import json
import sqlite3
from pathlib import Path

from .defaults import create_default_config, merge_config


class ConfigStore:
  def __init__(self, db_path: Path):
    self.db_path = Path(db_path)
    self.db_path.parent.mkdir(parents=True, exist_ok=True)
    self._initialize()

  def _connect(self):
    connection = sqlite3.connect(self.db_path)
    connection.row_factory = sqlite3.Row
    return connection

  def _initialize(self):
    with self._connect() as connection:
      connection.execute(
        '''
        CREATE TABLE IF NOT EXISTS app_config (
          id INTEGER PRIMARY KEY CHECK (id = 1),
          config_json TEXT NOT NULL,
          updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
        )
        '''
      )
      connection.commit()

  def get_config(self):
    with self._connect() as connection:
      row = connection.execute(
        'SELECT config_json FROM app_config WHERE id = 1'
      ).fetchone()

    if not row:
      config = create_default_config()
      self.save_config(config)
      return config

    return merge_config(json.loads(row['config_json']))

  def save_config(self, config):
    normalized_config = merge_config(config)

    with self._connect() as connection:
      connection.execute(
        '''
        INSERT INTO app_config (id, config_json, updated_at)
        VALUES (1, ?, CURRENT_TIMESTAMP)
        ON CONFLICT(id) DO UPDATE SET
          config_json = excluded.config_json,
          updated_at = CURRENT_TIMESTAMP
        ''',
        (json.dumps(normalized_config),)
      )
      connection.commit()

    return normalized_config