#!/usr/bin/lua
-- a heavy duty test.
-- makes thousends of random changes to the source tree
-- checks every X changes if lsyncd managed to keep target tree in sync.
require("posix")
dofile("tests/testlib.lua")

-- always makes the same "random", so failures can be debugged.
math.randomseed(2) 

local tdir = mktempd().."/"
cwriteln("using ", tdir, " as test root")

local srcdir = tdir.."src/"
local trgdir = tdir.."trg/"

posix.mkdir(srcdir)
posix.mkdir(trgdir)
local pid = spawn("./lsyncd","-nodaemon","-rsync",srcdir,trgdir)

cwriteln("waiting for Lsyncd to startup")
posix.sleep(1)

-- all dirs created, indexed by integer and path
root = {name=""}
alldirs = {root}
dirsWithFileI = {}
dirsWithFileD = {}

-----
-- returns the name of a directory
-- call it with name=nil
local function dirname(dir, name)
	name = name or ""
	if not dir then
		return name
	end
	return dirname(dir.parent, dir.name .. "/" .. name)
end

-----
-- Picks a random dir.
--
local function pickDir(notRoot)
	if notRoot then
		if #alldirs <= 2 then
			return nil
		end
		return alldirs[math.random(2, #alldirs)]
	end
	return alldirs[math.random(#alldirs)]
end

----
-- Picks a random file.
--
-- Returns 3 values: 
--  * the directory
--  * the filename
--  * number of files in directory
--
local function pickFile()
	-- picks the random directory
	if #dirsWithFileI < 1 then
		return
	end
	local rdir = dirsWithFileI[math.random(1, #dirsWithFileI)]
	if not rdir then
		return
	end

	-- counts the files in there
	local c = 0
	for name, _ in pairs(rdir) do
		if #name == 2 then
			c = c + 1
		end
	end

	-- picks one file at random
	local cr = math.random(1, c)
	local fn 
	for name, _ in pairs(rdir) do
		if #name == 2 then
			-- filenames are 2 chars wide.
			cr = cr - 1
			if cr == 0 then
				fn = name
				break
			end
		end
	end
	return rdir, fn, c
end

-----
-- Removes a reference to a file
--
-- @param dir  --- directory reference
-- @param fn   --- filename
-- @param c    --- number of files in dir
--
local function rmFileReference(dir, fn, c)
	dir[fn] = nil
	if c == 1 then
		-- if last file from origin dir, it has no files anymore
		for i, v in ipairs(dirsWithFileI) do
			if v == dir then 
				table.remove(dirsWithFileI, i)
				break
			end
		end
		dirsWithFileD[dir] = nil
	end
end

----
-- possible randomized behaviour. 
-- just gives it a pause
--
local function sleep()
	cwriteln("..zzz..")
	posix.sleep(1)
end

----
-- possible randomized behaviour. 
-- creates a directory
--
local function mkdir()
	-- chooses a random directory to create it into
	local rdir = pickDir()
	-- creates a new random one letter name
	local nn = string.char(96 + math.random(26))
	if not rdir[nn] then
		local ndir = {
			name   = nn,
			parent = rdir, 
		}
		local dn = dirname(ndir)
		rdir[nn] = dn
		table.insert(alldirs, ndir)
		cwriteln("mkdir  "..srcdir..dn)
		posix.mkdir(srcdir..dn)
	end
end

----
-- possible randomized behaviour. 
-- creates a directory
--
local function mkfile()
	-- chooses a random directory to create it into
	local rdir = pickDir()
	-- creates a new random one letter name
	local nn = 'f'..string.char(96 + math.random(26))
	local fn = dirname(rdir) .. nn
	cwriteln("mkfile "..srcdir..fn)
	local f = io.open(srcdir..fn, "w")
	if f then
		for i=1,10 do
			f:write(string.char(96 + math.random(26)))
		end
		f:write('\n')
		f:close()
		rdir[nn]=true
		if not dirsWithFileD[rdir] then
			table.insert(dirsWithFileI, rdir)
			dirsWithFileD[rdir]=true
		end
	end
end

----
-- possible randomized behaviour. 
-- moves a directory
--
local function mvdir()
	if #alldirs <= 2 then
		return
	end
	-- chooses a random directory to move 
	local odir = pickDir(true)
	-- chooses a random directory to move to
	local tdir = pickDir()

	-- makes sure tdir is not a subdir of odir
	local dd = tdir
	while dd do
		if odir == dd then
			return
		end
		dd = dd.parent
	end
	-- origin name in the target dir already
	if tdir[odir.name] ~= nil then
		return
	end
	local on = dirname(odir)
	local tn = dirname(tdir)
	cwriteln("mvdir  ",srcdir,on," -> ",srcdir,tn,odir.name)
	os.rename(srcdir..on, srcdir..tn..odir.name)
	odir.parent[odir.name] = nil
	odir.parent = tdir
	tdir[odir.name] = odir
end

----
-- possible randomized behaviour. 
-- moves a directory
--
local function mvfile()
	local odir, fn, c = pickFile()
	if not odir then
		return
	end
	-- picks a directory with a file at random
	-- picks a target directory at random
	local tdir = pickDir()
	local on = dirname(odir)
	local tn = dirname(tdir)
	cwriteln("mvfile ",srcdir,on,fn," -> ",srcdir,tn,fn)
	os.rename(srcdir..on..fn, srcdir..tn..fn)
	rmFileReference(odir, fn, c)
	
	tdir[fn] = true
	if not dirsWithFileD[tdir] then
		dirsWithFileD[tdir] = true
		table.insert(dirsWithFileI, tdir)
	end
end

----
-- possible randomized behaviour. 
-- moves a directory
--
local function rmfile()
	local dir, fn, c = pickFile()
	if dir then
		local dn = dirname(dir)
		cwriteln("rmfile ",srcdir,dn,fn)
		posix.unlink(srcdir..dn..fn)
		rmFileReference(dir, fn, c)
	end
end

local dice = {
	{ 1,	sleep  },
	{ 20,   mkfile },
	{ 20, 	mkdir  },
	{ 20,   mvdir  },
	{ 20,   rmfile },
}

cwriteln("making random data")
local ndice = 0
for i, d in ipairs(dice) do
	ndice = ndice + d[1]
	d[1] = ndice
end

for ai=1,20 do
	-- throw a die what to do
	local acn = math.random(ndice)
	for i, d in ipairs(dice) do
		if acn <= d[1] then
			d[2]()
			break
		end
	end
end

cwriteln("waiting for Lsyncd to finish its jobs.")
posix.sleep(20)

-- cwriteln("killing the Lsyncd daemon")
-- posix.kill(pid)
-- local _, exitmsg, exitcode = posix.wait(lpid)
-- cwriteln("Exitcode of Lsyncd = ", exitmsg, " ", exitcode)

exitcode = os.execute("diff -r "..srcdir.." "..trgdir)
cwriteln("Exitcode of diff = ", exitcode)
os.exit(exitcode)