package main

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"

	"rescribe.xyz/bookpipeline"
)

const usage = `Usage: getpipelinebook [-a] [-c] [-v] bookname

Downloads the pipeline results for a book.

By default this downloads the best hOCR version for each page with
the corresponding binarised image, and the best, conf and graph.png
analysis files.
`

// null writer to enable non-verbose logging to be discarded
type NullWriter bool

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

type Pipeliner interface {
	Init() error
	ListObjects(bucket string, prefix string) ([]string, error)
	Download(bucket string, key string, fn string) error
	Upload(bucket string, key string, path string) error
	CheckQueue(url string, timeout int64) (bookpipeline.Qmsg, error)
	AddToQueue(url string, msg string) error
	DelFromQueue(url string, handle string) error
	WIPStorageId() string
}

func main() {
	all := flag.Bool("a", false, "Get all files for book")
	colour := flag.Bool("c", false, "Also get the original page images")
	verbose := flag.Bool("v", false, "Verbose")
	flag.Usage = func() {
		fmt.Fprintf(flag.CommandLine.Output(), usage)
		flag.PrintDefaults()
	}
	flag.Parse()

	if flag.NArg() < 1 {
		flag.Usage()
		return
	}

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

	var conn Pipeliner
	conn = &bookpipeline.AwsConn{Region: "eu-west-2", Logger: verboselog}

	verboselog.Println("Setting up AWS session")
	err := conn.Init()
	if err != nil {
		log.Fatalln("Error setting up cloud connection:", err)
	}
	verboselog.Println("Finished setting up AWS session")

	bookname := flag.Arg(0)

	err = os.MkdirAll(bookname, 0755)
	if err != nil {
		log.Fatalln("Failed to create directory", bookname, err)
	}

	if *all {
		verboselog.Println("Downloading all files for", bookname)
		objs, err := conn.ListObjects(conn.WIPStorageId(), bookname)
		if err != nil {
			log.Fatalln("Failed to get list of files for book", bookname, err)
		}
		for _, i := range objs {
			verboselog.Println("Downloading", i)
			err = conn.Download(conn.WIPStorageId(), i, i)
			if err != nil {
				log.Fatalln("Failed to download file", i, err)
			}
		}
		return
	}

	verboselog.Println("Downloading best file")
	fn := filepath.Join(bookname, "best")
	err = conn.Download(conn.WIPStorageId(), fn, fn)
	if err != nil {
		log.Fatalln("Failed to download 'best' file", err)
	}
	f, err := os.Open(fn)
	if err != nil {
		log.Fatalln("Failed to open best file", err)
	}
	defer f.Close()

	verboselog.Println("Downloading HOCR and corresponding image files")
	s := bufio.NewScanner(f)
	for s.Scan() {
		fn = filepath.Join(bookname, s.Text())
		verboselog.Println("Downloading file", fn)
		err = conn.Download(conn.WIPStorageId(), fn, fn)
		if err != nil {
			log.Fatalln("Failed to download file", fn, err)
		}
		b := strings.TrimSuffix(s.Text(), ".hocr")
		fn = filepath.Join(bookname, b + ".png")
		verboselog.Println("Downloading file", fn)
		err = conn.Download(conn.WIPStorageId(), fn, fn)
		if err != nil {
			log.Fatalln("Failed to download file", fn, err)
		}
		if *colour {
			parts := strings.SplitN(s.Text(), "_bin", 2)
			if len(parts) < 2 {
				verboselog.Println("Can't find page number for original page image, skipping", b)
				continue
			}
			num := parts[0]
			fn = filepath.Join(bookname, num + ".jpg")
			verboselog.Println("Downloading file", fn)
			err = conn.Download(conn.WIPStorageId(), fn, fn)
			if err != nil {
				fn = filepath.Join(bookname, num + ".png")
				verboselog.Println("Downloading file", fn)
				err = conn.Download(conn.WIPStorageId(), fn, fn)
				if err != nil {
					log.Fatalln("Failed to download file", fn, err)
				}
			}
		}
	}

	analyses := []string{"conf", "graph.png"}
	verboselog.Println("Downloading analysis files")
	for _, a := range analyses {
		fn = filepath.Join(bookname, a)
		verboselog.Println("Downloading file", fn)
		err = conn.Download(conn.WIPStorageId(), fn, fn)
		if err != nil {
			log.Fatalln("Failed to download file", fn, err)
		}
	}
}