// Copyright 2016 Google Inc. All rights reserved.
//
// 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.

package config

import (
	"android/soong/android"
	"strings"
)

func init() {
	// Most Android source files are not clang-tidy clean yet.
	// Global tidy checks include only google*, performance*,
	// and misc-macro-parentheses, but not google-readability*
	// or google-runtime-references.
	pctx.VariableFunc("TidyDefaultGlobalChecks", func(ctx android.PackageVarContext) string {
		if override := ctx.Config().Getenv("DEFAULT_GLOBAL_TIDY_CHECKS"); override != "" {
			return override
		}
		return strings.Join([]string{
			"-*",
			"clang-diagnostic-unused-command-line-argument",
			"google*",
			"misc-macro-parentheses",
			"performance*",
			"-google-readability*",
			"-google-runtime-references",
		}, ",")
	})

	// There are too many clang-tidy warnings in external and vendor projects.
	// Enable only some google checks for these projects.
	pctx.VariableFunc("TidyExternalVendorChecks", func(ctx android.PackageVarContext) string {
		if override := ctx.Config().Getenv("DEFAULT_EXTERNAL_VENDOR_TIDY_CHECKS"); override != "" {
			return override
		}
		return strings.Join([]string{
			"-*",
			"clang-diagnostic-unused-command-line-argument",
			"google*",
			"-google-build-using-namespace",
			"-google-default-arguments",
			"-google-explicit-constructor",
			"-google-readability*",
			"-google-runtime-int",
			"-google-runtime-references",
		}, ",")
	})

	// Give warnings to header files only in selected directories.
	// Do not give warnings to external or vendor header files, which contain too
	// many warnings.
	pctx.VariableFunc("TidyDefaultHeaderDirs", func(ctx android.PackageVarContext) string {
		if override := ctx.Config().Getenv("DEFAULT_TIDY_HEADER_DIRS"); override != "" {
			return override
		}
		return strings.Join([]string{
			"art/",
			"bionic/",
			"bootable/",
			"build/",
			"cts/",
			"dalvik/",
			"developers/",
			"development/",
			"frameworks/",
			"libcore/",
			"libnativehelper/",
			"system/",
		}, "|")
	})

	// Use WTIH_TIDY_FLAGS to pass extra global default clang-tidy flags.
	pctx.VariableFunc("TidyWithTidyFlags", func(ctx android.PackageVarContext) string {
		return ctx.Config().Getenv("WITH_TIDY_FLAGS")
	})
}

type PathBasedTidyCheck struct {
	PathPrefix string
	Checks     string
}

const tidyDefault = "${config.TidyDefaultGlobalChecks}"
const tidyExternalVendor = "${config.TidyExternalVendorChecks}"

// This is a map of local path prefixes to the set of default clang-tidy checks
// to be used.
// The last matched local_path_prefix should be the most specific to be used.
var DefaultLocalTidyChecks = []PathBasedTidyCheck{
	{"external/", tidyExternalVendor},
	{"external/google", tidyDefault},
	{"external/webrtc", tidyDefault},
	{"frameworks/compile/mclinker/", tidyExternalVendor},
	{"hardware/qcom", tidyExternalVendor},
	{"vendor/", tidyExternalVendor},
	{"vendor/google", tidyDefault},
	{"vendor/google_devices", tidyExternalVendor},
}

var reversedDefaultLocalTidyChecks = reverseTidyChecks(DefaultLocalTidyChecks)

func reverseTidyChecks(in []PathBasedTidyCheck) []PathBasedTidyCheck {
	ret := make([]PathBasedTidyCheck, len(in))
	for i, check := range in {
		ret[len(in)-i-1] = check
	}
	return ret
}

func TidyChecksForDir(dir string) string {
	for _, pathCheck := range reversedDefaultLocalTidyChecks {
		if strings.HasPrefix(dir, pathCheck.PathPrefix) {
			return pathCheck.Checks
		}
	}
	return tidyDefault
}