// Copyright 2020 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"
	"sort"
	"strings"

	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/java/config"
	"android/soong/remoteexec"
)

type LintProperties struct {
	// Controls for running Android Lint on the module.
	Lint struct {

		// If true, run Android Lint on the module.  Defaults to true.
		Enabled *bool

		// Flags to pass to the Android Lint tool.
		Flags []string

		// Checks that should be treated as fatal.
		Fatal_checks []string

		// Checks that should be treated as errors.
		Error_checks []string

		// Checks that should be treated as warnings.
		Warning_checks []string

		// Checks that should be skipped.
		Disabled_checks []string

		// Modules that provide extra lint checks
		Extra_check_modules []string

		// Name of the file that lint uses as the baseline. Defaults to "lint-baseline.xml".
		Baseline_filename *string
	}
}

type linter struct {
	name                string
	manifest            android.Path
	mergedManifest      android.Path
	srcs                android.Paths
	srcJars             android.Paths
	resources           android.Paths
	classpath           android.Paths
	classes             android.Path
	extraLintCheckJars  android.Paths
	test                bool
	library             bool
	minSdkVersion       string
	targetSdkVersion    string
	compileSdkVersion   string
	javaLanguageLevel   string
	kotlinLanguageLevel string
	outputs             lintOutputs
	properties          LintProperties

	reports android.Paths

	buildModuleReportZip bool
}

type lintOutputs struct {
	html android.Path
	text android.Path
	xml  android.Path

	depSets LintDepSets
}

type lintOutputsIntf interface {
	lintOutputs() *lintOutputs
}

type lintDepSetsIntf interface {
	LintDepSets() LintDepSets
}

type LintDepSets struct {
	HTML, Text, XML *android.DepSet
}

type LintDepSetsBuilder struct {
	HTML, Text, XML *android.DepSetBuilder
}

func NewLintDepSetBuilder() LintDepSetsBuilder {
	return LintDepSetsBuilder{
		HTML: android.NewDepSetBuilder(android.POSTORDER),
		Text: android.NewDepSetBuilder(android.POSTORDER),
		XML:  android.NewDepSetBuilder(android.POSTORDER),
	}
}

func (l LintDepSetsBuilder) Direct(html, text, xml android.Path) LintDepSetsBuilder {
	l.HTML.Direct(html)
	l.Text.Direct(text)
	l.XML.Direct(xml)
	return l
}

func (l LintDepSetsBuilder) Transitive(depSets LintDepSets) LintDepSetsBuilder {
	if depSets.HTML != nil {
		l.HTML.Transitive(depSets.HTML)
	}
	if depSets.Text != nil {
		l.Text.Transitive(depSets.Text)
	}
	if depSets.XML != nil {
		l.XML.Transitive(depSets.XML)
	}
	return l
}

func (l LintDepSetsBuilder) Build() LintDepSets {
	return LintDepSets{
		HTML: l.HTML.Build(),
		Text: l.Text.Build(),
		XML:  l.XML.Build(),
	}
}

func (l *linter) LintDepSets() LintDepSets {
	return l.outputs.depSets
}

var _ lintDepSetsIntf = (*linter)(nil)

var _ lintOutputsIntf = (*linter)(nil)

func (l *linter) lintOutputs() *lintOutputs {
	return &l.outputs
}

func (l *linter) enabled() bool {
	return BoolDefault(l.properties.Lint.Enabled, true)
}

func (l *linter) deps(ctx android.BottomUpMutatorContext) {
	if !l.enabled() {
		return
	}

	extraCheckModules := l.properties.Lint.Extra_check_modules

	if checkOnly := ctx.Config().Getenv("ANDROID_LINT_CHECK"); checkOnly != "" {
		if checkOnlyModules := ctx.Config().Getenv("ANDROID_LINT_CHECK_EXTRA_MODULES"); checkOnlyModules != "" {
			extraCheckModules = strings.Split(checkOnlyModules, ",")
		}
	}

	ctx.AddFarVariationDependencies(ctx.Config().BuildOSCommonTarget.Variations(),
		extraLintCheckTag, extraCheckModules...)
}

// lintPaths contains the paths to lint's inputs and outputs to make it easier to pass them
// around.
type lintPaths struct {
	projectXML android.WritablePath
	configXML  android.WritablePath
	cacheDir   android.WritablePath
	homeDir    android.WritablePath
	srcjarDir  android.WritablePath

	deps android.Paths

	remoteInputs    android.Paths
	remoteRSPInputs android.Paths
}

func lintRBEExecStrategy(ctx android.ModuleContext) string {
	return ctx.Config().GetenvWithDefault("RBE_LINT_EXEC_STRATEGY", remoteexec.LocalExecStrategy)
}

func (l *linter) writeLintProjectXML(ctx android.ModuleContext, rule *android.RuleBuilder) lintPaths {
	var deps android.Paths
	var remoteInputs android.Paths
	var remoteRSPInputs android.Paths

	// Paths passed to trackInputDependency will be added as dependencies of the rule that runs
	// lint and passed as inputs to the remote execution proxy.
	trackInputDependency := func(paths ...android.Path) {
		deps = append(deps, paths...)
		remoteInputs = append(remoteInputs, paths...)
	}

	// Paths passed to trackRSPDependency will be added as dependencies of the rule that runs
	// lint, but the RSP file will be used by the remote execution proxy to find the files so that
	// it doesn't overflow command line limits.
	trackRSPDependency := func(paths android.Paths, rsp android.Path) {
		deps = append(deps, paths...)
		remoteRSPInputs = append(remoteRSPInputs, rsp)
	}

	var resourcesList android.WritablePath
	if len(l.resources) > 0 {
		// The list of resources may be too long to put on the command line, but
		// we can't use the rsp file because it is already being used for srcs.
		// Insert a second rule to write out the list of resources to a file.
		resourcesList = android.PathForModuleOut(ctx, "lint", "resources.list")
		resListRule := android.NewRuleBuilder(pctx, ctx)
		resListRule.Command().Text("cp").FlagWithRspFileInputList("", l.resources).Output(resourcesList)
		resListRule.Build("lint_resources_list", "lint resources list")
		trackRSPDependency(l.resources, resourcesList)
	}

	projectXMLPath := android.PathForModuleOut(ctx, "lint", "project.xml")
	// Lint looks for a lint.xml file next to the project.xml file, give it one.
	configXMLPath := android.PathForModuleOut(ctx, "lint", "lint.xml")
	cacheDir := android.PathForModuleOut(ctx, "lint", "cache")
	homeDir := android.PathForModuleOut(ctx, "lint", "home")

	srcJarDir := android.PathForModuleOut(ctx, "lint-srcjars")
	srcJarList := zipSyncCmd(ctx, rule, srcJarDir, l.srcJars)
	// TODO(ccross): this is a little fishy.  The files extracted from the srcjars are referenced
	// by the project.xml and used by the later lint rule, but the lint rule depends on the srcjars,
	// not the extracted files.
	trackRSPDependency(l.srcJars, srcJarList)

	// TODO(ccross): some of the files in l.srcs are generated sources and should be passed to
	// lint separately.
	srcsList := android.PathForModuleOut(ctx, "lint", "srcs.list")
	rule.Command().Text("cp").FlagWithRspFileInputList("", l.srcs).Output(srcsList)
	trackRSPDependency(l.srcs, srcsList)

	cmd := rule.Command().
		BuiltTool("lint-project-xml").
		FlagWithOutput("--project_out ", projectXMLPath).
		FlagWithOutput("--config_out ", configXMLPath).
		FlagWithArg("--name ", ctx.ModuleName())

	if l.library {
		cmd.Flag("--library")
	}
	if l.test {
		cmd.Flag("--test")
	}
	if l.manifest != nil {
		cmd.FlagWithArg("--manifest ", l.manifest.String())
		trackInputDependency(l.manifest)
	}
	if l.mergedManifest != nil {
		cmd.FlagWithArg("--merged_manifest ", l.mergedManifest.String())
		trackInputDependency(l.mergedManifest)
	}

	cmd.FlagWithInput("--srcs ", srcsList)

	cmd.FlagWithInput("--generated_srcs ", srcJarList)

	if resourcesList != nil {
		cmd.FlagWithInput("--resources ", resourcesList)
	}

	if l.classes != nil {
		cmd.FlagWithArg("--classes ", l.classes.String())
		trackInputDependency(l.classes)
	}

	cmd.FlagForEachArg("--classpath ", l.classpath.Strings())
	trackInputDependency(l.classpath...)

	cmd.FlagForEachArg("--extra_checks_jar ", l.extraLintCheckJars.Strings())
	trackInputDependency(l.extraLintCheckJars...)

	if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_LINT") &&
		lintRBEExecStrategy(ctx) != remoteexec.LocalExecStrategy {
		// TODO(b/181912787): remove these and use "." instead.
		cmd.FlagWithArg("--root_dir ", "/b/f/w")
	} else {
		cmd.FlagWithArg("--root_dir ", "$PWD")
	}

	// The cache tag in project.xml is relative to the root dir, or the project.xml file if
	// the root dir is not set.
	cmd.FlagWithArg("--cache_dir ", cacheDir.String())

	cmd.FlagWithInput("@",
		android.PathForSource(ctx, "build/soong/java/lint_defaults.txt"))

	cmd.FlagForEachArg("--disable_check ", l.properties.Lint.Disabled_checks)
	cmd.FlagForEachArg("--warning_check ", l.properties.Lint.Warning_checks)
	cmd.FlagForEachArg("--error_check ", l.properties.Lint.Error_checks)
	cmd.FlagForEachArg("--fatal_check ", l.properties.Lint.Fatal_checks)

	return lintPaths{
		projectXML: projectXMLPath,
		configXML:  configXMLPath,
		cacheDir:   cacheDir,
		homeDir:    homeDir,

		deps: deps,

		remoteInputs:    remoteInputs,
		remoteRSPInputs: remoteRSPInputs,
	}

}

// generateManifest adds a command to the rule to write a simple manifest that contains the
// minSdkVersion and targetSdkVersion for modules (like java_library) that don't have a manifest.
func (l *linter) generateManifest(ctx android.ModuleContext, rule *android.RuleBuilder) android.Path {
	manifestPath := android.PathForModuleOut(ctx, "lint", "AndroidManifest.xml")

	rule.Command().Text("(").
		Text(`echo "<?xml version='1.0' encoding='utf-8'?>" &&`).
		Text(`echo "<manifest xmlns:android='http://schemas.android.com/apk/res/android'" &&`).
		Text(`echo "    android:versionCode='1' android:versionName='1' >" &&`).
		Textf(`echo "  <uses-sdk android:minSdkVersion='%s' android:targetSdkVersion='%s'/>" &&`,
			l.minSdkVersion, l.targetSdkVersion).
		Text(`echo "</manifest>"`).
		Text(") >").Output(manifestPath)

	return manifestPath
}

func (l *linter) lint(ctx android.ModuleContext) {
	if !l.enabled() {
		return
	}

	extraLintCheckModules := ctx.GetDirectDepsWithTag(extraLintCheckTag)
	for _, extraLintCheckModule := range extraLintCheckModules {
		if ctx.OtherModuleHasProvider(extraLintCheckModule, JavaInfoProvider) {
			dep := ctx.OtherModuleProvider(extraLintCheckModule, JavaInfoProvider).(JavaInfo)
			l.extraLintCheckJars = append(l.extraLintCheckJars, dep.ImplementationAndResourcesJars...)
		} else {
			ctx.PropertyErrorf("lint.extra_check_modules",
				"%s is not a java module", ctx.OtherModuleName(extraLintCheckModule))
		}
	}

	rule := android.NewRuleBuilder(pctx, ctx)

	if l.manifest == nil {
		manifest := l.generateManifest(ctx, rule)
		l.manifest = manifest
	}

	lintPaths := l.writeLintProjectXML(ctx, rule)

	html := android.PathForModuleOut(ctx, "lint-report.html")
	text := android.PathForModuleOut(ctx, "lint-report.txt")
	xml := android.PathForModuleOut(ctx, "lint-report.xml")

	depSetsBuilder := NewLintDepSetBuilder().Direct(html, text, xml)

	ctx.VisitDirectDepsWithTag(staticLibTag, func(dep android.Module) {
		if depLint, ok := dep.(lintDepSetsIntf); ok {
			depSetsBuilder.Transitive(depLint.LintDepSets())
		}
	})

	rule.Command().Text("rm -rf").Flag(lintPaths.cacheDir.String()).Flag(lintPaths.homeDir.String())
	rule.Command().Text("mkdir -p").Flag(lintPaths.cacheDir.String()).Flag(lintPaths.homeDir.String())
	rule.Command().Text("rm -f").Output(html).Output(text).Output(xml)

	var annotationsZipPath, apiVersionsXMLPath android.Path
	if ctx.Config().AlwaysUsePrebuiltSdks() {
		annotationsZipPath = android.PathForSource(ctx, "prebuilts/sdk/current/public/data/annotations.zip")
		apiVersionsXMLPath = android.PathForSource(ctx, "prebuilts/sdk/current/public/data/api-versions.xml")
	} else {
		annotationsZipPath = copiedAnnotationsZipPath(ctx)
		apiVersionsXMLPath = copiedAPIVersionsXmlPath(ctx)
	}

	cmd := rule.Command()

	cmd.Flag("JAVA_OPTS=-Xmx3072m").
		FlagWithArg("ANDROID_SDK_HOME=", lintPaths.homeDir.String()).
		FlagWithInput("SDK_ANNOTATIONS=", annotationsZipPath).
		FlagWithInput("LINT_OPTS=-DLINT_API_DATABASE=", apiVersionsXMLPath)

	if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_LINT") {
		pool := ctx.Config().GetenvWithDefault("RBE_LINT_POOL", "java16")
		// TODO(b/181912787): this should be local fallback once the hack that passes /b/f/w in project.xml
		// is removed.
		execStrategy := lintRBEExecStrategy(ctx)
		labels := map[string]string{"type": "tool", "name": "lint"}
		rule.Remoteable(android.RemoteRuleSupports{RBE: true})
		remoteInputs := lintPaths.remoteInputs
		remoteInputs = append(remoteInputs,
			lintPaths.projectXML,
			lintPaths.configXML,
			lintPaths.homeDir,
			lintPaths.cacheDir,
			ctx.Config().HostJavaToolPath(ctx, "lint.jar"),
			annotationsZipPath,
			apiVersionsXMLPath,
		)

		cmd.Text((&remoteexec.REParams{
			Labels:          labels,
			ExecStrategy:    execStrategy,
			ToolchainInputs: []string{config.JavaCmd(ctx).String()},
			Inputs:          remoteInputs.Strings(),
			OutputFiles:     android.Paths{html, text, xml}.Strings(),
			RSPFile:         strings.Join(lintPaths.remoteRSPInputs.Strings(), ","),
			EnvironmentVariables: []string{
				"JAVA_OPTS",
				"ANDROID_SDK_HOME",
				"SDK_ANNOTATIONS",
				"LINT_OPTS",
				"LANG",
			},
			Platform: map[string]string{remoteexec.PoolKey: pool},
		}).NoVarTemplate(ctx.Config()))
	}

	cmd.BuiltTool("lint").
		Flag("--quiet").
		FlagWithInput("--project ", lintPaths.projectXML).
		FlagWithInput("--config ", lintPaths.configXML).
		FlagWithOutput("--html ", html).
		FlagWithOutput("--text ", text).
		FlagWithOutput("--xml ", xml).
		FlagWithArg("--compile-sdk-version ", l.compileSdkVersion).
		FlagWithArg("--java-language-level ", l.javaLanguageLevel).
		FlagWithArg("--kotlin-language-level ", l.kotlinLanguageLevel).
		FlagWithArg("--url ", fmt.Sprintf(".=.,%s=out", android.PathForOutput(ctx).String())).
		Flag("--exitcode").
		Flags(l.properties.Lint.Flags).
		Implicit(annotationsZipPath).
		Implicit(apiVersionsXMLPath).
		Implicits(lintPaths.deps)

	if checkOnly := ctx.Config().Getenv("ANDROID_LINT_CHECK"); checkOnly != "" {
		cmd.FlagWithArg("--check ", checkOnly)
	}

	if lintFilename := proptools.StringDefault(l.properties.Lint.Baseline_filename, "lint-baseline.xml"); lintFilename != "" {
		var lintBaseline android.OptionalPath
		if String(l.properties.Lint.Baseline_filename) != "" {
			// if manually specified, we require the file to exist
			lintBaseline = android.OptionalPathForPath(android.PathForModuleSrc(ctx, lintFilename))
		} else {
			lintBaseline = android.ExistentPathForSource(ctx, ctx.ModuleDir(), lintFilename)
		}
		if lintBaseline.Valid() {
			cmd.FlagWithInput("--baseline ", lintBaseline.Path())
		}
	}

	cmd.Text("|| (").Text("if [ -e").Input(text).Text("]; then cat").Input(text).Text("; fi; exit 7)")

	rule.Command().Text("rm -rf").Flag(lintPaths.cacheDir.String()).Flag(lintPaths.homeDir.String())

	rule.Build("lint", "lint")

	l.outputs = lintOutputs{
		html: html,
		text: text,
		xml:  xml,

		depSets: depSetsBuilder.Build(),
	}

	if l.buildModuleReportZip {
		l.reports = BuildModuleLintReportZips(ctx, l.LintDepSets())
	}
}

func BuildModuleLintReportZips(ctx android.ModuleContext, depSets LintDepSets) android.Paths {
	htmlList := depSets.HTML.ToSortedList()
	textList := depSets.Text.ToSortedList()
	xmlList := depSets.XML.ToSortedList()

	if len(htmlList) == 0 && len(textList) == 0 && len(xmlList) == 0 {
		return nil
	}

	htmlZip := android.PathForModuleOut(ctx, "lint-report-html.zip")
	lintZip(ctx, htmlList, htmlZip)

	textZip := android.PathForModuleOut(ctx, "lint-report-text.zip")
	lintZip(ctx, textList, textZip)

	xmlZip := android.PathForModuleOut(ctx, "lint-report-xml.zip")
	lintZip(ctx, xmlList, xmlZip)

	return android.Paths{htmlZip, textZip, xmlZip}
}

type lintSingleton struct {
	htmlZip android.WritablePath
	textZip android.WritablePath
	xmlZip  android.WritablePath
}

func (l *lintSingleton) GenerateBuildActions(ctx android.SingletonContext) {
	l.generateLintReportZips(ctx)
	l.copyLintDependencies(ctx)
}

func (l *lintSingleton) copyLintDependencies(ctx android.SingletonContext) {
	if ctx.Config().AlwaysUsePrebuiltSdks() {
		return
	}

	var frameworkDocStubs android.Module
	ctx.VisitAllModules(func(m android.Module) {
		if ctx.ModuleName(m) == "framework-doc-stubs" {
			if frameworkDocStubs == nil {
				frameworkDocStubs = m
			} else {
				ctx.Errorf("lint: multiple framework-doc-stubs modules found: %s and %s",
					ctx.ModuleSubDir(m), ctx.ModuleSubDir(frameworkDocStubs))
			}
		}
	})

	if frameworkDocStubs == nil {
		if !ctx.Config().AllowMissingDependencies() {
			ctx.Errorf("lint: missing framework-doc-stubs")
		}
		return
	}

	ctx.Build(pctx, android.BuildParams{
		Rule:   android.CpIfChanged,
		Input:  android.OutputFileForModule(ctx, frameworkDocStubs, ".annotations.zip"),
		Output: copiedAnnotationsZipPath(ctx),
	})

	ctx.Build(pctx, android.BuildParams{
		Rule:   android.CpIfChanged,
		Input:  android.OutputFileForModule(ctx, frameworkDocStubs, ".api_versions.xml"),
		Output: copiedAPIVersionsXmlPath(ctx),
	})
}

func copiedAnnotationsZipPath(ctx android.PathContext) android.WritablePath {
	return android.PathForOutput(ctx, "lint", "annotations.zip")
}

func copiedAPIVersionsXmlPath(ctx android.PathContext) android.WritablePath {
	return android.PathForOutput(ctx, "lint", "api_versions.xml")
}

func (l *lintSingleton) generateLintReportZips(ctx android.SingletonContext) {
	if ctx.Config().UnbundledBuild() {
		return
	}

	var outputs []*lintOutputs
	var dirs []string
	ctx.VisitAllModules(func(m android.Module) {
		if ctx.Config().KatiEnabled() && !m.ExportedToMake() {
			return
		}

		if apex, ok := m.(android.ApexModule); ok && apex.NotAvailableForPlatform() {
			apexInfo := ctx.ModuleProvider(m, android.ApexInfoProvider).(android.ApexInfo)
			if apexInfo.IsForPlatform() {
				// There are stray platform variants of modules in apexes that are not available for
				// the platform, and they sometimes can't be built.  Don't depend on them.
				return
			}
		}

		if l, ok := m.(lintOutputsIntf); ok {
			outputs = append(outputs, l.lintOutputs())
		}
	})

	dirs = android.SortedUniqueStrings(dirs)

	zip := func(outputPath android.WritablePath, get func(*lintOutputs) android.Path) {
		var paths android.Paths

		for _, output := range outputs {
			if p := get(output); p != nil {
				paths = append(paths, p)
			}
		}

		lintZip(ctx, paths, outputPath)
	}

	l.htmlZip = android.PathForOutput(ctx, "lint-report-html.zip")
	zip(l.htmlZip, func(l *lintOutputs) android.Path { return l.html })

	l.textZip = android.PathForOutput(ctx, "lint-report-text.zip")
	zip(l.textZip, func(l *lintOutputs) android.Path { return l.text })

	l.xmlZip = android.PathForOutput(ctx, "lint-report-xml.zip")
	zip(l.xmlZip, func(l *lintOutputs) android.Path { return l.xml })

	ctx.Phony("lint-check", l.htmlZip, l.textZip, l.xmlZip)
}

func (l *lintSingleton) MakeVars(ctx android.MakeVarsContext) {
	if !ctx.Config().UnbundledBuild() {
		ctx.DistForGoal("lint-check", l.htmlZip, l.textZip, l.xmlZip)
	}
}

var _ android.SingletonMakeVarsProvider = (*lintSingleton)(nil)

func init() {
	android.RegisterSingletonType("lint",
		func() android.Singleton { return &lintSingleton{} })
}

func lintZip(ctx android.BuilderContext, paths android.Paths, outputPath android.WritablePath) {
	paths = android.SortedUniquePaths(android.CopyOfPaths(paths))

	sort.Slice(paths, func(i, j int) bool {
		return paths[i].String() < paths[j].String()
	})

	rule := android.NewRuleBuilder(pctx, ctx)

	rule.Command().BuiltTool("soong_zip").
		FlagWithOutput("-o ", outputPath).
		FlagWithArg("-C ", android.PathForIntermediates(ctx).String()).
		FlagWithRspFileInputList("-r ", paths)

	rule.Build(outputPath.Base(), outputPath.Base())
}