#!/usr/bin/python3
"""Creates the image thumbnails or icons for sledruns to be used in the sledmap or other application.
Can be used in a python session or at the command line.

usage: createthumbnails.py [-h] {thumbnail,icon} inifile [inifile ...]

Creates the image thumbnails or icons for sledruns to be used in the sledmap
application.

positional arguments:
  {thumbnail,icon}  thumbnails or icons?
  inifile           inifile.ini (See:
                    https://www.winterrodeln.org/trac/wiki/ConfigIni)

optional arguments:
  -h, --help        show this help message and exit


Command line usage:
$ export LANG=de_AT.utf8
$ export LC_CTYPE=de_AT.utf8
$ python createthumbnails.py thumbnail inifile1.ini ...
$ # or:
$ python createthumbnails.py icon inifile1.ini ...

One or more .ini configuration files can be given.
At the end, the following entries have to be present:

    [mysql]
    host=localhost
    dbname=philipp_winterrodeln_wiki
    user_name=philipp_www
    user_pass=YYYYYY

    [mediawiki]
    imagedir=/home/philipp/www/winterrodeln.org/mediawiki/images

    [sledmap]
    sledrunimagedir=/home/philipp/www/winterrodeln.org/karte/mediawiki_images
    sledrunicondir=/home/philipp/www/winterrodeln.org/karte/mediawiki_icons

"""
import argparse
import configparser
import os
import hashlib
import MySQLdb
from PIL import Image, ImageFilter


def image_to_icon(im, width, height):
    """The icon will have a size of width times height and contains a centered sub-part of the image."""
    if im.size[0] / float(width) > im.size[1] / float(height):
        # scale image to height
        im.thumbnail((int(round(im.size[0] * im.size[1] / height)), height), Image.ANTIALIAS)
        # crop image (left, upper, right (excl), lower (excl))
        left = (im.size[0] - width) // 2
        im = im.crop((left, 0, left + width, height))
    else:
        # scale image to width
        im.thumbnail((width, int(round(im.size[1] * im.size[0] / width))), Image.ANTIALIAS)
        # crop image (left, upper, right (excl), lower (excl))
        upper = (im.size[1] - height) // 2
        im = im.crop((0, upper, width, upper + height))
    # sharpen
    im = im.filter(ImageFilter.SHARPEN)
    return im


def image_to_thumbnail(im, width, height):
    """The thumbnail will have a equal or smaller width and height as given. The aspect ratio stays the same."""
    im.thumbnail((width, height), Image.ANTIALIAS)
    im = im.filter(ImageFilter.SHARPEN)
    return im


def update_image_dir(mcon, mediawiki_image_dir, dest_dir, image_function, ignore_existing=True):
    """Takes all image names from the mysql database (mcon), reads it from mediawiki_image_dir, 
    processed it as given in the image_function and stores it in the dest_dir with the original filename.
    It does not delete the images that might be present in dest_dir, but overwrites the images with the 
    same filenames.

    :param mcon: mysql connection
    :param mediawiki_image_dir: directory of the mediawiki image directory
    :param dest_dir: output directory
    :param image_function: python function that takes a PIL Image as parameter and returns a modified PIL Image.
    :param ignore_existing: True (default) if already existing image file names in the dest dir should be ignored.
    """
    cu = mcon.cursor()
    sql = "select image from wrsledruncache where image is not null order by image"
    cu.execute(sql)
    for image, in cu:
        image = image.replace(' ', '_')
        # Create md5sum out of the image filename
        md5 = hashlib.md5()
        md5.update(image.encode('UTF8'))
        hd = md5.hexdigest()
        # Build source and destination path names
        source_file = os.path.join(mediawiki_image_dir, hd[0], hd[0:2], image)
        dest_file = os.path.join(dest_dir, image)
        if ignore_existing and os.path.exists(dest_file): continue
        print(('{0}...'.format(image)))
        im = Image.open(source_file)
        im = image_function(im)
        im.save(dest_file, "JPEG")


def update_image_dir_by_inifile(inifile, mode):
    """ Same as update_image_dir but reads the arguments from an .ini file.

    :param inifile: filename of an .ini file or a list of .ini files.
    :param mode: 'thumbnail' or 'icon'
    """
    config = configparser.ConfigParser()
    config.read(inifile)

    host = config.get('mysql', 'host')
    dbname = config.get('mysql', 'dbname')
    user = config.get('mysql', 'user_name')
    passwd = config.get('mysql', 'user_pass')
    mcon = MySQLdb.connect(host=host, db=dbname, user=user, passwd=passwd, charset='utf8mb4')

    mediawiki_image_dir = config.get('mediawiki', 'imagedir')
    if mode == 'thumbnail':
        dest_dir = config.get('sledmap', 'sledrunimagedir')
        image_function = lambda img: image_to_thumbnail(img, 200, 200)
    elif mode == 'icon':
        dest_dir = config.get('sledmap', 'sledrunicondir')
        image_function = lambda img: image_to_icon(img, 80, 80)
    update_image_dir(mcon, mediawiki_image_dir, dest_dir, image_function)

    mcon.close()


if __name__ == '__main__':
    parser = argparse.ArgumentParser(
        description='Creates the image thumbnails or icons for sledruns to be used in the sledmap application.')
    parser.add_argument('type', choices=['thumbnail', 'icon'], help='thumbnails or icons?')
    parser.add_argument('inifile', nargs='+', help='inifile.ini, see: https://www.winterrodeln.org/trac/wiki/ConfigIni')
    args = parser.parse_args()

    update_image_dir_by_inifile(args.inifile, args.type)