// Copyright 2015 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

// This file contains the module types for compiling Android apps.

import (
	"path/filepath"
	"reflect"
	"strings"

	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/cc"
	"android/soong/tradefed"
)

var supportedDpis = [...]string{"Ldpi", "Mdpi", "Hdpi", "Xhdpi", "Xxhdpi", "Xxxhdpi"}
var dpiVariantsStruct reflect.Type

func init() {
	android.RegisterModuleType("android_app", AndroidAppFactory)
	android.RegisterModuleType("android_test", AndroidTestFactory)
	android.RegisterModuleType("android_test_helper_app", AndroidTestHelperAppFactory)
	android.RegisterModuleType("android_app_certificate", AndroidAppCertificateFactory)
	android.RegisterModuleType("override_android_app", OverrideAndroidAppModuleFactory)
	android.RegisterModuleType("android_app_import", AndroidAppImportFactory)

	// Dynamically construct a struct for the dpi_variants property in android_app_import.
	perDpiStruct := reflect.StructOf([]reflect.StructField{
		{
			Name: "Apk",
			Type: reflect.TypeOf((*string)(nil)),
		},
	})
	dpiVariantsFields := make([]reflect.StructField, len(supportedDpis))
	for i, dpi := range supportedDpis {
		dpiVariantsFields[i] = reflect.StructField{
			Name: string(dpi),
			Type: perDpiStruct,
		}
	}
	dpiVariantsStruct = reflect.StructOf(dpiVariantsFields)
}

// AndroidManifest.xml merging
// package splits

type appProperties struct {
	// Names of extra android_app_certificate modules to sign the apk with in the form ":module".
	Additional_certificates []string

	// If set, create package-export.apk, which other packages can
	// use to get PRODUCT-agnostic resource data like IDs and type definitions.
	Export_package_resources *bool

	// Specifies that this app should be installed to the priv-app directory,
	// where the system will grant it additional privileges not available to
	// normal apps.
	Privileged *bool

	// list of resource labels to generate individual resource packages
	Package_splits []string

	// Names of modules to be overridden. Listed modules can only be other binaries
	// (in Make or Soong).
	// This does not completely prevent installation of the overridden binaries, but if both
	// binaries would be installed by default (in PRODUCT_PACKAGES) the other binary will be removed
	// from PRODUCT_PACKAGES.
	Overrides []string

	// list of native libraries that will be provided in or alongside the resulting jar
	Jni_libs []string `android:"arch_variant"`

	// STL library to use for JNI libraries.
	Stl *string `android:"arch_variant"`

	// Store native libraries uncompressed in the APK and set the android:extractNativeLibs="false" manifest
	// flag so that they are used from inside the APK at runtime.  Defaults to true for android_test modules unless
	// sdk_version or min_sdk_version is set to a version that doesn't support it (<23), defaults to false for other
	// module types where the native libraries are generally preinstalled outside the APK.
	Use_embedded_native_libs *bool

	// Store dex files uncompressed in the APK and set the android:useEmbeddedDex="true" manifest attribute so that
	// they are used from inside the APK at runtime.
	Use_embedded_dex *bool

	// Forces native libraries to always be packaged into the APK,
	// Use_embedded_native_libs still selects whether they are stored uncompressed and aligned or compressed.
	// True for android_test* modules.
	AlwaysPackageNativeLibs bool `blueprint:"mutated"`
}

// android_app properties that can be overridden by override_android_app
type overridableAppProperties struct {
	// The name of a certificate in the default certificate directory, blank to use the default product certificate,
	// or an android_app_certificate module name in the form ":module".
	Certificate *string

	// the package name of this app. The package name in the manifest file is used if one was not given.
	Package_name *string
}

type AndroidApp struct {
	Library
	aapt
	android.OverridableModuleBase

	usesLibrary usesLibrary

	certificate Certificate

	appProperties appProperties

	overridableAppProperties overridableAppProperties

	installJniLibs []jniLib

	bundleFile android.Path

	// the install APK name is normally the same as the module name, but can be overridden with PRODUCT_PACKAGE_NAME_OVERRIDES.
	installApkName string

	additionalAaptFlags []string
}

func (a *AndroidApp) ExportedProguardFlagFiles() android.Paths {
	return nil
}

func (a *AndroidApp) ExportedStaticPackages() android.Paths {
	return nil
}

var _ AndroidLibraryDependency = (*AndroidApp)(nil)

type Certificate struct {
	Pem, Key android.Path
}

func (a *AndroidApp) DepsMutator(ctx android.BottomUpMutatorContext) {
	a.Module.deps(ctx)

	if String(a.appProperties.Stl) == "c++_shared" && a.sdkVersion() == "" {
		ctx.PropertyErrorf("stl", "sdk_version must be set in order to use c++_shared")
	}

	if !Bool(a.properties.No_framework_libs) && !Bool(a.properties.No_standard_libs) {
		a.aapt.deps(ctx, sdkContext(a))
	}

	embedJni := a.shouldEmbedJnis(ctx)
	for _, jniTarget := range ctx.MultiTargets() {
		variation := []blueprint.Variation{
			{Mutator: "arch", Variation: jniTarget.String()},
			{Mutator: "link", Variation: "shared"},
		}
		tag := &jniDependencyTag{
			target: jniTarget,
		}
		ctx.AddFarVariationDependencies(variation, tag, a.appProperties.Jni_libs...)
		if String(a.appProperties.Stl) == "c++_shared" {
			if embedJni {
				ctx.AddFarVariationDependencies(variation, tag, "libc++")
			}
		}
	}

	a.usesLibrary.deps(ctx, Bool(a.properties.No_framework_libs))
}

func (a *AndroidApp) OverridablePropertiesDepsMutator(ctx android.BottomUpMutatorContext) {
	cert := android.SrcIsModule(a.getCertString(ctx))
	if cert != "" {
		ctx.AddDependency(ctx.Module(), certificateTag, cert)
	}

	for _, cert := range a.appProperties.Additional_certificates {
		cert = android.SrcIsModule(cert)
		if cert != "" {
			ctx.AddDependency(ctx.Module(), certificateTag, cert)
		} else {
			ctx.PropertyErrorf("additional_certificates",
				`must be names of android_app_certificate modules in the form ":module"`)
		}
	}
}

func (a *AndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	a.aapt.useEmbeddedNativeLibs = a.useEmbeddedNativeLibs(ctx)
	a.aapt.useEmbeddedDex = Bool(a.appProperties.Use_embedded_dex)
	a.generateAndroidBuildActions(ctx)
}

// Returns true if the native libraries should be stored in the APK uncompressed and the
// extractNativeLibs application flag should be set to false in the manifest.
func (a *AndroidApp) useEmbeddedNativeLibs(ctx android.ModuleContext) bool {
	minSdkVersion, err := sdkVersionToNumber(ctx, a.minSdkVersion())
	if err != nil {
		ctx.PropertyErrorf("min_sdk_version", "invalid value %q: %s", a.minSdkVersion(), err)
	}

	return minSdkVersion >= 23 && Bool(a.appProperties.Use_embedded_native_libs)
}

// Returns whether this module should have the dex file stored uncompressed in the APK.
func (a *AndroidApp) shouldUncompressDex(ctx android.ModuleContext) bool {
	if Bool(a.appProperties.Use_embedded_dex) {
		return true
	}

	if ctx.Config().UnbundledBuild() {
		return false
	}

	// Uncompress dex in APKs of privileged apps
	if ctx.Config().UncompressPrivAppDex() && Bool(a.appProperties.Privileged) {
		return true
	}

	return shouldUncompressDex(ctx, &a.dexpreopter)
}

func (a *AndroidApp) shouldEmbedJnis(ctx android.BaseModuleContext) bool {
	return ctx.Config().UnbundledBuild() || Bool(a.appProperties.Use_embedded_native_libs) ||
		a.appProperties.AlwaysPackageNativeLibs
}

func (a *AndroidApp) aaptBuildActions(ctx android.ModuleContext) {
	a.aapt.usesNonSdkApis = Bool(a.Module.deviceProperties.Platform_apis)

	// Ask manifest_fixer to add or update the application element indicating this app has no code.
	a.aapt.hasNoCode = !a.hasCode(ctx)

	aaptLinkFlags := []string{}

	// Add TARGET_AAPT_CHARACTERISTICS values to AAPT link flags if they exist and --product flags were not provided.
	hasProduct := false
	for _, f := range a.aaptProperties.Aaptflags {
		if strings.HasPrefix(f, "--product") {
			hasProduct = true
			break
		}
	}
	if !hasProduct && len(ctx.Config().ProductAAPTCharacteristics()) > 0 {
		aaptLinkFlags = append(aaptLinkFlags, "--product", ctx.Config().ProductAAPTCharacteristics())
	}

	if !Bool(a.aaptProperties.Aapt_include_all_resources) {
		// Product AAPT config
		for _, aaptConfig := range ctx.Config().ProductAAPTConfig() {
			aaptLinkFlags = append(aaptLinkFlags, "-c", aaptConfig)
		}

		// Product AAPT preferred config
		if len(ctx.Config().ProductAAPTPreferredConfig()) > 0 {
			aaptLinkFlags = append(aaptLinkFlags, "--preferred-density", ctx.Config().ProductAAPTPreferredConfig())
		}
	}

	manifestPackageName, overridden := ctx.DeviceConfig().OverrideManifestPackageNameFor(ctx.ModuleName())
	if overridden || a.overridableAppProperties.Package_name != nil {
		// The product override variable has a priority over the package_name property.
		if !overridden {
			manifestPackageName = *a.overridableAppProperties.Package_name
		}
		aaptLinkFlags = append(aaptLinkFlags, "--rename-manifest-package "+manifestPackageName)
	}

	aaptLinkFlags = append(aaptLinkFlags, a.additionalAaptFlags...)

	a.aapt.splitNames = a.appProperties.Package_splits
	a.aapt.sdkLibraries = a.exportedSdkLibs

	a.aapt.buildActions(ctx, sdkContext(a), aaptLinkFlags...)

	// apps manifests are handled by aapt, don't let Module see them
	a.properties.Manifest = nil
}

func (a *AndroidApp) proguardBuildActions(ctx android.ModuleContext) {
	var staticLibProguardFlagFiles android.Paths
	ctx.VisitDirectDeps(func(m android.Module) {
		if lib, ok := m.(AndroidLibraryDependency); ok && ctx.OtherModuleDependencyTag(m) == staticLibTag {
			staticLibProguardFlagFiles = append(staticLibProguardFlagFiles, lib.ExportedProguardFlagFiles()...)
		}
	})

	staticLibProguardFlagFiles = android.FirstUniquePaths(staticLibProguardFlagFiles)

	a.Module.extraProguardFlagFiles = append(a.Module.extraProguardFlagFiles, staticLibProguardFlagFiles...)
	a.Module.extraProguardFlagFiles = append(a.Module.extraProguardFlagFiles, a.proguardOptionsFile)
}

func (a *AndroidApp) dexBuildActions(ctx android.ModuleContext) android.Path {

	var installDir string
	if ctx.ModuleName() == "framework-res" {
		// framework-res.apk is installed as system/framework/framework-res.apk
		installDir = "framework"
	} else if Bool(a.appProperties.Privileged) {
		installDir = filepath.Join("priv-app", a.installApkName)
	} else {
		installDir = filepath.Join("app", a.installApkName)
	}

	a.dexpreopter.installPath = android.PathForModuleInstall(ctx, installDir, a.installApkName+".apk")
	a.dexpreopter.isInstallable = Bool(a.properties.Installable)
	a.dexpreopter.uncompressedDex = a.shouldUncompressDex(ctx)

	a.dexpreopter.enforceUsesLibs = a.usesLibrary.enforceUsesLibraries()
	a.dexpreopter.usesLibs = a.usesLibrary.usesLibraryProperties.Uses_libs
	a.dexpreopter.optionalUsesLibs = a.usesLibrary.presentOptionalUsesLibs(ctx)
	a.dexpreopter.libraryPaths = a.usesLibrary.usesLibraryPaths(ctx)
	a.dexpreopter.manifestFile = a.mergedManifestFile

	a.deviceProperties.UncompressDex = a.dexpreopter.uncompressedDex

	if ctx.ModuleName() != "framework-res" {
		a.Module.compile(ctx, a.aaptSrcJar)
	}

	return a.maybeStrippedDexJarFile
}

func (a *AndroidApp) jniBuildActions(jniLibs []jniLib, ctx android.ModuleContext) android.WritablePath {
	var jniJarFile android.WritablePath
	if len(jniLibs) > 0 {
		if a.shouldEmbedJnis(ctx) {
			jniJarFile = android.PathForModuleOut(ctx, "jnilibs.zip")
			TransformJniLibsToJar(ctx, jniJarFile, jniLibs, a.useEmbeddedNativeLibs(ctx))
		} else {
			a.installJniLibs = jniLibs
		}
	}
	return jniJarFile
}

// Reads and prepends a main cert from the default cert dir if it hasn't been set already, i.e. it
// isn't a cert module reference. Also checks and enforces system cert restriction if applicable.
func processMainCert(m android.ModuleBase, certPropValue string, certificates []Certificate, ctx android.ModuleContext) []Certificate {
	if android.SrcIsModule(certPropValue) == "" {
		var mainCert Certificate
		if certPropValue != "" {
			defaultDir := ctx.Config().DefaultAppCertificateDir(ctx)
			mainCert = Certificate{
				defaultDir.Join(ctx, certPropValue+".x509.pem"),
				defaultDir.Join(ctx, certPropValue+".pk8"),
			}
		} else {
			pem, key := ctx.Config().DefaultAppCertificate(ctx)
			mainCert = Certificate{pem, key}
		}
		certificates = append([]Certificate{mainCert}, certificates...)
	}

	if !m.Platform() {
		certPath := certificates[0].Pem.String()
		systemCertPath := ctx.Config().DefaultAppCertificateDir(ctx).String()
		if strings.HasPrefix(certPath, systemCertPath) {
			enforceSystemCert := ctx.Config().EnforceSystemCertificate()
			whitelist := ctx.Config().EnforceSystemCertificateWhitelist()

			if enforceSystemCert && !inList(m.Name(), whitelist) {
				ctx.PropertyErrorf("certificate", "The module in product partition cannot be signed with certificate in system.")
			}
		}
	}

	return certificates
}

func (a *AndroidApp) generateAndroidBuildActions(ctx android.ModuleContext) {
	var apkDeps android.Paths

	// Check if the install APK name needs to be overridden.
	a.installApkName = ctx.DeviceConfig().OverridePackageNameFor(a.Name())

	// Process all building blocks, from AAPT to certificates.
	a.aaptBuildActions(ctx)

	if a.usesLibrary.enforceUsesLibraries() {
		manifestCheckFile := a.usesLibrary.verifyUsesLibrariesManifest(ctx, a.mergedManifestFile)
		apkDeps = append(apkDeps, manifestCheckFile)
	}

	a.proguardBuildActions(ctx)

	dexJarFile := a.dexBuildActions(ctx)

	jniLibs, certificateDeps := collectAppDeps(ctx)
	jniJarFile := a.jniBuildActions(jniLibs, ctx)

	if ctx.Failed() {
		return
	}

	certificates := processMainCert(a.ModuleBase, a.getCertString(ctx), certificateDeps, ctx)
	a.certificate = certificates[0]

	// Build a final signed app package.
	// TODO(jungjw): Consider changing this to installApkName.
	packageFile := android.PathForModuleOut(ctx, ctx.ModuleName()+".apk")
	CreateAndSignAppPackage(ctx, packageFile, a.exportPackage, jniJarFile, dexJarFile, certificates, apkDeps)
	a.outputFile = packageFile

	for _, split := range a.aapt.splits {
		// Sign the split APKs
		packageFile := android.PathForModuleOut(ctx, ctx.ModuleName()+"_"+split.suffix+".apk")
		CreateAndSignAppPackage(ctx, packageFile, split.path, nil, nil, certificates, apkDeps)
		a.extraOutputFiles = append(a.extraOutputFiles, packageFile)
	}

	// Build an app bundle.
	bundleFile := android.PathForModuleOut(ctx, "base.zip")
	BuildBundleModule(ctx, bundleFile, a.exportPackage, jniJarFile, dexJarFile)
	a.bundleFile = bundleFile

	// Install the app package.
	var installDir android.OutputPath
	if ctx.ModuleName() == "framework-res" {
		// framework-res.apk is installed as system/framework/framework-res.apk
		installDir = android.PathForModuleInstall(ctx, "framework")
	} else if Bool(a.appProperties.Privileged) {
		installDir = android.PathForModuleInstall(ctx, "priv-app", a.installApkName)
	} else {
		installDir = android.PathForModuleInstall(ctx, "app", a.installApkName)
	}

	ctx.InstallFile(installDir, a.installApkName+".apk", a.outputFile)
	for _, split := range a.aapt.splits {
		ctx.InstallFile(installDir, a.installApkName+"_"+split.suffix+".apk", split.path)
	}
}

func collectAppDeps(ctx android.ModuleContext) ([]jniLib, []Certificate) {
	var jniLibs []jniLib
	var certificates []Certificate

	ctx.VisitDirectDeps(func(module android.Module) {
		otherName := ctx.OtherModuleName(module)
		tag := ctx.OtherModuleDependencyTag(module)

		if jniTag, ok := tag.(*jniDependencyTag); ok {
			if dep, ok := module.(*cc.Module); ok {
				lib := dep.OutputFile()
				if lib.Valid() {
					jniLibs = append(jniLibs, jniLib{
						name:   ctx.OtherModuleName(module),
						path:   lib.Path(),
						target: jniTag.target,
					})
				} else {
					ctx.ModuleErrorf("dependency %q missing output file", otherName)
				}
			} else {
				ctx.ModuleErrorf("jni_libs dependency %q must be a cc library", otherName)
			}
		} else if tag == certificateTag {
			if dep, ok := module.(*AndroidAppCertificate); ok {
				certificates = append(certificates, dep.Certificate)
			} else {
				ctx.ModuleErrorf("certificate dependency %q must be an android_app_certificate module", otherName)
			}
		}
	})

	return jniLibs, certificates
}

func (a *AndroidApp) getCertString(ctx android.BaseContext) string {
	certificate, overridden := ctx.DeviceConfig().OverrideCertificateFor(ctx.ModuleName())
	if overridden {
		return ":" + certificate
	}
	return String(a.overridableAppProperties.Certificate)
}

// android_app compiles sources and Android resources into an Android application package `.apk` file.
func AndroidAppFactory() android.Module {
	module := &AndroidApp{}

	module.Module.deviceProperties.Optimize.EnabledByDefault = true
	module.Module.deviceProperties.Optimize.Shrink = proptools.BoolPtr(true)

	module.Module.properties.Instrument = true
	module.Module.properties.Installable = proptools.BoolPtr(true)

	module.AddProperties(
		&module.Module.properties,
		&module.Module.deviceProperties,
		&module.Module.dexpreoptProperties,
		&module.Module.protoProperties,
		&module.aaptProperties,
		&module.appProperties,
		&module.overridableAppProperties,
		&module.usesLibrary.usesLibraryProperties)

	module.Prefer32(func(ctx android.BaseModuleContext, base *android.ModuleBase, class android.OsClass) bool {
		return class == android.Device && ctx.Config().DevicePrefer32BitApps()
	})

	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
	android.InitDefaultableModule(module)
	android.InitOverridableModule(module, &module.appProperties.Overrides)

	return module
}

type appTestProperties struct {
	Instrumentation_for *string
}

type AndroidTest struct {
	AndroidApp

	appTestProperties appTestProperties

	testProperties testProperties

	testConfig android.Path
	data       android.Paths
}

func (a *AndroidTest) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	// Check if the instrumentation target package is overridden before generating build actions.
	if a.appTestProperties.Instrumentation_for != nil {
		manifestPackageName, overridden := ctx.DeviceConfig().OverrideManifestPackageNameFor(*a.appTestProperties.Instrumentation_for)
		if overridden {
			a.additionalAaptFlags = append(a.additionalAaptFlags, "--rename-instrumentation-target-package "+manifestPackageName)
		}
	}
	a.aapt.useEmbeddedNativeLibs = a.useEmbeddedNativeLibs(ctx)
	a.aapt.useEmbeddedDex = Bool(a.appProperties.Use_embedded_dex)
	a.generateAndroidBuildActions(ctx)

	a.testConfig = tradefed.AutoGenInstrumentationTestConfig(ctx, a.testProperties.Test_config, a.testProperties.Test_config_template, a.manifestPath, a.testProperties.Test_suites)
	a.data = android.PathsForModuleSrc(ctx, a.testProperties.Data)
}

func (a *AndroidTest) DepsMutator(ctx android.BottomUpMutatorContext) {
	a.AndroidApp.DepsMutator(ctx)
	if a.appTestProperties.Instrumentation_for != nil {
		// The android_app dependency listed in instrumentation_for needs to be added to the classpath for javac,
		// but not added to the aapt2 link includes like a normal android_app or android_library dependency, so
		// use instrumentationForTag instead of libTag.
		ctx.AddVariationDependencies(nil, instrumentationForTag, String(a.appTestProperties.Instrumentation_for))
	}
}

// android_test compiles test sources and Android resources into an Android application package `.apk` file and
// creates an `AndroidTest.xml` file to allow running the test with `atest` or a `TEST_MAPPING` file.
func AndroidTestFactory() android.Module {
	module := &AndroidTest{}

	module.Module.deviceProperties.Optimize.EnabledByDefault = true

	module.Module.properties.Instrument = true
	module.Module.properties.Installable = proptools.BoolPtr(true)
	module.appProperties.Use_embedded_native_libs = proptools.BoolPtr(true)
	module.appProperties.AlwaysPackageNativeLibs = true
	module.Module.dexpreopter.isTest = true

	module.AddProperties(
		&module.Module.properties,
		&module.Module.deviceProperties,
		&module.Module.dexpreoptProperties,
		&module.Module.protoProperties,
		&module.aaptProperties,
		&module.appProperties,
		&module.appTestProperties,
		&module.overridableAppProperties,
		&module.usesLibrary.usesLibraryProperties,
		&module.testProperties)

	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
	android.InitDefaultableModule(module)
	return module
}

type appTestHelperAppProperties struct {
	// list of compatibility suites (for example "cts", "vts") that the module should be
	// installed into.
	Test_suites []string `android:"arch_variant"`
}

type AndroidTestHelperApp struct {
	AndroidApp

	appTestHelperAppProperties appTestHelperAppProperties
}

// android_test_helper_app compiles sources and Android resources into an Android application package `.apk` file that
// will be used by tests, but does not produce an `AndroidTest.xml` file so the module will not be run directly as a
// test.
func AndroidTestHelperAppFactory() android.Module {
	module := &AndroidTestHelperApp{}

	module.Module.deviceProperties.Optimize.EnabledByDefault = true

	module.Module.properties.Installable = proptools.BoolPtr(true)
	module.appProperties.Use_embedded_native_libs = proptools.BoolPtr(true)
	module.appProperties.AlwaysPackageNativeLibs = true
	module.Module.dexpreopter.isTest = true

	module.AddProperties(
		&module.Module.properties,
		&module.Module.deviceProperties,
		&module.Module.dexpreoptProperties,
		&module.Module.protoProperties,
		&module.aaptProperties,
		&module.appProperties,
		&module.appTestHelperAppProperties,
		&module.overridableAppProperties,
		&module.usesLibrary.usesLibraryProperties)

	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
	android.InitDefaultableModule(module)
	return module
}

type AndroidAppCertificate struct {
	android.ModuleBase
	properties  AndroidAppCertificateProperties
	Certificate Certificate
}

type AndroidAppCertificateProperties struct {
	// Name of the certificate files.  Extensions .x509.pem and .pk8 will be added to the name.
	Certificate *string
}

// android_app_certificate modules can be referenced by the certificates property of android_app modules to select
// the signing key.
func AndroidAppCertificateFactory() android.Module {
	module := &AndroidAppCertificate{}
	module.AddProperties(&module.properties)
	android.InitAndroidModule(module)
	return module
}

func (c *AndroidAppCertificate) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	cert := String(c.properties.Certificate)
	c.Certificate = Certificate{
		android.PathForModuleSrc(ctx, cert+".x509.pem"),
		android.PathForModuleSrc(ctx, cert+".pk8"),
	}
}

type OverrideAndroidApp struct {
	android.ModuleBase
	android.OverrideModuleBase
}

func (i *OverrideAndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	// All the overrides happen in the base module.
	// TODO(jungjw): Check the base module type.
}

// override_android_app is used to create an android_app module based on another android_app by overriding
// some of its properties.
func OverrideAndroidAppModuleFactory() android.Module {
	m := &OverrideAndroidApp{}
	m.AddProperties(&overridableAppProperties{})

	android.InitAndroidMultiTargetsArchModule(m, android.DeviceSupported, android.MultilibCommon)
	android.InitOverrideModule(m)
	return m
}

type AndroidAppImport struct {
	android.ModuleBase
	android.DefaultableModuleBase
	prebuilt android.Prebuilt

	properties AndroidAppImportProperties

	outputFile  android.Path
	certificate *Certificate

	dexpreopter

	usesLibrary usesLibrary
}

type AndroidAppImportProperties struct {
	// A prebuilt apk to import
	Apk string

	// Per-DPI settings. This property makes it possible to specify a different source apk path for
	// each DPI.
	//
	// Example:
	//
	//     android_app_import {
	//         name: "example_import",
	//         apk: "prebuilts/example.apk",
	//         dpi_variants: {
	//             mdpi: {
	//                 apk: "prebuilts/example_mdpi.apk",
	//             },
	//             xhdpi: {
	//                 apk: "prebuilts/example_xhdpi.apk",
	//             },
	//         },
	//         certificate: "PRESIGNED",
	//     }
	Dpi_variants interface{}

	// The name of a certificate in the default certificate directory, blank to use the default
	// product certificate, or an android_app_certificate module name in the form ":module".
	Certificate *string

	// Set this flag to true if the prebuilt apk is already signed. The certificate property must not
	// be set for presigned modules.
	Presigned *bool

	// Specifies that this app should be installed to the priv-app directory,
	// where the system will grant it additional privileges not available to
	// normal apps.
	Privileged *bool

	// Names of modules to be overridden. Listed modules can only be other binaries
	// (in Make or Soong).
	// This does not completely prevent installation of the overridden binaries, but if both
	// binaries would be installed by default (in PRODUCT_PACKAGES) the other binary will be removed
	// from PRODUCT_PACKAGES.
	Overrides []string
}

func getApkPathForDpi(dpiVariantsValue reflect.Value, dpi string) string {
	dpiField := dpiVariantsValue.FieldByName(proptools.FieldNameForProperty(dpi))
	if !dpiField.IsValid() {
		return ""
	}
	apkValue := dpiField.FieldByName("Apk").Elem()
	if apkValue.IsValid() {
		return apkValue.String()
	}
	return ""
}

// Chooses a source APK path to use based on the module's per-DPI settings and the product config.
func (a *AndroidAppImport) getSrcApkPath(ctx android.ModuleContext) string {
	config := ctx.Config()
	dpiVariantsValue := reflect.ValueOf(a.properties.Dpi_variants).Elem()
	if !dpiVariantsValue.IsValid() {
		return a.properties.Apk
	}
	// Match PRODUCT_AAPT_PREF_CONFIG first and then PRODUCT_AAPT_PREBUILT_DPI.
	if config.ProductAAPTPreferredConfig() != "" {
		if apk := getApkPathForDpi(dpiVariantsValue, config.ProductAAPTPreferredConfig()); apk != "" {
			return apk
		}
	}
	for _, dpi := range config.ProductAAPTPrebuiltDPI() {
		if apk := getApkPathForDpi(dpiVariantsValue, dpi); apk != "" {
			return apk
		}
	}

	// No match. Use the generic one.
	return a.properties.Apk
}

func (a *AndroidAppImport) DepsMutator(ctx android.BottomUpMutatorContext) {
	cert := android.SrcIsModule(String(a.properties.Certificate))
	if cert != "" {
		ctx.AddDependency(ctx.Module(), certificateTag, cert)
	}

	a.usesLibrary.deps(ctx, false)
}

func (a *AndroidAppImport) uncompressEmbeddedJniLibs(
	ctx android.ModuleContext, inputPath android.Path, outputPath android.OutputPath) {
	rule := android.NewRuleBuilder()
	rule.Command().
		Textf(`if (zipinfo %s 'lib/*.so' 2>/dev/null | grep -v ' stor ' >/dev/null) ; then`, inputPath).
		Tool(ctx.Config().HostToolPath(ctx, "zip2zip")).
		FlagWithInput("-i ", inputPath).
		FlagWithOutput("-o ", outputPath).
		FlagWithArg("-0 ", "'lib/**/*.so'").
		Textf(`; else cp -f %s %s; fi`, inputPath, outputPath)
	rule.Build(pctx, ctx, "uncompress-embedded-jni-libs", "Uncompress embedded JIN libs")
}

// Returns whether this module should have the dex file stored uncompressed in the APK.
func (a *AndroidAppImport) shouldUncompressDex(ctx android.ModuleContext) bool {
	if ctx.Config().UnbundledBuild() {
		return false
	}

	// Uncompress dex in APKs of privileged apps
	if ctx.Config().UncompressPrivAppDex() && Bool(a.properties.Privileged) {
		return true
	}

	return shouldUncompressDex(ctx, &a.dexpreopter)
}

func (a *AndroidAppImport) uncompressDex(
	ctx android.ModuleContext, inputPath android.Path, outputPath android.OutputPath) {
	rule := android.NewRuleBuilder()
	rule.Command().
		Textf(`if (zipinfo %s '*.dex' 2>/dev/null | grep -v ' stor ' >/dev/null) ; then`, inputPath).
		Tool(ctx.Config().HostToolPath(ctx, "zip2zip")).
		FlagWithInput("-i ", inputPath).
		FlagWithOutput("-o ", outputPath).
		FlagWithArg("-0 ", "'classes*.dex'").
		Textf(`; else cp -f %s %s; fi`, inputPath, outputPath)
	rule.Build(pctx, ctx, "uncompress-dex", "Uncompress dex files")
}

func (a *AndroidAppImport) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	if String(a.properties.Certificate) == "" && !Bool(a.properties.Presigned) {
		ctx.PropertyErrorf("certificate", "No certificate specified for prebuilt")
	}
	if String(a.properties.Certificate) != "" && Bool(a.properties.Presigned) {
		ctx.PropertyErrorf("certificate", "Certificate can't be specified for presigned modules")
	}

	_, certificates := collectAppDeps(ctx)

	// TODO: LOCAL_EXTRACT_APK/LOCAL_EXTRACT_DPI_APK
	// TODO: LOCAL_PACKAGE_SPLITS

	var srcApk android.Path
	srcApk = android.PathForModuleSrc(ctx, a.getSrcApkPath(ctx))

	if a.usesLibrary.enforceUsesLibraries() {
		srcApk = a.usesLibrary.verifyUsesLibrariesAPK(ctx, srcApk)
	}

	// TODO: Install or embed JNI libraries

	// Uncompress JNI libraries in the apk
	jnisUncompressed := android.PathForModuleOut(ctx, "jnis-uncompressed", ctx.ModuleName()+".apk")
	a.uncompressEmbeddedJniLibs(ctx, srcApk, jnisUncompressed.OutputPath)

	installDir := android.PathForModuleInstall(ctx, "app", a.BaseModuleName())
	a.dexpreopter.installPath = installDir.Join(ctx, a.BaseModuleName()+".apk")
	a.dexpreopter.isInstallable = true
	a.dexpreopter.isPresignedPrebuilt = Bool(a.properties.Presigned)
	a.dexpreopter.uncompressedDex = a.shouldUncompressDex(ctx)

	a.dexpreopter.enforceUsesLibs = a.usesLibrary.enforceUsesLibraries()
	a.dexpreopter.usesLibs = a.usesLibrary.usesLibraryProperties.Uses_libs
	a.dexpreopter.optionalUsesLibs = a.usesLibrary.presentOptionalUsesLibs(ctx)
	a.dexpreopter.libraryPaths = a.usesLibrary.usesLibraryPaths(ctx)

	dexOutput := a.dexpreopter.dexpreopt(ctx, jnisUncompressed)
	if a.dexpreopter.uncompressedDex {
		dexUncompressed := android.PathForModuleOut(ctx, "dex-uncompressed", ctx.ModuleName()+".apk")
		a.uncompressDex(ctx, dexOutput, dexUncompressed.OutputPath)
		dexOutput = dexUncompressed
	}

	// Sign or align the package
	// TODO: Handle EXTERNAL
	if !Bool(a.properties.Presigned) {
		certificates = processMainCert(a.ModuleBase, *a.properties.Certificate, certificates, ctx)
		if len(certificates) != 1 {
			ctx.ModuleErrorf("Unexpected number of certificates were extracted: %q", certificates)
		}
		a.certificate = &certificates[0]
		signed := android.PathForModuleOut(ctx, "signed", ctx.ModuleName()+".apk")
		SignAppPackage(ctx, signed, dexOutput, certificates)
		a.outputFile = signed
	} else {
		alignedApk := android.PathForModuleOut(ctx, "zip-aligned", ctx.ModuleName()+".apk")
		TransformZipAlign(ctx, alignedApk, dexOutput)
		a.outputFile = alignedApk
	}

	// TODO: Optionally compress the output apk.

	ctx.InstallFile(installDir, a.BaseModuleName()+".apk", a.outputFile)

	// TODO: androidmk converter jni libs
}

func (a *AndroidAppImport) Prebuilt() *android.Prebuilt {
	return &a.prebuilt
}

func (a *AndroidAppImport) Name() string {
	return a.prebuilt.Name(a.ModuleBase.Name())
}

// android_app_import imports a prebuilt apk with additional processing specified in the module.
func AndroidAppImportFactory() android.Module {
	module := &AndroidAppImport{}
	module.properties.Dpi_variants = reflect.New(dpiVariantsStruct).Interface()
	module.AddProperties(&module.properties)
	module.AddProperties(&module.dexpreoptProperties)
	module.AddProperties(&module.usesLibrary.usesLibraryProperties)

	InitJavaModule(module, android.DeviceSupported)
	android.InitSingleSourcePrebuiltModule(module, &module.properties.Apk)

	return module
}

type UsesLibraryProperties struct {
	// A list of shared library modules that will be listed in uses-library tags in the AndroidManifest.xml file.
	Uses_libs []string

	// A list of shared library modules that will be listed in uses-library tags in the AndroidManifest.xml file with
	// required=false.
	Optional_uses_libs []string

	// If true, the list of uses_libs and optional_uses_libs modules must match the AndroidManifest.xml file.  Defaults
	// to true if either uses_libs or optional_uses_libs is set.  Will unconditionally default to true in the future.
	Enforce_uses_libs *bool
}

// usesLibrary provides properties and helper functions for AndroidApp and AndroidAppImport to verify that the
// <uses-library> tags that end up in the manifest of an APK match the ones known to the build system through the
// uses_libs and optional_uses_libs properties.  The build system's values are used by dexpreopt to preopt apps
// with knowledge of their shared libraries.
type usesLibrary struct {
	usesLibraryProperties UsesLibraryProperties
}

func (u *usesLibrary) deps(ctx android.BottomUpMutatorContext, noFrameworkLibs bool) {
	ctx.AddVariationDependencies(nil, usesLibTag, u.usesLibraryProperties.Uses_libs...)
	ctx.AddVariationDependencies(nil, usesLibTag, u.presentOptionalUsesLibs(ctx)...)
	if !noFrameworkLibs {
		// dexpreopt/dexpreopt.go needs the paths to the dex jars of these libraries in case construct_context.sh needs
		// to pass them to dex2oat.  Add them as a dependency so we can determine the path to the dex jar of each
		// library to dexpreopt.
		ctx.AddVariationDependencies(nil, usesLibTag,
			"org.apache.http.legacy",
			"android.hidl.base-V1.0-java",
			"android.hidl.manager-V1.0-java")
	}
}

// presentOptionalUsesLibs returns optional_uses_libs after filtering out MissingUsesLibraries, which don't exist in the
// build.
func (u *usesLibrary) presentOptionalUsesLibs(ctx android.BaseModuleContext) []string {
	optionalUsesLibs, _ := android.FilterList(u.usesLibraryProperties.Optional_uses_libs, ctx.Config().MissingUsesLibraries())
	return optionalUsesLibs
}

// usesLibraryPaths returns a map of module names of shared library dependencies to the paths to their dex jars.
func (u *usesLibrary) usesLibraryPaths(ctx android.ModuleContext) map[string]android.Path {
	usesLibPaths := make(map[string]android.Path)

	if !ctx.Config().UnbundledBuild() {
		ctx.VisitDirectDepsWithTag(usesLibTag, func(m android.Module) {
			if lib, ok := m.(Dependency); ok {
				if dexJar := lib.DexJar(); dexJar != nil {
					usesLibPaths[ctx.OtherModuleName(m)] = dexJar
				} else {
					ctx.ModuleErrorf("module %q in uses_libs or optional_uses_libs must produce a dex jar, does it have installable: true?",
						ctx.OtherModuleName(m))
				}
			} else if ctx.Config().AllowMissingDependencies() {
				ctx.AddMissingDependencies([]string{ctx.OtherModuleName(m)})
			} else {
				ctx.ModuleErrorf("module %q in uses_libs or optional_uses_libs must be a java library",
					ctx.OtherModuleName(m))
			}
		})
	}

	return usesLibPaths
}

// enforceUsesLibraries returns true of <uses-library> tags should be checked against uses_libs and optional_uses_libs
// properties.  Defaults to true if either of uses_libs or optional_uses_libs is specified.  Will default to true
// unconditionally in the future.
func (u *usesLibrary) enforceUsesLibraries() bool {
	defaultEnforceUsesLibs := len(u.usesLibraryProperties.Uses_libs) > 0 ||
		len(u.usesLibraryProperties.Optional_uses_libs) > 0
	return BoolDefault(u.usesLibraryProperties.Enforce_uses_libs, defaultEnforceUsesLibs)
}

// verifyUsesLibrariesManifest checks the <uses-library> tags in an AndroidManifest.xml against the ones specified
// in the uses_libs and optional_uses_libs properties.  It returns the path to a copy of the manifest.
func (u *usesLibrary) verifyUsesLibrariesManifest(ctx android.ModuleContext, manifest android.Path) android.Path {
	outputFile := android.PathForModuleOut(ctx, "manifest_check", "AndroidManifest.xml")

	rule := android.NewRuleBuilder()
	cmd := rule.Command().Tool(ctx.Config().HostToolPath(ctx, "manifest_check")).
		Flag("--enforce-uses-libraries").
		Input(manifest).
		FlagWithOutput("-o ", outputFile)

	for _, lib := range u.usesLibraryProperties.Uses_libs {
		cmd.FlagWithArg("--uses-library ", lib)
	}

	for _, lib := range u.usesLibraryProperties.Optional_uses_libs {
		cmd.FlagWithArg("--optional-uses-library ", lib)
	}

	rule.Build(pctx, ctx, "verify_uses_libraries", "verify <uses-library>")

	return outputFile
}

// verifyUsesLibrariesAPK checks the <uses-library> tags in the manifest of an APK against the ones specified
// in the uses_libs and optional_uses_libs properties.  It returns the path to a copy of the APK.
func (u *usesLibrary) verifyUsesLibrariesAPK(ctx android.ModuleContext, apk android.Path) android.Path {
	outputFile := android.PathForModuleOut(ctx, "verify_uses_libraries", apk.Base())

	rule := android.NewRuleBuilder()
	aapt := ctx.Config().HostToolPath(ctx, "aapt")
	rule.Command().
		Textf("aapt_binary=%s", aapt.String()).Implicit(aapt).
		Textf(`uses_library_names="%s"`, strings.Join(u.usesLibraryProperties.Uses_libs, " ")).
		Textf(`optional_uses_library_names="%s"`, strings.Join(u.usesLibraryProperties.Optional_uses_libs, " ")).
		Tool(android.PathForSource(ctx, "build/make/core/verify_uses_libraries.sh")).Input(apk)
	rule.Command().Text("cp -f").Input(apk).Output(outputFile)

	rule.Build(pctx, ctx, "verify_uses_libraries", "verify <uses-library>")

	return outputFile
}