--!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, Xmake Open Source Community.
--
-- @author      ruki
-- @file        main.lua
--

-- imports
import("core.base.option")
import("core.base.global")
import("core.base.hashset")
import("core.tool.toolchain")
import("core.project.config")
import("core.project.project")
import("core.platform.platform")
import("private.detect.find_platform")
import("core.cache.localcache")
import("core.cache.detectcache")
import("scangen")
import("menuconf", {alias = "menuconf_show"})
import("configfiles", {alias = "generate_configfiles"})
import("private.action.require.register", {alias = "register_packages"})
import("private.action.require.install", {alias = "install_packages"})
import("private.service.remote_build.action", {alias = "remote_build_action"})
import("private.utils.target", {alias = "target_utils"})

-- filter option
function _option_filter(name)
    local options =
    {
        target      = true
    ,   file        = true
    ,   root        = true
    ,   yes         = true
    ,   quiet       = true
    ,   confirm     = true
    ,   project     = true
    ,   verbose     = true
    ,   diagnosis   = true
    ,   require     = true
    ,   export      = true
    ,   import      = true
    ,   check       = true
    ,   menu        = true
    }
    return not options[name]
end

-- host changed?
function _host_changed()
    return os.host() ~= config.read("host")
end

-- need check
function _need_check(changed)

    -- clean?
    if not changed then
        changed = option.get("clean") or option.get("check")
    end

    -- check for all project files
    local mtimes = project.mtimes()
    if not changed then
        local mtimes_prev = localcache.get("config", "mtimes")
        if mtimes_prev then
            for file, mtime in pairs(mtimes) do
                -- modified? reconfig and rebuild it
                local mtime_prev = mtimes_prev[file]
                if not mtime_prev or mtime > mtime_prev then
                    changed = true
                    break
                end
            end
        end
    end

    -- unfinished config/recheck
    if not changed and localcache.get("config", "recheck") then
        changed = true
    end

    -- Has xmake been updated? force to check config again
    -- we need to clean the dirty config cache of the old version
    if not changed then
        if os.mtime(path.join(os.programdir(), "core", "main.lua")) > os.mtime(config.filepath()) then
            changed = true
            os.touch(config.filepath(), {mtime = os.time()})
        end
    end
    return changed
end

-- check target
function _check_target(target, checked_targets)
    if not checked_targets[target:fullname()] then
        checked_targets[target:fullname()] = target
        for _, depname in ipairs(target:get("deps")) do
            local deptarget = project.target(depname, {namespace = target:namespace()})
            assert(deptarget, "unknown target(%s) for %s.deps!", depname, target:fullname())
            _check_target(deptarget, checked_targets)
        end
    end
end

-- check targets
function _check_targets()
    assert(not project.is_loaded(), "project and targets may have been loaded early!")
    local checked_targets = {}
    for _, target in pairs(project.targets()) do
        _check_target(target, checked_targets)
    end
end

-- find default mode
function _find_default_mode()
    local mode = config.mode()
    if not mode then
        mode = project.get("defaultmode")
        if not mode then
            mode = "release"
        end
        config.set("mode", mode)
    end
    return mode
end

-- check configs
function _check_configs()
    -- check allowed modes
    local mode = config.mode()
    local allowed_modes = project.allowed_modes()
    if allowed_modes then
        if not allowed_modes:has(mode) then
            local allowed_modes_str = table.concat(allowed_modes:to_array(), ", ")
            raise("`%s` is not a valid complation mode for this project, please use one of %s", mode, allowed_modes_str)
        end
    end

    -- check allowed plats
    local plat = config.plat()
    local allowed_plats = project.allowed_plats()
    if allowed_plats then
        if not allowed_plats:has(plat) then
            local allowed_plats_str = table.concat(allowed_plats:to_array(), ", ")
            raise("`%s` is not a valid platform for this project, please use one of %s", plat, allowed_plats_str)
        end
    end

    -- check allowed archs
    local arch = config.arch()
    local allowed_archs = project.allowed_archs(config.plat())
    if allowed_archs then
        if not allowed_archs:has(arch) then
            local allowed_archs_str = table.concat(allowed_archs:to_array(), ", ")
            raise("`%s` is not a valid complation arch for this project, please use one of %s", arch, allowed_archs_str)
        end
    end
end

-- export configs
function _export_configs()
    local exportfile = option.get("export")
    if exportfile then
        config.save(exportfile, {public = true})
    end
end

function main(opt)

    -- do action for remote?
    if remote_build_action.enabled() then
        return remote_build_action()
    end

    -- avoid running this task repeatly
    opt = opt or {}
    if _g.configured then return end
    _g.configured = true

    -- scan project and generate it if xmake.lua not exists
    local autogen = false
    local trybuild = option.get("trybuild")
    if not os.isfile(project.rootfile()) and not trybuild then
        autogen = utils.confirm({default = false, description = "xmake.lua not found, try generating it"})
        if autogen then
            scangen()
        else
            os.exit()
        end
    end

    -- check the working directory
    if not option.get("project") and not option.get("file") and -- no given project path
        not localcache.get("project", "projectdir") and -- no cached project path
        not localcache.get("project", "projectfile") and
        os.isdir(os.projectdir()) then
        if path.translate(os.projectdir()) ~= path.translate(os.workingdir()) then
            wprint([[You are working in the project directory(%s) and you can also
force to build in current directory via run `xmake -P .`]], os.projectdir())
        end
    end

    -- lock the whole project
    project.lock()

    -- enter menu config
    local options_changed = false
    if option.get("menu") then
        options_changed = menuconf_show()
    end

    -- load the project configuration
    --
    -- priority: option > option_cache > global > option_default > config_check > project_check > config_cache
    --

    -- get the options
    local options = nil
    for name, value in pairs(option.options()) do
        if _option_filter(name) then
            options = options or {}
            options[name] = value
        end
    end

    -- merge options from the given import file
    local importfile = option.get("import")
    if importfile then
        assert(os.isfile(importfile), "%s not found!", importfile)
        -- we need to use readonly, @see https://github.com/xmake-io/xmake/issues/2278
        local import_configs = io.load(importfile)
        if import_configs then
            for name, value in pairs(import_configs) do
                options = options or {}
                if options[name] == nil then
                    options[name] = value
                end
            end
        end
    end

    -- override configuration from the options or cache
    local options_history = {}
    if not option.get("clean") and not autogen then
        options_history = localcache.get("config", "options") or {}
        options = options or options_history
    end
    for name, value in pairs(options) do
        -- Is options changed by argument options?
        options_changed = options_changed or options_history[name] ~= value
        -- @note override it and mark as readonly (highest priority)
        config.set(name, value, {readonly = true})
    end

    -- merge the cached configuration
    --
    -- @note we cannot load cache config when switching platform, arch ..
    -- so we need known whether options have been changed
    --
    local configcache_loaded = false
    if not options_changed and not option.get("clean") and not _host_changed() then
        configcache_loaded = config.load()
    end

    -- merge the global configuration
    for name, value in pairs(global.options()) do
        if config.get(name) == nil then
            config.set(name, value)
        end
    end

    -- merge the default options
    for name, value in pairs(option.defaults()) do
        if _option_filter(name) and config.get(name) == nil then
            config.set(name, value)
        end
    end

    -- merge the project options after default options
    for name, value in pairs(project.get("config")) do
        local value = table.unwrap(value)
        assert(type(value) == "string" or type(value) == "boolean" or type(value) == "number", "set_config(%s): unsupported value type(%s)", name, type(value))
        if not config.readonly(name) then
            config.set(name, value)
        end
    end

    -- find default mode
    local mode = _find_default_mode()
    assert(mode == config.mode())

    -- find default platform and save to configuration
    local plat, arch = find_platform({global = true})
    assert(plat == config.plat())
    assert(arch == config.arch())

    -- load platform instance
    local instance_plat = platform.load(plat, arch)

    -- merge the checked configuration
    local recheck = _need_check(options_changed or not configcache_loaded or autogen)
    if recheck then

        -- clear cached configuration
        if option.get("clean") then
            localcache.clear("config")
        end

        -- clear some local caches
        localcache.clear("detect")
        localcache.clear("option")
        localcache.clear("package")
        localcache.clear("toolchain")
        localcache.set("config", "recheck", true)
        if not opt.loadonly then
            localcache.save()
        end

        -- check platform
        instance_plat:check()

        -- check project options
        if not trybuild then
            project.check_options()
        end
    end

    -- translate the build directory
    local builddir = config.get("builddir")
    if config.get("buildir") then
        wprint("`xmake f --buildir=` has been deprecated, please use `xmake f -o/--builddir=`")
        builddir = config.get("buildir")
        config.set("builddir", builddir, {readonly = true, force = true})
    end
    if builddir and path.is_absolute(builddir) then
        config.set("builddir", path.relative(builddir, project.directory()), {readonly = true, force = true})
    end

    -- only config for building project using third-party buildsystem
    if not trybuild then

        -- check configs
        _check_configs()

        -- install and register packages
        local require_enable = option.boolean(option.get("require"))
        if (recheck or require_enable) then
            if require_enable ~= false then
                install_packages()
            else
                register_packages()
            end
        end

        -- check target and ensure to load all targets, @note we must load targets after installing required packages,
        -- otherwise has_package() will be invalid.
        _check_targets()

        -- check target toolchains
        if recheck then
            target_utils.check_target_toolchains()
        end

        -- load targets
        project.load_targets({recheck = recheck})

        -- update the config files
        generate_configfiles({force = recheck})
    end

    -- dump config
    if option.get("verbose") and not opt.disable_dump then
        config.dump()
    end

    -- export configs
    if option.get("export") then
        _export_configs()
    end

    -- save configs and caches
    if not opt.loadonly then
        -- we need to save it and enable external working mode
        -- if we configure the given project directory
        --
        -- @see https://github.com/xmake-io/xmake/issues/3342
        --
        local projectdir = option.get("project")
        local projectfile = option.get("file")
        if projectdir or projectfile then
            localcache.set("project", "projectdir", projectdir)
            localcache.set("project", "projectfile", projectfile)
            localcache.save("project")
        end

        -- save options and config cache
        localcache.set("config", "recheck", false)
        localcache.set("config", "mtimes", project.mtimes())
        config.save()
        localcache.set("config", "options", options)
        localcache.save("config")

        -- save toolchain cache
        toolchain.save()

        -- save detect cache
        detectcache:save()
    end

    -- unlock the whole project
    project.unlock()
end