import logging
import os
import re
import textwrap
from PIL import Image, ImageDraw, ImageFont

def scale_box(inbox, imgsize):
    (i1x, i1y, i2x, i2y) = inbox
    (w, h) = imgsize
    return (i1x*w, i1y*h,
            i2x*w, i2y*h)

def max_size(draw, inbox, text, font, size):
    anchor='lt'
    if '\n' in text:
        anchor=None
    f = ImageFont.truetype(font, size)
    (i1x, i1y, i2x, i2y) = inbox
    (b1x, b1y, b2x, b2y) = draw.textbbox((i1x, i1y), text,
                                         font=f, anchor=anchor)
    if (b1x < i1x or b1y < i1y or
        b2x > i2x or b2y > i2y):
        return max_size(draw, inbox, text, font, size-5)
    return size

def fix_outliers(text):
    modifiers = [('[ÖQ]', 'O'),
                 ('[ÅÄ]', 'A'),
                 ('[yqpg]', 'u'),
                 ('j', 'i')]
    for (pat, rep) in modifiers:
        text = re.sub(pat, rep, text)
    return text
    

class Thumbnailer:
    def __init__(self, config, ldap):
        self.base = config['base']
        self.fill = config['textcolor']
        self.ldap = ldap
        self.logger = logging.getLogger('play-daemon')
        self.thumbname = 'thumb.png'
        self.font = 'verdana.ttf'
        self.titlebox  = (1/8, 0.4,
                          7/8, 0.5)
        self.descrbox  = (1/8, 0.55,
                          7/8, 0.8)

    def create_if_missing(self, package):
        if not package['thumb']:
            title       = package['title']['sv']
            description = package['description']
            courses     = ', '.join(package['courses'])
            presenters  = ', '.join([self.ldap.get_name(uid)
                                     for uid in package['presenters']])
            extras = []
            if courses:
                extras.append(courses)
            if presenters:
                extras.append(presenters)
            extra       = ': '.join(extras)
            workbase    = package['workbase']

            pres_id     = package['id']
            self.logger.debug('%s - Creating thumbnail', pres_id)
            self.logger.debug('%s - Title: %s', pres_id, title)
            self.logger.debug('%s - Description: %s', pres_id, description)
            self.logger.debug('%s - Extra: %s', pres_id, extra)
            package['thumb'] = self.make_thumb(workbase,
                                               title, description, extra)
            self.logger.info('%s - Thumbnail created', pres_id)
        return package

    def make_thumb(self, workbase, title, description, extra):
        with Image.open(self.base) as im:
            draw = ImageDraw.Draw(im)

            # Size and draw title
            s_titlebox = scale_box(self.titlebox, im.size)
            (t1x, t1y, t2x, t2y) = s_titlebox
            title_size = max_size(draw, s_titlebox, fix_outliers(title),
                                  self.font, 140)
            draw.text((t1x, t2y), title, fill=self.fill, anchor='ls',
                      font=ImageFont.truetype(self.font, title_size))

            # Size and draw description
            s_descrbox = scale_box(self.descrbox, im.size)
            (d1x, d1y, d2x, d2y) = s_descrbox
            descr = textwrap.fill(description)
            descr_size = max_size(draw, s_descrbox, descr, self.font, 75)
            f = ImageFont.truetype(self.font, descr_size)
            draw.multiline_text((d1x, d1y), descr, fill=self.fill, font=f)

            # Size and draw extra
            if extra:
                # Get effective size of the description text
                (b1x, b1y, b2x, b2y) = draw.textbbox((d1x, d1y),
                                                     descr,
                                                     font=f)
                # Create a preliminary bounding box for extra
                extrabox = (d1x, b2y,
                            d2x, im.height)
                # Make sure the text fits in the box
                extra_size = max_size(draw, extrabox, extra,
                                      self.font, 50)
                # Offset the extra box by one line height
                extrabox = (extrabox[0], extrabox[1] + extra_size,
                            extrabox[2], extrabox[3])
                (p1x, p1y, p2x, p2y) = extrabox
                f = ImageFont.truetype(self.font, extra_size)
                # Draw it
                draw.text((p1x, p1y), extra, fill=self.fill,
                          font=f, anchor='lt')

            im.save(os.path.join(workbase, self.thumbname))
        return self.thumbname