--!A cross-platform build utility based on Lua
--
-- Licensed 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-present, TBOOX Open Source Group.
--
-- @author      ruki
-- @file        policy.lua
--

-- define module: policy
local policy  = policy or {}

-- load modules
local os      = require("base/os")
local io      = require("base/io")
local path    = require("base/path")
local table   = require("base/table")
local utils   = require("base/utils")
local string  = require("base/string")

-- get all defined policies
function policy.policies()
    local policies = policy._POLICIES
    if not policies then
        policies = {
            -- we will check and ignore all unsupported flags by default, but we can also pass `{force = true}` to force to set flags, e.g. add_ldflags("-static", {force = true})
            ["check.auto_ignore_flags"]           = {description = "Enable check and ignore unsupported flags automatically.", default = true, type = "boolean"},
            -- we will map gcc flags to the current compiler and linker by default.
            ["check.auto_map_flags"]              = {description = "Enable map gcc flags to the current compiler and linker automatically.", default = true, type = "boolean"},
            -- we will check the compatibility of target and package licenses
            ["check.target_package_licenses"]     = {description = "Enable check the compatibility of target and package licenses.", default = true, type = "boolean"},
            -- we can compile the source files for each target in parallel
            ["build.across_targets_in_parallel"]  = {description = "Enable compile the source files for each target in parallel.", default = true, type = "boolean"},
            -- merge archive intead of linking for all dependent targets
            ["build.merge_archive"]               = {description = "Enable merge archive intead of linking for all dependent targets.", default = false, type = "boolean"},
            -- C/C++ build cache
            ["build.ccache"]                      = {description = "Enable C/C++ build cache.", type = "boolean"},
            -- enable build warning output, it's disabled by default and we need `xmake -w/-vD` to look at it.
            ["build.warning"]                     = {description = "Enable build warning output.", type = "boolean"},
            -- enable LTO linker-time optimization for c/c++ building.
            ["build.optimization.lto"]            = {description = "Enable LTO linker-time optimization for c/c++ building.", type = "boolean"},
            -- enable C++ modules for C++ building, even if no .mpp is involved in the compilation
            ["build.c++.modules"]                 = {description = "Enable C++ modules for C++ building.", type = "boolean"},
            -- enable clang std modulemap
            ["build.c++.clang.stdmodules"]        = {description = "Enable clang std modulemap.", default = false, type = "boolean"},
            -- force C++ modules fallback dependency scanner for clang
            ["build.c++.clang.fallbackscanner"]   = {description = "Force clang fallback module dependency scanner.", default = false, type = "boolean"},
            -- force C++ modules fallback dependency scanner for msvc
            ["build.c++.msvc.fallbackscanner"]    = {description = "Force msvc fallback module dependency scanner.", default = false, type = "boolean"},
            -- force C++ modules fallback dependency scanner for gcc
            ["build.c++.gcc.fallbackscanner"]     = {description = "Force gcc fallback module dependency scanner.", default = false, type = "boolean"},
            -- enable cuda device link
            ["build.cuda.devlink"]                = {description = "Enable Cuda devlink.", type = "boolean"},
            -- preprocessor configuration for ccache/distcc, we can disable linemarkers to speed up preprocess
            ["preprocessor.linemarkers"]          = {description = "Enable linemarkers for preprocessor.", default = true, type = "boolean"},
            -- preprocessor configuration for ccache/distcc, we can disable it to avoid cache object file with __DATE__, __TIME__
            ["preprocessor.gcc.directives_only"]  = {description = "Enable -fdirectives-only for gcc preprocessor.", type = "boolean"},
            -- we need enable longpaths when building target or installing package
            ["platform.longpaths"]                = {description = "Enable long paths when building target or installing package on windows.", default = false, type = "boolean"},
            -- lock required packages
            ["package.requires_lock"]             = {description = "Enable xmake-requires.lock to lock required packages.", default = false, type = "boolean"},
            -- enable the precompiled packages, it will be enabled by default
            ["package.precompiled"]               = {description = "Enable precompiled packages.", default = true, type = "boolean"},
            -- only fetch packages on system
            ["package.fetch_only"]                = {description = "Only fetch packages on system.", type = "boolean"},
            -- only install packages from remote
            ["package.install_only"]              = {description = "Only install packages from remote.", type = "boolean"},
            -- always install packages every time
            ["package.install_always"]            = {description = "Always install packages every time.", type = "boolean"},
            -- set custom headers when downloading package
            ["package.download.http_headers"]     = {description = "Set the custom http headers when downloading package."},
            -- use includes as external header files? e.g. -isystem ..
            ["package.include_external_headers"]  = {description = "Use includes as external headers.", type = "boolean"},
            -- inherit the configs from the external command arguments, e.g. toolchains, `xmake f --toolchain=`
            ["package.inherit_external_configs"]  = {description = "Inherit the configs from the external command arguments.", default = true, type = "boolean"},
            -- set strict compatibility for package and it's all child packages. we can just set it in package().
            -- if true, then any updates to this package, such as buildhash changes due to version changes,
            -- will force all installed child packages to be recompiled and installed, @see https://github.com/xmake-io/xmake/issues/2719
            ["package.strict_compatibility"]      = {description = "Set strict compatibility for package and it's all child packages.", type = "boolean"},
            -- set strict compatibility for package and it's all library dependencies. we can set it in package() and user project configuration.
            -- if true, then any updates to library dependencies, such as buildhash changes due to version changes,
            -- will force the installed packages to be recompiled and installed. @see https://github.com/xmake-io/xmake/issues/2719
            ["package.librarydeps.strict_compatibility"] = {description = "Set strict compatibility for package and it's all library dependencies.", type = "boolean"}
        }
        policy._POLICIES = policies
    end
    return policies
end

-- check policy value
function policy.check(name, value)
    local defined_policy = policy.policies()[name]
    if defined_policy then
        if value == nil then
            value = defined_policy.default
        else
            local valtype = type(value)
            if valtype ~= defined_policy.type then
                utils.warning("policy(%s): invalid value type(%s), it shound be '%s'!", name, valtype, defined_policy.type)
            end
        end
        return value
    else
        os.raise("unknown policy(%s)!", name)
    end
end

-- return module: policy
return policy