import yaml
import subprocess
import crypt
import os
import globals
import pwd
# users:
#   - username: alice
#     authorized_keys: publich ssh key
#   - username: bob
#     password: hunter2


def user_exists(username):
    try:
        pwd.getpwnam(username)
        return True
    except KeyError:
        return False

def create_user(uid, username ,password, shell="/bin/bash"):

    if not shell: shell = "/bin/bash"

    if not username:
        return

    useradd_cmd = [ 
            'useradd',
            '-m', 
            '-s', shell,
           ]
    
    if uid: useradd_cmd.append("-u " + str(uid)) 
    if password: useradd_cmd.append("-p" + crypt.crypt(password, crypt.mksalt(crypt.METHOD_SHA512)))    
    useradd_cmd.append(username)
    
    try:
        subprocess.run(useradd_cmd
            , check=True)
        print(f"✅ User '{username}' created with shell '{shell}' and password.")
    except subprocess.CalledProcessError as e:
        print(f"❌ Failed to create user '{username}': {e}")




def setup_ssh(username, public_key):
    ssh_dir = f"/home/{username}/.ssh"
    auth_keys = os.path.join(ssh_dir, "authorized_keys")
    uid = pwd.getpwnam(username).pw_uid
    gid = pwd.getpwnam(username).pw_gid

    os.makedirs(ssh_dir, mode=0o700, exist_ok=True)

    # Check if key already exists
    key_exists = False
    if os.path.exists(auth_keys):
        with open(auth_keys, "r") as f:
            existing_keys = f.read().splitlines()
            key_exists = public_key.strip() in existing_keys

    if not key_exists:
        with open(auth_keys, "a") as f:
            f.write(public_key.strip() + "\n")
        print(f"🔐 SSH key added for '{username}'.")
    else:
        print(f"⚠️ SSH key already exists for '{username}'. Skipping.")

    os.chmod(ssh_dir, 0o700)
    os.chmod(auth_keys, 0o600)
    os.chown(ssh_dir, uid, gid)
    os.chown(auth_keys, uid, gid)
     
def load():
    users = globals.get_config()["users"] if globals.config_exits() else None
    if users:
        for user in users:
            if not user_exists(user.get('username')):
                create_user(user.get('uid'), user.get('username'),user.get('password'), user.get('shell'))
                if user.get('public_keys'):
                    for public_key in user.get('public_keys'):
                        setup_ssh(user.get('username'), public_key)
    else:
        print(f"⚠️ missing users configuration")


if __name__ == "__main__":
    globals.load_config()
    load()