// 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 (
	"fmt"
	"path/filepath"
	"strings"

	"android/soong/android"
	"android/soong/dexpreopt"
)

// systemServerClasspath returns the on-device locations of the modules in the system server classpath.  It is computed
// once the first time it is called for any ctx.Config(), and returns the same slice for all future calls with the same
// ctx.Config().
func systemServerClasspath(ctx android.MakeVarsContext) []string {
	return ctx.Config().OnceStringSlice(systemServerClasspathKey, func() []string {
		global := dexpreopt.GetGlobalConfig(ctx)
		var systemServerClasspathLocations []string
		nonUpdatable := dexpreopt.NonUpdatableSystemServerJars(ctx, global)
		// 1) Non-updatable jars.
		for _, m := range nonUpdatable {
			systemServerClasspathLocations = append(systemServerClasspathLocations,
				filepath.Join("/system/framework", m+".jar"))
		}
		// 2) The jars that are from an updatable apex.
		for _, m := range global.UpdatableSystemServerJars {
			systemServerClasspathLocations = append(systemServerClasspathLocations,
				dexpreopt.GetJarLocationFromApexJarPair(m))
		}
		if len(systemServerClasspathLocations) != len(global.SystemServerJars)+len(global.UpdatableSystemServerJars) {
			panic(fmt.Errorf("Wrong number of system server jars, got %d, expected %d",
				len(systemServerClasspathLocations),
				len(global.SystemServerJars)+len(global.UpdatableSystemServerJars)))
		}
		return systemServerClasspathLocations
	})
}

var systemServerClasspathKey = android.NewOnceKey("systemServerClasspath")

// dexpreoptTargets returns the list of targets that are relevant to dexpreopting, which excludes architectures
// supported through native bridge.
func dexpreoptTargets(ctx android.PathContext) []android.Target {
	var targets []android.Target
	for _, target := range ctx.Config().Targets[android.Android] {
		if target.NativeBridge == android.NativeBridgeDisabled {
			targets = append(targets, target)
		}
	}
	// We may also need the images on host in order to run host-based tests.
	for _, target := range ctx.Config().Targets[android.BuildOs] {
		targets = append(targets, target)
	}

	return targets
}

func stemOf(moduleName string) string {
	// b/139391334: the stem of framework-minus-apex is framework
	// This is hard coded here until we find a good way to query the stem
	// of a module before any other mutators are run
	if moduleName == "framework-minus-apex" {
		return "framework"
	}
	return moduleName
}

func getDexLocation(ctx android.PathContext, target android.Target, module string) string {
	apex, jar := android.SplitApexJarPair(module)

	name := stemOf(jar) + ".jar"

	var subdir string
	if apex == "platform" {
		// Special apex name "platform" denotes jars do not come from an apex, but are part
		// of the platform. Such jars are installed on the /system partition on device.
		subdir = "system/framework"
	} else if apex == "system_ext" {
		subdir = "system_ext/framework"
	} else {
		subdir = filepath.Join("apex", apex, "javalib")
	}

	if target.Os.Class == android.Host {
		return filepath.Join(ctx.Config().Getenv("OUT_DIR"), "host", ctx.Config().PrebuiltOS(), subdir, name)
	} else {
		return filepath.Join("/", subdir, name)
	}
}

var (
	bootImageConfigKey     = android.NewOnceKey("bootImageConfig")
	artBootImageName       = "art"
	frameworkBootImageName = "boot"
)

// Construct the global boot image configs.
func genBootImageConfigs(ctx android.PathContext) map[string]*bootImageConfig {
	return ctx.Config().Once(bootImageConfigKey, func() interface{} {

		global := dexpreopt.GetGlobalConfig(ctx)
		targets := dexpreoptTargets(ctx)
		deviceDir := android.PathForOutput(ctx, ctx.Config().DeviceName())

		artModules := global.ArtApexJars
		// With EMMA_INSTRUMENT_FRAMEWORK=true the Core libraries depend on jacoco.
		if ctx.Config().IsEnvTrue("EMMA_INSTRUMENT_FRAMEWORK") {
			artModules = append(artModules, "com.android.art:jacocoagent")
		}
		frameworkModules := android.RemoveListFromList(global.BootJars, artModules)

		artSubdir := "apex/com.android.art/javalib"
		frameworkSubdir := "system/framework"

		// ART config for the primary boot image in the ART apex.
		// It includes the Core Libraries.
		artCfg := bootImageConfig{
			name:          artBootImageName,
			stem:          "boot",
			installSubdir: artSubdir,
			modules:       artModules,
		}

		// Framework config for the boot image extension.
		// It includes framework libraries and depends on the ART config.
		frameworkCfg := bootImageConfig{
			extends:       &artCfg,
			name:          frameworkBootImageName,
			stem:          "boot",
			installSubdir: frameworkSubdir,
			modules:       frameworkModules,
		}

		configs := map[string]*bootImageConfig{
			artBootImageName:       &artCfg,
			frameworkBootImageName: &frameworkCfg,
		}

		// common to all configs
		for _, c := range configs {
			c.dir = deviceDir.Join(ctx, "dex_"+c.name+"jars")
			c.symbolsDir = deviceDir.Join(ctx, "dex_"+c.name+"jars_unstripped")

			// expands to <stem>.art for primary image and <stem>-<1st module>.art for extension
			imageName := c.firstModuleNameOrStem() + ".art"

			// The path to bootclasspath dex files needs to be known at module
			// GenerateAndroidBuildAction time, before the bootclasspath modules have been compiled.
			// Set up known paths for them, the singleton rules will copy them there.
			// TODO(b/143682396): use module dependencies instead
			inputDir := deviceDir.Join(ctx, "dex_"+c.name+"jars_input")
			for _, m := range c.modules {
				_, jar := android.SplitApexJarPair(m)
				c.dexPaths = append(c.dexPaths, inputDir.Join(ctx, stemOf(jar)+".jar"))
			}
			c.dexPathsDeps = c.dexPaths

			// Create target-specific variants.
			for _, target := range targets {
				arch := target.Arch.ArchType
				imageDir := c.dir.Join(ctx, target.Os.String(), c.installSubdir, arch.String())
				variant := &bootImageVariant{
					bootImageConfig: c,
					target:          target,
					images:          imageDir.Join(ctx, imageName),
					imagesDeps:      c.moduleFiles(ctx, imageDir, ".art", ".oat", ".vdex"),
				}
				for _, m := range c.modules {
					variant.dexLocations = append(variant.dexLocations, getDexLocation(ctx, target, m))
				}
				variant.dexLocationsDeps = variant.dexLocations
				c.variants = append(c.variants, variant)
			}

			c.zip = c.dir.Join(ctx, c.name+".zip")
		}

		// specific to the framework config
		frameworkCfg.dexPathsDeps = append(artCfg.dexPathsDeps, frameworkCfg.dexPathsDeps...)
		for i := range targets {
			frameworkCfg.variants[i].primaryImages = artCfg.variants[i].images
			frameworkCfg.variants[i].dexLocationsDeps = append(artCfg.variants[i].dexLocations, frameworkCfg.variants[i].dexLocationsDeps...)
		}

		return configs
	}).(map[string]*bootImageConfig)
}

func artBootImageConfig(ctx android.PathContext) *bootImageConfig {
	return genBootImageConfigs(ctx)[artBootImageName]
}

func defaultBootImageConfig(ctx android.PathContext) *bootImageConfig {
	return genBootImageConfigs(ctx)[frameworkBootImageName]
}

func defaultBootclasspath(ctx android.PathContext) []string {
	return ctx.Config().OnceStringSlice(defaultBootclasspathKey, func() []string {
		global := dexpreopt.GetGlobalConfig(ctx)
		image := defaultBootImageConfig(ctx)

		updatableBootclasspath := make([]string, len(global.UpdatableBootJars))
		for i, p := range global.UpdatableBootJars {
			updatableBootclasspath[i] = dexpreopt.GetJarLocationFromApexJarPair(p)
		}

		bootclasspath := append(copyOf(image.getAnyAndroidVariant().dexLocationsDeps), updatableBootclasspath...)
		return bootclasspath
	})
}

var defaultBootclasspathKey = android.NewOnceKey("defaultBootclasspath")

var copyOf = android.CopyOf

func init() {
	android.RegisterMakeVarsProvider(pctx, dexpreoptConfigMakevars)
}

func dexpreoptConfigMakevars(ctx android.MakeVarsContext) {
	ctx.Strict("PRODUCT_BOOTCLASSPATH", strings.Join(defaultBootclasspath(ctx), ":"))
	ctx.Strict("PRODUCT_DEX2OAT_BOOTCLASSPATH", strings.Join(defaultBootImageConfig(ctx).getAnyAndroidVariant().dexLocationsDeps, ":"))
	ctx.Strict("PRODUCT_SYSTEM_SERVER_CLASSPATH", strings.Join(systemServerClasspath(ctx), ":"))

	ctx.Strict("DEXPREOPT_BOOT_JARS_MODULES", strings.Join(defaultBootImageConfig(ctx).modules, ":"))
}