package main

import (
	"flag"
	"fmt"
	"log"
	"os"

	"rescribe.xyz/go.git/bookpipeline"
)

const usage = `Usage: lspipeline [-v]

Lists useful things related to the pipeline.

- Instances running
- Messages in each queue
- Books not completed (from S3 without a best file)
- Books completed (from S3 with a best file)
- Last 5 lines of bookpipeline logs from each running instance (with -v)
`

type LsPipeliner interface {
	Init() error
	PreQueueId() string
	OCRQueueId() string
	AnalyseQueueId() string
	GetQueueDetails(url string) (string, string, error)
	GetInstanceDetails() ([]bookpipeline.InstanceDetails, error)
}

// NullWriter is used so non-verbose logging may be discarded
type NullWriter bool

func (w NullWriter) Write(p []byte) (n int, err error) {
	return len(p), nil
}

type queueDetails struct {
	name, numAvailable, numInProgress string
}

func getInstances(conn LsPipeliner, detailsc chan bookpipeline.InstanceDetails) {
	details, err := conn.GetInstanceDetails()
	if err != nil {
		log.Println("Error getting instance details:", err)
	}
	for _, d := range details {
		detailsc <- d
	}
	close(detailsc)
}

func getQueueDetails(conn LsPipeliner, qdetails chan queueDetails) {
	queues := []struct{ name, id string }{
		{"preprocess", conn.PreQueueId()},
		{"ocr", conn.OCRQueueId()},
		{"analyse", conn.AnalyseQueueId()},
	}
	for _, q := range queues {
		avail, inprog, err := conn.GetQueueDetails(q.id)
		if err != nil {
			log.Println("Error getting queue details:", err)
		}
		var qd queueDetails
		qd.name = q.name
		qd.numAvailable = avail
		qd.numInProgress = inprog
		qdetails <- qd
	}
	close(qdetails)
}

func main() {
	verbose := flag.Bool("v", false, "verbose")
	flag.Usage = func() {
		fmt.Fprintf(flag.CommandLine.Output(), usage)
		flag.PrintDefaults()
	}
	flag.Parse()

	var verboselog *log.Logger
	if *verbose {
		verboselog = log.New(os.Stdout, "", 0)
	} else {
		var n NullWriter
		verboselog = log.New(n, "", 0)
	}

	var conn LsPipeliner
	conn = &bookpipeline.AwsConn{Region: "eu-west-2", Logger: verboselog}
	err := conn.Init()
	if err != nil {
		log.Fatalln("Failed to set up cloud connection:", err)
	}

	instances := make(chan bookpipeline.InstanceDetails, 100)
	queues := make(chan queueDetails)

	go getInstances(conn, instances)
	go getQueueDetails(conn, queues)

	fmt.Println("# Instances")
	for i := range instances {
		fmt.Printf("ID: %s, Type: %s, LaunchTime: %s, State: %s", i.Id, i.Type, i.LaunchTime, i.State)
		if i.Name != "" {
			fmt.Printf(", Name: %s", i.Name)
		}
		if i.Ip != "" {
			fmt.Printf(", IP: %s", i.Ip)
		}
		if i.Spot != "" {
			fmt.Printf(", SpotRequest: %s", i.Spot)
		}
		fmt.Printf("\n")
	}

	fmt.Println("\n# Queues")
	for i := range queues {
		fmt.Printf("%s: %s available, %s in progress\n", i.name, i.numAvailable, i.numInProgress)
	}

	// TODO: See remaining items in the usage statement
}