// 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 main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"android/soong/ui/build"
	"android/soong/ui/logger"
	"android/soong/ui/metrics"
	"android/soong/ui/status"
	"android/soong/ui/terminal"
	"android/soong/ui/tracer"
)

// A command represents an operation to be executed in the soong build
// system.
type command struct {
	// the flag name (must have double dashes)
	flag string

	// description for the flag (to display when running help)
	description string

	// Creates the build configuration based on the args and build context.
	config func(ctx build.Context, args ...string) build.Config

	// Returns what type of IO redirection this Command requires.
	stdio func() terminal.StdioInterface

	// run the command
	run func(ctx build.Context, config build.Config, args []string, logsDir string)
}

const makeModeFlagName = "--make-mode"

// list of supported commands (flags) supported by soong ui
var commands []command = []command{
	{
		flag:        makeModeFlagName,
		description: "build the modules by the target name (i.e. soong_docs)",
		config: func(ctx build.Context, args ...string) build.Config {
			return build.NewConfig(ctx, args...)
		},
		stdio: func() terminal.StdioInterface {
			return terminal.StdioImpl{}
		},
		run: make,
	}, {
		flag:        "--dumpvar-mode",
		description: "print the value of the legacy make variable VAR to stdout",
		config:      dumpVarConfig,
		stdio:       customStdio,
		run:         dumpVar,
	}, {
		flag:        "--dumpvars-mode",
		description: "dump the values of one or more legacy make variables, in shell syntax",
		config:      dumpVarConfig,
		stdio:       customStdio,
		run:         dumpVars,
	},
}

// indexList returns the index of first found s. -1 is return if s is not
// found.
func indexList(s string, list []string) int {
	for i, l := range list {
		if l == s {
			return i
		}
	}
	return -1
}

// inList returns true if one or more of s is in the list.
func inList(s string, list []string) bool {
	return indexList(s, list) != -1
}

// Main execution of soong_ui. The command format is as follows:
//
//    soong_ui <command> [<arg 1> <arg 2> ... <arg n>]
//
// Command is the type of soong_ui execution. Only one type of
// execution is specified. The args are specific to the command.
func main() {
	c, args := getCommand(os.Args)
	if c == nil {
		fmt.Fprintf(os.Stderr, "The `soong` native UI is not yet available.\n")
		os.Exit(1)
	}

	writer := terminal.NewWriter(c.stdio())
	defer writer.Finish()

	log := logger.New(writer)
	defer log.Cleanup()

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	trace := tracer.New(log)
	defer trace.Close()

	met := metrics.New()

	stat := &status.Status{}
	defer stat.Finish()
	stat.AddOutput(terminal.NewStatusOutput(writer, os.Getenv("NINJA_STATUS"),
		build.OsEnvironment().IsEnvTrue("ANDROID_QUIET_BUILD")))
	stat.AddOutput(trace.StatusTracer())

	build.SetupSignals(log, cancel, func() {
		trace.Close()
		log.Cleanup()
		stat.Finish()
	})

	buildCtx := build.Context{ContextImpl: &build.ContextImpl{
		Context: ctx,
		Logger:  log,
		Metrics: met,
		Tracer:  trace,
		Writer:  writer,
		Status:  stat,
	}}

	config := c.config(buildCtx, args...)

	build.SetupOutDir(buildCtx, config)

	logsDir := config.OutDir()
	if config.Dist() {
		logsDir = filepath.Join(config.DistDir(), "logs")
	}

	os.MkdirAll(logsDir, 0777)
	log.SetOutput(filepath.Join(logsDir, "soong.log"))
	trace.SetOutput(filepath.Join(logsDir, "build.trace"))
	stat.AddOutput(status.NewVerboseLog(log, filepath.Join(logsDir, "verbose.log")))
	stat.AddOutput(status.NewErrorLog(log, filepath.Join(logsDir, "error.log")))

	defer met.Dump(filepath.Join(logsDir, "build_metrics"))

	if start, ok := os.LookupEnv("TRACE_BEGIN_SOONG"); ok {
		if !strings.HasSuffix(start, "N") {
			if start_time, err := strconv.ParseUint(start, 10, 64); err == nil {
				log.Verbosef("Took %dms to start up.",
					time.Since(time.Unix(0, int64(start_time))).Nanoseconds()/time.Millisecond.Nanoseconds())
				buildCtx.CompleteTrace(metrics.RunSetupTool, "startup", start_time, uint64(time.Now().UnixNano()))
			}
		}

		if executable, err := os.Executable(); err == nil {
			trace.ImportMicrofactoryLog(filepath.Join(filepath.Dir(executable), "."+filepath.Base(executable)+".trace"))
		}
	}

	f := build.NewSourceFinder(buildCtx, config)
	defer f.Shutdown()
	build.FindSources(buildCtx, config, f)

	c.run(buildCtx, config, args, logsDir)
}

func dumpVar(ctx build.Context, config build.Config, args []string, _ string) {
	flags := flag.NewFlagSet("dumpvar", flag.ExitOnError)
	flags.Usage = func() {
		fmt.Fprintf(os.Stderr, "usage: %s --dumpvar-mode [--abs] <VAR>\n\n", os.Args[0])
		fmt.Fprintln(os.Stderr, "In dumpvar mode, print the value of the legacy make variable VAR to stdout")
		fmt.Fprintln(os.Stderr, "")

		fmt.Fprintln(os.Stderr, "'report_config' is a special case that prints the human-readable config banner")
		fmt.Fprintln(os.Stderr, "from the beginning of the build.")
		fmt.Fprintln(os.Stderr, "")
		flags.PrintDefaults()
	}
	abs := flags.Bool("abs", false, "Print the absolute path of the value")
	flags.Parse(args)

	if flags.NArg() != 1 {
		flags.Usage()
		os.Exit(1)
	}

	varName := flags.Arg(0)
	if varName == "report_config" {
		varData, err := build.DumpMakeVars(ctx, config, nil, build.BannerVars)
		if err != nil {
			ctx.Fatal(err)
		}

		fmt.Println(build.Banner(varData))
	} else {
		varData, err := build.DumpMakeVars(ctx, config, nil, []string{varName})
		if err != nil {
			ctx.Fatal(err)
		}

		if *abs {
			var res []string
			for _, path := range strings.Fields(varData[varName]) {
				if abs, err := filepath.Abs(path); err == nil {
					res = append(res, abs)
				} else {
					ctx.Fatalln("Failed to get absolute path of", path, err)
				}
			}
			fmt.Println(strings.Join(res, " "))
		} else {
			fmt.Println(varData[varName])
		}
	}
}

func dumpVars(ctx build.Context, config build.Config, args []string, _ string) {
	flags := flag.NewFlagSet("dumpvars", flag.ExitOnError)
	flags.Usage = func() {
		fmt.Fprintf(os.Stderr, "usage: %s --dumpvars-mode [--vars=\"VAR VAR ...\"]\n\n", os.Args[0])
		fmt.Fprintln(os.Stderr, "In dumpvars mode, dump the values of one or more legacy make variables, in")
		fmt.Fprintln(os.Stderr, "shell syntax. The resulting output may be sourced directly into a shell to")
		fmt.Fprintln(os.Stderr, "set corresponding shell variables.")
		fmt.Fprintln(os.Stderr, "")

		fmt.Fprintln(os.Stderr, "'report_config' is a special case that dumps a variable containing the")
		fmt.Fprintln(os.Stderr, "human-readable config banner from the beginning of the build.")
		fmt.Fprintln(os.Stderr, "")
		flags.PrintDefaults()
	}

	varsStr := flags.String("vars", "", "Space-separated list of variables to dump")
	absVarsStr := flags.String("abs-vars", "", "Space-separated list of variables to dump (using absolute paths)")

	varPrefix := flags.String("var-prefix", "", "String to prepend to all variable names when dumping")
	absVarPrefix := flags.String("abs-var-prefix", "", "String to prepent to all absolute path variable names when dumping")

	flags.Parse(args)

	if flags.NArg() != 0 {
		flags.Usage()
		os.Exit(1)
	}

	vars := strings.Fields(*varsStr)
	absVars := strings.Fields(*absVarsStr)

	allVars := append([]string{}, vars...)
	allVars = append(allVars, absVars...)

	if i := indexList("report_config", allVars); i != -1 {
		allVars = append(allVars[:i], allVars[i+1:]...)
		allVars = append(allVars, build.BannerVars...)
	}

	if len(allVars) == 0 {
		return
	}

	varData, err := build.DumpMakeVars(ctx, config, nil, allVars)
	if err != nil {
		ctx.Fatal(err)
	}

	for _, name := range vars {
		if name == "report_config" {
			fmt.Printf("%sreport_config='%s'\n", *varPrefix, build.Banner(varData))
		} else {
			fmt.Printf("%s%s='%s'\n", *varPrefix, name, varData[name])
		}
	}
	for _, name := range absVars {
		var res []string
		for _, path := range strings.Fields(varData[name]) {
			abs, err := filepath.Abs(path)
			if err != nil {
				ctx.Fatalln("Failed to get absolute path of", path, err)
			}
			res = append(res, abs)
		}
		fmt.Printf("%s%s='%s'\n", *absVarPrefix, name, strings.Join(res, " "))
	}
}

func customStdio() terminal.StdioInterface {
	return terminal.NewCustomStdio(os.Stdin, os.Stderr, os.Stderr)
}

// dumpVarConfig does not require any arguments to be parsed by the NewConfig.
func dumpVarConfig(ctx build.Context, args ...string) build.Config {
	return build.NewConfig(ctx)
}

func make(ctx build.Context, config build.Config, _ []string, logsDir string) {
	if config.IsVerbose() {
		writer := ctx.Writer
		writer.Print("! The argument `showcommands` is no longer supported.")
		writer.Print("! Instead, the verbose log is always written to a compressed file in the output dir:")
		writer.Print("!")
		writer.Print(fmt.Sprintf("!   gzip -cd %s/verbose.log.gz | less -R", logsDir))
		writer.Print("!")
		writer.Print("! Older versions are saved in verbose.log.#.gz files")
		writer.Print("")
		time.Sleep(5 * time.Second)
	}

	toBuild := build.BuildAll
	if config.Checkbuild() {
		toBuild |= build.RunBuildTests
	}
	build.Build(ctx, config, toBuild)
}

// getCommand finds the appropriate command based on args[1] flag. args[0]
// is the soong_ui filename.
func getCommand(args []string) (*command, []string) {
	if len(args) < 2 {
		return nil, args
	}

	for _, c := range commands {
		if c.flag == args[1] {
			return &c, args[2:]
		}

		// special case for --make-mode: if soong_ui was called from
		// build/make/core/main.mk, the makeparallel with --ninja
		// option specified puts the -j<num> before --make-mode.
		// TODO: Remove this hack once it has been fixed.
		if c.flag == makeModeFlagName {
			if inList(makeModeFlagName, args) {
				return &c, args[1:]
			}
		}
	}

	// command not found
	return nil, args
}