// Copyright 2023 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 aconfig

import (
	"fmt"
	"slices"

	"android/soong/android"
)

// A singleton module that collects all of the aconfig flags declared in the
// tree into a single combined file for export to the external flag setting
// server (inside Google it's Gantry).
//
// Note that this is ALL aconfig_declarations modules present in the tree, not just
// ones that are relevant to the product currently being built, so that that infra
// doesn't need to pull from multiple builds and merge them.
func AllAconfigDeclarationsFactory() android.Singleton {
	return &allAconfigDeclarationsSingleton{releaseMap: make(map[string]allAconfigReleaseDeclarationsSingleton)}
}

type allAconfigReleaseDeclarationsSingleton struct {
	intermediateBinaryProtoPath android.OutputPath
	intermediateTextProtoPath   android.OutputPath
}

type allAconfigDeclarationsSingleton struct {
	releaseMap map[string]allAconfigReleaseDeclarationsSingleton
}

func (this *allAconfigDeclarationsSingleton) sortedConfigNames() []string {
	var names []string
	for k := range this.releaseMap {
		names = append(names, k)
	}
	slices.Sort(names)
	return names
}

func (this *allAconfigDeclarationsSingleton) GenerateBuildActions(ctx android.SingletonContext) {
	for _, rcName := range append([]string{""}, ctx.Config().ReleaseAconfigExtraReleaseConfigs()...) {
		// Find all of the aconfig_declarations modules
		var packages = make(map[string]int)
		var cacheFiles android.Paths
		ctx.VisitAllModules(func(module android.Module) {
			decl, ok := android.OtherModuleProvider(ctx, module, android.AconfigReleaseDeclarationsProviderKey)
			if !ok {
				return
			}
			cacheFiles = append(cacheFiles, decl[rcName].IntermediateCacheOutputPath)
			packages[decl[rcName].Package]++
		})

		var numOffendingPkg = 0
		for pkg, cnt := range packages {
			if cnt > 1 {
				fmt.Printf("%d aconfig_declarations found for package %s\n", cnt, pkg)
				numOffendingPkg++
			}
		}

		if numOffendingPkg > 0 {
			panic(fmt.Errorf("Only one aconfig_declarations allowed for each package."))
		}

		// Generate build action for aconfig (binary proto output)
		paths := allAconfigReleaseDeclarationsSingleton{
			intermediateBinaryProtoPath: android.PathForIntermediates(ctx, assembleFileName(rcName, "all_aconfig_declarations.pb")),
			intermediateTextProtoPath:   android.PathForIntermediates(ctx, assembleFileName(rcName, "all_aconfig_declarations.textproto")),
		}
		this.releaseMap[rcName] = paths
		ctx.Build(pctx, android.BuildParams{
			Rule:        AllDeclarationsRule,
			Inputs:      cacheFiles,
			Output:      this.releaseMap[rcName].intermediateBinaryProtoPath,
			Description: "all_aconfig_declarations",
			Args: map[string]string{
				"cache_files": android.JoinPathsWithPrefix(cacheFiles, "--cache "),
			},
		})
		ctx.Phony("all_aconfig_declarations", this.releaseMap[rcName].intermediateBinaryProtoPath)

		// Generate build action for aconfig (text proto output)
		ctx.Build(pctx, android.BuildParams{
			Rule:        AllDeclarationsRuleTextProto,
			Inputs:      cacheFiles,
			Output:      this.releaseMap[rcName].intermediateTextProtoPath,
			Description: "all_aconfig_declarations_textproto",
			Args: map[string]string{
				"cache_files": android.JoinPathsWithPrefix(cacheFiles, "--cache "),
			},
		})
		ctx.Phony("all_aconfig_declarations_textproto", this.releaseMap[rcName].intermediateTextProtoPath)
	}
}

func (this *allAconfigDeclarationsSingleton) MakeVars(ctx android.MakeVarsContext) {
	for _, rcName := range this.sortedConfigNames() {
		ctx.DistForGoal("droid", this.releaseMap[rcName].intermediateBinaryProtoPath)
		for _, goal := range []string{"docs", "droid", "sdk"} {
			ctx.DistForGoalWithFilename(goal, this.releaseMap[rcName].intermediateBinaryProtoPath, assembleFileName(rcName, "flags.pb"))
			ctx.DistForGoalWithFilename(goal, this.releaseMap[rcName].intermediateTextProtoPath, assembleFileName(rcName, "flags.textproto"))
		}
	}
}