# coding: utf-8

import sys
import re
import os
import zipfile
import shutil

import requests
import sqlite3
import urllib.parse
from typing import Optional, Tuple

from nhentai import constant
from nhentai.logger import logger
from nhentai.serializer import serialize_json, serialize_comic_xml, set_js_database

MAX_FIELD_LENGTH = 100


def request(method, url, **kwargs):
    session = requests.Session()
    session.headers.update({
        'Referer': constant.LOGIN_URL,
        'User-Agent': constant.CONFIG['useragent'],
        'Cookie': constant.CONFIG['cookie']
    })

    if not kwargs.get('proxies', None):
        kwargs['proxies'] = constant.CONFIG['proxy']

    return getattr(session, method)(url, verify=False, **kwargs)


def check_cookie():
    response = request('get', constant.BASE_URL)
    if response.status_code == 403 and 'Just a moment...' in response.text:
        logger.error('Blocked by Cloudflare captcha, please set your cookie and useragent')
        sys.exit(1)

    username = re.findall('"/users/[0-9]+/(.*?)"', response.text)
    if not username:
        logger.warning(
            'Cannot get your username, please check your cookie or use `nhentai --cookie` to set your cookie')
    else:
        logger.log(16, f'Login successfully! Your username: {username[0]}')


class _Singleton(type):
    """ A metaclass that creates a Singleton base class when called. """
    _instances = {}

    def __call__(cls, *args, **kwargs):
        if cls not in cls._instances:
            cls._instances[cls] = super(_Singleton, cls).__call__(*args, **kwargs)
        return cls._instances[cls]


class Singleton(_Singleton(str('SingletonMeta'), (object,), {})):
    pass


def readfile(path):
    loc = os.path.dirname(__file__)

    with open(os.path.join(loc, path), 'r') as file:
        return file.read()


def parse_doujinshi_obj(
        output_dir: str,
        doujinshi_obj=None,
        file_type: str = ''
) -> Tuple[str, str]:

    filename = f'./doujinshi.{file_type}'
    doujinshi_dir = os.path.join(output_dir, doujinshi_obj.filename)
    if doujinshi_obj is not None:
        _filename = f'{doujinshi_obj.filename}.{file_type}'

        if file_type == 'cbz':
            serialize_comic_xml(doujinshi_obj, doujinshi_dir)

        if file_type == 'pdf':
            _filename = _filename.replace('/', '-')

        filename = os.path.join(output_dir, _filename)

    return doujinshi_dir, filename


def generate_html(output_dir='.', doujinshi_obj=None, template='default'):
    doujinshi_dir, filename = parse_doujinshi_obj(output_dir, doujinshi_obj, '.html')
    image_html = ''

    if not os.path.exists(doujinshi_dir):
        logger.warning(f'Path "{doujinshi_dir}" does not exist, creating.')
        try:
            os.makedirs(doujinshi_dir)
        except EnvironmentError as e:
            logger.critical(e)

    file_list = os.listdir(doujinshi_dir)
    file_list.sort()

    for image in file_list:
        if not os.path.splitext(image)[1] in ('.jpg', '.png', '.webp'):
            continue
        image_html += f'<img src="{image}" class="image-item"/>\n'

    html = readfile(f'viewer/{template}/index.html')
    css = readfile(f'viewer/{template}/styles.css')
    js = readfile(f'viewer/{template}/scripts.js')

    if doujinshi_obj is not None:
        serialize_json(doujinshi_obj, doujinshi_dir)
        name = doujinshi_obj.name
    else:
        name = {'title': 'nHentai HTML Viewer'}

    data = html.format(TITLE=name, IMAGES=image_html, SCRIPTS=js, STYLES=css)
    try:
        with open(os.path.join(doujinshi_dir, 'index.html'), 'wb') as f:
            f.write(data.encode('utf-8'))

        logger.log(16, f'HTML Viewer has been written to "{os.path.join(doujinshi_dir, "index.html")}"')
    except Exception as e:
        logger.warning(f'Writing HTML Viewer failed ({e})')


def move_to_folder(output_dir='.', doujinshi_obj=None, file_type=None):
    if not file_type:
        raise RuntimeError('no file_type specified')

    doujinshi_dir, filename = parse_doujinshi_obj(output_dir, doujinshi_obj, file_type)

    for fn in os.listdir(doujinshi_dir):
        file_path = os.path.join(doujinshi_dir, fn)
        _, ext = os.path.splitext(file_path)
        if ext in ['.pdf', '.cbz']:
            continue

        if os.path.isfile(file_path):
            try:
                os.remove(file_path)
            except Exception as e:
                print(f"Error deleting file: {e}")

    shutil.move(filename, os.path.join(doujinshi_dir, os.path.basename(filename)))


def generate_main_html(output_dir='./'):
    """
    Generate a main html to show all the contains doujinshi.
    With a link to their `index.html`.
    Default output folder will be the CLI path.
    """

    image_html = ''

    main = readfile('viewer/main.html')
    css = readfile('viewer/main.css')
    js = readfile('viewer/main.js')

    element = '\n\
            <div class="gallery-favorite">\n\
                <div class="gallery">\n\
                    <a href="./{FOLDER}/index.html" class="cover" style="padding:0 0 141.6% 0"><img\n\
                            src="./{FOLDER}/{IMAGE}" />\n\
                        <div class="caption">{TITLE}</div>\n\
                    </a>\n\
                </div>\n\
            </div>\n'

    os.chdir(output_dir)
    doujinshi_dirs = next(os.walk('.'))[1]

    for folder in doujinshi_dirs:
        files = os.listdir(folder)
        files.sort()

        if 'index.html' in files:
            logger.info(f'Add doujinshi "{folder}"')
        else:
            continue

        image = files[0]  # 001.jpg or 001.png
        if folder is not None:
            title = folder.replace('_', ' ')
        else:
            title = 'nHentai HTML Viewer'

        image_html += element.format(FOLDER=urllib.parse.quote(folder), IMAGE=image, TITLE=title)
    if image_html == '':
        logger.warning('No index.html found, --gen-main paused.')
        return
    try:
        data = main.format(STYLES=css, SCRIPTS=js, PICTURE=image_html)
        with open('./main.html', 'wb') as f:
            f.write(data.encode('utf-8'))
        shutil.copy(os.path.dirname(__file__) + '/viewer/logo.png', './')
        set_js_database()
        output_dir = output_dir[:-1] if output_dir.endswith('/') else output_dir
        logger.log(16, f'Main Viewer has been written to "{output_dir}/main.html"')
    except Exception as e:
        logger.warning(f'Writing Main Viewer failed ({e})')


def generate_doc(file_type='', output_dir='.', doujinshi_obj=None, regenerate=False):

    doujinshi_dir, filename = parse_doujinshi_obj(output_dir, doujinshi_obj, file_type)

    if os.path.exists(f'{doujinshi_dir}.{file_type}') and not regenerate:
        logger.info(f'Skipped {file_type} file generation: {doujinshi_dir}.{file_type} already exists')
        return

    if file_type == 'cbz':
        file_list = os.listdir(doujinshi_dir)
        file_list.sort()

        logger.info(f'Writing CBZ file to path: {filename}')
        with zipfile.ZipFile(filename, 'w') as cbz_pf:
            for image in file_list:
                image_path = os.path.join(doujinshi_dir, image)
                cbz_pf.write(image_path, image)

        logger.log(16, f'Comic Book CBZ file has been written to "{filename}"')
    elif file_type == 'pdf':
        try:
            import img2pdf

            """Write images to a PDF file using img2pdf."""
            file_list = [f for f in os.listdir(doujinshi_dir) if f.lower().endswith(('.png', '.jpg', '.jpeg', '.gif', '.webp'))]
            file_list.sort()

            logger.info(f'Writing PDF file to path: {filename}')
            with open(filename, 'wb') as pdf_f:
                full_path_list = (
                    [os.path.join(doujinshi_dir, image) for image in file_list]
                )
                pdf_f.write(img2pdf.convert(full_path_list, rotation=img2pdf.Rotation.ifvalid))

            logger.log(16, f'PDF file has been written to "{filename}"')

        except ImportError:
            logger.error("Please install img2pdf package by using pip.")


def format_filename(s, length=MAX_FIELD_LENGTH, _truncate_only=False):
    """
    It used to be a whitelist approach allowed only alphabet and a part of symbols.
    but most doujinshi's names include Japanese 2-byte characters and these was rejected.
    so it is using blacklist approach now.
    if filename include forbidden characters (\'/:,;*?"<>|) ,it replace space character(' '). 
    """
    # maybe you can use `--format` to select a suitable filename

    if not _truncate_only:
        ban_chars = '\\\'/:,;*?"<>|\t\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b'
        filename = s.translate(str.maketrans(ban_chars, ' ' * len(ban_chars))).strip()
        filename = ' '.join(filename.split())

        while filename.endswith('.'):
            filename = filename[:-1]
    else:
        filename = s

    # limit `length` chars
    if len(filename) >= length:
        filename = filename[:length - 1] + u'…'

    # Remove [] from filename
    filename = filename.replace('[]', '').strip()
    return filename


def signal_handler(signal, frame):
    logger.error('Ctrl-C signal received. Stopping...')
    sys.exit(1)


def paging(page_string):
    # 1,3-5,14 -> [1, 3, 4, 5, 14]
    if not page_string:
        return []

    page_list = []
    for i in page_string.split(','):
        if '-' in i:
            start, end = i.split('-')
            if not (start.isdigit() and end.isdigit()):
                raise Exception('Invalid page number')
            page_list.extend(list(range(int(start), int(end) + 1)))
        else:
            if not i.isdigit():
                raise Exception('Invalid page number')
            page_list.append(int(i))

    return page_list


def generate_metadata_file(output_dir, doujinshi_obj):

    info_txt_path = os.path.join(output_dir, doujinshi_obj.filename, 'info.txt')

    f = open(info_txt_path, 'w', encoding='utf-8')

    fields = ['TITLE', 'ORIGINAL TITLE', 'AUTHOR', 'ARTIST', 'GROUPS', 'CIRCLE', 'SCANLATOR',
              'TRANSLATOR', 'PUBLISHER', 'DESCRIPTION', 'STATUS', 'CHAPTERS', 'PAGES',
              'TAGS', 'TYPE', 'LANGUAGE', 'RELEASED', 'READING DIRECTION', 'CHARACTERS',
              'SERIES', 'PARODY', 'URL']
    special_fields = ['PARODY', 'TITLE', 'ORIGINAL TITLE', 'DATE', 'CHARACTERS', 'AUTHOR', 'GROUPS',
                      'LANGUAGE', 'TAGS', 'URL', 'PAGES']

    for i in range(len(fields)):
        f.write(f'{fields[i]}: ')
        if fields[i] in special_fields:
            f.write(str(doujinshi_obj.table[special_fields.index(fields[i])][1]))
        f.write('\n')

    f.close()
    logger.log(16, f'Metadata Info has been written to "{info_txt_path}"')


class DB(object):
    conn = None
    cur = None

    def __enter__(self):
        self.conn = sqlite3.connect(constant.NHENTAI_HISTORY)
        self.cur = self.conn.cursor()
        self.cur.execute('CREATE TABLE IF NOT EXISTS download_history (id text)')
        self.conn.commit()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.conn.close()

    def clean_all(self):
        self.cur.execute('DELETE FROM download_history WHERE 1')
        self.conn.commit()

    def add_one(self, data):
        self.cur.execute('INSERT INTO download_history VALUES (?)', [data])
        self.conn.commit()

    def get_all(self):
        data = self.cur.execute('SELECT id FROM download_history')
        return [i[0] for i in data]