"""strip presigned query params from avatar URLs

Revision ID: a1b2c3d4e5f6
Revises: 6a41fa07bd94
Create Date: 2026-02-21 12:00:00.000000

"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision: str = "a1b2c3d4e5f6"
down_revision: Union[str, None] = "6a41fa07bd94"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    conn = op.get_bind()

    # Extract bare S3 key from presigned URLs.
    # Example: http://localhost:9000/coffee-bucket/avatars/abc.jpg?X-Amz-...
    #       -> avatars/abc.jpg
    #
    # Strategy: strip the query string, then remove the scheme+host+bucket prefix.
    # Only touch rows where avatar looks like a full URL (contains '://').
    result = conn.execute(
        sa.text("SELECT id, avatar FROM users WHERE avatar IS NOT NULL AND avatar LIKE :pattern"),
        {"pattern": "%://%"},
    )
    for row in result:
        avatar_url: str = row[1]
        # Remove query string
        path = avatar_url.split("?")[0]
        # Remove scheme + host + bucket prefix: everything up to and including the bucket segment
        # e.g. "http://localhost:9000/coffee-bucket/avatars/abc.jpg" -> "avatars/abc.jpg"
        parts = path.split("/")
        # Find the bucket segment (after host) and take everything after it
        # URL structure: scheme: / / host:port / bucket / key...
        # parts: ['http:', '', 'localhost:9000', 'coffee-bucket', 'avatars', 'abc.jpg']
        try:
            # Skip scheme ('http:'), empty (''), host, bucket -> index 4 onward is the key
            key = "/".join(parts[4:])
        except IndexError:
            continue

        if key:
            conn.execute(
                sa.text("UPDATE users SET avatar = :key WHERE id = :id"),
                {"key": key, "id": row[0]},
            )


def downgrade() -> None:
    # Data-only migration; cannot restore original presigned URLs.
    pass