import sqlite3
import os
from datetime import datetime

class DataStore:
    def __init__(self, dbfile):
        if not os.path.exists(dbfile):
            self.createdb(dbfile)
        self.conn = sqlite3.connect(dbfile)

    def __del__(self):
        self.conn.close()

    def createdb(self, dbfile):
        conn = sqlite3.connect(dbfile)
        c = conn.cursor()
        c.execute('''
CREATE TABLE projects (
    id INTEGER PRIMARY KEY,
    name TEXT
)''')
        c.execute('''
CREATE TABLE tasks (
    id INTEGER PRIMARY KEY,
    projectid INTEGER,
    name TEXT,
    UNIQUE (projectid, name),
    FOREIGN KEY (projectid) REFERENCES projects(id)
)''')
        c.execute('''
CREATE TABLE hours (
    date TEXT,
    taskid INTEGER,
    seconds INTEGER,
    PRIMARY KEY (date, taskid),
    FOREIGN KEY (taskid) REFERENCES tasks(id)
)''')
        conn.commit()
        c.close()
        conn.close()