// Copyright 2016 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 cc

import (
	"android/soong/android"
)

func init() {
	android.RegisterModuleType("cc_prebuilt_library_shared", prebuiltSharedLibraryFactory)
	android.RegisterModuleType("cc_prebuilt_library_static", prebuiltStaticLibraryFactory)
	android.RegisterModuleType("cc_prebuilt_binary", prebuiltBinaryFactory)
}

type prebuiltLinkerInterface interface {
	Name(string) string
	prebuilt() *android.Prebuilt
}

type prebuiltLinker struct {
	android.Prebuilt

	properties struct {
		Srcs []string `android:"arch_variant"`

		// Check the prebuilt ELF files (e.g. DT_SONAME, DT_NEEDED, resolution of undefined
		// symbols, etc), default true.
		Check_elf_files *bool
	}
}

func (p *prebuiltLinker) prebuilt() *android.Prebuilt {
	return &p.Prebuilt
}

func (p *prebuiltLinker) PrebuiltSrcs() []string {
	return p.properties.Srcs
}

type prebuiltLibraryLinker struct {
	*libraryDecorator
	prebuiltLinker
}

var _ prebuiltLinkerInterface = (*prebuiltLibraryLinker)(nil)

func (p *prebuiltLibraryLinker) linkerInit(ctx BaseModuleContext) {}

func (p *prebuiltLibraryLinker) linkerDeps(ctx DepsContext, deps Deps) Deps {
	return p.libraryDecorator.linkerDeps(ctx, deps)
}

func (p *prebuiltLibraryLinker) linkerFlags(ctx ModuleContext, flags Flags) Flags {
	return flags
}

func (p *prebuiltLibraryLinker) linkerProps() []interface{} {
	return p.libraryDecorator.linkerProps()
}

func (p *prebuiltLibraryLinker) link(ctx ModuleContext,
	flags Flags, deps PathDeps, objs Objects) android.Path {
	// TODO(ccross): verify shared library dependencies
	if len(p.properties.Srcs) > 0 {
		p.libraryDecorator.exportIncludes(ctx, "-I")
		p.libraryDecorator.reexportFlags(deps.ReexportedFlags)
		p.libraryDecorator.reexportDeps(deps.ReexportedFlagsDeps)

		builderFlags := flagsToBuilderFlags(flags)

		in := p.Prebuilt.SingleSourcePath(ctx)

		if p.shared() {
			p.unstrippedOutputFile = in
			libName := ctx.baseModuleName() + flags.Toolchain.ShlibSuffix()
			if p.needsStrip(ctx) {
				stripped := android.PathForModuleOut(ctx, "stripped", libName)
				p.strip(ctx, in, stripped, builderFlags)
				in = stripped
			}

			// Optimize out relinking against shared libraries whose interface hasn't changed by
			// depending on a table of contents file instead of the library itself.
			tocFile := android.PathForModuleOut(ctx, libName+".toc")
			p.tocFile = android.OptionalPathForPath(tocFile)
			TransformSharedObjectToToc(ctx, in, tocFile, builderFlags)
		}

		return in
	}

	return nil
}

func (p *prebuiltLibraryLinker) shared() bool {
	return p.libraryDecorator.shared()
}

func prebuiltSharedLibraryFactory() android.Module {
	module, _ := NewPrebuiltSharedLibrary(android.HostAndDeviceSupported)
	return module.Init()
}

func NewPrebuiltSharedLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorator) {
	module, library := NewLibrary(hod)
	library.BuildOnlyShared()
	module.compiler = nil

	prebuilt := &prebuiltLibraryLinker{
		libraryDecorator: library,
	}
	module.linker = prebuilt

	module.AddProperties(&prebuilt.properties)

	android.InitPrebuiltModule(module, &prebuilt.properties.Srcs)

	// Prebuilt libraries can be included in APEXes
	android.InitApexModule(module)

	return module, library
}

func prebuiltStaticLibraryFactory() android.Module {
	module, _ := NewPrebuiltStaticLibrary(android.HostAndDeviceSupported)
	return module.Init()
}

func NewPrebuiltStaticLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorator) {
	module, library := NewLibrary(hod)
	library.BuildOnlyStatic()
	module.compiler = nil

	prebuilt := &prebuiltLibraryLinker{
		libraryDecorator: library,
	}
	module.linker = prebuilt

	module.AddProperties(&prebuilt.properties)

	android.InitPrebuiltModule(module, &prebuilt.properties.Srcs)
	return module, library
}

type prebuiltBinaryLinker struct {
	*binaryDecorator
	prebuiltLinker
}

var _ prebuiltLinkerInterface = (*prebuiltBinaryLinker)(nil)

func (p *prebuiltBinaryLinker) link(ctx ModuleContext,
	flags Flags, deps PathDeps, objs Objects) android.Path {
	// TODO(ccross): verify shared library dependencies
	if len(p.properties.Srcs) > 0 {
		builderFlags := flagsToBuilderFlags(flags)

		fileName := p.getStem(ctx) + flags.Toolchain.ExecutableSuffix()
		in := p.Prebuilt.SingleSourcePath(ctx)

		p.unstrippedOutputFile = in

		if p.needsStrip(ctx) {
			stripped := android.PathForModuleOut(ctx, "stripped", fileName)
			p.strip(ctx, in, stripped, builderFlags)
			in = stripped
		}

		// Copy binaries to a name matching the final installed name
		outputFile := android.PathForModuleOut(ctx, fileName)
		ctx.Build(pctx, android.BuildParams{
			Rule:        android.CpExecutable,
			Description: "prebuilt",
			Output:      outputFile,
			Input:       in,
		})

		return outputFile
	}

	return nil
}

func prebuiltBinaryFactory() android.Module {
	module, _ := NewPrebuiltBinary(android.HostAndDeviceSupported)
	return module.Init()
}

func NewPrebuiltBinary(hod android.HostOrDeviceSupported) (*Module, *binaryDecorator) {
	module, binary := NewBinary(hod)
	module.compiler = nil

	prebuilt := &prebuiltBinaryLinker{
		binaryDecorator: binary,
	}
	module.linker = prebuilt

	module.AddProperties(&prebuilt.properties)

	android.InitPrebuiltModule(module, &prebuilt.properties.Srcs)
	return module, binary
}