"""Create hmrc_sync.tax_year_snapshot + hmrc_sync.fetch_log.

These two tables hold everything hmrc-sync persists. The snapshot table
keeps HMRC's `hmrc-held` PAYE/NI view per (tax_year, employer, day);
fetch_log is the audit trail of every outbound API call (for
fraud-header compliance reviews HMRC may trigger).
"""
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

from alembic import op

revision = "0001"
down_revision = None
branch_labels = None
depends_on = None

SCHEMA = "hmrc_sync"


def upgrade() -> None:
    op.create_table(
        "tax_year_snapshot",
        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
        sa.Column("tax_year", sa.String(), nullable=False),
        sa.Column("employer_paye_ref", sa.String(), nullable=False),
        sa.Column("snapshot_date", sa.TIMESTAMP(timezone=True), nullable=False),
        sa.Column("gross_pay", sa.Numeric(12, 2), nullable=False),
        sa.Column("income_tax", sa.Numeric(12, 2), nullable=False),
        sa.Column("ni_contributions", sa.Numeric(12, 2), nullable=False),
        sa.Column("source", sa.String(), nullable=False, server_default="hmrc-held"),
        sa.Column(
            "raw_response",
            postgresql.JSONB().with_variant(sa.JSON(), "sqlite"),
            nullable=False,
        ),
        sa.Column(
            "fetched_at",
            sa.TIMESTAMP(timezone=True),
            nullable=False,
            server_default=sa.text("now()"),
        ),
        sa.UniqueConstraint(
            "tax_year",
            "employer_paye_ref",
            "snapshot_date",
            name="uq_tax_year_snapshot",
        ),
        schema=SCHEMA,
    )
    op.create_index(
        "ix_tax_year_snapshot_tax_year",
        "tax_year_snapshot",
        ["tax_year"],
        schema=SCHEMA,
    )

    op.create_table(
        "fetch_log",
        sa.Column("id", sa.Integer(), primary_key=True, autoincrement=True),
        sa.Column("endpoint", sa.String(), nullable=False),
        sa.Column("status_code", sa.Integer(), nullable=False),
        sa.Column("request_id", sa.String(), nullable=True),
        sa.Column("correlation_id", sa.String(), nullable=True),
        sa.Column(
            "fraud_headers_sent",
            postgresql.JSONB().with_variant(sa.JSON(), "sqlite"),
            nullable=False,
        ),
        sa.Column("response_snippet", sa.String(), nullable=True),
        sa.Column("duration_ms", sa.Integer(), nullable=False),
        sa.Column(
            "fetched_at",
            sa.TIMESTAMP(timezone=True),
            nullable=False,
            server_default=sa.text("now()"),
        ),
        schema=SCHEMA,
    )


def downgrade() -> None:
    op.drop_table("fetch_log", schema=SCHEMA)
    op.drop_index("ix_tax_year_snapshot_tax_year", table_name="tax_year_snapshot", schema=SCHEMA)
    op.drop_table("tax_year_snapshot", schema=SCHEMA)