-- Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>

 --

 -- 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>

 --[[

 sdl_file.lua

 	This function contains a wrapper for the I/O file operations, providing a few

 	custom functions which simplify the file I/O process (especially useful for

 	the vast amount of generation used by the meta-build system).

 ]]

 -- Given a filename and open mode (look at io.open for more information), opens

 -- the file with various contained functions for printing to the file, writing

 -- to the file, reading from the file, or closing the file. If the filename is

 -- nil, then this will open a file in a special text mode. In that case, the

 -- mode is ignored. Returned is an instanced table with all of the

 -- aforementioned functions.

 --

 -- The print function is associated with textprint/fileprint, the write function

 -- with textwrite/filewrite, the read function with fileread, and the close

 -- function with textclose/fileclose.

 function fileopen(file, mode)

 	if file == nil then

 		return { texth = "", print = textprint, write = textwrite, read = nil, close = textclose }

 	else

 		return { fileh = io.open(file, mode), print = fileprint, write = filewrite, read = fileread, close = fileclose }

 	end

 end

 -- Given a filename and file mode, reads the entire contents of the file and

 -- returns the contents as a string.

 function readfile(file, mode)

 	local file = fileopen(file, mode)

 	local content = file:read()

 	file:close()

 	return content

 end

 -- Given a file, the number of tabs to indent, and a line to print, append the

 -- line tabbed n times with an appended newline to the end of the input text.

 function textprint(f, tabs, line)

 	for i = 0, tabs - 1, 1 do

 		f.texth = f.texth .. "\t"

 	end

 	f.texth = f.texth .. line .. "\n"

 end

 -- Given a file, the number of tabs to indent, and a line to print, append the

 -- line tabbed n times with an appended newline to the end of the input file.

 function fileprint(f, tabs, line)

 	for i = 0, tabs - 1, 1 do

 		f.fileh:write("\t")

 	end

 	f.fileh:write(line .. "\n")

 end

 -- Given a file and some text, append the text to the end of the input text.

 function textwrite(f, text)

 	f.texth = f.texth .. text

 end

 -- Given a file and some text, append the text to the end of the input file.

 function filewrite(f, text)

 	f.fileh:write(text)

 end

 -- Given a file, read all the contents of the file and return them as a string.

 function fileread(file)

 	return file.fileh:read("*all")

 end

 -- Given a file opened in text mode, return the result of the current file

 -- operations as a text string.

 function textclose(file)

 	return file.texth

 end

 -- Given a file opened regularly, close the file handle resource, preventing

 -- any future I/O operations.

 function fileclose(file)

 	file.fileh:close()

 end

 -- Given a source path, builds a table containing all directories and recursive

 -- subdirectories which contain files, and returns the table. Each entry in the

 -- table will have a '/' at the end of its path, plus they will all be relative

 -- to the parent source path. The table will contain a single entry with the

 -- value '/' to indicate the source path itself.

 function createDirTable(sourcePath)

 	local dirs = os.matchdirs(sourcePath.."/**")

 	for k,d in pairs(dirs) do

 		dirs[k] = string.sub(d, #sourcePath + 1) .. "/"

 	end

 	table.insert(dirs, "/")

 	return dirs

 end

 -- This works like os.pathsearch, but for directories. Look at the premake

 -- documentation for os.pathsearch for more information.

 os.dirpathsearch = function(subdir, path, path_delimiter)

 	for i,p in ipairs(explode(path, path_delimiter)) do

 		local needle = p .. "/" .. subdir

 		if os.isdir(needle) then

 			return needle

 		end

 	end

 	return nil

 end

 -- Given a variable number of environmental variable names, this will join them

 -- together based on the current OS path delimeter and quietly ignoring those

 -- variables which do not exist on this system. The resulting path is always

 -- normalized for Unix-based path separators, regardless of the system.

 os.getenvpath = function(...)

 	local path = ""

 	local pathDelimeter = ":"

 	if os.is("windows") then

 		pathDelimeter = ";"

 	end

 	for i,a in ipairs(arg) do

 		local value = os.getenv(a)

 		if value then

 			if #path > 0 then

 				path = path .. pathDelimeter

 			end

 			path = path .. value

 		end

 	end

 	-- normalize path to unix

 	return path:gsub("\\", "/"):gsub("//", "/")

 end