--

-- 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_gen_config.lua

	Given a series of set configuration values from the project definitions,

	this file contains a series of functions that generate valid preprocessor

	definitions to enable or disable various features of the SDL2 library. These

	definitions are pasted into a template SDL config header file, which is then

	saved in the local directory and referenced to in generated project files.

	This file depends on sdl_file.lua.

]]

-- The line that must exist in the template file in order to properly paste

-- the generated definitions.

local searchKey = "/%* Paste generated code here %*/\n"

local configFile, templateFileContents

local insertLocation

-- This function begins config header generation given the name of the generated

-- file and the name of the template file to use.

function startGeneration(file, template)

	configFile = fileopen(file, "wt")

	templateFileContents = readfile(template, "rt")

	insertLocation = templateFileContents:find(searchKey)

	if insertLocation then

		configFile:write(templateFileContents:sub(1, insertLocation - 1))

	end

end

-- Adds a table of configuration values to the generated file. Each

-- configuration line is wrapped around a preprocessor definition check, so they

-- can be manually overwritten by the developer if necessary. The definition

-- pastes string versions of both the key and the value on the line, where

-- either is allowed to be empty. That means the table stores key-value pairs.

function addConfig(tbl)

	-- if no insert location, don't paste anything

	if not insertLocation then return end

	for k,v in pairs(tbl) do

		configFile:print(0, "#ifndef " .. k)

		configFile:print(0, "#define " .. tostring(k) .. " " .. tostring(v))

		configFile:print(0, "#endif")

	end

end

-- Finishes the generation and writes the remains of the template file into the

-- generated config file.

function endGeneration()

	if insertLocation then

		configFile:write(templateFileContents:sub(insertLocation + #searchKey - 2))

	else -- write entire file since nothing is being pasted

		configFile:write(templateFileContents)

	end

	configFile:close()

end