#!/usr/bin/env python

import time
import tempfile
import shutil
import subprocess
import re
import datetime
import hurry.filesize

import os
import sys
import termios
import fcntl

global INCOMINGDIR
INCOMINGDIR = "/home/swhitton/lib/annex/doc/incoming"

global WARMED
WARMED = True

# Epson scanner in Tucson doesn't support --depth
global SCANNER_SUPPORTS_DEPTH
SCANNER_SUPPORTS_DEPTH = False

# from: http://stackoverflow.com/questions/510357/python-read-a-single-character-from-the-user
def getch():
    fd = sys.stdin.fileno()

    oldterm = termios.tcgetattr(fd)
    newattr = termios.tcgetattr(fd)
    newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
    termios.tcsetattr(fd, termios.TCSANOW, newattr)

    oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

    try:
        while 1:
            try:
                c = sys.stdin.read(1)
                break
            except IOError: pass
    finally:
       termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
       fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
       return c

def main():
    desktop = 1
    while True:
        if not(desktop):
            savestr = "incoming folder"
        else:
            savestr = "desktop"

        operation = menu("Choose an operation:",
                         [("Single page B&W PDF", '1'),
                          ("Multi-page B&W PDF", '2'),
                          ("Single page colour PDF", '3'),
                          ("Multi-page colour PDF", '4'),
                          ("Single page OCR'd PDF, letter size", '5'), # greyscale 400dpi best for ocr http://web.archive.org/web/20080529012847/http://groundstate.ca/ocr
                          ("Multi-page OCR'd PDF, letter size", '6'),
                          ("Standard dpi full colour scan to PNG, autocrop", '7'),
                          ("High dpi full colour scan to PNG, cropped to printed photo size", '8'),
                          ("Single page colour PDF, letter size", '9'),
                          ("Multi-page colour PDF, letter size", '0'),
                          ("Single-page colour 300 dpi to PNG", 'a'),
                          ("Multi-page gray 150 dpi to PDF, no OCR, letter size (for handwritten notes)", 'h'),
                          ("Toggle save location (currently: " + savestr + ")", 'd'),
                          ("Quit", 'q')])

        outdir = lambda desktop: subprocess.check_output(['xdg-user-dir', 'DESKTOP']).rstrip() if desktop else INCOMINGDIR
        outdir = outdir(desktop)

        if operation == 'q':
            sys.exit()
        elif operation == 'd':
            if desktop:
                desktop = 0
            else:
                desktop = 1

        elif operation == '1':
            scan(outdir, 150)
        elif operation == '2':
            scan(outdir, 150, True)
        elif operation == '3':
            scan(outdir, colour=True)
        elif operation == '4':
            scan(outdir, colour=True, multi=True)
        elif operation == '9':
            scan(outdir, colour=True, crop=3)
        elif operation == '0':
            scan(outdir, colour=True, multi=True, crop=3)
        elif operation == 'a':
            scan(outdir, colour=True, multi=False, crop=4)
        elif operation == '8':
            scan(outdir, dpi=600, multi=False, colour=True, depth=16, crop=2)
        elif operation == '7':
            scan(outdir, colour=True, crop=0)
        elif operation == '5':
            scan(outdir, gray=True, ocr=True, crop=3)
        elif operation == '6':
            scan(outdir, gray=True, ocr=True, crop=3, multi=True)
        elif operation == 'h':
            scan(outdir, gray=True, ocr=False, crop=3, multi=True, dpi=75)

def scan(outdir, dpi = 300, multi = False, colour = False, gray = False, ocr = False, depth = 8, crop = 1, lineartFilter = "None"):
    workdir = tempfile.mkdtemp()
    print "scanning at " + str(dpi) + " dpi"

    # build the command
    scanimage = ["scanimage", "-vp", "--format=tiff"]
    scanimage.append("--resolution=" + str(dpi))

    if SCANNER_SUPPORTS_DEPTH:
        scanimage.append("--depth=" + str(depth))

    if colour:
        scanimage.append("--mode=Color")
    elif gray:
        scanimage.append("--mode=Gray")
    else:
        scanimage = scanimage + ["--mode=Lineart",
                                 # "--swdespeck=yes",
                                 # "--color-filter=" + lineartFilter
        ]

    if crop == 2:
        scanimage = scanimage + ['-x', '150', '-y', '100'] # dimensions of a standard photo
    elif crop == 0:
        scanimage.append("--swcrop=yes")
    elif crop == 1:
        scanimage = scanimage + ['-x', '210', '-y', '297'] # dimensions of A4
    elif crop == 3:
        scanimage = scanimage + ['-x', '215.9', '-y', '279.4'] # dimensions of American letter paper

    # do the scan
    i = 1
    if multi:
        while True:
            print "\nscanning page #" + str(i)
            doScan(scanimage, workdir, str(i))
            i = 1 + i
            print "hit q to quit, anything else to scan another image"
            choice = getch()
            if choice == 'q':
                i = i - 1
                break
    else:
        tiff = "1"
        doScan(scanimage, workdir, tiff)

    # post-processing

    if crop == 1 or crop == 3:               # A4/LTR PDF output
        output = workdir + '/output.pdf'
        pages = []
        for j in range(i):
            pages.append(workdir + '/' + str(j + 1))
        # if output TIFF isn't in monochrome, try first mogrify -monochrome file.png
        subprocess.call(['convert'] + pages + [output])

        if ocr:
            print "commencing OCR; please be patient ...",
            subprocess.call(['ocrmypdf', '-c', '-i', '-r',
                             '--title', 'scan of ' + datetime.datetime.now().strftime("%Y-%b-%d").lower(),
                             '--author', 'spw',
                             output, workdir + '/process.pdf'])
            shutil.move(workdir + '/process.pdf', output)
            print " done"
        else:
            # set PDF metadata
            metadata = workdir + '/metadata'
            metadataf = open(metadata, 'w')
            metadataf.write("InfoKey: Title\nInfoValue: scan of "
                            + datetime.datetime.now().strftime("%Y-%b-%d").lower()
                            + "\nInfoKey: Author\nInfoValue: spw\n")
            metadataf.close()
            subprocess.call(['pdftk', output, 'update_info', metadata, 'output', workdir + '/process.pdf'])
            shutil.move(workdir + '/process.pdf', output)

            # compress PDF by flattening it
            # more aggressive compression is possible: http://stackoverflow.com/questions/5296667/pdftk-compression-option

            # (ocrmypdf does this for us, hence wrapped in else clause)
            subprocess.call(['qpdf', '--linearize', output, output + '~'])
            shutil.move(output + '~', output)
    else:                       # single image output
        output = workdir + '/output.png'
        # subprocess.call(['convert', workdir + '/1', "-crop 7090x4760+0+0", output])
        subprocess.call(['convert', workdir + '/1', output])

    # output the file
    outfile = outdir + '/' + str(int(time.time())) + '.' + output.split('.')[-1]
    if not os.path.exists(outdir):
        os.mkdir(outdir, 755)
    shutil.copyfile(output, outfile)
    print "wrote", hurry.filesize.size(os.path.getsize(outfile)), "to", outfile
    shutil.rmtree(workdir)
    print "press any key to return to main menu, or q to quit"
    choice = getch()
    if choice == 'q':
        sys.exit()

def doScan(scanimage, filedir, filename):

    # # work around genesys bug by resetting scanner, rather than physically replugging it
    # # the following code only required when connected via a USB 3.0 port
    # print "\nResetting scanner's USB connection ..."
    # lsusb = subprocess.check_output(['lsusb'])
    # match = re.search('Bus ([0-9]+) Device ([0-9]+): ID 04a9:190a Canon, Inc. CanoScan LiDE 210', lsusb)
    # dev = '/dev/bus/usb/' + match.group(1) + '/' + match.group(2)
    # subprocess.call(['usbreset', dev])

    # # Debian Jessie's version of scanimage doesn't tend to work unless
    # # we first call "scanimage -T" (which is oddly noisy).  xsane,
    # # though, seems to work right off the bat.  Sometimes the scanner
    # # gets caught up and xsane must be run to reset it (when it shows
    # # a red LED and doesn't move).  Possibly a hardware fault while
    # # scanner has been in storage as sound it makes while scanning has
    # # also changed.
    # global WARMED
    # if not WARMED:
    #     print "\nPlease wait, warming up the scanner for first scan ..."
    #     subprocess.call(["scanimage", "-T"], stdout = None, stderr = None)
    #     WARMED = True
    #     print "... done\n"

    tiff = open(filedir + '/' + filename, 'w')
    subprocess.call(scanimage, stdout = tiff)
    # TODO: attach stderr to terminal more consistently
    tiff.close()
    time.sleep(1)

def menu(title, options):
    while True:
        os.system('clear')
        print "\n",             # to deal with random char at start of
                                # first line after non-existent answer
        print title
        print "=" * len(title),"\n"
        for o in options:
            print o[1] + ") " + o[0]
        print "\n" + 'Your choice? ',
        choice = getch()
        if choice in [o[1] for o in options]:
            print choice, "\n"
            return choice

if __name__ == "__main__":
    main()