#
#  Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

import datetime
import time

def current_timestamp():
    """
    Get the current timestamp in milliseconds.

    Returns:
        int: Current Unix timestamp in milliseconds (13 digits)

    Example:
        >>> current_timestamp()
        1704067200000
    """
    return int(time.time() * 1000)


def timestamp_to_date(timestamp, format_string="%Y-%m-%d %H:%M:%S"):
    """
    Convert a timestamp to formatted date string.

    Args:
        timestamp: Unix timestamp in milliseconds. If None or empty, uses current time.
        format_string: Format string for the output date (default: "%Y-%m-%d %H:%M:%S")

    Returns:
        str: Formatted date string

    Example:
        >>> timestamp_to_date(1704067200000)
        '2024-01-01 08:00:00'
    """
    if not timestamp:
        timestamp = time.time()
    timestamp = int(timestamp) / 1000
    time_array = time.localtime(timestamp)
    str_date = time.strftime(format_string, time_array)
    return str_date


def date_string_to_timestamp(time_str, format_string="%Y-%m-%d %H:%M:%S"):
    """
    Convert a date string to timestamp in milliseconds.

    Args:
        time_str: Date string to convert
        format_string: Format of the input date string (default: "%Y-%m-%d %H:%M:%S")

    Returns:
        int: Unix timestamp in milliseconds

    Example:
        >>> date_string_to_timestamp("2024-01-01 00:00:00")
        1704067200000
    """
    time_array = time.strptime(time_str, format_string)
    time_stamp = int(time.mktime(time_array) * 1000)
    return time_stamp

def datetime_format(date_time: datetime.datetime) -> datetime.datetime:
    """
    Normalize a datetime object by removing microsecond component.

    Creates a new datetime object with only year, month, day, hour, minute, second.
    Microseconds are set to 0.

    Args:
        date_time: datetime object to normalize

    Returns:
        datetime.datetime: New datetime object without microseconds

    Example:
        >>> dt = datetime.datetime(2024, 1, 1, 12, 30, 45, 123456)
        >>> datetime_format(dt)
        datetime.datetime(2024, 1, 1, 12, 30, 45)
    """
    return datetime.datetime(date_time.year, date_time.month, date_time.day,
                             date_time.hour, date_time.minute, date_time.second)


def get_format_time() -> datetime.datetime:
    """
    Get current datetime normalized without microseconds.

    Returns:
        datetime.datetime: Current datetime with microseconds set to 0

    Example:
        >>> get_format_time()
        datetime.datetime(2024, 1, 1, 12, 30, 45)
    """
    return datetime_format(datetime.datetime.now())


def delta_seconds(date_string: str):
    """
    Calculate seconds elapsed from a given date string to now.

    Args:
        date_string: Date string in "YYYY-MM-DD HH:MM:SS" format

    Returns:
        float: Number of seconds between the given date and current time

    Example:
        >>> delta_seconds("2024-01-01 12:00:00")
        3600.0  # If current time is 2024-01-01 13:00:00
    """
    dt = datetime.datetime.strptime(date_string, "%Y-%m-%d %H:%M:%S")
    return (datetime.datetime.now() - dt).total_seconds()