from re import M
from markupsafe import escape
import sqlite3
from datetime import datetime
import click
from flask import current_app, g

def log(statement, user_id=None, before=None, after=None, change=None):
    db = get_db()
    c = db.cursor()
    c.execute("INSERT INTO transaction_log (timestamp, type, user_id, before, after, change) VALUES (?, ?, ?, ?, ?, ?)", [datetime.now(), statement, user_id, before, after, change])
    db.commit()

def add_user(after):
    db = get_db()
    c = db.cursor()
    c.execute("INSERT or IGNORE INTO users (username, balance) VALUES (?, 0)", [after])
    user_id = c.lastrowid
    log("add_user", user_id=user_id, after=after)
    db.commit()

def remove_user(user_id):
    db = get_db()
    c = db.cursor()
    c.execute("SELECT * FROM users WHERE id = ?", [user_id])
    user_name = c.fetchone()[1]
    c.execute("SELECT * FROM tags WHERE userid = ?", [user_id])
    for tag in c.fetchall():
        remove_tag(tag[0])
    c.execute("DELETE FROM users WHERE id = ?", [user_id])
    log("remove_user", user_id=user_id, before=user_name)
    db.commit()

def add_tag(user_id, tag_id):
    db = get_db()
    c = db.cursor()
    c.execute("INSERT OR IGNORE INTO tags (tagid, userid) VALUES ?, ?)", [tag_id, user_id])
    db.commit()
    log("add_tag", after=tag_id, user_id=user_id)

def remove_tag(tag_id):
    db = get_db()
    c = db.cursor()
    c.execute("SELECT * FROM tags WHERE tagid = ?", [tag_id])
    user_id = c.fetchone()[1]
    c.execute("DELETE FROM tags WHERE tagid = ?", [tag_id])
    log("remove_tag", before=tag_id, user_id=user_id)
    db.commit()

def change_balance(user_id, change):
    db = get_db()
    c = db.cursor()
    c.execute("UPDATE users SET balance = balance + ? WHERE id=?", [change, user_id])
    log("balance", user_id=user_id, change=change)
    db.commit()

def get_db():
    if 'db' not in g:
        g.db = sqlite3.connect(
            current_app.config['DATABASE'],
            detect_types=sqlite3.PARSE_DECLTYPES
        )
        g.db.row_factory = sqlite3.Row
        init_db()
    return g.db


def close_db(e=None):
    db = g.pop('db', None)

    if db is not None:
        db.close()

def init_db():
    db = get_db()

    with current_app.open_resource('schema.sql') as f:
        db.executescript(f.read().decode('utf8'))


@click.command('init-db')
def init_db_command():
    """Clear the existing data and create new tables."""
    init_db()
    click.echo('Initialized the database.')