-- Convert "@/path/file" to "/path/".
local function DebugPathToRealPath( p )
	if not p or p:sub( 1, 1 ) ~= "@" then
		return nil
	end

	local Path = p:sub( 2 )
	local pos = Path:find_last( '/' )
	return string.sub( Path, 1, pos )
end

local function MergeTables( left, right )
	local ret = { }
	for key, val in pairs(left) do
		ret[key] = val
	end

	for key, val in pairs(right) do
		if ret[key] then
			if type(val) == "function" and
			   type(ret[key]) == "function" then
				local f1 = ret[key]
				local f2 = val
				val = function(...)
					f1(...)
					return f2(...)
				end
			else
				Warn( string.format( "%s\n\nOverriding \"%s\": %s with %s",
					 debug.traceback(), key, type(ret[key]), type(val)) )
			end
		end

		ret[key] = val
	end
	setmetatable( ret, getmetatable(left) )
	return ret
end

DefMetatable = {
	__concat = function(left, right)
		return MergeTables( left, right )
	end
}

-- This is used as follows:
--
--   t = Def.Class { table }
Def = {}
setmetatable( Def, {
	__index = function(self, Class)
		-- t is an actor definition table.  name is the type
		-- given to Def.  Fill in standard fields.
		return function(t)
			if not ActorUtil.IsRegisteredClass(Class) then
				error( Class .. " is not a registered actor class", 2 )
			end

			t.Class = Class

			local level = 2
			if t._Level then
				level = t._Level + 1
			end
			local info

			-- Sometimes info.source will be "=(tail call)" when we need the actual
			-- file something came from.
			-- So this loop climbs the stack until it reaches an actual file path
			-- or reaches end.
			repeat
				info = debug.getinfo(level,"Sl");
				if info then
					-- Source file of caller:
					local source= info.source
					t._Source= source
					-- Line number of caller:
					t._Line = info.currentline
					t._Dir= DebugPathToRealPath(source)

					-- level is incremented for the next time through the loop.  Take
					-- that into account if level is used after the loop.
					level= level + 1
				end
			until t._Dir or not info

			setmetatable( t, DefMetatable )
			return t
		end
	end,
})

function ResolveRelativePath(path, level, optional)
	if path:sub(1,1) ~= "/" then
		-- "Working directory":
		local sDir = DebugPathToRealPath( debug.getinfo(level+1,"S").source )
		assert( sDir )

		path = sDir .. path
	end

	path = ActorUtil.ResolvePath(path, level+1, optional)
	return path
end

-- Load an actor template.
function LoadActorFunc( path, level )
	level = level or 1

	if path == "" then
		error( "Passing in a blank filename is a great way to eat up RAM. Good thing we warn you about this." )
	end

	local ResolvedPath = ResolveRelativePath( path, level+1 )
	if not ResolvedPath then
		error( path .. ": not found", level+1 )
	end
	path = ResolvedPath

	local Type = ActorUtil.GetFileType( path )
	Trace( "Loading " .. path .. ", type " .. tostring(Type) )

	if Type == "FileType_Lua" then
		-- Load the file.
		local chunk, errmsg = loadfile( path )
		if not chunk then error(errmsg) end
		return chunk
	end

	if Type == "FileType_Bitmap" or Type == "FileType_Movie" then
		return function()
			return Def.Sprite {
				_Level = level+1,
				Texture = path
			}
		end
	elseif Type == "FileType_Sound" then
		return function()
			return Def.Sound {
				_Level = level+1,
				File = path
			}
		end
	elseif Type == "FileType_Model" then
		return function()
			return Def.Model {
				_Level = level+1,
				Meshes = path,
				Materials = path,
				Bones = path
			}
		end
	elseif Type == "FileType_Directory" then
		return function()
			return Def.BGAnimation {
				_Level = level+1,
				AniDir = path
			}
		end
	end

	error( path .. ": unknown file type (" .. tostring(Type) .. ")", level+1 )
end

-- Load and create an actor template.
function LoadActor( path, ... )
	local t = LoadActorFunc( path, 2 )
	assert(t)
	return t(...)
end

function LoadActorWithParams( path, params, ... )
	local t = LoadActorFunc( path, 2 )
	assert(t)
	return lua.RunWithThreadVariables( function(...) return t(...) end, params, ... )
end

function LoadFont(a, b)
	local sSection = b and a or ""
	local sFile = b or a
	if sFile == "" or not sFile then
		sSection = "Common"
		sFile = "normal"
	end
	local sPath = THEME:GetPathF(sSection, sFile)
	return Def.BitmapText {
		_Level = 2,
		File = sPath
	}
end

function WrapInActorFrame( t )
	return Def.ActorFrame { children = t }
end

function StandardDecorationFromTable( MetricsName, t )
	if type(t) == "table" then
		t = t .. {
			InitCommand=function(self)
				self:name(MetricsName)
				ActorUtil.LoadAllCommandsAndSetXY(self,Var "LoadingScreen")
			end
		}
	end
	return t
end

function StandardDecorationFromFile( MetricsName, FileName )
	local t = LoadActor( THEME:GetPathG(Var "LoadingScreen",FileName) )
	return StandardDecorationFromTable( MetricsName, t )
end

function StandardDecorationFromFileOptional( MetricsName, FileName )
	if ShowStandardDecoration(MetricsName) then
		return StandardDecorationFromFile( MetricsName, FileName )
	end
end

function ShowStandardDecoration( MetricsName )
	return THEME:GetMetric(Var "LoadingScreen","Show"..MetricsName)
end

--blank actor because these come in handy from time to time
NullActor = { Class="Actor", _Source="(null actor)" }

-- (c) 2006 Glenn Maynard
-- All rights reserved.
--
-- Permission is hereby granted, free of charge, to any person obtaining a
-- copy of this software and associated documentation files (the
-- "Software"), to deal in the Software without restriction, including
-- without limitation the rights to use, copy, modify, merge, publish,
-- distribute, and/or sell copies of the Software, and to permit persons to
-- whom the Software is furnished to do so, provided that the above
-- copyright notice(s) and this permission notice appear in all copies of
-- the Software and that both the above copyright notice(s) and this
-- permission notice appear in supporting documentation.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
-- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
-- THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
-- INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
-- OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
-- OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
-- OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-- PERFORMANCE OF THIS SOFTWARE.
