"""Transfer from browser to S3."""

from datetime import datetime
from datetime import timedelta

from botocore.errorfactory import ClientError

from video import config
from video.connectors import s3
from video.constants import job_io_fields
from video.logic.activity_task_logger import activity_task_logger
from video.models import ows_video


@activity_task_logger([], is_first_handler=True, is_last_handler=False)
def transfer_from_browser_to_s3(inputs):
    """Start transfer from browser to s3.

    Args:
        inputs (dict): Inputs.

    Returns:
        dict: Outputs.
    """
    return {}


@activity_task_logger(
    [
        job_io_fields.TRANSFER_FROM_BROWSER_TO_S3_JOB_ID,
        job_io_fields.INPUT_VIDEO_S3_BUCKET,
        job_io_fields.INPUT_VIDEO_S3_KEY,
        job_io_fields.S3_TOKEN_EXPIRATION,
    ],
    is_first_handler=False,
    is_last_handler=False,
    job_type=transfer_from_browser_to_s3.__name__)
def is_transfer_from_browser_to_s3_done(inputs):
    """Check if transfer from browser to s3 is done.

    Args:
        inputs (dict): Inputs.

    Returns:
        dict: Outputs.
    """
    is_done = False

    job_id = inputs[job_io_fields.TRANSFER_FROM_BROWSER_TO_S3_JOB_ID]

    input_s3_bucket = inputs.get(job_io_fields.INPUT_VIDEO_S3_BUCKET)
    input_s3_key = inputs.get(job_io_fields.INPUT_VIDEO_S3_KEY)

    if not input_s3_bucket or not input_s3_key:
        job = ows_video.get_job(job_id)
        input_s3_bucket = job['inputs'][job_io_fields.INPUT_VIDEO_S3_BUCKET]
        input_s3_key = job['inputs'][job_io_fields.INPUT_VIDEO_S3_KEY]

    try:
        s3.get_s3_client().head_object(
            Bucket=input_s3_bucket, Key=input_s3_key)
        is_done = True
    except ClientError:
        pass

    has_transfer_from_browser_to_s3_timed_out = not is_done and (
        _has_s3_token_expired(inputs.get(job_io_fields.S3_TOKEN_EXPIRATION)))

    return {
        job_io_fields.IS_TRANSFER_FROM_BROWSER_TO_S3_DONE: is_done,
        job_io_fields.INPUT_VIDEO_S3_BUCKET: input_s3_bucket,
        job_io_fields.INPUT_VIDEO_S3_KEY: input_s3_key,
        job_io_fields.HAS_TRANSFER_FROM_BROWSER_TO_S3_TIMED_OUT:
            has_transfer_from_browser_to_s3_timed_out,
    }


@activity_task_logger(
    [], is_first_handler=False, is_last_handler=True,
    job_type=transfer_from_browser_to_s3.__name__)
def log_transfer_completed(inputs):
    """Log successful transfer from browser to S3.

    Args:
        inputs (dict): Inputs.

    Returns:
        dict: Outputs.
    """
    return {}


@activity_task_logger(
    [], is_first_handler=False, is_last_handler=True,
    job_type=transfer_from_browser_to_s3.__name__)
def log_transfer_timed_out(inputs):
    """Log timeout of transfer from browser to S3.

    Args:
        inputs (dict): Inputs.

    Returns:
        dict: Outputs.
    """
    return {
        job_io_fields.ERROR_TRANSFER_FROM_BROWSER_TO_S3_EXPIRED:
            'Transfer from browser to S3 timed out.'}


def _has_s3_token_expired(expiration_date):
    """Check if S3 token will expire soon.

    Args:
        expiration_date (datetime): S3 token expiration time by UTC.

    Returns:
        bool: True if the current time is within the threshold of the timeout,
            otherwise False.
    """
    if expiration_date:
        upload_expiration = datetime.strptime(
            expiration_date, config.S3_TOKEN_EXPIRATION_FORMAT)
        threshold = timedelta(
            seconds=config.UPLOAD_FROM_BROWSER_TO_S3_TIMEOUT_THRESHOLD)
        return (upload_expiration - threshold) < datetime.utcnow()
    return False