// Copyright (C) 2019 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 apex

import (
	"path/filepath"
	"strings"
	"sync"

	"android/soong/android"
	"android/soong/cc"

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

const (
	vndkApexName       = "com.android.vndk"
	vndkApexNamePrefix = vndkApexName + ".v"
)

// apex_vndk creates a special variant of apex modules which contains only VNDK libraries.
// If `vndk_version` is specified, the VNDK libraries of the specified VNDK version are gathered automatically.
// If not specified, then the "current" versions are gathered.
func vndkApexBundleFactory() android.Module {
	bundle := newApexBundle()
	bundle.vndkApex = true
	bundle.AddProperties(&bundle.vndkProperties)
	android.AddLoadHook(bundle, func(ctx android.LoadHookContext) {
		ctx.AppendProperties(&struct {
			Compile_multilib *string
		}{
			proptools.StringPtr("both"),
		})
	})
	return bundle
}

func (a *apexBundle) vndkVersion(config android.DeviceConfig) string {
	vndkVersion := proptools.StringDefault(a.vndkProperties.Vndk_version, "current")
	if vndkVersion == "current" {
		vndkVersion = config.PlatformVndkVersion()
	}
	return vndkVersion
}

type apexVndkProperties struct {
	// Indicates VNDK version of which this VNDK APEX bundles VNDK libs. Default is Platform VNDK Version.
	Vndk_version *string
}

var (
	vndkApexListKey   = android.NewOnceKey("vndkApexList")
	vndkApexListMutex sync.Mutex
)

func vndkApexList(config android.Config) map[string]string {
	return config.Once(vndkApexListKey, func() interface{} {
		return map[string]string{}
	}).(map[string]string)
}

func apexVndkMutator(mctx android.TopDownMutatorContext) {
	if ab, ok := mctx.Module().(*apexBundle); ok && ab.vndkApex {
		if ab.IsNativeBridgeSupported() {
			mctx.PropertyErrorf("native_bridge_supported", "%q doesn't support native bridge binary.", mctx.ModuleType())
		}

		vndkVersion := ab.vndkVersion(mctx.DeviceConfig())
		// Ensure VNDK APEX mount point is formatted as com.android.vndk.v###
		ab.properties.Apex_name = proptools.StringPtr(vndkApexNamePrefix + vndkVersion)

		// vndk_version should be unique
		vndkApexListMutex.Lock()
		defer vndkApexListMutex.Unlock()
		vndkApexList := vndkApexList(mctx.Config())
		if other, ok := vndkApexList[vndkVersion]; ok {
			mctx.PropertyErrorf("vndk_version", "%v is already defined in %q", vndkVersion, other)
		}
		vndkApexList[vndkVersion] = mctx.ModuleName()
	}
}

func apexVndkDepsMutator(mctx android.BottomUpMutatorContext) {
	if m, ok := mctx.Module().(*cc.Module); ok && cc.IsForVndkApex(mctx, m) {
		vndkVersion := m.VndkVersion()
		vndkApexList := vndkApexList(mctx.Config())
		if vndkApex, ok := vndkApexList[vndkVersion]; ok {
			mctx.AddReverseDependency(mctx.Module(), sharedLibTag, vndkApex)
		}
	} else if a, ok := mctx.Module().(*apexBundle); ok && a.vndkApex {
		vndkVersion := proptools.StringDefault(a.vndkProperties.Vndk_version, "current")
		mctx.AddDependency(mctx.Module(), prebuiltTag, cc.VndkLibrariesTxtModules(vndkVersion)...)
	}
}

// name is module.BaseModuleName() which is used as LOCAL_MODULE_NAME and also LOCAL_OVERRIDES_*
func makeCompatSymlinks(name string, ctx android.ModuleContext) (symlinks []string) {
	// small helper to add symlink commands
	addSymlink := func(target, dir, linkName string) {
		link := filepath.Join(dir, linkName)
		symlinks = append(symlinks, "mkdir -p "+dir+" && rm -rf "+link+" && ln -sf "+target+" "+link)
	}

	// TODO(b/142911355): [VNDK APEX] Fix hard-coded references to /system/lib/vndk
	// When all hard-coded references are fixed, remove symbolic links
	// Note that  we should keep following symlinks for older VNDKs (<=29)
	// Since prebuilt vndk libs still depend on system/lib/vndk path
	if strings.HasPrefix(name, vndkApexName) {
		vndkVersion := ctx.DeviceConfig().PlatformVndkVersion()
		if strings.HasPrefix(name, vndkApexNamePrefix) {
			vndkVersion = strings.TrimPrefix(name, vndkApexNamePrefix)
		}
		// the name of vndk apex is formatted "com.android.vndk.v" + version
		apexName := vndkApexNamePrefix + vndkVersion
		if ctx.Config().Android64() {
			addSymlink("/apex/"+apexName+"/lib64", "$(TARGET_OUT)/lib64", "vndk-sp-"+vndkVersion)
			addSymlink("/apex/"+apexName+"/lib64", "$(TARGET_OUT)/lib64", "vndk-"+vndkVersion)
		}
		if !ctx.Config().Android64() || ctx.DeviceConfig().DeviceSecondaryArch() != "" {
			addSymlink("/apex/"+apexName+"/lib", "$(TARGET_OUT)/lib", "vndk-sp-"+vndkVersion)
			addSymlink("/apex/"+apexName+"/lib", "$(TARGET_OUT)/lib", "vndk-"+vndkVersion)
		}
		return
	}

	// http://b/121248172 - create a link from /system/usr/icu to
	// /apex/com.android.i18n/etc/icu so that apps can find the ICU .dat file.
	// A symlink can't overwrite a directory and the /system/usr/icu directory once
	// existed so the required structure must be created whatever we find.
	if name == "com.android.i18n" {
		addSymlink("/apex/com.android.i18n/etc/icu", "$(TARGET_OUT)/usr", "icu")
		return
	}

	// TODO(b/124106384): Clean up compat symlinks for ART binaries.
	if strings.HasPrefix(name, "com.android.art.") {
		artBinaries := []string{"dalvikvm", "dex2oat"}
		for _, b := range artBinaries {
			addSymlink("/apex/com.android.art/bin/"+b, "$(TARGET_OUT)/bin", b)
		}
		return
	}
	return
}