--[[
	A thing that kinda works like require, or at least, works how I wish require worked.
	calls hooks:
		artery_nrequire_defined
		artery_core_loaded
]]
if nrequire ~= nil then return end

--The files we want clients to load
local clienttoload = {}

local searchpaths = {
	{"gamemodes/artery/gamemode","GAME"},
	{"artery/global","DATA"},
	{"data/artery/global","GAME"},
}

if SERVER then
	--Network messages
	util.AddNetworkString("artery_downloadfile")
	util.AddNetworkString("art_downloadfiles")
	util.AddNetworkString("art_requestfile")
	util.AddNetworkString("art_respondfile")
	util.AddNetworkString("artery_request_client_download")
	--[[Server tells the client to load a file]]
	util.AddNetworkString("artery_loadfile")
	--[[Client tells server we don't have that file]]
	util.AddNetworkString("artery_requestcsfile")
	--[[Server gives client the contents of a file]]
	util.AddNetworkString("artery_respondfile")
	util.AddNetworkString("art_requestclientreload")
	util.AddNetworkString("art_client_reload_file")
	util.AddNetworkString("art_refresh")
	util.AddNetworkString("art_manualrefresh")
end

--dir is a table of {string_path, string_directory}
local function TraverseFolder(dir,func)
	local find_path = table.concat({dir[1],"/*"},"")
	local files,directories = file.Find(find_path,dir[2])
	for k,v in pairs(files) do
		local callpath = table.concat({dir[1],"/",v},"")
		func({callpath,dir[2]})
	end
	for k,v in pairs(directories) do
		local npath = table.concat({dir[1],"/",v},"")
		TraverseFolder({npath,dir[2]},func)
	end
end

local function BuildIncludeTable(tbl)
	local output = {}
	for k,v in pairs(tbl) do
		local filepath = v[1]
		local fileloc = v[2]
		local pathparts = {}
		for part in filepath:gmatch("/?[%w_]+/") do
			local foldername = part:gsub("/$",""):gsub("^/","")
			pathparts[#pathparts + 1] = foldername
		end
		local filename = filepath:gfind("[%w_%.]+%.[%w_]+$")()
		if output[filename] == nil then
			output[filename] = {}
		end
		local cursor = output[filename]
		for folder = #pathparts, 2, -1 do
			if cursor[pathparts[folder]] == nil then
				cursor[pathparts[folder]] = {}
			end
			cursor = cursor[pathparts[folder]]
		end
		assert(cursor[pathparts[1]] == nil, string.format("Found 2 files with the same path:\n\t%s",table.ToString(pathparts,"pathparts",true)))
		cursor[pathparts[1]] = v
	end
	return output
end

--Finds the number of elements in a table, even if it is not an array
local function tbllen(tbl)
	local count = 0
	for k,v in pairs(tbl) do count = count + 1 end
	return count
end

--[[
	Finds all the paths from a include table
]]
local function collect_paths(pretbl)
	local ret = {}
	for k,v in pairs(pretbl) do
		if v[1] == nil then
			local resp = collect_paths(v)
			for i,j in pairs(resp) do
				ret[#ret + 1] = j
			end
		else
			ret[#ret + 1] = string.format("%s (%s)",v[1],v[2])
		end
	end
	return ret
end

--[[
	Scans the prefix table built by rebuild_include_table to find the file path for the partial name of an included file.
	If two files are named the same, you will need to include part of the file path until it can be resolved.
]]
local function scan(pretbl, name)
	local pathparts = {}
	for part in name:gmatch("/?[%w_]+/") do
		pathparts[#pathparts + 1] = part:gsub("/$",""):gsub("^/","")
	end
	local filename = name:gfind("[%w_%.]+%.[%w_]+$")()
	assert(filename ~= nil,string.format("Could not file a filename for %q from parts: %s valid files are:\n\t%s",name,table.concat(pathparts,","),table.concat(collect_paths(pretbl),"\n\t")))
	local cursor = pretbl[filename]
	assert(cursor ~= nil,string.format("Scan did not find a file named %q.\n",filename))
	local rev = {}
	for i = 1, #pathparts do rev[#pathparts - i + 1] = pathparts[i] end
	for k,v in ipairs(rev) do
		if cursor == nil then error(string.format("Scan could not complete file path translation while translateing %q at %s",table.concat(rev,","),v)) end
		cursor = cursor[v]
	end
	while cursor ~= nil and #cursor ~= 2 do
		assert(type(cursor) ~= "nil",string.format("Could not find a valid file for path %q, file paths:\n\t%s",name,table.concat(collect_paths(pretbl),"\n\t")))
		assert(tbllen(cursor) == 1,string.format("Ambiguous scan, there are two or more paths that match %q\n\t%s\nSpecify more of the file path.",name,table.concat(collect_paths(cursor),"\n\t")))
		cursor = cursor[next(cursor)]
	end
	assert(type(cursor) ~= "nil", string.format("Could not find %s under %s, found under\n\t %s",filename,name, table.concat(collect_paths(pretbl[filename]),"\n\t")))
	return cursor
end

local paths = {}
local ntbl = {}

local reqtbl = {} --Holds already nrequire()'d things
local lastcall = {} --Holds when things were loaded
local location = {} --Holds the location of files ("DATA","GAME","LUA",...)
local deptbl = {} --Holds the dependencies between files
local pathstack = {}
function nrequire(req,...)
	local varargs = {...}
	local tpath-- Find the full path for the nrequired() module
	if CLIENT then
		xpcall(function()
			tpath = scan(ntbl,req)
		end,function()
			tpath = scan(ntbl,req .. ".txt")
		end)
	else
		tpath = scan(ntbl,req)
	end
	if tpath == nil then
		MsgC(Color(209,96,196), "Unable to find file for include:" .. req)
		error(debug.traceback())
	end

	local trace = debug.getinfo(2,"flnSu")
	local source = trace.source
	--print("Adding to deptbl, src:",source,"tpath:",tpath)
	deptbl[source] = tpath

	--If we've already run it (and its up to date), just return it
	local filetime = file.Time(tpath[1],tpath[2])
	if reqtbl[tpath[1]] and lastcall[tpath[1]] and lastcall[tpath[1]] > filetime then
		return reqtbl[tpath[1]]
	end

	--Otherwise, make sure we don't have a circular depedency
	for k,v in pairs(pathstack) do
		assert(v ~= tpath[1],string.format("Circular dependancy detected:\n\t%s\n\t\t|\n\t\tV\n\t%s",table.concat(pathstack,"\n\t\t|\n\t\tV\n\t"),v))
	end

	--Actually run the file
	pathstack[#pathstack + 1] = tpath[1] --add this to circular dependency checker
	local filetxt = file.Read(tpath[1],tpath[2])
	if #filetxt == 0 then
		pathstack[#pathstack] = nil
		return
	end

	--Compile the file
	local filefunc = CompileString(filetxt,tpath[1],false)
	if type(filefunc) ~= "function" then
		error(filefunc)
	else
		xpcall(function()
			--and run it
			local m = filefunc(varargs)
			if reqtbl[tpath[1]] then --We already included the file before, we're updating
				setmetatable(reqtbl[tpath[1]],{__index = m})
			else
				local m_proxy = {}
				setmetatable(m_proxy,{__index = m})
				reqtbl[tpath[1]] = m_proxy
			end
			hook.Run("artery_file_included",tpath,m)
			--print(string.format("In nrequire(), not skipping compile and setting lastcall[%s] to %d",tpath[1],file.Time(tpath[1],tpath[2])))
			lastcall[tpath[1]] = os.time()
			location[tpath[1]] = tpath[2]
		end,function(err)
			MsgC(Color(209,96,196),debug.traceback(),"\n")
			MsgC(Color(209,96,196),"nrequire Error:",err,"\n")
		end)
	end

	pathstack[#pathstack] = nil

	return reqtbl[tpath[1]]

end

local update_file_co = coroutine.create(function()
	while true do
		for k,v in pairs(reqtbl) do
			local loc = location[k]
			if file.Time(k,loc) > lastcall[k] then
				print(string.format("Found updated file:%s",k))
				nrequire(k)
				lastcall[k] = os.time() --file.Time(k,loc)
				for ind,tbl in pairs(clienttoload) do
					if tbl.name == k then
						clienttoload[ind] = {
							name = k,
							hash = util.CRC(file.Read(k,loc)),
							directory = loc,
						}
					end
				end
				net.Start("art_client_reload_file")
				net.WriteString(k)
				net.WriteString(loc)
				net.WriteString(file.Read(k,loc))
				net.Broadcast()
			end
			coroutine.yield()
		end
	end
end)

hook.Add("Tick","nrequire_update_tick",function()
	if coroutine.status(update_file_co) == "suspended" then
		coroutine.resume(update_file_co)
	end
end)

if SERVER then
	net.Receive("artery_requestcsfile",function(ln,ply)
	    local which = net.ReadString()
		local path = net.ReadString()
		local found = false
		for k,v in pairs(clienttoload) do
			if v.name == which and v.directory == path then
				net.Start("artery_respondfile")
				net.WriteString(which)
				net.WriteString(path)
				net.WriteString(file.Read(which,path))
				net.Send(ply)
				return
			end
		end
	end)
else
	local function run_csfile(txt,name)
		assert(#txt > 0, "File was size 0 on: " .. name)
		local ptr = CompileString(txt,name,false)
		local ret = nil
		if type(ptr) == "function"  then
			xpcall(function()
				ret = ptr()
			end,function(err)
				MsgC(Color(209,96,196),debug.traceback(),"\n")
				MsgC(Color(209,96,196),"nrequire Error:",err,"\n")
			end)
		else
			error(ptr)
		end
		return ret
	end
	net.Receive("artery_loadfile",function()
		local filename = net.ReadString()
		local hash = net.ReadUInt(32)
		local path = net.ReadString()
		local cache = file.Read("artery/client/files/" .. path .. "/" .. filename,"DATA")
		if cache == nil then --We don't have this file downloaded!
			net.Start("artery_requestcsfile")
			net.WriteString(filename)
			net.WriteString(path)
			net.SendToServer()
			return
		end
		local thash = tonumber(util.CRC(cache))
		if hash != thash then
			print("I need to load a file",filename," but my hash was old, redownloading!")
			net.Start("artery_requestcsfile")
			net.WriteString(filename)
			net.WriteString(path)
			net.SendToServer()
		else
			run_csfile(cache,filename)
		end
	end)
	net.Receive("artery_respondfile",function()
		local filename = net.ReadString()
		local filepath = net.ReadString()
		local filetext = net.ReadString()
		local dirname = string.GetPathFromFilename(filename)
		file.CreateDir("artery/client/files/" .. dirname)
		assert(#filetext > 0, "Retreived a size 0 file: " .. filename)
		file.Write("artery/client/files/" .. filename,filetext)
		local mod = run_csfile(filetext,filename)
		local mod_proxy = {}
		setmetatable(mod_proxy,{__index = mod})
		reqtbl[filepath] = mod_proxy
		lastcall[filepath] = os.time()
	end)
end

--[[
	Automatically include all the files in the gamemode directory based on the file name.
	If the file starts with cl_ it will only be included on the client, if it starts with sv_ it will only be included on the server. If it starts with anything else, it will be shared. Will detect and error on circuar dependancy.
]]
local function doincludes()
	paths = {}
	for k,v in pairs(searchpaths) do
		TraverseFolder(v,function(n)
			paths[#paths + 1] = n
		end)
	end
	ntbl = BuildIncludeTable(paths)
	reqtbl = reqtbl or {}
	for k,v in pairs(paths) do
		local filename = v[1]
		-- MsgN("Filename:",filename)
		if filename == "gamemodes/artery/gamemode/init.lua" then
			continue
		end
		if filename:match("/?sv_[%w_]+%.[%w_]+$") then
			if SERVER then
				nrequire(filename)
			end
		elseif filename:match("/?cl_[%w_]+%.[%w_]+$") then
			if CLIENT then
				nrequire(filename)
			else
				clienttoload[#clienttoload+1] = {
					name  = filename,
					hash = util.CRC(file.Read(filename,v[2])),
					directory = v[2]
				}
			end
		else
			if SERVER then
				clienttoload[#clienttoload + 1] = {
					name  = filename,
					hash = util.CRC(file.Read(filename,v[2])),
					directory = v[2]
				}
			end
			nrequire(filename)
		end
		pathstack = {}
	end
end

local function redoincludes()
	print("redoing includes")
	paths = {} -- Defined above somewhere
	for k,v in pairs(searchpaths) do
		-- print("Searching path:")
		-- PrintTable(v)
		TraverseFolder(v,function(n)
			-- print("found file:")
			-- PrintTable(n)
			paths[#paths + 1] = n
		end)
	end
	ntbl =  BuildIncludeTable(paths)
	doincludes()
	hook.Call("artery_core_loaded")
end

if SERVER then
	redoincludes()
	concommand.Add("artery_doincludes",function(ply,cmd,args)
		redoincludes()
	end)
end
local runclient = nil
if SERVER then
	local function downloadclient(who)
		print("Loading client",who)
		net.Start("art_downloadfiles")
		net.WriteTable(clienttoload)
		net.Send(who)
		-- local routine = coroutine.create(function()
		-- 	for k,v in pairs(clienttoload) do
		-- 		print("Asking client to load",k)
		-- 		net.Start("artery_downloadfile")
		-- 		net.WriteString(v.name)
		-- 		net.WriteUInt(v.hash,32)
		-- 		net.WriteString(v.directory)
		-- 		net.WriteString(file.Read(v.name,v.directory))
		-- 		net.Send(who)
		-- 		coroutine.yield()
		-- 	end
		-- end)
		-- timer.Create("artery_downloadload_client_timer",1,#clienttoload,function()
		-- 	coroutine.resume(routine)
		-- end)
	end
	net.Receive("artery_request_client_download",function(ln,pl)
		print("artery_request_client_download received by server")
		downloadclient(pl)
	end)
	net.Receive("art_requestfile",function(ln,pl)
		local filedata = net.ReadTable()
		local filetxt = file.Read(filedata.name,filedata.directory)
		net.Start("art_respondfile")
		net.WriteTable({
			name = filedata.name,
			directory = filedata.directory,
			text = filetxt
		})
		net.Send(pl)
	end)
else
	net.Receive("art_client_reload_file",function(ln,pl)
		local filename = net.ReadString()
		local directory = net.ReadString()
		local filetext = net.ReadString()
		local fullpath = "artery/client/" .. directory .. "/" .. filename .. ".txt"
		file.Write(fullpath,filetext)
		redoincludes()
	end)
	net.Receive("art_downloadfiles",function(ln,pl)
		local clientfiles = net.ReadTable()
		local todownload = {}
		local needs_restart = false
		for k,v in pairs(clientfiles) do
			local fullpath = "artery/client/" .. v.directory .. "/" .. v.name .. ".txt"
			if not file.Exists(fullpath,"DATA") then
				local thisdownload = {
					name = v.name,
					directory = v.directory
				}
				todownload[#todownload + 1] = thisdownload
				needs_restart = true
			elseif util.CRC(file.Read(fullpath,"DATA")) ~= v.hash then
				local thisdownload = {
					name = v.name,
					directory = v.directory
				}
				todownload[#todownload + 1] = thisdownload
				needs_restart = true
			-- else file is up to date and dosn't need re-downloading.
			end
		end

		local routine = coroutine.create(function()
			for k,v in pairs(todownload) do
				net.Start("art_requestfile")
				net.WriteTable(v)
				net.SendToServer()
				coroutine.yield()
			end
			runclient()
		end)
		timer.Create("artery_download_files_timer",0.1,#todownload,function()
			coroutine.resume(routine)
		end)
	end)

	net.Receive("art_respondfile",function(ln,pl)
		local tbl = net.ReadTable()
		print("Received response file:",tbl.name)
		local fullpath = "artery/client/" .. tbl.directory .. "/" .. tbl.name .. ".txt"
		local path = string.GetPathFromFilename(fullpath)
		file.CreateDir(path)
		print("Writing to ", fullpath)
		file.Write(fullpath,tbl.text)
		nrequire(tbl.name)
		--timer.Simple(10,function() RunConsoleCommand("retry") end)
		redoincludes()
	end)

	net.Receive("artery_downloadfile",function(ln,pl)
		print("Asked to download file")
		local clientfiles = net.ReadTable()
		-- local filename = net.ReadString()
		-- local filehash = net.ReadUInt(32)
		-- local filedir = net.ReadString()
		-- local filetext = net.ReadString()
		-- print("got filename:",filename,"and filedir:",filedir)
		-- local dirname = string.GetPathFromFilename(filename)
		-- file.CreateDir("artery/client/files/" .. dirname)
		-- assert(#filetext > 0, "Retreived a size 0 file: " .. filename)
		-- file.Write("artery/client/files/" .. filename,"")
	end)
	local function request_file_download()
		print("Requesting to download client files")
		net.Start("artery_request_client_download")
		net.SendToServer()
	end
	timer.Simple(0,function()
		request_file_download()
	end)
	concommand.Add("artery_DownloadClient",function(ply,cmd,args)
		request_file_download()
	end)
end

concommand.Add("PrintDepTbl",function(ply,cmd,args)
	PrintTable(deptbl)
end)
concommand.Add("PrintReqTbl",function(ply,cmd,args)
	PrintTable(reqtbl)
end)
if SERVER then
	concommand.Add("PrintClientToLoad",function(ply,cmd,args)
		PrintTable(clienttoload)
	end)
end

if SERVER then
	net.Receive("art_requestclientreload",function(ln,pl)
		loadclient(pl)
	end)
else
	concommand.Add("artery_LoadClient",function(ply,cmd,args)
		net.Start("art_requestclientreload")
		net.SendToServer()
		--loadclient(ply)
	end)
	runclient = function()
		searchpaths = {
			{"artery/client/game/","DATA"},
			{"artery/client/" .. game.GetMap() .. "/", "DATA"}
		}
		redoincludes()
	end
	runclient()
	concommand.Add("artery_RunClient",function(ply,cmd,args)
		runclient()
	end)
end

if SERVER then
	concommand.Add("art_refresh",function(ply,cmd,args)
		print("Doing soft refresh")
		doincludes()
		net.Start("art_refresh")
		net.Broadcast()
	end)
else
	net.Receive("art_manualrefresh",doincludes)
end

if SERVER then
	concommand.Add("art_manualrefresh",function(ply,cmd,args)
		if not ply:IsAdmin() then return end
		reqtbl = {}
		doincludes()
		net.Start("art_refresh")
		net.Broadcast()
	end)
end
if CLIENT then net.Receive("art_manualrefresh",doincludes) end

concommand.Add("artery_manualrefresh",function(ply,cmd,args)
	doincludes()
end)