--

-- This software is provided 'as-is', without any express or implied

-- warranty.  In no event will the authors be held liable for any damages

-- arising from the use of this software.

--

-- Permission is granted to anyone to use this software for any purpose,

-- including commercial applications, and to alter it and redistribute it

-- freely.

--

-- Meta-build system using premake created and maintained by

-- Benjamin Henning <b.henning@digipen.edu>

-- This is kept just for windows because the other platforms use different means

-- for determining dependence or compatibility.

--[[

sdl_depends.lua

	This file simply contains a function for determining whether a dependency

	exists on the Windows platform, given a possible environmental variable,

	delimited search paths, and a main and/or sub-directory paths for more

	elaborate pattern matching.

]]

-- find_dependency_dir_windows(env, main_search_path, main_dir_path)

--   Attempt to resolve a dependency (true or false) folder based on either an

--   environmental variable, start search path, or both. If both are present,

--   the environmental variable will be preferred. If neither are present, this

--   function returns false.

--

--   Arguments:

--     env                The name of the environmental variable to treat as a path

--     main_search_paths  Paths to look for the main directory in

--     main_dir_path      The a path that must be contained between main_search_path and sub_dir_path

--     sub_dir_path       The path of the directories that should exist at the searched path

function find_dependency_dir_windows(env, main_search_paths, main_dir_path, sub_dir_path)

	if not os.is("windows") then -- if not windows, then fail

		return false

	end

	if env == nil and (main_search_paths == nil or #main_search_paths == 0) then

		return false

	end

	local env_path = nil

	local main_path = nil

	if env ~= nil then env_path = os.getenv(env) end

	local search_table = { n = 0 }

	if main_search_paths ~= nil then

		for k,main_search_path in ipairs(explode(main_search_paths, ";")) do

			local directories = os.matchdirs(main_search_path .. "/**" .. main_dir_path .. "*")

			for k,v in pairs(directories) do

				table.insert(search_table, v)

			end

		end

	end

	if env_path ~= nil then table.insert(search_table, env_path) end

	local search_path = table.concat(search_table, ";")

	local result_path = os.dirpathsearch(sub_dir_path, search_path, ";")

	if result_path == nil then

		return false

	end

	local found_dir = os.isdir(result_path)

	local abs_path = path.getabsolute(result_path)

	if found_dir and env_path ~= nil then

		abs_path = abs_path:gsub("\\", "/")

		env_path = env_path:gsub("\\", "/")

		local pos = abs_path:indexOf(env_path)

		if pos ~= nil then

			abs_path = abs_path:sub(1, pos - 1) .. "$(" .. env .. ")/" .. abs_path:sub(pos + #env_path)

		end

	end

	-- we want the path in terms of '/'

	return found_dir, abs_path