import os.path
from contextlib import contextmanager
from typing import Any, Generator

import keyring
from injectable import injectable
from pykeepass import PyKeePass, create_database

class KeyRequest:
  def __init__(self, prompt: str):
    self.field_name = None
    self.entry_name = None
    self.path = None
    self._parse_prompt(prompt)

  def _parse_prompt(self, prompt: str):
    prompt_parts = prompt.split("/")
    key = None
    match len(prompt_parts):
      case 1:
        self.field_name = 'password'
        key = prompt_parts[0]
      case 2:
        self.field_name = prompt_parts[1]
        key = prompt_parts[0]
      case _:
        key = None
    if key is None:
      return
    key_parts = key.split(".")
    self.path = key_parts[:] if len(key_parts) > 1 else None
    self.entry_name = key_parts[-1]

@injectable(singleton=True)
class Passwords:
  def __init__(self):
    from app.config import get_settings
    settings = get_settings()

    with open(settings.kp.secret, "r") as fh:
      keyring.set_password("karl", "kp", fh.read().splitlines()[0])
    self._path = settings.kp.file

  @contextmanager
  def open(self, mode: str = "r") -> Generator[PyKeePass | Any, Any, None]:
    kp = PyKeePass(self._path, password=keyring.get_password("karl", "kp")) \
      if os.path.exists(self._path) else create_database(self._path, password=keyring.get_password("karl", "kp"))
    yield kp
    if mode == "rw":
      kp.save()

  def get_values(self, keys: list[str]) -> dict[str, str]:
    output = {}
    for k in keys:
      request = KeyRequest(k)
      with self.open() as kp:
        kp_entry = kp.find_entries(path=request.path, first=True, title=request.entry_name)
      output[k] = self._get_field_value(kp_entry, request.field_name)
    return output

  @staticmethod
  def _get_field_value(kp_entry, field_name):
    if kp_entry is None:
      return None
    match field_name:
      case "username":
        return kp_entry.username
      case "password":
        return kp_entry.password
      case "url":
        return kp_entry.url
      case _:
        return kp_entry.get_custom_property(field_name)