from flask import Flask, request, render_template, session, redirect
import database, logging, os, hashlib, html
from flask_session import Session


# Global variables
SYSTEMUID = None
SYSTEMBID = None
allowed_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%£^&()-_=+[]{};:'\",.<>?/\\|`~ "


# Configure logging
console_log = logging.StreamHandler()
console_log.setFormatter(logging.Formatter("\033[1;32m%(asctime)s\033[0m - \033[1;34m%(levelname)s\033[0m - \033[1;31m%(name)s\033[0m - %(message)s"))
logger = logging.getLogger()
logger.addHandler(console_log)
logger.setLevel(logging.INFO)


# Initialize Flask app
logger.info("Initializing Flask app...")
app = Flask(__name__, template_folder=os.getenv('TEMPLATE_FOLDER', 'html'), static_folder=os.getenv('STATIC_FOLDER', 'static'))
app.config["SESSION_PERMANENT"] = True
app.config["SESSION_TYPE"] = "filesystem"
Session(app)
logger.info("Flask app initialized.")


# Initialize database
logger.info("Initializing database...")
db = database.Database('app.db')

if db.get_user('SYSTEM') is None:
    logger.info("Running first time setup...")

    logger.info("Creating SYSTEM user...")
    db.create_user('SYSTEM', 'SYSTEM')
    SYSTEMUID = db.get_user('SYSTEM')[0]
    logger.info("SYSTEM user created with UID: %s", SYSTEMUID)

    logger.info("Creating SYSTEM board...")
    db.create_board('System', 'System messages', SYSTEMUID)
    db.create_board('General', 'General discussion', SYSTEMUID)
    db.create_board('Linux', 'Linux discussion', SYSTEMUID)
    db.create_board('Random', 'Random discussion', SYSTEMUID)
    db.create_board('Tech', 'Tech discussion', SYSTEMUID)
    db.create_board('Games', 'Games discussion', SYSTEMUID)
    SYSTEMBID = db.get_board('System')[0]
    logger.info("SYSTEM board created.")

    logger.info("Creating First time setup post...")
    db.create_post(SYSTEMBID, SYSTEMUID, 'Welcome!')
    logger.info("First time setup post created.")

else:
    SYSTEMUID = db.get_user('SYSTEM')[0]
    SYSTEMBID = db.get_board('System')[0]
    logger.info("SYSTEM user and board already exist.")
    logger.info("SYSTEM user UID: %s", SYSTEMUID)
    logger.info("SYSTEM board BID: %s", SYSTEMBID)

logger.info("Database initialized.")


# Helper functions

def sanitize_input(input_string):
    logger.info("Sanitizing input...")
    # Sanitize input to allow only certain characters
    if not isinstance(input_string, str):
        logger.error("Input is not a string.")
        return None
    sanitized = ''.join(c for c in input_string if c in allowed_chars)
    sanitized = html.escape(sanitized)
    logger.info("Sanitized input")
    return sanitized


def hash_password(password):
    logger.info("Hashing password...")
    # Hash the password using SHA-256
    if not isinstance(password, str):
        logger.error("Password is not a string.")
        return None
    hashed = hashlib.sha256(password.encode()).hexdigest()
    logger.info("Hashed password")
    return hashed


# Define routes
@app.route('/')
def index():
    logger.info("Rendering index page...")
    latest_posts = db.get_latest_posts(5)
    return render_template('index.html', posts=[db.post_to_dict(post) for post in latest_posts])


@app.route('/posts/<int:post_id>')
def post(post_id):
    logger.info("Rendering post page for post ID: %s", post_id)
    post = db.get_post(post_id)
    if post is None:
        logger.error("Post not found: %s", post_id)
        return "Post not found", 404
    
    post = db.post_to_dict(post)
    page = request.args.get('page', 1, type=int)

    logger.info("Post found: %s", post_id)
    replies = db.get_post_references(post_id, 10, 10 * (page - 1))
    if replies is None:
        logger.error("No replies found for post ID: %s", post_id)
        post['replies'] = []
    else:
        logger.info("Found %s replies for post ID: %s", len(replies), post_id)
        post['replies'] = [db.post_to_dict(reply) for reply in replies]
        post['replies'].sort(key=lambda x: x['created_at'], reverse=True)

    return render_template('post.html', post=post, page=page)


@app.route('/login', methods=['GET', 'POST'])
def login():
    logger.info("Rendering login page...")
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        username = sanitize_input(username)
        password = sanitize_input(password)
        token = db.create_session(username, hash_password(password))
        if token:
            logger.info("User %s logged in successfully.", username)
            session['name'] = username
            session['id'] = db.get_user(username)[0]
            session['session'] = token
            return redirect('/')
        else:
            logger.error("Invalid login attempt for user: %s", username)
            return render_template('login.html', error="Invalid username or password.")
        
    return render_template('login.html')


@app.route('/user/<string:username>')
def user(username):
    logger.info("Rendering user page for user: %s", username)
    username = sanitize_input(username)
    user = db.get_user(username)
    if user is None:
        logger.error("User not found: %s", username)
        return "User not found", 404
    
    user = db.user_to_dict(user)
    page = request.args.get('page', 1, type=int)

    posts = db.get_user_posts(user['id'], 10, 10 * (page - 1))
    if posts is None:
        logger.error("No posts found for user: %s", username)
        user['posts'] = []
    else:
        logger.info("Found %s posts for user: %s", len(posts), username)
        user['posts'] = [db.post_to_dict(post) for post in posts]

    return render_template('user.html', user=user, page=page)


@app.route('/logout')
def logout():
    logger.info("Logging out user: %s", session.get('name'))
    session.clear()
    return redirect('/')


@app.route('/posts')
def posts():
    logger.info("Rendering posts page...")
    page = request.args.get('page', 1, type=int)
    posts = db.get_posts(None, 10, 10 * (page - 1))
    if posts is None:
        logger.error("No posts found.")
        return "No posts found", 404
    
    logger.info("Found %s posts.", len(posts))
    return render_template('posts.html', posts=[db.post_to_dict(post) for post in posts], page=page)


@app.route('/boards')
def boards():
    logger.info("Rendering boards page...")

    page = request.args.get('page', 1, type=int)
    boards = db.get_boards(10, 10 * (page - 1))

    if boards is None:
        logger.error("No boards found.")
        return "No boards found", 404

    logger.info("Found %s boards.", len(boards))
    return render_template('boards.html', boards=[db.board_to_dict(board) for board in boards], page=page)


@app.route('/boards/<string:board>')
def board(board):
    logger.info("Rendering board page for board: %s", board)
    board = sanitize_input(board)
    board = db.get_board(board)
    if board is None:
        logger.error("Board not found: %s", board)
        return "Board not found", 404
    board_id = board[0]
    
    board = db.board_to_dict(board)
    page = request.args.get('page', 1, type=int)

    posts = db.get_board_posts(board_id, 10, 10 * (page - 1))
    if posts is None:
        logger.error("No posts found for board ID: %s", board_id)
        board['posts'] = []
    else:
        logger.info("Found %s posts for board ID: %s", len(posts), board_id)
        board['posts'] = [db.post_to_dict(post) for post in posts]

    return render_template('board.html', board=board, page=page)


@app.route('/post', methods=['POST', 'GET'])
def post_create():
    logger.info("Rendering post creation page...")
    if request.method == 'POST':
        content = request.form['content']
        board_id = request.form['board']
        ref = request.form.get('ref', None)
        token = session.get('session')

        # sanitize input
        content = sanitize_input(content)
        try:
            board_id = int(board_id)
        except ValueError:
            logger.error("Invalid board ID: %s", board_id)
            return render_template('newpost.html', error="Invalid board ID.")
        if not content:
            logger.error("Post content is empty.")
            return render_template('newpost.html', error="Post content cannot be empty.")
        if not board_id:
            logger.error("Board ID is empty.")
            return render_template('newpost.html', error="Board ID cannot be empty.")
        if not token:
            logger.error("Session token is missing.")
            return render_template('newpost.html', error="Session expired. Please log in again.")
        if ref:
            try:
                ref = int(ref)
            except ValueError:
                logger.error("Invalid reference post ID: %s", ref)
                return render_template('newpost.html', error="Invalid reference post ID.")
        if len(content) > 10000:
            logger.error("Post content exceeds maximum length.")
            return render_template('newpost.html', error="Post content exceeds maximum length.")

        user = db.get_session(token)
        if user is None:
            logger.error("Session not found or expired.")
            return render_template('newpost.html', error="Session expired. Please log in again.")
        user_id = user[0]

        if board_id == SYSTEMBID and user_id != SYSTEMUID:
            logger.error("User %s is not allowed to post in SYSTEM board.", user_id)
            return render_template('newpost.html', error="You are not allowed to post in this board.")

        if ref:
            ref = db.get_post(ref)
            if ref is None:
                logger.error("Reference post not found: %s", ref)
                return render_template('newpost.html', error="Reference post not found.")
            ref = ref[0]

        logger.info("Creating post in board ID: %s", board_id)
        status = db.create_post(user_id, board_id, content, ref)

        if type(status) is not int:
            logger.error("Post creation failed.")
            return "Post creation failed", 500
        
        logger.info("Post created successfully.")
        if request.form.get('redirect'):
            return redirect(request.form.get('redirect'))
        return redirect('/posts/' + str(status))
    return render_template('newpost.html', boards=db.get_all_boards_for_post())


@app.route('/register', methods=['GET', 'POST'])
def register():
    logger.info("Rendering registration page...")
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        username = sanitize_input(username)
        password = sanitize_input(password)

        if not username or not password:
            logger.error("Username or password is empty.")
            return render_template('register.html', error="Username and password cannot be empty.")
        
        if len(username) > 20:
            logger.error("Username length is invalid.")
            return render_template('register.html', error="Username must be less than 20 characters.")
        
        if len(password) < 6 or len(password) > 200:
            logger.error("Password length is invalid.")
            return render_template('register.html', error="Password must be between 6 and 200 characters.")

        if db.get_user(username):
            logger.error("Username already exists: %s", username)
            return render_template('register.html', error="Username already exists.")

        hashed_password = hash_password(password)
        db.create_user(username, hashed_password)
        logger.info("User %s registered successfully.", username)
        db.create_post(SYSTEMUID, SYSTEMUID, f"New user \"{username}\" registered.")
        # Create a session for the new user
        token = db.create_session(username, hashed_password)
        if token:
            session['name'] = username
            session['id'] = db.get_user(username)[0]
            session['session'] = token
            logger.info("User %s logged in after registration.", username)
            return redirect('/')
        else:
            logger.error("Session creation failed for user: %s", username)
            return render_template('register.html', error="Session creation failed.")
        
    logger.info("GET request for registration page.")
    if session.get('name'):
        logger.info("User %s is already logged in.", session['name'])
        return redirect('/')
    logger.info("Rendering registration form.")

    return render_template('register.html')


# Main function
if __name__ == '__main__':
    logger.info("Starting Flask app...")
    app.run(host=os.getenv('FLASK_HOST', '0.0.0.0'), port=int(os.getenv('FLASK_PORT', 5000)), debug=os.getenv('FLASK_DEBUG', 'false').lower() == 'true')