--!A cross-platform build utility based on Lua
--
-- Licensed to the Apache Software Foundation (ASF) under one
-- or more contributor license agreements.  See the NOTICE file
-- distributed with this work for additional information
-- regarding copyright ownership.  The ASF licenses this file
-- to you under the Apache License, Version 2.0 (the
-- "License"); you may not use this file except in compliance
-- with the License.  You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
-- 
-- Copyright (C) 2015 - 2018, TBOOX Open Source Group.
--
-- @author      ruki
-- @file        has_flags.lua
--

-- imports
import("lib.detect.cache")
import("core.language.language")

-- is linker?
function _islinker(flags, opt)
  
    -- the flags is "-Wl,<arg>" or "-Xlinker <arg>"?
    local flags_str = table.concat(flags, " ")
    if flags_str:startswith("-Wl,") or flags_str:startswith("-Xlinker ") then
        return true
    end

    -- the tool kind is ld or sh?
    local toolkind = opt.toolkind or ""
    return toolkind == "ld" or toolkind == "sh" or toolkind:endswith("-ld") or toolkind:endswith("-sh")
end

-- try running 
function _try_running(...)

    local argv = {...}
    local errors = nil
    return try { function () os.runv(unpack(argv)); return true end, catch { function (errs) errors = (errs or ""):trim() end }}, errors
end

-- attempt to check it from the argument list
function _check_from_arglist(flags, opt, islinker)

    -- check for the builtin flags
    local builtin_flags = {["-code"] = true, ["--gpu-code"] = true, ["-gencode"] = true, ["--generate-code"] = true, ["-arch"] = true, ["--gpu-architecture"] = true}
    if builtin_flags[flags[1]] then
        return true
    end

    -- check from the `--help` menu, only for linker
    if islinker or #flags > 1 then
        return 
    end

    -- make cache key
    local key = "detect.tools.nvcc.has_flags"

    -- make flags key
    local flagskey = opt.program .. "_" .. (opt.programver or "")

    -- load cache
    local cacheinfo  = cache.load(key)

    -- get all flags from argument list
    local allflags = cacheinfo[flagskey]
    if not allflags then

        -- get argument list
        allflags = {}
        local arglist = os.iorunv(opt.program, {"--help"})
        if arglist then
            for arg in arglist:gmatch("%s+(%-[%-%a%d]+)%s+") do
                allflags[arg] = true
            end
        end

        -- save cache
        cacheinfo[flagskey] = allflags
        cache.save(key, cacheinfo)
    end

    -- ok?
    return allflags[flags[1]]
end

-- try running to check flags
function _check_try_running(flags, opt, islinker)

    -- make an stub source file
    local sourcefile = path.join(os.tmpdir(), "detect", "nvcc_has_flags.cu")
    if not os.isfile(sourcefile) then
        io.writefile(sourcefile, "int main(int argc, char** argv)\n{return 0;}")
    end

    -- check flags
    return _try_running(opt.program, table.join(flags, "-o", os.nuldev(), sourcefile))
end

-- has_flags(flags)?
-- 
-- @param opt   the argument options, .e.g {toolname = "", program = "", programver = "", toolkind = "cu"}
--
-- @return      true or false
--
function main(flags, opt)

    -- is linker?
    local islinker = _islinker(flags, opt)

    -- attempt to check it from the argument list
    if _check_from_arglist(flags, opt, islinker) then
        return true
    end

    -- try running to check it
    return _check_try_running(flags, opt, islinker)
end