--[[
Advanced Trains - Minetest Mod

Copyright (C) 2016-2020  Moritz Blei (orwell96) and contributors

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

]]

local lot = os.clock()
minetest.log("action", "[advtrains] Loading...")

-- There is no need to support 0.4.x anymore given that the compatitability with it is already broken by 1bb1d825f46af3562554c12fba35a31b9f7973ff
attrans = minetest.get_translator ("advtrains")

--advtrains

DUMP_DEBUG_SAVE = false
GENERATE_ATRICIFIAL_LAG = false

--Constant for maximum connection value/division of the circle
AT_CMAX = 16

advtrains = {trains={}, player_to_train_mapping={}}

-- get wagon loading range
advtrains.wagon_load_range = tonumber(minetest.settings:get("advtrains_wagon_load_range"))
if not advtrains.wagon_load_range then
	advtrains.wagon_load_range = tonumber(minetest.settings:get("active_block_range"))*16
end

--pcall
local no_action=false

local function reload_saves()
	atwarn("Restoring saved state in 1 second...")
	no_action=true
	advtrains.lock_path_inval = false
	--read last save state and continue, as if server was restarted
	for aoi, le in pairs(minetest.luaentities) do
		if le.is_wagon then
			le.object:remove()
		end
	end
	minetest.after(1, function()
		advtrains.load()
		atwarn("Reload successful!")
		advtrains.ndb.restore_all()
	end)
end

function advtrains.pcall(fun)
	if no_action then return end
	
	local succ, return1, return2, return3, return4=xpcall(fun, function(err)
			atwarn("Lua Error occured: ", err)
			atwarn(debug.traceback())
			if advtrains.atprint_context_tid then
				advtrains.path_print(advtrains.trains[advtrains.atprint_context_tid], atdebug)
				atwarn(advtrains.trains[advtrains.atprint_context_tid].debug)
			end
		end)
	if not succ then
		reload_saves()
	else
		return return1, return2, return3, return4
	end
end


advtrains.modpath = minetest.get_modpath("advtrains")

--Advtrains dump (special treatment of pos and sigd)
function atdump(t, intend)
	local str
	if type(t)=="table" then
		if t.x and t.y and t.z then
			str=minetest.pos_to_string(t)
		elseif t.p and t.s then -- interlocking sigd
			str="S["..minetest.pos_to_string(t.p).."/"..t.s.."]"
		elseif advtrains.lines and t.s and t.m then -- RwT
			str=advtrains.lines.rwt.to_string(t)
		else
			str="{"
			local intd = (intend or "") .. "  "
			for k,v in pairs(t) do
				if type(k)~="string" or not string.match(k, "^path[_]?") then
					-- do not print anything path-related
					str = str .. "\n" .. intd .. atdump(k, intd) .. " = " ..atdump(v, intd)
				end
			end
			str = str .. "\n" .. (intend or "") .. "}"
		end
	elseif type(t)=="boolean" then
		if t then
			str="true"
		else
			str="false"
		end
	elseif type(t)=="function" then
		str="<function>"
	elseif type(t)=="userdata" then
		str="<userdata>"
	else
		str=""..t
	end
	return str
end

function advtrains.print_concat_table(a)
	local str=""
	local stra=""
	local t
	for i=1,20 do
		t=a[i]
		if t==nil then
			stra=stra.."nil "
		else
			str=str..stra
			stra=""
			str=str..atdump(t).." "
		end
	end
	return str
end

atprint=function() end
atlog=function(t, ...)
	local text=advtrains.print_concat_table({t, ...})
	minetest.log("action", "[advtrains]"..text)
end
atwarn=function(t, ...)
	local text=advtrains.print_concat_table({t, ...})
	minetest.log("warning", "[advtrains]"..text)
	minetest.chat_send_all("[advtrains] -!- "..text)
end
sid=function(id) if id then return string.sub(id, -6) end end


--ONLY use this function for temporary debugging. for consistent debug prints use atprint
atdebug=function(t, ...)
	local text=advtrains.print_concat_table({t, ...})
	minetest.log("action", "[advtrains]"..text)
	minetest.chat_send_all("[advtrains]"..text)
end

if minetest.settings:get_bool("advtrains_enable_debugging") then
	atprint=function(t, ...)
		local context=advtrains.atprint_context_tid or ""
		if not context then return end
		local text=advtrains.print_concat_table({t, ...})
		advtrains.drb_record(context, text)
		
		--atlog("@@",advtrains.atprint_context_tid,t,...)
	end
	dofile(advtrains.modpath.."/debugringbuffer.lua")
	
end

function assertt(var, typ)
	if type(var)~=typ then
		error("Assertion failed, variable has to be of type "..typ)
	end
end

dofile(advtrains.modpath.."/helpers.lua");
--dofile(advtrains.modpath.."/debugitems.lua");

advtrains.meseconrules = 
{{x=0,  y=0,  z=-1},
 {x=1,  y=0,  z=0},
 {x=-1, y=0,  z=0},
 {x=0,  y=0,  z=1},
 {x=1,  y=1,  z=0},
 {x=1,  y=-1, z=0},
 {x=-1, y=1,  z=0},
 {x=-1, y=-1, z=0},
 {x=0,  y=1,  z=1},
 {x=0,  y=-1, z=1},
 {x=0,  y=1,  z=-1},
 {x=0,  y=-1, z=-1},
 {x=0, y=-2, z=0}}

advtrains.fpath=minetest.get_worldpath().."/advtrains"

dofile(advtrains.modpath.."/path.lua")
dofile(advtrains.modpath.."/trainlogic.lua")
dofile(advtrains.modpath.."/trainhud.lua")
dofile(advtrains.modpath.."/trackplacer.lua")
dofile(advtrains.modpath.."/copytool.lua")
dofile(advtrains.modpath.."/tracks.lua")
dofile(advtrains.modpath.."/occupation.lua")