local wea_c = worldeditadditions_core
local Vector3 = wea_c.Vector3


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-- ██      ██    ██ ██   ██  ██  ██
-- ██      ██    ██ ██████    ████
-- ██      ██    ██ ██         ██
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--- Copies a region to another location, potentially overwriting the exiting region.
-- @param	source_pos1		Vector3		pos1 of the source region to copy.
-- @param	source_pos2		Vector3		pos2 of the source region to copy.
-- @param	target_pos1		Vector3		pos1 of the target region to copy to.
-- @param	target_pos2		Vector3		pos2 of the target region to copy to.
-- @param	airapply=false	bool		Whether to only replace target nodes that are air-like, leaving those that are not air-like. If false, then all target nodes are replaced regardless of whether they are air-like nodes or not.
-- @returns	bool,numbers	1. Whether the copy operation was successful or not
-- 							2. The total number of nodes copied.
function worldeditadditions.copy(source_pos1, source_pos2, target_pos1, target_pos2, airapply)
	if airapply == nil then airapply = false end
	source_pos1, source_pos2 = Vector3.sort(source_pos1, source_pos2)
	target_pos1, target_pos2 = Vector3.sort(target_pos1, target_pos2)
	
	local offset = source_pos1:subtract(target_pos1)
	-- {source,target}_pos2 will always have the highest co-ordinates now
	
	-- Fetch the nodes in the source area
	local manip_source, area_source = worldedit.manip_helpers.init(source_pos1, source_pos2)
	local data_source = manip_source:get_data()
	
	-- Fetch a manip for the target area
	local manip_target, area_target = worldedit.manip_helpers.init(target_pos1, target_pos2)
	local data_target = manip_target:get_data()
	
	-- z y x is the preferred loop order (because CPU cache, since then we're iterating linearly through the data array backwards. This only holds true for little-endian machines however)
	local total_replaced = 0
	for z = source_pos2.z, source_pos1.z, -1 do
		for y = source_pos2.y, source_pos1.y, -1 do
			for x = source_pos2.x, source_pos1.x, -1 do
				local source = Vector3.new(x, y, z)
				local source_i = area_source:index(x, y, z)
				local target = source - offset
				local target_i = area_target:index(target.x, target.y, target.z)
				
				local should_replace = true
				if airapply then
					should_replace = wea_c.is_airlike(data_target[target_i])
				end
				if should_replace then
					data_target[target_i] = data_source[source_i]
					total_replaced = total_replaced + 1
				end
			end
		end
	end
	
	-- Save the modified nodes back to disk & return
	worldedit.manip_helpers.finish(manip_target, data_target)
	
	return true, total_replaced
end
