"""Create connection_requests and user_connections tables.

Revision ID: 042
Revises: 041
"""
from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects.postgresql import JSONB

revision = "042"
down_revision = "041"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # ── connection_requests ──────────────────────────────────────────
    op.create_table(
        "connection_requests",
        sa.Column("id", sa.Integer, primary_key=True, index=True),
        sa.Column(
            "sender_id",
            sa.Integer,
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "receiver_id",
            sa.Integer,
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "status",
            sa.String(20),
            nullable=False,
            server_default="pending",
        ),
        sa.Column(
            "created_at",
            sa.DateTime,
            nullable=False,
            server_default=sa.func.now(),
        ),
        sa.Column("resolved_at", sa.DateTime, nullable=True),
        sa.CheckConstraint(
            "status IN ('pending', 'accepted', 'rejected', 'cancelled')",
            name="ck_connection_requests_status",
        ),
    )

    # Only one pending request per sender→receiver pair
    op.execute(
        'CREATE UNIQUE INDEX "ix_connection_requests_pending" '
        "ON connection_requests (sender_id, receiver_id) "
        "WHERE status = 'pending'"
    )
    # Incoming request listing
    op.create_index(
        "ix_connection_requests_receiver_status",
        "connection_requests",
        ["receiver_id", "status"],
    )
    # Outgoing request listing
    op.create_index(
        "ix_connection_requests_sender_status",
        "connection_requests",
        ["sender_id", "status"],
    )

    # ── user_connections ─────────────────────────────────────────────
    op.create_table(
        "user_connections",
        sa.Column("id", sa.Integer, primary_key=True, index=True),
        sa.Column(
            "user_id",
            sa.Integer,
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "connected_user_id",
            sa.Integer,
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "person_id",
            sa.Integer,
            sa.ForeignKey("people.id", ondelete="SET NULL"),
            nullable=True,
        ),
        sa.Column("sharing_overrides", JSONB, nullable=True),
        sa.Column(
            "created_at",
            sa.DateTime,
            nullable=False,
            server_default=sa.func.now(),
        ),
        sa.UniqueConstraint("user_id", "connected_user_id", name="uq_user_connections"),
    )


def downgrade() -> None:
    op.drop_table("user_connections")
    op.drop_index("ix_connection_requests_sender_status", table_name="connection_requests")
    op.drop_index("ix_connection_requests_receiver_status", table_name="connection_requests")
    op.execute('DROP INDEX IF EXISTS "ix_connection_requests_pending"')
    op.drop_table("connection_requests")