"""add income_stream table

Revision ID: 0003
Revises: 0002
Create Date: 2026-05-10 00:00:00.000000

ProjectionLab parity Wave 1: first-class typed income streams. Replaces
the scalar `savings_per_year_gbp` + generic `life_event.delta` model for
recurring income.
"""
from collections.abc import Sequence

import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

from alembic import op

revision: str = "0003"
down_revision: str | None = "0002"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None

SCHEMA = "fire_planner"


def _jsonb() -> sa.types.TypeEngine[object]:
    return postgresql.JSONB().with_variant(sa.JSON(), "sqlite")


def upgrade() -> None:
    op.create_table(
        "income_stream",
        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
        sa.Column("scenario_id", sa.Integer(), nullable=False),
        sa.Column("kind", sa.Text(), nullable=False),
        sa.Column("name", sa.Text(), nullable=False),
        sa.Column("start_year", sa.Integer(), nullable=False, server_default=sa.text("0")),
        sa.Column("end_year", sa.Integer(), nullable=True),
        sa.Column("amount_gbp_per_year",
                  sa.Numeric(12, 2),
                  nullable=False,
                  server_default=sa.text("0")),
        sa.Column("growth_pct",
                  sa.Numeric(6, 4),
                  nullable=False,
                  server_default=sa.text("0")),
        sa.Column("tax_treatment",
                  sa.Text(),
                  nullable=False,
                  server_default=sa.text("'income'")),
        sa.Column("enabled",
                  sa.Boolean(),
                  nullable=False,
                  server_default=sa.text("true")),
        sa.Column("payload", _jsonb(), nullable=True),
        sa.Column("created_at",
                  sa.TIMESTAMP(timezone=True),
                  nullable=False,
                  server_default=sa.text("now()")),
        schema=SCHEMA,
    )
    op.create_index("idx_income_stream_scenario",
                    "income_stream", ["scenario_id"],
                    schema=SCHEMA)


def downgrade() -> None:
    op.drop_index("idx_income_stream_scenario", table_name="income_stream", schema=SCHEMA)
    op.drop_table("income_stream", schema=SCHEMA)