from flask import Flask, request, jsonify
import os
import sqlite3
import bcrypt
import base64
import hashlib
from cryptography.fernet import Fernet

# Configurazione
db_file = "data/passwords.db"
hash_file = "data/master_hash.txt"
app = Flask(__name__)

# Inizializza il database
def init_db():
    conn = sqlite3.connect(db_file)
    cursor = conn.cursor()
    cursor.execute("""
        CREATE TABLE IF NOT EXISTS passwords (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            site TEXT NOT NULL,
            username TEXT NOT NULL,
            password TEXT NOT NULL
        )
    """)
    conn.commit()
    conn.close()

# Salva l'hash della master password
def save_master_hash(hash):
    with open(hash_file, "wb") as f:
        f.write(hash)

# Carica l'hash della master password
def load_master_hash():
    if not os.path.exists(hash_file):
        return None
    with open(hash_file, "rb") as f:
        return f.read()

# Deriva una chiave di crittografia dalla master password
def derive_key(master_password):
    hash = hashlib.sha256(master_password.encode()).digest()
    return base64.urlsafe_b64encode(hash)

# Autenticazione della master password
def authenticate(master_password):
    master_hash = load_master_hash()
    if master_hash is None:
        hashed_password = bcrypt.hashpw(master_password.encode(), bcrypt.gensalt())
        save_master_hash(hashed_password)
        return True
    return bcrypt.checkpw(master_password.encode(), master_hash)

# Aggiungi una password al database
def add_password(site, username, password, cipher):
    conn = sqlite3.connect(db_file)
    cursor = conn.cursor()
    encrypted_password = cipher.encrypt(password.encode()).decode()
    cursor.execute("INSERT INTO passwords (site, username, password) VALUES (?, ?, ?)",
                   (site, username, encrypted_password))
    conn.commit()
    conn.close()

# Recupera una password dal database
def get_password(site, cipher):
    conn = sqlite3.connect(db_file)
    cursor = conn.cursor()
    cursor.execute("SELECT username, password FROM passwords WHERE site = ?", (site,))
    row = cursor.fetchone()
    conn.close()
    if row:
        username, encrypted_password = row
        decrypted_password = cipher.decrypt(encrypted_password.encode()).decode()
        return username, decrypted_password
    return None, None

# Cancella una password dal database
def delete_password(site):
    conn = sqlite3.connect(db_file)
    cursor = conn.cursor()
    cursor.execute("DELETE FROM passwords WHERE site = ?", (site,))
    conn.commit()
    conn.close()

# Ottieni la lista di tutti i siti
def list_sites():
    conn = sqlite3.connect(db_file)
    cursor = conn.cursor()
    cursor.execute("SELECT site FROM passwords")
    sites = [row[0] for row in cursor.fetchall()]
    conn.close()
    return sites

# Endpoint per aggiungere una password
@app.route('/add', methods=['POST'])
def add_password_api():
    master_password = request.json.get('master_password')
    site = request.json.get('site')
    username = request.json.get('username')
    password = request.json.get('password')

    if not authenticate(master_password):
        return jsonify({"error": "Master password errata"}), 403

    key = derive_key(master_password)
    cipher = Fernet(key)
    add_password(site, username, password, cipher)
    return jsonify({"message": "Password aggiunta con successo"})

# Endpoint per recuperare una password
@app.route('/get', methods=['POST'])
def get_password_api():
    master_password = request.json.get('master_password')
    site = request.json.get('site')

    if not authenticate(master_password):
        return jsonify({"error": "Master password errata"}), 403

    key = derive_key(master_password)
    cipher = Fernet(key)
    username, password = get_password(site, cipher)

    if username is None:
        return jsonify({"error": "Sito non trovato"}), 404

    return jsonify({"site": site, "username": username, "password": password})

# Endpoint per cancellare una password
@app.route('/delete', methods=['POST'])
def delete_password_api():
    master_password = request.json.get('master_password')
    site = request.json.get('site')

    if not authenticate(master_password):
        return jsonify({"error": "Master password errata"}), 403

    delete_password(site)
    return jsonify({"message": "Password cancellata con successo"})

# Endpoint per listare tutti i siti
@app.route('/list', methods=['POST'])
def list_sites_api():
    master_password = request.json.get('master_password')

    if not authenticate(master_password):
        return jsonify({"error": "Master password errata"}), 403

    sites = list_sites()
    return jsonify({"sites": sites})

# Avvio dell'app
if __name__ == '__main__':
    init_db()
    app.run(host='0.0.0.0', port=5000)