from flask import url_for, request
from markupsafe import Markup
from bleach.sanitizer import Cleaner
from datetime import datetime
from pathlib import Path
from mistune import HTMLRenderer, escape
from PIL import Image
import mistune
import humanize
import mysql.connector
import os
import random
import json
import constants as const

# load json file
def loadJSON(file_path):
    # open the file
    path = Path.cwd() / file_path
    with open(path, 'r', encoding="utf-8") as file:
        # return loaded file
        return json.load(file)

# save json file
def saveJSON(dict, file_path):
    # open the file
    path = Path.cwd() / file_path
    with open(path, 'w', encoding="utf-8") as file:
        # dump the contents
        json.dump(dict, file, indent=4)

cfg = loadJSON(const.configFile)

def formatRelativeTime(date_str):
    date_format = "%Y-%m-%d %H:%M:%S"
    past_date = datetime.strptime(date_str, date_format)

    now = datetime.now()
    time_difference = now - past_date

    return humanize.naturaltime(time_difference)

dbHost = os.environ.get("DB_HOST")
dbUser = os.environ.get("DB_USER")
dbPass = os.environ.get("DB_PASS")
dbName = os.environ.get("DB_NAME")
dbPort = os.environ.get("DB_PORT")
if not dbPort:
    dbPort = 3306

def createDatabase(cursor, dbName):
	try:
		cursor.execute("CREATE DATABASE {} DEFAULT CHARACTER SET 'utf8'".format(dbName))
		print(f"Database {dbName} created successfully")
	except mysql.connector.Error as error:
		print("Failed to create database:", error)
		exit(1)

def connectToDb():
	conn = mysql.connector.connect(
		host=dbHost,
		user=dbUser,
		password=dbPass,
		database=dbName,
		port=dbPort,
		autocommit=True
	)
	return conn

def getQuestion(question_id: int):
    conn = connectToDb()
    cursor = conn.cursor(dictionary=True)
    cursor.execute("SELECT * FROM questions WHERE id=%s", (question_id,))
    question = cursor.fetchone()
    cursor.close()
    conn.close()
    return question

def getAnswer(question_id: int):
    conn = connectToDb()
    cursor = conn.cursor(dictionary=True)
    cursor.execute("SELECT * FROM answers WHERE question_id=%s", (question_id,))
    answer = cursor.fetchone()
    cursor.close()
    conn.close()
    return answer

def readPlainFile(file, split=False):
    if os.path.exists(file):
        with open(file, 'r', encoding="utf-8") as file:
            if split == False:
                return file.read()
            if split == True:
                return file.read().splitlines()
    else:
        return []

def getRandomWord():
    items = readPlainFile(const.antiSpamFile, split=True)
    return random.choice(items)

def trimContent(var, trim):
    trim = int(trim)
    if trim > 0:
        trimmed = var[:trim] + '…' if len(var) >= trim else var
        trimmed = trimmed.rstrip()
        return trimmed
    else:
        return var

# mistune plugin
inlineBtnPattern = r'\[btn\](?P<button_text>.+?)\[/btn\]'

def parse_inline_button(inline, m, state):
    text = m.group("button_text")
    state.append_token({"type": "inline_button", "raw": text})
    return m.end()

def render_inline_button(renderer, text):
    return f"<button class='btn btn-outline-secondary'>{text}</button>"


def button(md):
    md.inline.register('inline_button', inlineBtnPattern, parse_inline_button, before='link')
    if md.renderer and md.renderer.NAME == 'html':
        md.renderer.register('inline_button', render_inline_button)

def renderMarkdown(text):
    plugins = [
        'strikethrough',
        button
    ]
    allowed_tags = [
        'p',
        'em',
        'b',
        'strong',
        'i',
        'br',
        's',
        'del',
        'a',
        'button',
        'ol',
        'li',
        'hr'
    ]
    allowed_attrs = {
        'a': 'href',
        'button': 'class'
    }
    # hard_wrap=True means that newlines will be
    # converted into <br> tags
    #
    # yes, markdown usually lets you make line breaks only
    # with 2 spaces or <br> tag, but hard_wrap is enabled to keep
    # sanity of whoever will use this software
    # (after all, not everyone knows markdown syntax)
    md = mistune.create_markdown(
        escape=True,
        plugins=plugins,
        hard_wrap=True
    )
    html = md(text)
    cleaner = Cleaner(tags=allowed_tags, attributes=allowed_attrs)
    clean_html = cleaner.clean(html)
    return Markup(clean_html)

def generateMetadata(question=None, answer=None):
    metadata = {
        'title': cfg['instance']['title'],
        'description': cfg['instance']['description'],
        'url': cfg['instance']['fullBaseUrl'],
        'image': cfg['instance']['image']
    }

    # if question is specified, generate metadata for that question
    if question and answer:
        metadata.update({
            'title': trimContent(question['content'], 150) + " | " + cfg['instance']['title'],
            'description': trimContent(answer['content'], 150),
            'url': cfg['instance']['fullBaseUrl'] + url_for('viewQuestion', question_id=question['id']),
            'image': cfg['instance']['image']
        })

    # return 'metadata' dictionary
    return metadata

allowedFileExtensions = {'png', 'jpg', 'jpeg', 'webp', 'bmp', 'jxl'}

def allowedFile(filename):
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in allowedFileExtensions

def generateFavicon(file_name):
	sizes = {
		'apple-touch-icon.png': (180, 180),
        'android-chrome-192x192.png': (192, 192),
        'android-chrome-512x512.png': (512, 512),
		'favicon-32x32.png': (32, 32),
		'favicon-16x16.png': (16, 16),
		'favicon.ico': (16, 16)
	}

	img = Image.open(const.faviconDir / file_name)

	if not os.path.exists(const.faviconDir):
		os.makedirs(const.faviconDir)

	for filename, size in sizes.items():
		resized_img = img.resize(size)
		resized_img_absolute_path = const.faviconDir / filename
		resized_img.save(resized_img_absolute_path)