// Copyright 2019 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 java

import (
	"android/soong/android"
	"fmt"
)

func init() {
	android.RegisterSingletonType("platform_compat_config_singleton", platformCompatConfigSingletonFactory)
	android.RegisterModuleType("platform_compat_config", PlatformCompatConfigFactory)
	android.RegisterModuleType("global_compat_config", globalCompatConfigFactory)
}

func platformCompatConfigPath(ctx android.PathContext) android.OutputPath {
	return android.PathForOutput(ctx, "compat_config", "merged_compat_config.xml")
}

type platformCompatConfigSingleton struct {
	metadata android.Path
}

type platformCompatConfigProperties struct {
	Src *string `android:"path"`
}

type platformCompatConfig struct {
	android.ModuleBase

	properties     platformCompatConfigProperties
	installDirPath android.InstallPath
	configFile     android.OutputPath
	metadataFile   android.OutputPath
}

func (p *platformCompatConfig) compatConfigMetadata() android.OutputPath {
	return p.metadataFile
}

func (p *platformCompatConfig) CompatConfig() android.OutputPath {
	return p.configFile
}

func (p *platformCompatConfig) SubDir() string {
	return "compatconfig"
}

type PlatformCompatConfigIntf interface {
	android.Module

	compatConfigMetadata() android.OutputPath
	CompatConfig() android.OutputPath
	// Sub dir under etc dir.
	SubDir() string
}

var _ PlatformCompatConfigIntf = (*platformCompatConfig)(nil)

// compat singleton rules
func (p *platformCompatConfigSingleton) GenerateBuildActions(ctx android.SingletonContext) {

	var compatConfigMetadata android.Paths

	ctx.VisitAllModules(func(module android.Module) {
		if c, ok := module.(PlatformCompatConfigIntf); ok {
			metadata := c.compatConfigMetadata()
			compatConfigMetadata = append(compatConfigMetadata, metadata)
		}
	})

	if compatConfigMetadata == nil {
		// nothing to do.
		return
	}

	rule := android.NewRuleBuilder()
	outputPath := platformCompatConfigPath(ctx)

	rule.Command().
		BuiltTool(ctx, "process-compat-config").
		FlagForEachInput("--xml ", compatConfigMetadata).
		FlagWithOutput("--merged-config ", outputPath)

	rule.Build(pctx, ctx, "merged-compat-config", "Merge compat config")

	p.metadata = outputPath
}

func (p *platformCompatConfigSingleton) MakeVars(ctx android.MakeVarsContext) {
	if p.metadata != nil {
		ctx.Strict("INTERNAL_PLATFORM_MERGED_COMPAT_CONFIG", p.metadata.String())
	}
}

func (p *platformCompatConfig) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	rule := android.NewRuleBuilder()

	configFileName := p.Name() + ".xml"
	metadataFileName := p.Name() + "_meta.xml"
	p.configFile = android.PathForModuleOut(ctx, configFileName).OutputPath
	p.metadataFile = android.PathForModuleOut(ctx, metadataFileName).OutputPath
	path := android.PathForModuleSrc(ctx, String(p.properties.Src))

	rule.Command().
		BuiltTool(ctx, "process-compat-config").
		FlagWithInput("--jar ", path).
		FlagWithOutput("--device-config ", p.configFile).
		FlagWithOutput("--merged-config ", p.metadataFile)

	p.installDirPath = android.PathForModuleInstall(ctx, "etc", "compatconfig")
	rule.Build(pctx, ctx, configFileName, "Extract compat/compat_config.xml and install it")

}

func (p *platformCompatConfig) AndroidMkEntries() []android.AndroidMkEntries {
	return []android.AndroidMkEntries{android.AndroidMkEntries{
		Class:      "ETC",
		OutputFile: android.OptionalPathForPath(p.configFile),
		Include:    "$(BUILD_PREBUILT)",
		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
			func(entries *android.AndroidMkEntries) {
				entries.SetString("LOCAL_MODULE_PATH", p.installDirPath.ToMakePath().String())
				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", p.configFile.Base())
			},
		},
	}}
}

func platformCompatConfigSingletonFactory() android.Singleton {
	return &platformCompatConfigSingleton{}
}

func PlatformCompatConfigFactory() android.Module {
	module := &platformCompatConfig{}
	module.AddProperties(&module.properties)
	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
	return module
}

//============== merged_compat_config =================
type globalCompatConfigProperties struct {
	// name of the file into which the metadata will be copied.
	Filename *string
}

type globalCompatConfig struct {
	android.ModuleBase

	properties globalCompatConfigProperties

	outputFilePath android.OutputPath
}

func (c *globalCompatConfig) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	filename := String(c.properties.Filename)

	inputPath := platformCompatConfigPath(ctx)
	c.outputFilePath = android.PathForModuleOut(ctx, filename).OutputPath

	// This ensures that outputFilePath has the correct name for others to
	// use, as the source file may have a different name.
	ctx.Build(pctx, android.BuildParams{
		Rule:   android.Cp,
		Output: c.outputFilePath,
		Input:  inputPath,
	})
}

func (h *globalCompatConfig) OutputFiles(tag string) (android.Paths, error) {
	switch tag {
	case "":
		return android.Paths{h.outputFilePath}, nil
	default:
		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
	}
}

// global_compat_config provides access to the merged compat config xml file generated by the build.
func globalCompatConfigFactory() android.Module {
	module := &globalCompatConfig{}
	module.AddProperties(&module.properties)
	android.InitAndroidArchModule(module, android.HostAndDeviceSupported, android.MultilibCommon)
	return module
}