"""relocate vote decisions into TUVote

Revision ID: 84cd90073dde
Revises: d64e5571bc8d
Create Date: 2022-03-07 18:02:28.791103

This migration allows us to give Trusted Users the ability to
modify a vote they made on a proposal. Previously, the decision
was tracked purely through TU_VoteInfo records, which removes
tracking of what decisions users made. This blocks us from being
able to modify votes, because we can't update the TU_VoteInfo
Yes, No or Abstain columns properly.

"""
import sqlalchemy as sa

from alembic import op
from sqlalchemy.dialects.mysql import TINYINT

from aurweb import db, logging, time
from aurweb.models import TUVoteInfo

logger = logging.get_logger("alembic")

# revision identifiers, used by Alembic.
revision = '84cd90073dde'
down_revision = 'd64e5571bc8d'
branch_labels = None
depends_on = None

TABLE = "TU_Votes"


def upgrade():
    decision = sa.Column("Decision", TINYINT(unsigned=True))
    op.add_column(TABLE, decision)

    # For each proposal which is running at the time this migration
    # is applied, eradicate all related votes. We will restart the votes.
    # In addition, reset the Submitted and End columns based on the current
    # timestamp; essentially resetting the proposal's state.
    utcnow = time.utcnow()
    running_proposals = db.query(TUVoteInfo).filter(TUVoteInfo.End > utcnow)
    with db.begin():
        for proposal in running_proposals:
            logger.info(f"Resetting proposal with ID {proposal.ID}: "
                        "Yes = 0, No = 0, Abstain = 0, deleted vote records")

            # Reset the Submitted and End columns.
            length = proposal.End - proposal.Submitted
            proposal.Submitted = utcnow
            proposal.End = utcnow + length

            proposal.Yes = proposal.No = proposal.Abstain = 0
            db.delete_all(proposal.tu_votes)
            logger.info(f"Proposal time range was reset: Submitted = "
                        f"{proposal.Submitted} and End = {proposal.End}")


def downgrade():
    op.drop_column(TABLE, "Decision")