--- Executes multiple worldedit commands in sequence.
-- @module worldeditadditions.multi

-- explode(seperator, string)
-- From http://lua-users.org/wiki/SplitJoin
local function explode(delim, str)
	local ll, is_done
	local delim_length = string.len(delim)
	ll = 0
	is_done = false
	
	return function()
		if is_done then return end
		
		local result = nil
		local loc = string.find(str, delim, ll, true) -- find the next d in the string
		if loc ~= nil then -- if "not not" found then..
			result = string.sub(str, ll, loc - 1) -- Save it in our array.
			ll = loc + delim_length -- save just after where we found it for searching next time.
		else
			result = string.sub(str, ll) -- Save what's left in our array.
			is_done = true
		end
		
		return result
	end
end

-- From http://lua-users.org/wiki/StringTrim
local function trim(s)
   return (s:gsub("^%s*(.-)%s*$", "%1"))
end

local function step(params)
	local start_time = worldeditadditions.get_ms_time()
	
	local full_cmd = params.cmd_name.." "..params.args
	worldedit.player_notify(params.name, "[ many ] [ /"..full_cmd.." ] "..(params.i + 1).." / "..params.count.." (~"..worldeditadditions.round(((params.i + 1) / params.count)*100, 2).."%)")
	
	local cmd = minetest.chatcommands[params.cmd_name]
	
	minetest.log("action", params.name.." runs "..full_cmd.." (time "..tostring(params.i).." of "..tostring(times)..")")
	cmd.func(params.name, params.args)
	
	
	params.times[#params.times + 1] = (worldeditadditions.get_ms_time() - start_time)
	
	params.i = params.i + 1
	if params.i < params.count then
		minetest.after(0, step, params)
	else
		local total_time = (worldeditadditions.get_ms_time() - params.master_start_time)
		local done_message = {}
		table.insert(done_message,
			string.format("Executed '"..full_cmd.."' %d times in %s (~%s / time",
				#params.times,
				worldeditadditions.human_time(total_time),
				worldeditadditions.human_time(
					worldeditadditions.average(params.times)
				)
			)
		)
		-- Don't drown the player if the command was executed many times
		if #params.times < 10 then
			local message_parts = {}
			for j=1,#params.times do
				table.insert(message_parts, worldeditadditions.human_time(params.times[j]))
			end
			table.insert(done_message, "; ")
			table.insert(done_message, table.concat(message_parts, ", "))
		end
		table.insert(done_message, ")")
		worldedit.player_notify(params.name, table.concat(done_message, ""))
	end
end

minetest.register_chatcommand("/many", {
	params = "<times> /<command_a> <args>",
	description = "Executes a single chat command multiple times. The number of times to repeat the command should be specified first. The command to execute follows, and the forward slashes at the beginning thereof must be the same as if you were executing it normally. Note that this command yields with minetest.after to allow other things to happen at the same time.",
	privs = { worldedit = true },
	func = function(name, params_text)
		
		local i = 1 -- For feedback only
		local master_start_time = worldeditadditions.get_ms_time()
		local times = {}
		
		local count, cmd_name, args = params_text:match("^(%d+)%s([^%s]+)%s(.+)$")
		if not count then return false, "Error: Invalid syntax" end
		print("[many] count", count, "cmd_name", cmd_name, "args", args)
		
		count = tonumber(count)
		cmd_name = trim(cmd_name):sub(2) -- Things start at 1, not 0 in Lua :-(
		
		-- Check the command we're going to execute
		local cmd = minetest.chatcommands[cmd_name]
		if not cmd then
			return false, "Error: "..cmd_name.." isn't a valid command."
		end
		if not minetest.check_player_privs(name, cmd.privs) then
			return false, "Your privileges are insufficient to run that command."
		end
		
		step({
			master_start_time = master_start_time,
			count = count,
			i = 0,
			times = {},
			cmd_name = cmd_name,
			args = args,
			name = name
		})
	end
})