"""szenario zeitraum, neuer betrag, szenario-eigene wiederkehrende zahlungen

Revision ID: e7f1a9c3b214
Revises: d5e8b3c7a410
Create Date: 2026-09-30

"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa


revision: str = 'e7f1a9c3b214'
down_revision: Union[str, Sequence[str], None] = 'd5e8b3c7a410'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None

FK_PLANNED_CATEGORY = 'fk_scenario_planned_items_category_id'


def upgrade() -> None:
    # Bestandsdaten: percent/absolute/remove haben end_date NULL (API hat es
    # bisher genullt) und gelten damit unverändert unbegrenzt.
    op.add_column('scenario_modifiers', sa.Column('start_date', sa.Date(), nullable=True))
    # Batch-Modus: SQLite kennt kein ALTER von Constraints (Tabelle wird neu
    # angelegt); auf Postgres entspricht das den direkten ALTER-Befehlen.
    with op.batch_alter_table('scenario_planned_items') as batch:
        batch.add_column(sa.Column('category_id', sa.Integer(), nullable=True))
        batch.create_foreign_key(FK_PLANNED_CATEGORY, 'categories',
                                 ['category_id'], ['id'])
    op.create_table(
        'scenario_recurring_items',
        sa.Column('id', sa.Integer(), primary_key=True),
        sa.Column('scenario_id', sa.Integer(), sa.ForeignKey('scenarios.id'), nullable=False),
        sa.Column('name', sa.String(length=200), nullable=False),
        sa.Column('amount', sa.Numeric(precision=12, scale=2), nullable=False),
        sa.Column('rhythm', sa.String(length=20), nullable=False),
        sa.Column('due_day', sa.Integer(), nullable=False),
        sa.Column('start_date', sa.Date(), nullable=True),
        sa.Column('end_date', sa.Date(), nullable=True),
        sa.Column('category_id', sa.Integer(), sa.ForeignKey('categories.id'), nullable=True),
    )
    op.create_index('ix_scenario_recurring_items_scenario_id',
                    'scenario_recurring_items', ['scenario_id'])


def downgrade() -> None:
    # Alte Semantik: "set" gab es nicht, end_date nur bei "ende".
    op.execute("DELETE FROM scenario_modifiers WHERE kind = 'set'")
    op.execute("UPDATE scenario_modifiers SET end_date = NULL WHERE kind <> 'ende'")
    op.drop_index('ix_scenario_recurring_items_scenario_id', 'scenario_recurring_items')
    op.drop_table('scenario_recurring_items')
    with op.batch_alter_table('scenario_planned_items') as batch:
        batch.drop_column('category_id')
    op.drop_column('scenario_modifiers', 'start_date')