"""fires hypertable: NASA FIRMS active fire/hotspot detections

Revision ID: 002_fires
Revises: 001_initial
Create Date: 2026-08-24
"""

from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = '002_fires'
down_revision = '001_initial'
branch_labels = None
depends_on = None


def upgrade() -> None:
    # The PK IS the idempotency natural key (latitude, longitude, acq_time,
    # satellite). acq_time is the hypertable partitioning column and is part of
    # the PK, which satisfies TimescaleDB's requirement that every unique index
    # include all partitioning columns.
    op.create_table(
        'fires',
        sa.Column('latitude', sa.Float(), nullable=False),
        sa.Column('longitude', sa.Float(), nullable=False),
        sa.Column('brightness', sa.Float(), nullable=False),      # bright_ti4, K
        sa.Column('confidence', sa.String(10), nullable=False),   # n/l/h or %
        sa.Column('acq_time', sa.DateTime(timezone=True), nullable=False),
        sa.Column('satellite', sa.String(16), nullable=False),
        sa.Column('instrument', sa.String(16)),
        sa.Column('bright_ti5', sa.Float()),
        sa.Column('frp', sa.Float()),
        sa.Column('daynight', sa.String(1)),
        sa.Column('scan', sa.Float()),
        sa.Column('track', sa.Float()),
        sa.Column('version', sa.String(32)),
        sa.Column('raw', sa.JSON()),
        sa.Column('ingested_at', sa.DateTime(timezone=True),
                  server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint(
            'latitude', 'longitude', 'acq_time', 'satellite',
            name='pk_fires_natural_key',
        ),
    )

    # 1-day chunks keep retention/drop_chunks operations cheap and scans local.
    # (TimescaleDB auto-creates an index on the partition column acq_time.)
    op.execute(
        "SELECT create_hypertable('fires', 'acq_time', "
        "if_not_exists => TRUE, chunk_time_interval => INTERVAL '1 day')"
    )
    op.create_index('ix_fires_bbox', 'fires', ['longitude', 'latitude'])


def downgrade() -> None:
    op.drop_index('ix_fires_bbox', table_name='fires')
    op.execute("SELECT drop_hypertable('fires', if_exists => TRUE)")
    op.drop_table('fires')