"""add social graph tables (friendships, follows, blocks)

Revision ID: 0007_add_social_graph_tables
Revises: 0006_add_presence_columns
Create Date: 2026-09-15 00:00:00.000000

docs/planning/social.md US-1 / app/models/social.py. Models + migration
only -- the request/accept/block business logic lives in the sibling
"Friends & follow API router" task.
"""
from typing import Sequence, Union

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

# revision identifiers, used by Alembic.
revision: str = "0007_add_social_graph_tables"
down_revision: Union[str, None] = "0006_add_presence_columns"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    friendship_status = postgresql.ENUM(
        "pending", "accepted", name="friendship_status"
    )
    friendship_status.create(op.get_bind(), checkfirst=True)

    op.create_table(
        "friendships",
        sa.Column("id", sa.Integer(), primary_key=True),
        sa.Column(
            "requester_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "addressee_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "status",
            postgresql.ENUM(
                "pending", "accepted", name="friendship_status", create_type=False
            ),
            nullable=False,
            server_default="pending",
        ),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.UniqueConstraint("requester_id", "addressee_id", name="uq_friendships_pair"),
    )
    op.create_index("ix_friendships_requester_id", "friendships", ["requester_id"])
    op.create_index("ix_friendships_addressee_id", "friendships", ["addressee_id"])

    op.create_table(
        "follows",
        sa.Column("id", sa.Integer(), primary_key=True),
        sa.Column(
            "follower_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "followed_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.UniqueConstraint("follower_id", "followed_id", name="uq_follows_pair"),
    )
    op.create_index("ix_follows_follower_id", "follows", ["follower_id"])
    op.create_index("ix_follows_followed_id", "follows", ["followed_id"])

    op.create_table(
        "blocks",
        sa.Column("id", sa.Integer(), primary_key=True),
        sa.Column(
            "blocker_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "blocked_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.UniqueConstraint("blocker_id", "blocked_id", name="uq_blocks_pair"),
    )
    op.create_index("ix_blocks_blocker_id", "blocks", ["blocker_id"])
    op.create_index("ix_blocks_blocked_id", "blocks", ["blocked_id"])


def downgrade() -> None:
    op.drop_index("ix_blocks_blocked_id", table_name="blocks")
    op.drop_index("ix_blocks_blocker_id", table_name="blocks")
    op.drop_table("blocks")

    op.drop_index("ix_follows_followed_id", table_name="follows")
    op.drop_index("ix_follows_follower_id", table_name="follows")
    op.drop_table("follows")

    op.drop_index("ix_friendships_addressee_id", table_name="friendships")
    op.drop_index("ix_friendships_requester_id", table_name="friendships")
    op.drop_table("friendships")

    postgresql.ENUM(name="friendship_status").drop(op.get_bind(), checkfirst=True)