def migrate(db, trackers):
    c = db.cursor()
    habits = trackers_to_habits(trackers)
    for habit in habits:
        existing_habit = check_habit_duplicate(c, habit)
        if not existing_habit:
            add_to_database(c, habit)
        else:
            print(f"Found duplicate Habit: {existing_habit} - skipping.")
    return habits


def trackers_to_habits(trackers):
    habits = []
    for tracker_name in trackers.keys():
        t = trackers[tracker_name]
        habits.append(
            {
                "archived": 0 if t["hidden"] == False else 1,
                "color": 11 if t.get("score", 0) != "-1" else 0,
                "description": t["tag"],
                "freq_den": 1,
                "freq_num": 1,
                "highlight": 0,
                "name": f"{t['emoji']} {t['label']}",
                "question": "",
                "position": 0,
                "unit": "" if t["uom"] == "num" else t["uom"],
                "uuid": t["id"],
            }
        )
        if t["type"] == "range" and len(habits) > 0:
            habits[-1]["type"] = "1"
            habits[-1]["target_value"] = t["max"]
    return habits


def check_habit_duplicate(cursor, habit):
    cursor.execute("select name from Habits where uuid = ?", [habit["uuid"]])
    name = cursor.fetchone()
    if name:
        return name[0]
    return False


def add_to_database(cursor, habit):
    """Takes a habit in the form of a dictionary and inserts it into the Habits table.
    Parameters:
    cursor (db.cursor): SQL executing cursor
    habit (dict): A Loop habit to be added to the database. Must contain a minimum of
        'archived','color','description','freq_den','freq_num','highlight','name',
        'question','position','unit','uuid' as keys.
    """

    placeholder = ", ".join("?" * len(habit))
    columns = ", ".join(habit.keys())
    sql = "insert into `{table}` ({columns}) values ({values});".format(
        table="Habits", columns=columns, values=placeholder
    )
    values = list(habit.values())
    cursor.execute(sql, values)