"""Immutable revisions. Old fork bases cannot be reconstructed reliably."""
import json
import uuid

import sqlalchemy as sa
from alembic import op
from sqlalchemy.dialects import postgresql

revision = "0003"
down_revision = "0002"
branch_labels = depends_on = None


def upgrade():
    op.create_table("revisions",
        sa.Column("id", sa.String(36), primary_key=True),
        sa.Column("game_id", sa.Integer, sa.ForeignKey("games.id", ondelete="CASCADE"), nullable=False),
        sa.Column("user_id", sa.Integer, sa.ForeignKey("users.id", ondelete="SET NULL")),
        sa.Column("parents", postgresql.ARRAY(sa.String), nullable=False),
        sa.Column("manifest", postgresql.JSONB, nullable=False),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False))
    op.create_index("ix_revisions_game_id", "revisions", ["game_id"])
    op.add_column("game_versions", sa.Column("revision_id", sa.String(36)))
    op.add_column("game_versions", sa.Column("base_revision_id", sa.String(36)))
    bind = op.get_bind()
    for row in bind.execute(sa.text("SELECT id, game_id, owner_id, manifest FROM game_versions WHERE manifest IS NOT NULL")).mappings():
        rid = str(uuid.uuid4())
        bind.execute(sa.text("INSERT INTO revisions (id, game_id, user_id, parents, manifest) VALUES (:id, :game, :user, '{}', CAST(:manifest AS jsonb))"),
                     dict(id=rid, game=row["game_id"], user=row["owner_id"], manifest=json.dumps(row["manifest"])))
        bind.execute(sa.text("UPDATE game_versions SET revision_id=:rid WHERE id=:id"), dict(rid=rid, id=row["id"]))


def downgrade():
    op.drop_column("game_versions", "base_revision_id")
    op.drop_column("game_versions", "revision_id")
    op.drop_table("revisions")