--!The Automatic Cross-platform Build Tool
-- 
-- XMake is free software; you can redistribute it and/or modify
-- it under the terms of the GNU Lesser General Public License as published by
-- the Free Software Foundation; either version 2.1 of the License, or
-- (at your option) any later version.
-- 
-- XMake is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU Lesser General Public License for more details.
-- 
-- You should have received a copy of the GNU Lesser General Public License
-- along with XMake; 
-- If not, see <a href="http://www.gnu.org/licenses/"> http://www.gnu.org/licenses/</a>
-- 
-- Copyright (C) 2015 - 2016, ruki All rights reserved.
--
-- @author      ruki
-- @file        configheader.lua
--

-- imports
import("core.base.option")
import("core.project.config")
import("core.project.project")

-- make configure for the given target name
function _make_for_target(files, target)

    -- get the target configure file 
    local configheader = target:configheader()
    if not configheader then return end

    -- the prefix
    local prefix = target:get("config_h_prefix") or (target:name():upper() .. "_CONFIG")

    -- open the file
    local file = files[configheader] or io.open(configheader, "w")

    -- make the head
    if files[configheader] then file:print("") end
    file:print("#ifndef %s_H", prefix)
    file:print("#define %s_H", prefix)
    file:print("")

    -- make version
    local version = target:get("version")
    if version then
        file:print("// version")
        file:print("#define %s_VERSION \"%s\"", prefix, version)
        local i = 1
        local m = {"MAJOR", "MINOR", "ALTER"}
        for v in version:gmatch("%d+") do
            file:print("#define %s_VERSION_%s %s", prefix, m[i], v)
            i = i + 1
            if i > 3 then break end
        end
        file:print("#define %s_VERSION_BUILD %s", prefix, os.date("%Y%m%d%H%M", os.time()))
        file:print("")
    end

    -- make the defines
    local defines = table.copy(target:get("defines_h")) 

    -- make the undefines
    local undefines = table.copy(target:get("undefines_h")) 

    -- make the options
    for name, opt in pairs(target:options()) do

        -- get the option defines
        table.join2(defines, opt:get("defines_h_if_ok")) 

        -- get the option undefines
        table.join2(undefines, opt:get("undefines_h_if_ok")) 
    end

    -- make the defines
    if #defines ~= 0 then
        file:print("// defines")
        for _, define in ipairs(defines) do
            if define:find("=") then
                file:print("#define %s", define:gsub("=", " "):gsub("%$%((.-)%)", function (w) if w == "prefix" then return prefix end end))
            else
                file:print("#define %s 1", define:gsub("%$%((.-)%)", function (w) if w == "prefix" then return prefix end end))
            end
        end
        file:print("")
    end

    -- make the undefines 
    if #undefines ~= 0 then
        file:print("// undefines")
        for _, undefine in ipairs(undefines) do
            file:print("#undef %s", undefine:gsub("%$%((.-)%)", function (w) if w == "prefix" then return prefix end end))
        end
        file:print("")
    end

    -- make the tail
    file:print("#endif")

    -- cache the file
    files[configheader] = file

end

-- make the configure file for the given target and dependents
function _make_for_target_with_deps(files, targetname)

    -- the target
    local target = project.target(targetname)

    -- make configure for the target
    _make_for_target(files, target)
     
    -- make configure for the dependent targets?
    for _, dep in ipairs(target:get("deps")) do
        _make_for_target_with_deps(files, dep)
    end

end

-- make the config.h
function make()

    -- the target name
    local targetname = option.get("target")

    -- enter project directory
    local olddir = os.cd(project.directory())

    -- init files
    local files = {}

    -- make configure for the given target name
    if targetname and targetname ~= "all" then
        _make_for_target_with_deps(files, targetname)
    else

        -- make configure for all targets
        for _, target in pairs(project.targets()) do
            _make_for_target(files, target)
        end
    end

    -- exit files
    for _, file in pairs(files) do
        file:close()
    end
 
    -- leave project directory
    os.cd(olddir)
end