-- Loader from Saver
-- by Stefan Ihringer <stefan@bildfehler.de>
--
-- Creates a loader for the selected saver.
-- Copies the Path of a saver to a loader if both are selected.
--
-- version 0.2, 2010-10-09
--     works with path mappings
--     detects first frame of rendered sequence amd shifts loader's global in to match saver
-- version 0.1, 2010-09-25
--     initial release
--
-- ideas for improvement:
-- * display dialog box if more than one saver is selected?

---------------
-- helper function to update a loader with a new file name and global in frame
function update_loader(ld, new_clip, new_in)
	ld.Clip[TIME_UNDEFINED] = ""
	ld.Clip[TIME_UNDEFINED] = new_clip
	if new_in ~= nil then 
		ld.GlobalIn = new_in
		ld.HoldFirstFrame = 0
		ld.ClipTimeStart = 0
	end
	ld:SetAttrs({TOOLB_PassThrough = true})
	ld:SetAttrs({TOOLB_PassThrough = false})
end

-- helper function to scan a file sequence and return its smalles frame number
function getFirstFrameOfSequence(clip)
	local smallest = nil
	local fp = eyeon.parseFilename(composition:MapPath(clip))
	local dirlist = eyeon.readdir(fp.Path .. fp.CleanName .. "*" .. fp.Extension)
	for i, f in ipairs(dirlist) do
		if not f.IsDir then
			-- find smallest frame number
			string.gsub(f.Name, "(%d+)"..fp.Extension.."$", function(n) if smallest == nil or tonumber(n) < smallest then smallest = tonumber(n) end end)
		end
	end
	return smallest
end
------------------------------------------------


if composition == nil then
	composition:GetFrameList()[1]:SwitchMainView('ConsoleView') 
	print("This is a composition script, it should be run from within Fusion.")
	exit()
end

local savers = composition:GetToolList(true, "Saver")
local loaders = composition:GetToolList(true, "Loader")

if savers == nil or #savers < 1 then
	composition:GetFrameList()[1]:SwitchMainView('ConsoleView') 
	print("Please select a saver or a saver and a loader first.")
	exit()
end

local the_saver = savers[1]

-- saver needs its path set
local clipname = the_saver.Clip[TIME_UNDEFINED]
if clipname == "" then
	composition:GetFrameList()[1]:SwitchMainView('ConsoleView') 
	print("The saver needs to have an output filename.")
	exit()
end

-- if clipname doesn't include a frame counter, add one to look for
local fp = eyeon.parseFilename(clipname)
if fp.SNum == "" then
	clipname = fp.Path .. fp.CleanName .. "0000" .. fp.Extension
	fp.SNum = "0000"
	fp.Number = 0
	fp.Padding = 4
end

-- calculate correct in point for the loader, so the clip will be in sync with the saver
-- instead of being placed at frame 0 (or whatever is set in the preferences).
-- First, detect the first frame number of the rendered sequence (nil = not rendered or other error occured):
local firstframe = getFirstFrameOfSequence(clipname)
if firstframe ~= nil then
	-- build new clip name with correct frame number
	clipname = fp.Path .. fp.CleanName .. string.format("%0" .. fp.Padding .. "d", firstframe) .. fp.Extension
	--print("Rendered sequence starts at frame "..firstframe)
	--print("new clip name: ", clipname)
end

-- Next, do the frame offset calculation
local globalin = firstframe
if globalin ~= nil then
	globalin = globalin - the_saver.SequenceStartFrame[TIME_UNDEFINED]
	if the_saver.SetSequenceStart[TIME_UNDEFINED] == 1 then
		globalin = globalin + composition:GetAttrs().COMPN_GlobalStart
	end
end

composition:StartUndo("Loader from Saver script")

if loaders == nil or #loaders < 1 then
	-- no loader selected: create a new one next to the selected saver
	local posX, posY = composition.CurrentFrame.FlowView:GetPos(the_saver)

	composition:Lock()
	local new_loader = composition:AddTool("Loader", posX + 1, posY)
	new_loader:SetAttrs({TOOLS_Name = "Loader_" .. the_saver:GetAttrs()['TOOLS_Name'], TOOLB_NameSet = true})
	print("Created Loader from " .. the_saver:GetAttrs()['TOOLS_Name'])
	if firstframe ~= nil and globalin ~= firstframe then
		print("First frame at ".. globalin)
	end
	composition:Unlock()

	update_loader(new_loader, clipname, globalin)
	composition:SetActiveTool(new_loader)
else
	-- update all selected loaders
	for n, the_loader in ipairs(loaders) do
		update_loader(the_loader, clipname, globalin)
		print("Updated " .. the_loader:GetAttrs()['TOOLS_Name'] .. " to " .. clipname)
		if firstframe ~= nil and globalin ~= firstframe then
			print("First frame at ".. globalin)
		end
	end
end

composition:EndUndo(true)