// 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 android

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
	"sync"

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

var Bool = proptools.Bool
var String = proptools.String

// The configuration file name
const configFileName = "soong.config"
const productVariablesFileName = "soong.variables"

// A FileConfigurableOptions contains options which can be configured by the
// config file. These will be included in the config struct.
type FileConfigurableOptions struct {
	Mega_device *bool `json:",omitempty"`
	Ndk_abis    *bool `json:",omitempty"`
	Host_bionic *bool `json:",omitempty"`
}

func (f *FileConfigurableOptions) SetDefaultConfig() {
	*f = FileConfigurableOptions{}
}

// A Config object represents the entire build configuration for Android.
type Config struct {
	*config
}

// A DeviceConfig object represents the configuration for a particular device being built.  For
// now there will only be one of these, but in the future there may be multiple devices being
// built
type DeviceConfig struct {
	*deviceConfig
}

type config struct {
	FileConfigurableOptions
	ProductVariables productVariables

	ConfigFileName           string
	ProductVariablesFileName string

	Targets        map[OsClass][]Target
	BuildOsVariant string

	deviceConfig *deviceConfig

	srcDir   string // the path of the root source directory
	buildDir string // the path of the build output directory

	envLock   sync.Mutex
	envDeps   map[string]string
	envFrozen bool

	inMake bool

	OncePer
}

type deviceConfig struct {
	config  *config
	targets []Arch
	OncePer
}

type jsonConfigurable interface {
	SetDefaultConfig()
}

func loadConfig(config *config) error {
	err := loadFromConfigFile(&config.FileConfigurableOptions, config.ConfigFileName)
	if err != nil {
		return err
	}

	return loadFromConfigFile(&config.ProductVariables, config.ProductVariablesFileName)
}

// loads configuration options from a JSON file in the cwd.
func loadFromConfigFile(configurable jsonConfigurable, filename string) error {
	// Try to open the file
	configFileReader, err := os.Open(filename)
	defer configFileReader.Close()
	if os.IsNotExist(err) {
		// Need to create a file, so that blueprint & ninja don't get in
		// a dependency tracking loop.
		// Make a file-configurable-options with defaults, write it out using
		// a json writer.
		configurable.SetDefaultConfig()
		err = saveToConfigFile(configurable, filename)
		if err != nil {
			return err
		}
	} else {
		// Make a decoder for it
		jsonDecoder := json.NewDecoder(configFileReader)
		err = jsonDecoder.Decode(configurable)
		if err != nil {
			return fmt.Errorf("config file: %s did not parse correctly: "+err.Error(), filename)
		}
	}

	// No error
	return nil
}

// atomically writes the config file in case two copies of soong_build are running simultaneously
// (for example, docs generation and ninja manifest generation)
func saveToConfigFile(config jsonConfigurable, filename string) error {
	data, err := json.MarshalIndent(&config, "", "    ")
	if err != nil {
		return fmt.Errorf("cannot marshal config data: %s", err.Error())
	}

	f, err := ioutil.TempFile(filepath.Dir(filename), "config")
	if err != nil {
		return fmt.Errorf("cannot create empty config file %s: %s\n", filename, err.Error())
	}
	defer os.Remove(f.Name())
	defer f.Close()

	_, err = f.Write(data)
	if err != nil {
		return fmt.Errorf("default config file: %s could not be written: %s", filename, err.Error())
	}

	_, err = f.WriteString("\n")
	if err != nil {
		return fmt.Errorf("default config file: %s could not be written: %s", filename, err.Error())
	}

	f.Close()
	os.Rename(f.Name(), filename)

	return nil
}

// TestConfig returns a Config object suitable for using for tests
func TestConfig(buildDir string) Config {
	return Config{&config{
		buildDir: buildDir,
	}}
}

// New creates a new Config object.  The srcDir argument specifies the path to
// the root source directory. It also loads the config file, if found.
func NewConfig(srcDir, buildDir string) (Config, error) {
	// Make a config with default options
	config := &config{
		ConfigFileName:           filepath.Join(buildDir, configFileName),
		ProductVariablesFileName: filepath.Join(buildDir, productVariablesFileName),

		srcDir:   srcDir,
		buildDir: buildDir,

		deviceConfig: &deviceConfig{},
	}

	deviceConfig := &deviceConfig{
		config: config,
	}

	config.deviceConfig = deviceConfig

	// Sanity check the build and source directories. This won't catch strange
	// configurations with symlinks, but at least checks the obvious cases.
	absBuildDir, err := filepath.Abs(buildDir)
	if err != nil {
		return Config{}, err
	}

	absSrcDir, err := filepath.Abs(srcDir)
	if err != nil {
		return Config{}, err
	}

	if strings.HasPrefix(absSrcDir, absBuildDir) {
		return Config{}, fmt.Errorf("Build dir must not contain source directory")
	}

	// Load any configurable options from the configuration file
	err = loadConfig(config)
	if err != nil {
		return Config{}, err
	}

	inMakeFile := filepath.Join(buildDir, ".soong.in_make")
	if _, err := os.Stat(inMakeFile); err == nil {
		config.inMake = true
	}

	targets, err := decodeTargetProductVariables(config)
	if err != nil {
		return Config{}, err
	}

	var archConfig []archConfig
	if Bool(config.Mega_device) {
		archConfig = getMegaDeviceConfig()
	} else if Bool(config.Ndk_abis) {
		archConfig = getNdkAbisConfig()
	}

	if archConfig != nil {
		deviceTargets, err := decodeArchSettings(archConfig)
		if err != nil {
			return Config{}, err
		}
		targets[Device] = deviceTargets
	}

	config.Targets = targets
	config.BuildOsVariant = targets[Host][0].String()

	return Config{config}, nil
}

func (c *config) RemoveAbandonedFiles() bool {
	return false
}

func (c *config) BlueprintToolLocation() string {
	return filepath.Join(c.buildDir, "host", c.PrebuiltOS(), "bin")
}

// HostSystemTool looks for non-hermetic tools from the system we're running on.
// Generally shouldn't be used, but useful to find the XCode SDK, etc.
func (c *config) HostSystemTool(name string) string {
	for _, dir := range filepath.SplitList(c.Getenv("PATH")) {
		path := filepath.Join(dir, name)
		if s, err := os.Stat(path); err != nil {
			continue
		} else if m := s.Mode(); !s.IsDir() && m&0111 != 0 {
			return path
		}
	}
	return name
}

// PrebuiltOS returns the name of the host OS used in prebuilts directories
func (c *config) PrebuiltOS() string {
	switch runtime.GOOS {
	case "linux":
		return "linux-x86"
	case "darwin":
		return "darwin-x86"
	default:
		panic("Unknown GOOS")
	}
}

// GoRoot returns the path to the root directory of the Go toolchain.
func (c *config) GoRoot() string {
	return fmt.Sprintf("%s/prebuilts/go/%s", c.srcDir, c.PrebuiltOS())
}

func (c *config) CpPreserveSymlinksFlags() string {
	switch runtime.GOOS {
	case "darwin":
		return "-R"
	case "linux":
		return "-d"
	default:
		return ""
	}
}

func (c *config) Getenv(key string) string {
	var val string
	var exists bool
	c.envLock.Lock()
	defer c.envLock.Unlock()
	if c.envDeps == nil {
		c.envDeps = make(map[string]string)
	}
	if val, exists = c.envDeps[key]; !exists {
		if c.envFrozen {
			panic("Cannot access new environment variables after envdeps are frozen")
		}
		val, _ = originalEnv[key]
		c.envDeps[key] = val
	}
	return val
}

func (c *config) GetenvWithDefault(key string, defaultValue string) string {
	ret := c.Getenv(key)
	if ret == "" {
		return defaultValue
	}
	return ret
}

func (c *config) IsEnvTrue(key string) bool {
	value := c.Getenv(key)
	return value == "1" || value == "y" || value == "yes" || value == "on" || value == "true"
}

func (c *config) IsEnvFalse(key string) bool {
	value := c.Getenv(key)
	return value == "0" || value == "n" || value == "no" || value == "off" || value == "false"
}

func (c *config) EnvDeps() map[string]string {
	c.envLock.Lock()
	defer c.envLock.Unlock()
	c.envFrozen = true
	return c.envDeps
}

func (c *config) EmbeddedInMake() bool {
	return c.inMake
}

// DeviceName returns the name of the current device target
// TODO: take an AndroidModuleContext to select the device name for multi-device builds
func (c *config) DeviceName() string {
	return *c.ProductVariables.DeviceName
}

func (c *config) DeviceUsesClang() bool {
	if c.ProductVariables.DeviceUsesClang != nil {
		return *c.ProductVariables.DeviceUsesClang
	}
	return true
}

func (c *config) ResourceOverlays() []SourcePath {
	return nil
}

func (c *config) PlatformVersion() string {
	return "M"
}

func (c *config) PlatformSdkVersionInt() int {
	return *c.ProductVariables.Platform_sdk_version
}

func (c *config) PlatformSdkVersion() string {
	return strconv.Itoa(c.PlatformSdkVersionInt())
}

func (c *config) PlatformVersionAllCodenames() []string {
	return c.ProductVariables.Platform_version_all_codenames
}

func (c *config) BuildNumber() string {
	return "000000"
}

func (c *config) ProductAaptConfig() []string {
	return []string{"normal", "large", "xlarge", "hdpi", "xhdpi", "xxhdpi"}
}

func (c *config) ProductAaptPreferredConfig() string {
	return "xhdpi"
}

func (c *config) ProductAaptCharacteristics() string {
	return "nosdcard"
}

func (c *config) DefaultAppCertificateDir(ctx PathContext) SourcePath {
	return PathForSource(ctx, "build/target/product/security")
}

func (c *config) DefaultAppCertificate(ctx PathContext) SourcePath {
	return c.DefaultAppCertificateDir(ctx).Join(ctx, "testkey")
}

func (c *config) AllowMissingDependencies() bool {
	return Bool(c.ProductVariables.Allow_missing_dependencies)
}

func (c *config) DevicePrefer32BitExecutables() bool {
	return Bool(c.ProductVariables.DevicePrefer32BitExecutables)
}

func (c *config) SkipDeviceInstall() bool {
	return c.EmbeddedInMake()
}

func (c *config) SkipMegaDeviceInstall(path string) bool {
	return Bool(c.Mega_device) &&
		strings.HasPrefix(path, filepath.Join(c.buildDir, "target", "product"))
}

func (c *config) SanitizeHost() []string {
	return append([]string(nil), c.ProductVariables.SanitizeHost...)
}

func (c *config) SanitizeDevice() []string {
	return append([]string(nil), c.ProductVariables.SanitizeDevice...)
}

func (c *config) SanitizeDeviceArch() []string {
	return append([]string(nil), c.ProductVariables.SanitizeDeviceArch...)
}

func (c *config) EnableCFI() bool {
	if c.ProductVariables.EnableCFI == nil {
		return true
	} else {
		return *c.ProductVariables.EnableCFI
	}
}

func (c *config) Android64() bool {
	for _, t := range c.Targets[Device] {
		if t.Arch.ArchType.Multilib == "lib64" {
			return true
		}
	}

	return false
}

func (c *config) UseGoma() bool {
	return Bool(c.ProductVariables.UseGoma)
}

func (c *config) ClangTidy() bool {
	return Bool(c.ProductVariables.ClangTidy)
}

func (c *config) TidyChecks() string {
	if c.ProductVariables.TidyChecks == nil {
		return ""
	}
	return *c.ProductVariables.TidyChecks
}

func (c *config) LibartImgHostBaseAddress() string {
	return "0x60000000"
}

func (c *config) LibartImgDeviceBaseAddress() string {
	switch c.Targets[Device][0].Arch.ArchType {
	default:
		return "0x70000000"
	case Mips, Mips64:
		return "0x64000000"
	}
}

func (c *config) ArtUseReadBarrier() bool {
	return Bool(c.ProductVariables.ArtUseReadBarrier)
}

func (c *deviceConfig) Arches() []Arch {
	var arches []Arch
	for _, target := range c.config.Targets[Device] {
		arches = append(arches, target.Arch)
	}
	return arches
}

func (c *deviceConfig) VendorPath() string {
	if c.config.ProductVariables.VendorPath != nil {
		return *c.config.ProductVariables.VendorPath
	}
	return "vendor"
}

func (c *deviceConfig) CompileVndk() bool {
	if c.config.ProductVariables.DeviceVndkVersion == nil {
		return false
	}
	return *c.config.ProductVariables.DeviceVndkVersion == "current"
}

func (c *deviceConfig) BtConfigIncludeDir() string {
	return String(c.config.ProductVariables.BtConfigIncludeDir)
}

func (c *deviceConfig) NativeCoverageEnabled() bool {
	return Bool(c.config.ProductVariables.NativeCoverage)
}

func (c *deviceConfig) CoverageEnabledForPath(path string) bool {
	coverage := false
	if c.config.ProductVariables.CoveragePaths != nil {
		for _, prefix := range *c.config.ProductVariables.CoveragePaths {
			if strings.HasPrefix(path, prefix) {
				coverage = true
				break
			}
		}
	}
	if coverage && c.config.ProductVariables.CoverageExcludePaths != nil {
		for _, prefix := range *c.config.ProductVariables.CoverageExcludePaths {
			if strings.HasPrefix(path, prefix) {
				coverage = false
				break
			}
		}
	}
	return coverage
}