"""Model and functions to work with task logs."""
from datetime import datetime

from sqlalchemy import Column
from sqlalchemy import DateTime
from sqlalchemy import Enum
from sqlalchemy import ForeignKey
from sqlalchemy import Text
from sqlalchemy.dialects import mysql

from availability.connectors import sql
from availability.constants import models
from availability.models import error_handlers


class TaskLog(sql.BaseModel):
    """Class representing a task_log table.

    Table is used to store information about failed task as well as information
    about failed and stuck tasks that have been re-queued.
    """

    __tablename__ = models.TASK_LOG_TABLE

    task_log_id = Column(
        'id', mysql.INTEGER(unsigned=True), primary_key=True,
        autoincrement=True)
    task_id = Column(
        mysql.INTEGER(unsigned=True), ForeignKey('task.id'), nullable=False)
    message_type = Column(
        Enum(*models.TASK_LOG_TYPES_ENUM), default=models.TASK_LOG_TYPE_FAILED)
    message = Column(Text, nullable=False)
    datetime = Column(DateTime, default=datetime.utcnow, nullable=False)


@error_handlers.sqlalchemy_error_handler
def create_task_log(task_id, message_type, message):
    """Create a records in task_log table.

    Args:
        task_id (int): Task PKs.
        message_type (str): One of models.TASK_LOG_TYPES_ENUM.
        message (str): Message that should be logged.
    """
    task_log = TaskLog(
        task_id=task_id, message=message, message_type=message_type)
    with sql.session_scope() as session:
        session.add(task_log)


@error_handlers.sqlalchemy_error_handler
def bulk_create_task_log(task_ids, message_type, message):
    """Create several records with the same message_type and message.

    Args:
        task_ids (list): List (or any other iterable) of Task PKs.
        message_type (str): One of models.TASK_LOG_TYPES_ENUM.
        message (str): Message that should be logged.
    """
    records = []
    for task_id in task_ids:
        records.append(TaskLog(
            task_id=task_id, message=message, message_type=message_type))
    if not records:
        return
    with sql.session_scope() as session:
        session.bulk_save_objects(records)