local VARIABLE_NONE = 0
local VARIABLE_WALL = 1
local VARIABLE_PLAYER = 2
local VARIABLE_DAMAGE = 3

local wallEffect = CONST_ME_BIGPLANTS
local playerEffect = 215
local damageEffect = 79

local itemId = 1498
local delay = 2 * 1000
local damageDelay = 0.4 * 1000

local config = {
				{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
				{0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 2, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 3, 3, 3, 3, 3, 3, 3, 1, 0},
				{0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0},
				{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
				}

local function doRemoveWallItem(position)
	local item = getTileItemById(position, itemId)
	if item.uid > 0 then
		if wallEffect ~= CONST_ME_NONE then
			doSendMagicEffect(position, wallEffect)
		end

		doRemoveItem(item.uid)
	end
end

local function canCreate(pos)
	local item = getTileThingByPos({x = pos.x, y = pos.y, z = pos.z, stackpos = STACKPOS_GROUND})
	if item.uid == 0 then
		return false
	end

	local info = getTileInfo(pos)
	if info.protection or info.nopvp then
		return false
	end

	for it = 0, info.items do
		item = getTileThingByPos({x = pos.x, y = pos.y, z = pos.z, stackpos = it})
		local floorChange = getItemInfo(item.itemid)
		if not floorChange then
			return true
		end

		for i = NORTH, NORTHEAST + 1 do
			if floorChange.floorChange[i] then
				return false
			end
		end
	end

	return true
end

local function doCreateWalls(position)
	for _, pos in pairs(position) do
		local item = getTileItemById(pos, itemId)
		if item.uid == 0 then
			if canCreate(pos) then
				doCreateItem(itemId, pos)
				if wallEffect ~= CONST_ME_NONE then
					doSendMagicEffect(pos, wallEffect)
				end

				addEvent(doRemoveWallItem, delay, pos)
			end
		end
	end
end

local function doSendEffect(position)
	if playerEffect == CONST_ME_NONE then
		return true
	end

	for _, pos in pairs(position) do
		doSendMagicEffect({x = pos.x + 3, y = pos.y + 4, z = pos.z}, playerEffect)
	end
end

local function canAttack(cid, target)
	if not cid then
		return true
	end

	if isNpc(target) then
		return false
	end

	if cid == target or not isCreature(target) then
		return false
	end

	if getTilePzInfo(getThingPos(target)) then
		return false
	end

	if isPlayer(cid) then
		if isInParty(cid) then
			if isPlayer(target) and getPlayerParty(cid) == getPlayerParty(target) then
				return false
			end
		end
	end

	if isPlayer(target) and (isPlayerGhost(target) or getPlayerLevel(target) <= getConfigValue('protectionLevel')) then
		return false
	end

	if isSummon(cid) then
		local master = getCreatureMaster(cid)
		if master == target then
			return false
		end

		if isSummon(target) then
			target = getCreatureMaster(target)
		end

		if isPlayer(master) and isPlayer(target) and isInParty(master) and getPlayerParty(master) == getPlayerParty(target) then
			return false
		end
	end

	return true
end

local function doDamage(cid, position, n)
	for _, pos in pairs(position) do
		if canCreate(pos) then
			if damageEffect ~= CONST_ME_NONE then
				doSendMagicEffect(pos, damageEffect)
			end

			local target = getTopCreature(pos).uid
			if canAttack(cid, target) then
				local health = -(getCreatureMaxHealth(target) * 0.1)
				doTargetCombatHealth(0, target, COMBAT_ENERGYDAMAGE, health, health, CONST_ME_NONE)
			end
		end
	end

	if n > 0 then
		addEvent(doDamage, damageDelay, cid, position, n - 1)
	end
end

function onCastSpell(cid, var)
	local pos = getThingPos(cid)

	local positions = {}
	positions[VARIABLE_WALL] = {}
	positions[VARIABLE_PLAYER] = {}
	positions[VARIABLE_DAMAGE] = {}

	for py = 1, #config do
		for px = 1, #config[py] do
			local var = config[py][px]
			if var ~= VARIABLE_NONE then
				local pos = {x = pos.x + (px - ((#config - 1) / 2) - 1), y = pos.y + (py - ((#config - 1) / 2) - 1), z = pos.z}

				if var == VARIABLE_WALL then
					table.insert(positions[VARIABLE_WALL], pos)
				elseif var == VARIABLE_PLAYER then
					table.insert(positions[VARIABLE_PLAYER], pos)
				elseif var == VARIABLE_DAMAGE then
					table.insert(positions[VARIABLE_DAMAGE], pos)
				end
			end
		end
	end

	doCreatureSetNoMove(cid, true)
	doCreateWalls(positions[VARIABLE_WALL])
	doSendEffect(positions[VARIABLE_PLAYER])
	doDamage(cid, positions[VARIABLE_DAMAGE], delay / damageDelay)
	addEvent(function()
					if isPlayer(cid) then
						doCreatureSetNoMove(cid, false)
					end
				end, delay)
	return true
end