// Copyright 2020 The Android Open Source Project
//
// 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 cc

// This file contains singletons to capture vendor and recovery snapshot. They consist of prebuilt
// modules under AOSP so older vendor and recovery can be built with a newer system in a single
// source tree.

import (
	"encoding/json"
	"path/filepath"
	"sort"
	"strings"

	"android/soong/android"
)

var vendorSnapshotSingleton = snapshotSingleton{
	"vendor",
	"SOONG_VENDOR_SNAPSHOT_ZIP",
	android.OptionalPath{},
	true,
	vendorSnapshotImageSingleton,
	false, /* fake */
}

var vendorFakeSnapshotSingleton = snapshotSingleton{
	"vendor",
	"SOONG_VENDOR_FAKE_SNAPSHOT_ZIP",
	android.OptionalPath{},
	true,
	vendorSnapshotImageSingleton,
	true, /* fake */
}

var recoverySnapshotSingleton = snapshotSingleton{
	"recovery",
	"SOONG_RECOVERY_SNAPSHOT_ZIP",
	android.OptionalPath{},
	false,
	recoverySnapshotImageSingleton,
	false, /* fake */
}

func VendorSnapshotSingleton() android.Singleton {
	return &vendorSnapshotSingleton
}

func VendorFakeSnapshotSingleton() android.Singleton {
	return &vendorFakeSnapshotSingleton
}

func RecoverySnapshotSingleton() android.Singleton {
	return &recoverySnapshotSingleton
}

type snapshotSingleton struct {
	// Name, e.g., "vendor", "recovery", "ramdisk".
	name string

	// Make variable that points to the snapshot file, e.g.,
	// "SOONG_RECOVERY_SNAPSHOT_ZIP".
	makeVar string

	// Path to the snapshot zip file.
	snapshotZipFile android.OptionalPath

	// Whether the image supports VNDK extension modules.
	supportsVndkExt bool

	// Implementation of the image interface specific to the image
	// associated with this snapshot (e.g., specific to the vendor image,
	// recovery image, etc.).
	image snapshotImage

	// Whether this singleton is for fake snapshot or not.
	// Fake snapshot is a snapshot whose prebuilt binaries and headers are empty.
	// It is much faster to generate, and can be used to inspect dependencies.
	fake bool
}

var (
	// Modules under following directories are ignored. They are OEM's and vendor's
	// proprietary modules(device/, kernel/, vendor/, and hardware/).
	vendorProprietaryDirs = []string{
		"device",
		"kernel",
		"vendor",
		"hardware",
	}

	// Modules under following directories are ignored. They are OEM's and vendor's
	// proprietary modules(device/, kernel/, vendor/, and hardware/).
	recoveryProprietaryDirs = []string{
		"device",
		"hardware",
		"kernel",
		"vendor",
	}

	// Modules under following directories are included as they are in AOSP,
	// although hardware/ and kernel/ are normally for vendor's own.
	aospDirsUnderProprietary = []string{
		"kernel/configs",
		"kernel/prebuilts",
		"kernel/tests",
		"hardware/interfaces",
		"hardware/libhardware",
		"hardware/libhardware_legacy",
		"hardware/ril",
	}
)

// Determine if a dir under source tree is an SoC-owned proprietary directory, such as
// device/, vendor/, etc.
func isVendorProprietaryPath(dir string) bool {
	return isProprietaryPath(dir, vendorProprietaryDirs)
}

func isRecoveryProprietaryPath(dir string) bool {
	return isProprietaryPath(dir, recoveryProprietaryDirs)
}

// Determine if a dir under source tree is an SoC-owned proprietary directory, such as
// device/, vendor/, etc.
func isProprietaryPath(dir string, proprietaryDirs []string) bool {
	for _, p := range proprietaryDirs {
		if strings.HasPrefix(dir, p) {
			// filter out AOSP defined directories, e.g. hardware/interfaces/
			aosp := false
			for _, p := range aospDirsUnderProprietary {
				if strings.HasPrefix(dir, p) {
					aosp = true
					break
				}
			}
			if !aosp {
				return true
			}
		}
	}
	return false
}

func isVendorProprietaryModule(ctx android.BaseModuleContext) bool {
	// Any module in a vendor proprietary path is a vendor proprietary
	// module.
	if isVendorProprietaryPath(ctx.ModuleDir()) {
		return true
	}

	// However if the module is not in a vendor proprietary path, it may
	// still be a vendor proprietary module. This happens for cc modules
	// that are excluded from the vendor snapshot, and it means that the
	// vendor has assumed control of the framework-provided module.
	if c, ok := ctx.Module().(*Module); ok {
		if c.ExcludeFromVendorSnapshot() {
			return true
		}
	}

	return false
}

func isRecoveryProprietaryModule(ctx android.BaseModuleContext) bool {

	// Any module in a recovery proprietary path is a recovery proprietary
	// module.
	if isRecoveryProprietaryPath(ctx.ModuleDir()) {
		return true
	}

	// However if the module is not in a recovery proprietary path, it may
	// still be a recovery proprietary module. This happens for cc modules
	// that are excluded from the recovery snapshot, and it means that the
	// vendor has assumed control of the framework-provided module.

	if c, ok := ctx.Module().(*Module); ok {
		if c.ExcludeFromRecoverySnapshot() {
			return true
		}
	}

	return false
}

// Determines if the module is a candidate for snapshot.
func isSnapshotAware(cfg android.DeviceConfig, m *Module, inProprietaryPath bool, apexInfo android.ApexInfo, image snapshotImage) bool {
	if !m.Enabled() || m.Properties.HideFromMake {
		return false
	}
	// When android/prebuilt.go selects between source and prebuilt, it sets
	// HideFromMake on the other one to avoid duplicate install rules in make.
	if m.IsHideFromMake() {
		return false
	}
	// skip proprietary modules, but (for the vendor snapshot only)
	// include all VNDK (static)
	if inProprietaryPath && (!image.includeVndk() || !m.IsVndk()) {
		return false
	}
	// If the module would be included based on its path, check to see if
	// the module is marked to be excluded. If so, skip it.
	if image.excludeFromSnapshot(m) {
		return false
	}
	if m.Target().Os.Class != android.Device {
		return false
	}
	if m.Target().NativeBridge == android.NativeBridgeEnabled {
		return false
	}
	// the module must be installed in target image
	if !apexInfo.IsForPlatform() || m.isSnapshotPrebuilt() || !image.inImage(m)() {
		return false
	}
	// skip kernel_headers which always depend on vendor
	if _, ok := m.linker.(*kernelHeadersDecorator); ok {
		return false
	}
	// skip llndk_library and llndk_headers which are backward compatible
	if m.IsLlndk() {
		return false
	}
	if _, ok := m.linker.(*llndkStubDecorator); ok {
		return false
	}
	if _, ok := m.linker.(*llndkHeadersDecorator); ok {
		return false
	}

	// Libraries
	if l, ok := m.linker.(snapshotLibraryInterface); ok {
		if m.sanitize != nil {
			// scs and hwasan export both sanitized and unsanitized variants for static and header
			// Always use unsanitized variants of them.
			for _, t := range []SanitizerType{scs, hwasan} {
				if !l.shared() && m.sanitize.isSanitizerEnabled(t) {
					return false
				}
			}
			// cfi also exports both variants. But for static, we capture both.
			// This is because cfi static libraries can't be linked from non-cfi modules,
			// and vice versa. This isn't the case for scs and hwasan sanitizers.
			if !l.static() && !l.shared() && m.sanitize.isSanitizerEnabled(cfi) {
				return false
			}
		}
		if l.static() {
			return m.outputFile.Valid() && !image.private(m)
		}
		if l.shared() {
			if !m.outputFile.Valid() {
				return false
			}
			if image.includeVndk() {
				if !m.IsVndk() {
					return true
				}
				return m.IsVndkExt()
			}
		}
		return true
	}

	// Binaries and Objects
	if m.binary() || m.object() {
		return m.outputFile.Valid()
	}

	return false
}

// This is to be saved as .json files, which is for development/vendor_snapshot/update.py.
// These flags become Android.bp snapshot module properties.
type snapshotJsonFlags struct {
	ModuleName          string `json:",omitempty"`
	RelativeInstallPath string `json:",omitempty"`
	AndroidMkSuffix     string `json:",omitempty"`

	// library flags
	ExportedDirs       []string `json:",omitempty"`
	ExportedSystemDirs []string `json:",omitempty"`
	ExportedFlags      []string `json:",omitempty"`
	Sanitize           string   `json:",omitempty"`
	SanitizeMinimalDep bool     `json:",omitempty"`
	SanitizeUbsanDep   bool     `json:",omitempty"`

	// binary flags
	Symlinks []string `json:",omitempty"`

	// dependencies
	SharedLibs  []string `json:",omitempty"`
	RuntimeLibs []string `json:",omitempty"`
	Required    []string `json:",omitempty"`

	// extra config files
	InitRc         []string `json:",omitempty"`
	VintfFragments []string `json:",omitempty"`
}

func (c *snapshotSingleton) GenerateBuildActions(ctx android.SingletonContext) {
	if !c.image.shouldGenerateSnapshot(ctx) {
		return
	}

	var snapshotOutputs android.Paths

	/*
		Vendor snapshot zipped artifacts directory structure:
		{SNAPSHOT_ARCH}/
			arch-{TARGET_ARCH}-{TARGET_ARCH_VARIANT}/
				shared/
					(.so shared libraries)
				static/
					(.a static libraries)
				header/
					(header only libraries)
				binary/
					(executable binaries)
				object/
					(.o object files)
			arch-{TARGET_2ND_ARCH}-{TARGET_2ND_ARCH_VARIANT}/
				shared/
					(.so shared libraries)
				static/
					(.a static libraries)
				header/
					(header only libraries)
				binary/
					(executable binaries)
				object/
					(.o object files)
			NOTICE_FILES/
				(notice files, e.g. libbase.txt)
			configs/
				(config files, e.g. init.rc files, vintf_fragments.xml files, etc.)
			include/
				(header files of same directory structure with source tree)
	*/

	snapshotDir := c.name + "-snapshot"
	if c.fake {
		// If this is a fake snapshot singleton, place all files under fake/ subdirectory to avoid
		// collision with real snapshot files
		snapshotDir = filepath.Join("fake", snapshotDir)
	}
	snapshotArchDir := filepath.Join(snapshotDir, ctx.DeviceConfig().DeviceArch())

	includeDir := filepath.Join(snapshotArchDir, "include")
	configsDir := filepath.Join(snapshotArchDir, "configs")
	noticeDir := filepath.Join(snapshotArchDir, "NOTICE_FILES")

	installedNotices := make(map[string]bool)
	installedConfigs := make(map[string]bool)

	var headers android.Paths

	copyFile := func(ctx android.SingletonContext, path android.Path, out string, fake bool) android.OutputPath {
		if fake {
			// All prebuilt binaries and headers are installed by copyFile function. This makes a fake
			// snapshot just touch prebuilts and headers, rather than installing real files.
			return writeStringToFileRule(ctx, "", out)
		} else {
			return copyFileRule(ctx, path, out)
		}
	}

	// installSnapshot function copies prebuilt file (.so, .a, or executable) and json flag file.
	// For executables, init_rc and vintf_fragments files are also copied.
	installSnapshot := func(m *Module, fake bool) android.Paths {
		targetArch := "arch-" + m.Target().Arch.ArchType.String()
		if m.Target().Arch.ArchVariant != "" {
			targetArch += "-" + m.Target().Arch.ArchVariant
		}

		var ret android.Paths

		prop := snapshotJsonFlags{}

		// Common properties among snapshots.
		prop.ModuleName = ctx.ModuleName(m)
		if c.supportsVndkExt && m.IsVndkExt() {
			// vndk exts are installed to /vendor/lib(64)?/vndk(-sp)?
			if m.isVndkSp() {
				prop.RelativeInstallPath = "vndk-sp"
			} else {
				prop.RelativeInstallPath = "vndk"
			}
		} else {
			prop.RelativeInstallPath = m.RelativeInstallPath()
		}
		prop.AndroidMkSuffix = m.Properties.SubName
		prop.RuntimeLibs = m.Properties.SnapshotRuntimeLibs
		prop.Required = m.RequiredModuleNames()
		for _, path := range m.InitRc() {
			prop.InitRc = append(prop.InitRc, filepath.Join("configs", path.Base()))
		}
		for _, path := range m.VintfFragments() {
			prop.VintfFragments = append(prop.VintfFragments, filepath.Join("configs", path.Base()))
		}

		// install config files. ignores any duplicates.
		for _, path := range append(m.InitRc(), m.VintfFragments()...) {
			out := filepath.Join(configsDir, path.Base())
			if !installedConfigs[out] {
				installedConfigs[out] = true
				ret = append(ret, copyFile(ctx, path, out, fake))
			}
		}

		var propOut string

		if l, ok := m.linker.(snapshotLibraryInterface); ok {
			exporterInfo := ctx.ModuleProvider(m, FlagExporterInfoProvider).(FlagExporterInfo)

			// library flags
			prop.ExportedFlags = exporterInfo.Flags
			for _, dir := range exporterInfo.IncludeDirs {
				prop.ExportedDirs = append(prop.ExportedDirs, filepath.Join("include", dir.String()))
			}
			for _, dir := range exporterInfo.SystemIncludeDirs {
				prop.ExportedSystemDirs = append(prop.ExportedSystemDirs, filepath.Join("include", dir.String()))
			}
			// shared libs dependencies aren't meaningful on static or header libs
			if l.shared() {
				prop.SharedLibs = m.Properties.SnapshotSharedLibs
			}
			if l.static() && m.sanitize != nil {
				prop.SanitizeMinimalDep = m.sanitize.Properties.MinimalRuntimeDep || enableMinimalRuntime(m.sanitize)
				prop.SanitizeUbsanDep = m.sanitize.Properties.UbsanRuntimeDep || enableUbsanRuntime(m.sanitize)
			}

			var libType string
			if l.static() {
				libType = "static"
			} else if l.shared() {
				libType = "shared"
			} else {
				libType = "header"
			}

			var stem string

			// install .a or .so
			if libType != "header" {
				libPath := m.outputFile.Path()
				stem = libPath.Base()
				if l.static() && m.sanitize != nil && m.sanitize.isSanitizerEnabled(cfi) {
					// both cfi and non-cfi variant for static libraries can exist.
					// attach .cfi to distinguish between cfi and non-cfi.
					// e.g. libbase.a -> libbase.cfi.a
					ext := filepath.Ext(stem)
					stem = strings.TrimSuffix(stem, ext) + ".cfi" + ext
					prop.Sanitize = "cfi"
					prop.ModuleName += ".cfi"
				}
				snapshotLibOut := filepath.Join(snapshotArchDir, targetArch, libType, stem)
				ret = append(ret, copyFile(ctx, libPath, snapshotLibOut, fake))
			} else {
				stem = ctx.ModuleName(m)
			}

			propOut = filepath.Join(snapshotArchDir, targetArch, libType, stem+".json")
		} else if m.binary() {
			// binary flags
			prop.Symlinks = m.Symlinks()
			prop.SharedLibs = m.Properties.SnapshotSharedLibs

			// install bin
			binPath := m.outputFile.Path()
			snapshotBinOut := filepath.Join(snapshotArchDir, targetArch, "binary", binPath.Base())
			ret = append(ret, copyFile(ctx, binPath, snapshotBinOut, fake))
			propOut = snapshotBinOut + ".json"
		} else if m.object() {
			// object files aren't installed to the device, so their names can conflict.
			// Use module name as stem.
			objPath := m.outputFile.Path()
			snapshotObjOut := filepath.Join(snapshotArchDir, targetArch, "object",
				ctx.ModuleName(m)+filepath.Ext(objPath.Base()))
			ret = append(ret, copyFile(ctx, objPath, snapshotObjOut, fake))
			propOut = snapshotObjOut + ".json"
		} else {
			ctx.Errorf("unknown module %q in vendor snapshot", m.String())
			return nil
		}

		j, err := json.Marshal(prop)
		if err != nil {
			ctx.Errorf("json marshal to %q failed: %#v", propOut, err)
			return nil
		}
		ret = append(ret, writeStringToFileRule(ctx, string(j), propOut))

		return ret
	}

	ctx.VisitAllModules(func(module android.Module) {
		m, ok := module.(*Module)
		if !ok {
			return
		}

		moduleDir := ctx.ModuleDir(module)
		inProprietaryPath := c.image.isProprietaryPath(moduleDir)
		apexInfo := ctx.ModuleProvider(module, android.ApexInfoProvider).(android.ApexInfo)

		if c.image.excludeFromSnapshot(m) {
			if inProprietaryPath {
				// Error: exclude_from_vendor_snapshot applies
				// to framework-path modules only.
				ctx.Errorf("module %q in vendor proprietary path %q may not use \"exclude_from_vendor_snapshot: true\"", m.String(), moduleDir)
				return
			}
		}

		if !isSnapshotAware(ctx.DeviceConfig(), m, inProprietaryPath, apexInfo, c.image) {
			return
		}

		// If we are using directed snapshot and a module is not included in the
		// list, we will still include the module as if it was a fake module.
		// The reason is that soong needs all the dependencies to be present, even
		// if they are not using during the build.
		installAsFake := c.fake
		if c.image.excludeFromDirectedSnapshot(ctx.DeviceConfig(), m.BaseModuleName()) {
			installAsFake = true
		}

		// installSnapshot installs prebuilts and json flag files
		snapshotOutputs = append(snapshotOutputs, installSnapshot(m, installAsFake)...)
		// just gather headers and notice files here, because they are to be deduplicated
		if l, ok := m.linker.(snapshotLibraryInterface); ok {
			headers = append(headers, l.snapshotHeaders()...)
		}

		if len(m.NoticeFiles()) > 0 {
			noticeName := ctx.ModuleName(m) + ".txt"
			noticeOut := filepath.Join(noticeDir, noticeName)
			// skip already copied notice file
			if !installedNotices[noticeOut] {
				installedNotices[noticeOut] = true
				snapshotOutputs = append(snapshotOutputs, combineNoticesRule(ctx, m.NoticeFiles(), noticeOut))
			}
		}
	})

	// install all headers after removing duplicates
	for _, header := range android.FirstUniquePaths(headers) {
		snapshotOutputs = append(snapshotOutputs, copyFile(ctx, header, filepath.Join(includeDir, header.String()), c.fake))
	}

	// All artifacts are ready. Sort them to normalize ninja and then zip.
	sort.Slice(snapshotOutputs, func(i, j int) bool {
		return snapshotOutputs[i].String() < snapshotOutputs[j].String()
	})

	zipPath := android.PathForOutput(
		ctx,
		snapshotDir,
		c.name+"-"+ctx.Config().DeviceName()+".zip")
	zipRule := android.NewRuleBuilder(pctx, ctx)

	// filenames in rspfile from FlagWithRspFileInputList might be single-quoted. Remove it with tr
	snapshotOutputList := android.PathForOutput(
		ctx,
		snapshotDir,
		c.name+"-"+ctx.Config().DeviceName()+"_list")
	zipRule.Command().
		Text("tr").
		FlagWithArg("-d ", "\\'").
		FlagWithRspFileInputList("< ", snapshotOutputs).
		FlagWithOutput("> ", snapshotOutputList)

	zipRule.Temporary(snapshotOutputList)

	zipRule.Command().
		BuiltTool("soong_zip").
		FlagWithOutput("-o ", zipPath).
		FlagWithArg("-C ", android.PathForOutput(ctx, snapshotDir).String()).
		FlagWithInput("-l ", snapshotOutputList)

	zipRule.Build(zipPath.String(), c.name+" snapshot "+zipPath.String())
	zipRule.DeleteTemporaryFiles()
	c.snapshotZipFile = android.OptionalPathForPath(zipPath)
}

func (c *snapshotSingleton) MakeVars(ctx android.MakeVarsContext) {
	ctx.Strict(
		c.makeVar,
		c.snapshotZipFile.String())
}