// Copyright 2017 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 python

// This file contains Ninja build actions for building Python program.

import (
	"fmt"
	"strings"

	"android/soong/android"

	"github.com/google/blueprint"
	_ "github.com/google/blueprint/bootstrap"
)

var (
	pctx = android.NewPackageContext("android/soong/python")

	host_par = pctx.AndroidStaticRule("host_par",
		blueprint.RuleParams{
			Command: `touch $initFile && ` +
				`sed -e 's/%interpreter%/$interp/g' -e 's/%main%/$main/g' $template > $stub && ` +
				`$parCmd -o $parFile $parArgs && echo '#!/usr/bin/env python' | cat - $parFile > $out && ` +
				`chmod +x $out && (rm -f $initFile; rm -f $stub; rm -f $parFile)`,
			CommandDeps: []string{"$parCmd", "$template"},
		},
		"initFile", "interp", "main", "template", "stub", "parCmd", "parFile", "parArgs")

	embedded_par = pctx.AndroidStaticRule("embedded_par",
		blueprint.RuleParams{
			Command: `touch $initFile && ` +
				`echo '$main' > $entry_point && ` +
				`$parCmd -o $parFile $parArgs && cat $launcher | cat - $parFile > $out && ` +
				`chmod +x $out && (rm -f $initFile; rm -f $entry_point; rm -f $parFile)`,
			CommandDeps: []string{"$parCmd"},
		},
		"initFile", "main", "entry_point", "parCmd", "parFile", "parArgs", "launcher")
)

func init() {
	pctx.Import("github.com/google/blueprint/bootstrap")
	pctx.Import("android/soong/common")

	pctx.HostBinToolVariable("parCmd", "soong_zip")
}

type fileListSpec struct {
	fileList     android.Path
	relativeRoot string
}

type parSpec struct {
	rootPrefix string

	fileListSpecs []fileListSpec
}

func (p parSpec) soongParArgs() string {
	ret := `-P ` + p.rootPrefix

	for _, spec := range p.fileListSpecs {
		ret += ` -C ` + spec.relativeRoot + ` -l ` + spec.fileList.String()
	}

	return ret
}

func registerBuildActionForModuleFileList(ctx android.ModuleContext,
	name string, files android.Paths) android.Path {
	fileList := android.PathForModuleOut(ctx, name+".list")

	content := []string{}
	for _, file := range files {
		content = append(content, file.String())
	}

	ctx.Build(pctx, android.BuildParams{
		Rule:        android.WriteFile,
		Description: "generate " + fileList.Rel(),
		Output:      fileList,
		Implicits:   files,
		Args: map[string]string{
			"content": strings.Join(content, `\n`),
		},
	})

	return fileList
}

func registerBuildActionForParFile(ctx android.ModuleContext, embedded_launcher bool,
	launcher_path android.Path, interpreter, main, binName string,
	newPyPkgs []string, parSpecs []parSpec) android.Path {

	// .intermediate output path for __init__.py
	initFile := android.PathForModuleOut(ctx, initFileName).String()

	// .intermediate output path for par file.
	parFile := android.PathForModuleOut(ctx, binName+parFileExt)

	// .intermediate output path for bin executable.
	binFile := android.PathForModuleOut(ctx, binName)

	// implicit dependency for parFile build action.
	implicits := android.Paths{}
	for _, p := range parSpecs {
		for _, f := range p.fileListSpecs {
			implicits = append(implicits, f.fileList)
		}
	}

	parArgs := []string{}
	parArgs = append(parArgs, `-P "" `+`-C `+strings.TrimSuffix(initFile, initFileName)+` -f `+initFile)
	for _, pkg := range newPyPkgs {
		parArgs = append(parArgs, `-P `+pkg+` -f `+initFile)
	}
	for _, p := range parSpecs {
		parArgs = append(parArgs, p.soongParArgs())
	}

	if !embedded_launcher {
		// the path of stub_template_host.txt from source tree.
		template := android.PathForSource(ctx, stubTemplateHost)

		// intermediate output path for __main__.py
		stub := android.PathForModuleOut(ctx, mainFileName).String()

		// added stub file to the soong_zip args.
		parArgs = append(parArgs, `-P "" `+`-C `+strings.TrimSuffix(stub, mainFileName)+` -f `+stub)

		ctx.Build(pctx, android.BuildParams{
			Rule:        host_par,
			Description: "host python archive",
			Output:      binFile,
			Implicits:   implicits,
			Args: map[string]string{
				"initFile": initFile,
				"interp":   strings.Replace(interpreter, "/", `\/`, -1),
				// we need remove "runfiles/" suffix since stub script starts
				// searching for main file in each sub-dir of "runfiles" directory tree.
				"main": strings.Replace(strings.TrimPrefix(main, runFiles+"/"),
					"/", `\/`, -1),
				"template": template.String(),
				"stub":     stub,
				"parFile":  parFile.String(),
				"parArgs":  strings.Join(parArgs, " "),
			},
		})
	} else {
		// added launcher_path to the implicits Ninja dependencies.
		implicits = append(implicits, launcher_path)

		// .intermediate output path for entry_point.txt
		entryPoint := android.PathForModuleOut(ctx, entryPointFile).String()

		// added entry_point file to the soong_zip args.
		parArgs = append(parArgs, `-P "" `+`-C `+fmt.Sprintf(
			"%q", strings.TrimSuffix(entryPoint, entryPointFile))+` -f `+entryPoint)

		ctx.Build(pctx, android.BuildParams{
			Rule:        embedded_par,
			Description: "embedded python archive",
			Output:      binFile,
			Implicits:   implicits,
			Args: map[string]string{
				"initFile":    initFile,
				"main":        main,
				"entry_point": entryPoint,
				"parFile":     parFile.String(),
				"parArgs":     strings.Join(parArgs, " "),
				"launcher":    launcher_path.String(),
			},
		})
	}

	return binFile
}