"""Add telemetry_samples table for aggregated orchestrator metrics.

Revision ID: 002
Revises: 001
Create Date: 2024-12-17

This table stores aggregated telemetry from orchestrator instances.
Uses a unique constraint on (instance_id, window_start) for de-duplication.
"""
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 = "002"
down_revision: Union[str, None] = "001"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # Create telemetry_samples table
    op.create_table(
        "telemetry_samples",
        sa.Column("id", sa.UUID(), nullable=False),
        sa.Column("instance_id", sa.UUID(), nullable=False),
        # Time window
        sa.Column("window_start", sa.DateTime(timezone=True), nullable=False),
        sa.Column("window_end", sa.DateTime(timezone=True), nullable=False),
        # Orchestrator uptime
        sa.Column("uptime_seconds", sa.Integer(), nullable=False),
        # Aggregated metrics stored as JSONB
        sa.Column("metrics", postgresql.JSONB(astext_type=sa.Text()), nullable=False),
        # Foreign key and primary key
        sa.ForeignKeyConstraint(
            ["instance_id"],
            ["instances.id"],
            ondelete="CASCADE",
        ),
        sa.PrimaryKeyConstraint("id"),
        # Unique constraint for de-duplication
        # Prevents double-counting if orchestrator retries submissions
        sa.UniqueConstraint(
            "instance_id",
            "window_start",
            name="uq_telemetry_instance_window",
        ),
    )
    # Index on instance_id for efficient queries
    op.create_index(
        op.f("ix_telemetry_samples_instance_id"),
        "telemetry_samples",
        ["instance_id"],
        unique=False,
    )


def downgrade() -> None:
    op.drop_index(op.f("ix_telemetry_samples_instance_id"), table_name="telemetry_samples")
    op.drop_table("telemetry_samples")