local enet = require"enet"
local json = require"common.dkjson"
local chunk = require"common.chunk"
local Chunk = require"common.chunk".Chunk
local noise = require"noise"
local coords = require"common.coords"
local worldgen = require"worldgen"
local MapS = require"map".MapS
local posix_time = require"posix.time"
math.randomseed(os.time())

local host = enet.host_create("*:8473")
print(host:get_socket_address())

-- sequential list of all players
local playerlist = {}
local nextid = 1

-- this is maybe suboptimal
-- but it is simplest for now
local function player_by_id(id)
	for i,pl in ipairs(playerlist) do
		if pl.id == id then return pl, i end
	end
	return nil
end
local function player_by_peer(peer)
	for i,pl in ipairs(playerlist) do
		if pl.peer == peer then return pl, i end
	end
	return nil
end

local function random_color()
	return {math.random(),math.random(),math.random()}
end
local function make_player(peer)
	local p = {pos={0,0},color=random_color(),peer=peer,id=nextid}
	nextid = nextid + 1
	return p
end

local function player_info_part(player)
	return {
		id=player.id,
		x=player.pos[1],
		y=player.pos[2],
		color=player.color,
	}
end
local function player_join_packet(player)
	return json.encode{t="join",pl=player_info_part(player)}
end
local function player_you_packet(player)
	return json.encode{t="you",pl=player_info_part(player)}
end
local function player_leave_packet(player)
	return json.encode{t="leave",id=player.id}
end
local function player_move_packet(player,x,y)
	return json.encode{t="move",id=player.id,x=x,y=y}
end

local map = MapS:make()

local function handle_ev(ev)
	-- handle network event
	if ev.type == "connect" then
		local player = make_player(ev.peer)
		table.insert(playerlist,player)
		print("connect",player.peer,player.id)
		player.peer:send(player_you_packet(player))
		local central_chunk = map:obtain(coords.ChunkPos:make(0,0))
		player.peer:send(central_chunk:data_packet())

		for i,otherplayer in ipairs(playerlist) do
			if otherplayer ~= player then
				-- tell new player about each other player
				player.peer:send(player_join_packet(otherplayer))
				-- tell each other player about new player
				otherplayer.peer:send(player_join_packet(player))
			end
		end
	elseif ev.type == "disconnect" then
		local player, idx = player_by_peer(ev.peer)
		if not player then error("sneeze "..ev.peer) end
		print("disconnect",player.peer,player.id)
		table.remove(playerlist,idx)
		for i,otherplayer in ipairs(playerlist) do
			otherplayer.peer:send(player_leave_packet(player))
		end
	elseif ev.type == "receive" then
		local player = player_by_peer(ev.peer)
		if not player then error("sneezey "..ev.peer) end
		local j = json.decode(ev.data)
		local op = j.t
		if op == "ppos" then
			local x,y = j.x,j.y
			player.pos[1] = x
			player.pos[2] = y
			-- print(player.id,"-->",player.pos[1],player.pos[2])
			for i,otherplayer in ipairs(playerlist) do
				if otherplayer ~= player then
					otherplayer.peer:send(player_move_packet(player,x,y))
				end
			end
		elseif op == "settile" then
			local h = coords.Hex:make(j.q,j.r)
			map:set_at(h,j.tile)
			-- print(player.id,"settile",h,j.tile)
			for i,otherplayer in ipairs(playerlist) do
				if otherplayer ~= player then
					-- same packet structure s2c as c2s
					-- when multiple chunks exist and players only get info
					-- about stuff near to them, that won't be the case any more
					otherplayer.peer:send(ev.data)
				end
			end
		elseif op == "reqchunk" then
			-- i am not certain this is the best way for this to work
			-- i might change it later
			local cp = coords.ChunkPos:make(j.u,j.v)
			local ch = map:obtain(cp)
			player.peer:send(ch:data_packet())
		end
	end
end

local function timenow()
	-- monotonic clock, guaranteed to never go backwards
	local tv = posix_time.clock_gettime(posix_time.CLOCK_MONOTONIC)
	-- this discards some precision but i don't care
	return tv.tv_sec + (tv.tv_nsec/1000000000)
end
-- do something only every x seconds
-- returns function(dt) -> bool
-- which returns true if you should, and false otherwise
local function every(interval)
	local time_since = interval+100
	return function(dt)
		time_since = time_since + dt
		if time_since > interval then
			time_since = 0
			return true
		else
			return false
		end
	end
end

local tick_interval = 1 -- seconds
local last_tick_time = timenow()

-- average tps calculation
local dts = {}
local ndt = 1
local ndts = 100
local ntick = 0


local function tick(ntick)
	if ntick % 30 == 0 then
		print("saving things...")
	end
end

while true do
	local now = timenow()
	local dt = now - last_tick_time

	if dt >= tick_interval then
		dts[ndt] = dt
		ndt = 1+(ndt%ndts)
		last_tick_time = now
		ntick = ntick + 1

		tick(ntick)

		local tps = 0
		for _,d in ipairs(dts) do tps = tps + 1/d end
		tps = tps/#dts


		print(ndt,ndts)
		if 1 == ndt%ndts then
			print("tps",tps)
		end
	end

	local now2 = timenow()
	local time_till_next_tick = (last_tick_time+tick_interval)-now2
	if time_till_next_tick > 0 then
		local ev = host:service(time_till_next_tick/1000)
		if ev then handle_ev(ev) end
	end
end