import json
import csv
import os


def activity_log_path(activity: str) -> str:
    """
    Returns the path of the activity log file in .csv format
    :param activity:
    :return:
    """
    filename = os.path.join("activity_logs", f"{activity}.csv")
    return filename


def activity_units_path(activity: str) -> str:
    """
    Returns the path of the activity activities file in .json format
    :param activity:
    :return:
    """
    filename = os.path.join("activities", f"{activity}.json")
    return filename


def is_convertable(activity: str) -> bool:
    """
    Returns True if the activity has multiple units that needed to be converted.
    i.e. distance may be sent in feet, but would require to be converted in meters.
    :param activity:
    :return:
    """
    filename = activity_units_path(activity)
    raw_data = json.load(open(filename))
    return raw_data.get("transformable")



def create_activity_log_file(activity: str) -> None:
    """
    Creates the activity log file in .csv format
    :param activity:
    :return:
    """
    if not os.path.exists(activity_units_path(activity)):
        raise ValueError(f"{activity} is not a valid activity")
    if not os.path.exists("activity_logs"):
        os.makedirs("activity_logs")
    filename = activity_log_path(activity)
    with open(filename, 'a') as f:
        writer = csv.writer(f)
        writer.writerow(["timestamp", "username", "value"])



def convert_units(activity: str, value: int | float, unit: str) -> float:
    """
    Returns the value of activity in a factor of 1, i.e. converting feet to meters
    :param activity:
    :param value:
    :param unit:
    :return:
    """
    filename = activity_units_path(activity)
    if not os.path.exists(filename):
        raise ValueError(f"{activity} is not a valid activity")

    # Consider None unit value as factor of 1
    if unit is None:
        return value

    raw_data = json.load(open(filename))
    units_data = raw_data.get("units")

    for unit_name, data in units_data.items():
        if unit in data["aliases"]:
            return value * data["factor"]

    raise ValueError(f"{unit} is not a valid unit")


def log_activity(
        timestamp: int,
        username: str,
        activity: str,
        value: int | float,
        unit: str | None
) -> None:
    """
    Logs the activity in .csv file
    :param timestamp:
    :param username:
    :param activity:
    :param value:
    :param unit:
    :return:
    """
    if value <= 0 or not isinstance(value, int | float):
        raise ValueError(f"{value} is not a valid value")
    filename = activity_log_path(activity)
    if not os.path.exists(filename):
        create_activity_log_file(activity)
    if is_convertable(activity):
        converted_value = round(convert_units(activity, value, unit), 2)
    else:
        converted_value = round(value, 2)
    with open(filename, 'a') as f:
        writer = csv.writer(f)
        writer.writerow([timestamp, username, converted_value])


if __name__ == "__main__":
    log_activity(
        timestamp=0,
        username="test",
        activity="climb",
        value=1,
        unit="m"
    )