#!/usr/bin/env python3

import os
import time
import sys
import requests
import json
import re

from lxml import etree

def usage():
    print("mangawindow.py command")
    print("commands:")
    print("  download")
    print("  list")
    exit(1)

def usage_list():
    print("mangawindow.py list <url>")
    exit(1)

def usage_download():
    print("mangawindow.py download <url> <download_dir>")
    print("examples:")
    print("  mangawindow.py download \"https://mangawindow.net/chapter/1430298\" /home/adam/Manga/MangaName")
    print("")
    print("Note: The manga directory has to exist.")
    exit(1)

if len(sys.argv) < 2:
    usage()

def download_file(url, save_path):
    with requests.get(url, stream=True) as response:
        response.raise_for_status()
        with open(save_path, "wb") as file:
            for chunk in response.iter_content(chunk_size=8192):
                if chunk:
                    file.write(chunk)

def list_chapters(url, chapter_list_input):
    response = requests.get(url)
    if response.status_code != 200:
        print("Failed to list chapters, server responded with status code %d" % response.status_code)
        exit(2)

    seen_titles = set()
    for item in chapter_list_input:
        title = item.get("title")
        if title and len(title) > 0:
            seen_titles.add(title.lower().replace(" ", ""))

    seen_urls = set()
    for item in chapter_list_input:
        url = item.get("url")
        if url and len(url) > 0:
            seen_urls.add(url)

    tree = etree.HTML(response.text)
    chapters = []
    for element in tree.xpath("//a[@class='chapt']"):
        title = element.findtext('b')
        if title is None:
            print("Failed to get title for chapter")
            exit(2)
        title = title.strip()
        url = "https://mangawindow.net" + element.attrib.get("href").strip()
        if title.lower().replace(" ", "") in seen_titles or url in seen_urls:
            break
        chapters.append({ "name": title, "url": url })
    print(json.dumps(chapters))

def download_chapter(url, download_dir):
    response = requests.get(url)
    if response.status_code != 200:
        print("Failed to list chapter images, server responded with status code %d" % response.status_code)
        exit(2)

    in_progress_filepath = os.path.join(download_dir, ".in_progress")
    with open(in_progress_filepath, "w") as file:
        file.write(url)

    img_number = 1
    image_urls = re.findall(r'mangawindow\.net/images[^"]+', response.text)
    for image_url in image_urls:
        image_url = "https://z-img-04." + image_url
        ext = image_url[image_url.rfind("."):]
        image_name = str(img_number) + ext
        image_path = os.path.join(download_dir, image_name)
        print("Downloading {} to {}".format(image_url, image_path))
        download_file(image_url, image_path)
        img_number += 1

    if img_number == 1:
        print("Failed to find images for chapter")
        exit(2)

    with open(os.path.join(download_dir, ".finished"), "w") as file:
        file.write("1")

    os.remove(in_progress_filepath)

command = sys.argv[1]
if command == "list":
    if len(sys.argv) < 3:
        usage_list()
    
    url = sys.argv[2]
    chapter_list_input = sys.stdin.read()
    if len(chapter_list_input) == 0:
        chapter_list_input = []
    else:
        chapter_list_input = json.loads(chapter_list_input)
    list_chapters(url, chapter_list_input)
elif command == "download":
    if len(sys.argv) < 4:
        usage_download()
    url = sys.argv[2]
    download_dir = sys.argv[3]
    download_chapter(url, download_dir)
else:
    usage()