#! /usr/bin/env python3
import os
import sys
from xdg import XDG_CONFIG_HOME, XDG_DATA_HOME
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from models import Category, Transaction

CONFIG_DIR = os.path.join(XDG_CONFIG_HOME, "schmeckels")
DATA_DIR = os.path.join(XDG_DATA_HOME, "schmeckels")


def create_dirs():
    for directory in [CONFIG_DIR, DATA_DIR]:
        try:
            os.mkdir(directory)
        except FileExistsError:
            pass


def build_database_filename(profile_name):
    return f"{DATA_DIR}/{profile_name}.db"


def get_session(profile_name):
    if not profile_name:
        count = len(os.listdir(DATA_DIR))
        if count == 1:
            filename = f"{DATA_DIR}/{os.listdir(DATA_DIR)[0]}"
        else:
            print("--profile is required when you have more than one database.")
            sys.exit(1)
    else:
        filename = build_database_filename(profile_name)

    if os.path.exists(filename) and os.path.isfile(filename):
        engine = create_engine(f"sqlite:///{filename}")
        Session = sessionmaker(bind=engine)
        return Session()
    else:
        print(f"No database for profile '{profile_name}'. Did you run 'init'?")
        sys.exit(1)


def create_category(name, parent, profile):
    session = get_session(profile)
    c = session.query(Category).filter(Category.name == name).first()
    if not c:
        c = Category(name=name, parent_id=parent)
        session.add(c)
        session.commit()
    return c.id


def add_category(name, profile):
    parts = name.split(":")
    if len(parts) == 1:
        return create_category(name, None, profile)
    else:
        for i in range(len(parts) - 1):
            parent = parts[i]
            child = parts[i + 1]
            parent_id = create_category(parent, None, profile)
            id = create_category(child, parent_id, profile)
        return id