#!/usr/bin/env python3

import os
import time
import sys
import requests
import json

from lxml import etree

headers = {
    'User-Agent': "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36"
}

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

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

def usage_download():
    print("manganelo.py download <url> <download_dir>")
    print("examples:")
    print("  manganelo.py download \"https://manganelo.com/chapter/read_naruto_manga_online_free3/chapter_700.5\" /home/user/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):
    file_size = 0
    headers = {
        "accept-language": "en-US,en;q=0.9",
        "accept": "image/webp,image/apng,image/*,*/*;q=0.8",
        "sec-fetch-site": "cross-site",
        "sec-fetch-mode": "no-cors",
        "sec-fetch-dest": "image",
        "referer": "https://manganelo.com/",
        "user-agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36"
    }
    with requests.get(url, stream=True, headers=headers, timeout=30) as response:
        if not response.ok:
            return 0
        with open(save_path, "wb") as file:
            for chunk in response.iter_content(chunk_size=8192):
                if chunk:
                    file.write(chunk)
                    file_size += len(chunk)
    return file_size

def redirect_check(response_text, url):
    idx = response_text.find('window.location.assign("')
    if idx == -1:
        return (response_text, url)

    idx += 24
    end = response_text.find('"', idx)
    if end == -1:
        return (response_text, url)

    response = requests.get(response_text[idx:end], timeout=30, headers=headers)
    response.raise_for_status()
    return (response.text, response.url)

def redirect_migrated_url(url, tree, is_chapter):
    for element in tree.xpath('//div[@class="panel-not-found"]'):
        if url[-1] == '/':
            url = url[:-1]

        url = url.replace("manganelo", "mangakakalot")
        chapter = None
        if is_chapter:
            idx = url.rfind('/')
            if idx == -1:
                print("Chapter not found in url")
                return None
            chapter = url[idx + 1:]
            url = url[0:idx]

        response = requests.get(url, timeout=30, headers=headers)
        response.raise_for_status()

        text, url = redirect_check(response.text, url)
        if chapter:
            url = url + "/" + chapter
            response = requests.get(url, timeout=30, headers=headers)
            response.raise_for_status()
            text = response.text

        return etree.HTML(text)

    return tree

def list_chapters(url, chapter_list_input):
    response = requests.get(url, timeout=30, headers=headers)
    response.raise_for_status()

    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(" ", "").replace("/", "_"))

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

    tree = etree.HTML(response.text)
    tree = redirect_migrated_url(url, tree, False)

    chapters = []

    for element in tree.xpath('//ul[@class="row-content-chapter"]//a'):
        element_text = element.text.strip().replace("/", "_")
        url = element.attrib.get("href").strip()
        if element_text.lower().replace(" ", "") in seen_titles or url in seen_urls:
            break
        chapters.append({ "name": element_text, "url": url })

    for element in tree.xpath('//div[@class="chapter-list"]//a'):
        element_text = element.text.strip().replace("/", "_")
        url = element.attrib.get("href").strip()
        if element_text.lower().replace(" ", "") in seen_titles or url in seen_urls:
            break
        chapters.append({ "name": element_text, "url": url })

    print(json.dumps(chapters))

def download_chapter_images(url, download_dir, use_backup_server):
    response = ""
    try:
        cookies = {}
        if use_backup_server:
            cookies = {"content_server": "server2"}
        response = requests.get(url, timeout=30, cookies=cookies)
        response.raise_for_status()
    except requests.HTTPError:
        return False

    tree = etree.HTML(response.text)
    tree = redirect_migrated_url(url, tree, True)
    if tree is None:
        return False

    img_number = 1
    for image_source in tree.xpath('//div[@class="container-chapter-reader"]/img/@src'):
        ext = image_source[image_source.rfind("."):]
        image_name = str(img_number) + ext
        image_path = os.path.join(download_dir, image_name)
        print("Downloading {} to {}".format(image_source, image_path))
        file_size = download_file(image_source, image_path)
        if file_size < 255:
            print("resource temporary unavailable: %s" % image_source)
            return False
        img_number += 1
    
    if img_number == 1:
        print("Failed to find images for chapter")
        return False

    return True

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

    if not download_chapter_images(url, download_dir, False):
        if not download_chapter_images(url, download_dir, True):
            os.remove(in_progress_filepath)
            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].replace("mangakakalot", "manganelo")
    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].replace("mangakakalot", "manganelo")
    download_dir = sys.argv[3]
    download_chapter(url, download_dir)
else:
    usage()