteamUser()->GetSteamID());
	if (out->name[0] == 0)
	{
		strcpy(out->name, "Pilot");
	}
	return 0;
}

//###########################################################################
// The room screen -- the FE's green-on-black style; lists members, host
// ENTER = GO, ESC = cancel.
//###########################################################################

static int  roomIsHost = 0;
static int  roomResult = 0;			// 0 pending, 1 go, -1 cancel

static void
	PaintRoom(HWND window)
{
	PAINTSTRUCT paint;
	HDC dc = BeginPaint(window, &paint);
	RECT client;
	GetClientRect(window, &client);
	HBRUSH background = CreateSolidBrush(RGB(4, 12, 4));
	FillRect(dc, &client, background);
	DeleteObject(background);
	SetBkMode(dc, TRANSPARENT);

	HFONT font = CreateFontW(-16, 0, 0, 0, FW_NORMAL, 0, 0, 0,
		DEFAULT_CHARSET, 0, 0, CLEARTYPE_QUALITY, FIXED_PITCH, L"Consolas");
	HFONT old_font = (HFONT)SelectObject(dc, font);
	SetTextColor(dc, RGB(90, 255, 90));

	WCHAR line[160];
	int y = 16;
	wsprintfW(line, L"STEAM LOBBY  --  %s",
		roomIsHost ? L"HOSTING (ENTER = launch, ESC = cancel)"
		           : L"WAITING FOR THE HOST (ESC = leave)");
	RECT row = { 24, y, client.right - 24, y + 24 };
	DrawTextW(dc, line, -1, &row, DT_LEFT | DT_TOP | DT_SINGLELINE);
	y += 40;

	ISteamMatchmaking *matchmaking = SteamMatchmaking();
	int count = matchmaking->GetNumLobbyMembers(currentLobby);
	for (int i = 0; i < count && i < 8; ++i)
	{
		BTLobbyMember member;
		WCHAR name[120];
		if (ReadMember(currentLobby, i, &member) == 0)
		{
			int n = 0;
			for (const char *s = member.name; *s && n < 60; ++s) name[n++] = (WCHAR)*s;
			name[n] = 0;
			wsprintfW(line, L"  %d. %s%s", i + 1, name,
				member.isSelf ? L"  (you)" : L"");
		}
		else
		{
			wsprintfW(line, L"  %d. (joining...)", i + 1);
		}
		RECT member_row = { 24, y, client.right - 24, y + 24 };
		DrawTextW(dc, line, -1, &member_row, DT_LEFT | DT_TOP | DT_SINGLELINE);
		y += 26;
	}

	SelectObject(dc, old_font);
	DeleteObject(font);
	EndPaint(window, &paint);
}

static LRESULT CALLBACK
	RoomWndProc(HWND window, UINT message, WPARAM wparam, LPARAM lparam)
{
	switch (message)
	{
	case WM_PAINT:
		PaintRoom(window);
		return 0;
	case WM_TIMER:
		SteamAPI_RunCallbacks();
		//
		// Members leave when the host signals GO.
		//
		if (!roomIsHost)
		{
			const char *go = SteamMatchmaking()->GetLobbyData(currentLobby, "btl4go");
			if (go != NULL && go[0] == '1')
			{
				roomResult = 1;
			}
		}
		InvalidateRect(window, NULL, FALSE);
		return 0;
	case WM_KEYDOWN:
		if (wparam == VK_RETURN && roomIsHost)
		{
			roomResult = 1;
		}
		else if (wparam == VK_ESCAPE)
		{
			roomResult = -1;
		}
		return 0;
	case WM_CLOSE:
		roomResult = -1;
		return 0;
	}
	return DefWindowProcW(window, message, wparam, lparam);
}

static int
	RunRoom(int is_host)
{
	roomIsHost = is_host;
	roomResult = 0;

	WNDCLASSW window_class;
	memset(&window_class, 0, sizeof(window_class));
	window_class.lpfnWndProc   = RoomWndProc;
	window_class.hInstance     = GetModuleHandleW(NULL);
	window_class.hCursor       = LoadCursorW(NULL, (LPCWSTR)IDC_ARROW);
	window_class.lpszClassName = L"BTLobbyRoomWnd";
	RegisterClassW(&window_class);

	HWND window = CreateWindowW(
		L"BTLobbyRoomWnd", L"BattleTech - Steam Lobby",
		WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU,
		160, 160, 560, 360,
		NULL, NULL, GetModuleHandleW(NULL), NULL);
	if (window == NULL)
	{
		return -1;
	}
	SetTimer(window, 1, 250, NULL);
	ShowWindow(window, SW_SHOW);
	SetForegroundWindow(window);

	MSG message;
	while (roomResult == 0 && GetMessageW(&message, NULL, 0, 0))
	{
		TranslateMessage(&message);
		DispatchMessageW(&message);
	}
	KillTimer(window, 1);
	DestroyWindow(window);
	return (roomResult == 1) ? 0 : 1;
}

//###########################################################################
// Host / member entries
//###########################################################################

int
	BTLobby_HostAndRoom(
		const char *pilot_name, const char *vehicle, const char *color,
		BTLobbyRoster *roster_out,
		char *my_token_out, int my_token_capacity,
		char *steam_map_out, int steam_map_capacity)
{
	memset(roster_out, 0, sizeof(*roster_out));
	if (BTSteamNet_Install() != 0 || !BTSteamNet_Active())
	{
		LobbyLog("host: Steam transport unavailable");
		return -1;
	}

	SteamAPICall_t call = SteamMatchmaking()->CreateLobby(k_ELobbyTypePublic, 8);
	LobbyCreated_t created;
	memset(&created, 0, sizeof(created));
	if (WaitApiCall(call, &created, sizeof(created),
		LobbyCreated_t::k_iCallback, 15000) != 0 ||
		created.m_eResult != k_EResultOK)
	{
		LobbyLog("host: CreateLobby failed");
		return -1;
	}
	currentLobby = created.m_ulSteamIDLobby;
	SteamMatchmaking()->SetLobbyData(currentLobby, "btl4", "1");
	PublishSelf(pilot_name, vehicle, color);
	LobbyLog("host: lobby up (%llu)", (unsigned long long)created.m_ulSteamIDLobby);

	if (RunRoom(1) != 0)
	{
		SteamMatchmaking()->LeaveLobby(currentLobby);
		return 1;
	}

	//
	// GO: snapshot the roster SELF FIRST (the egg's pilot order defines
	// the connect topology; the host must be pilot 1), MINT the tokens,
	// publish the token map, then signal.
	//
	ISteamMatchmaking *matchmaking = SteamMatchmaking();
	int count = matchmaking->GetNumLobbyMembers(currentLobby);
	for (int pass = 0; pass < 2; ++pass)
	{
		for (int i = 0; i < count && roster_out->memberCount < 8; ++i)
		{
			BTLobbyMember member;
			if (ReadMember(currentLobby, i, &member) != 0)
			{
				continue;
			}
			if ((pass == 0) == (member.isSelf != 0))
			{
				roster_out->members[roster_out->memberCount++] = member;
			}
		}
	}
	steam_map_out[0] = 0;
	my_token_out[0] = 0;
	for (int m = 0; m < roster_out->memberCount; ++m)
	{
		BTLobbyMember &member = roster_out->members[m];
		sprintf(member.fakeAddress, "169.254.77.%d", m + 1);
		char entry[96];
		sprintf(entry, "%s%s=%llu", (m > 0) ? ";" : "",
			member.fakeAddress, member.steamID);
		if ((int)(strlen(steam_map_out) + strlen(entry) + 1)
			< steam_map_capacity)
		{
			strcat(steam_map_out, entry);
		}
		if (member.isSelf)
		{
			strncpy(my_token_out, member.fakeAddress, my_token_capacity - 1);
			my_token_out[my_token_capacity - 1] = 0;
		}
	}
	matchmaking->SetLobbyData(currentLobby, "btl4map", steam_map_out);
	matchmaking->SetLobbyData(currentLobby, "btl4go", "1");
	SteamAPI_RunCallbacks();
	LobbyLog("host: GO with %d member(s), map [%s]",
		roster_out->memberCount, steam_map_out);
	//
	// The lobby will not survive the relaunch (documented); leave now so
	// members do not see a ghost host.
	//
	Sleep(1500);					// let the GO propagate
	SteamMatchmaking()->LeaveLobby(currentLobby);
	return 0;
}

int
	BTLobby_JoinAndWait(
		const char *pilot_name, const char *vehicle, const char *color,
		char *my_token_out, int my_token_capacity,
		char *steam_map_out, int steam_map_capacity)
{
	if (BTSteamNet_Install() != 0 || !BTSteamNet_Active())
	{
		LobbyLog("join: Steam transport unavailable");
		return -1;
	}

	ISteamMatchmaking *matchmaking = SteamMatchmaking();
	matchmaking->AddRequestLobbyListStringFilter(
		"btl4", "1", k_ELobbyComparisonEqual);
	SteamAPICall_t call = matchmaking->RequestLobbyList();
	LobbyMatchList_t match_list;
	memset(&match_list, 0, sizeof(match_list));
	if (WaitApiCall(call, &match_list, sizeof(match_list),
		LobbyMatchList_t::k_iCallback, 15000) != 0 ||
		match_list.m_nLobbiesMatching == 0)
	{
		LobbyLog("join: no btl4 lobby found");
		return -1;
	}

	CSteamID lobby = matchmaking->GetLobbyByIndex(0);
	call = matchmaking->JoinLobby(lobby);
	LobbyEnter_t entered;
	memset(&entered, 0, sizeof(entered));
	if (WaitApiCall(call, &entered, sizeof(entered),
		LobbyEnter_t::k_iCallback, 15000) != 0 ||
		entered.m_EChatRoomEnterResponse != k_EChatRoomEnterResponseSuccess)
	{
		LobbyLog("join: JoinLobby failed");
		return -1;
	}
	currentLobby = lobby;
	PublishSelf(pilot_name, vehicle, color);
	LobbyLog("join: in lobby, waiting for GO");

	int result = RunRoom(0);
	if (result == 0)
	{
		//
		// GO: read the token map, find my own token by my SteamID.
		//
		const char *map_text = matchmaking->GetLobbyData(currentLobby, "btl4map");
		steam_map_out[0] = 0;
		my_token_out[0] = 0;
		if (map_text != NULL)
		{
			strncpy(steam_map_out, map_text, steam_map_capacity - 1);
			steam_map_out[steam_map_capacity - 1] = 0;
			char needle[32];
			sprintf(needle, "=%llu", BTSteamNet_MySteamID());
			char map_copy[512];
			strncpy(map_copy, map_text, sizeof(map_copy) - 1);
			map_copy[sizeof(map_copy) - 1] = 0;
			char *cursor = strtok(map_copy, ";");
			while (cursor != NULL)
			{
				char *hit = strstr(cursor, needle);
				if (hit != NULL && hit[strlen(needle)] == 0)
				{
					*hit = 0;
					strncpy(my_token_out, cursor, my_token_capacity - 1);
					my_token_out[my_token_capacity - 1] = 0;
				}
				cursor = strtok(NULL, ";");
			}
		}
		LobbyLog("join: my token [%s], map [%s]", my_token_out, steam_map_out);
		if (my_token_out[0] == 0)
		{
			result = -1;			// the host's map is missing us
		}
	}
	SteamMatchmaking()->LeaveLobby(currentLobby);
	return result;
}