#!/usr/bin/env python2

# requires lxml, requests, cssselect, pillow

import sys
import os
from io import BytesIO
from lxml import html
import requests
from PIL import Image

if len(sys.argv) != 3:
    print "usage: shonenmagazine.py <url> <destination folder>"
    sys.exit(1)

dom = html.fromstring(requests.get(sys.argv[1]).content)
page_elements = dom.cssselect("img.page-image.js-page-image")

if len(page_elements) == 0:
    print "No pages found!"
    sys.exit(1)

print "%d pages found" % len(page_elements)
print ""

dir = sys.argv[2]
if not os.path.exists(dir):
    os.makedirs(dir)

i = 0
for page in page_elements:
    i += 1
    
    src = page.get("data-src") or page.get("src")
    if src is None or src == "":
            print "Page %d is missing source, skipping..." % i
            continue
    drm = page.get("data-cho-ju-giga") != "usagi"
    
    try:
        raw = BytesIO(requests.get(src).content)
    except:
        print "Page %d could not be downloaded, skipping..." % i
    try:
        source = Image.open(raw)
    except:
        print "Page %d could not be opened, skipping..." % i
    
    if not drm:
        filename = "%d.%s" % (i, source.format.lower())
        path = os.path.join(dir, filename)
        print "Page %d does not use DRM, saving original: %s" % (i, path)
        try:
            with open(path, 'wb') as file:
                file.write(raw)
        except:
            print "Error saving %s" % path
        continue
    
    dest = Image.new(source.mode, source.size)
    
    filename = "%d.png" % i
    path = os.path.join(dir, filename)
    print "Decoding page %d and saving to: %s" % (i, path)
    
    '''
    From bundle.js:
    
    r.DIVIDE_NUM = 4,
    r.MULTIPLE = 8,
    r.width = n.width,
    r.height = n.height,
    r.cell_width = Math.floor(r.width / (r.DIVIDE_NUM * r.MULTIPLE)) * r.MULTIPLE,
    r.cell_height = Math.floor(r.height / (r.DIVIDE_NUM * r.MULTIPLE)) * r.MULTIPLE
    
    [...]
    
    t.prototype.solve = function() {
        if (this.skipDrm)
            this.view.showOriginalImage();
        else {
            this.view.drawImage(0, 0, this.width, this.height, 0, 0);
            for (var e = 0; e < this.DIVIDE_NUM * this.DIVIDE_NUM; e++) {
                var t = Math.floor(e / this.DIVIDE_NUM) * this.cell_height
                  , n = e % this.DIVIDE_NUM * this.cell_width
                  , r = Math.floor(e / this.DIVIDE_NUM)
                  , i = e % this.DIVIDE_NUM
                  , o = r
                  , a = i
                  , u = a * this.DIVIDE_NUM + o
                  , s = u % this.DIVIDE_NUM * this.cell_width
                  , c = Math.floor(u / this.DIVIDE_NUM) * this.cell_height;
                this.view.drawImage(n, t, this.cell_width, this.cell_height, s, c)
                // ^- a.drawImage(this.$puzzledImage[0], sx, sy, sWidth, sHeight, dx, dy, sWidth, sHeight)
            }
            this.view.replaceImage()
        }
    }
    '''
    
    def draw_subimage(sx, sy, sWidth, sHeight, dx, dy):
        rect = source.crop((sx, sy, sx+sWidth, sy+sHeight))
        dest.paste(rect, (dx, dy, dx+sWidth, dy+sHeight))
    
    DIVIDE_NUM = 4
    MULTIPLE = 8
    cell_width = (source.width / (DIVIDE_NUM * MULTIPLE)) * MULTIPLE
    cell_height = (source.height / (DIVIDE_NUM * MULTIPLE)) * MULTIPLE
    for e in range(0, DIVIDE_NUM * DIVIDE_NUM):
        t = e / DIVIDE_NUM * cell_height
        n = e % DIVIDE_NUM * cell_width
        r = e / DIVIDE_NUM
        i_ = e % DIVIDE_NUM
        u = i_ * DIVIDE_NUM + r
        s = u % DIVIDE_NUM * cell_width
        c = (u / DIVIDE_NUM) * cell_height
        draw_subimage(n, t, cell_width, cell_height, s, c)
    
    dest.save(path)