// Copyright 2018 The Fuchsia Authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//    * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//    * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package main

import (
	"context"
	"encoding/csv"
	"flag"
	"fmt"
	"os"
	"os/signal"
	"strconv"

	"fuchsia.googlesource.com/zedmon"
	"github.com/google/subcommands"
)

type recordCmd struct{}

func (*recordCmd) Name() string     { return "record" }
func (*recordCmd) Synopsis() string { return "Record data from zedmon.  Saves to zedmon.csv." }
func (*recordCmd) Usage() string {
	return `record
`
}

func (*recordCmd) SetFlags(_ *flag.FlagSet) {
}

func (*recordCmd) Execute(_ context.Context, _ *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
	zedmon, err := zedmon.OpenZedmon()
	if err != nil {
		fmt.Printf("Can't open zendmon: %v", err)
		return subcommands.ExitFailure
	}
	defer zedmon.Close()

	f, err := os.OpenFile("zedmon.csv", os.O_CREATE|os.O_RDWR, 0666)
	if err != nil {
		fmt.Printf("Can't open zedmon.csv: %v", err)
		return subcommands.ExitFailure
	}
	defer f.Close()

	offset, delta, err := zedmon.GetTimeOffset()
	if err != nil {
		fmt.Printf("Get time offset: %v", err)
		return subcommands.ExitFailure
	}
	fmt.Printf("Time offset: %v ± %v\n", offset, delta)

	termChan := make(chan os.Signal, 1)
	signal.Notify(termChan, os.Interrupt)

	writer := csv.NewWriter(f)
	defer writer.Flush()

	fmt.Printf("Starting report recording. Send ^C to stop.\n")
	zedmon.EnableReporting()

RecordSampling:
	for {
		reports, err := zedmon.ReadReports()
		if err != nil {
			fmt.Printf("Error reading reports: %v\n", err)
			continue
		}
		for _, report := range reports {
			record := make([]string, 0, len(report.Values))
			record = append(record, strconv.FormatUint(report.Timestamp, 10))
			for _, value := range report.Values {
				record = append(record, strconv.FormatFloat(value, 'g', -1, 64))
			}
			writer.Write(record)
		}

		select {
		case <-termChan:
			break RecordSampling
		default:
		}
	}
	fmt.Printf("Stopping report recording.\n")

	return subcommands.ExitSuccess
}