"""Add Phase F fields to automation_agent_definitions.

Adds temperature, max_tokens, max_steps, trace_mode, skill_ids,
trigger_config, and ai_use_case_metadata to support the Phase F
context-builder, SSE streaming, and AI-use-case features.

Revision ID: 0122
Revises: 0121
"""

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

revision = "0122"
down_revision = "0121"
branch_labels = None
depends_on = None


def _table_exists(conn, table_name: str) -> bool:
    """True when the table exists (dual-path convergence, Gate B).

    On a fresh install the automation plugin SQL migration has not run yet
    when Alembic reaches this revision — skip instead of failing. The
    plugin-side convergence migration adds the same columns.
    """
    row = conn.execute(
        sa.text("SELECT to_regclass(:tname) IS NOT NULL"),
        {"tname": f"public.{table_name}"},
    ).scalar()
    return bool(row)


def upgrade() -> None:
    conn = op.get_bind()
    if not _table_exists(conn, "automation_agent_definitions"):
        return
    op.add_column(
        "automation_agent_definitions",
        sa.Column("temperature", sa.Float, nullable=False, server_default="0.3"),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column("max_tokens", sa.Integer, nullable=False, server_default="1000"),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column("max_steps", sa.Integer, nullable=False, server_default="20"),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column(
            "trace_mode", sa.String(20), nullable=False, server_default="standard"
        ),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column("skill_ids", JSONB, nullable=False, server_default=sa.text("'[]'::jsonb")),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column("trigger_config", JSONB, nullable=False, server_default=sa.text("'{}'::jsonb")),
    )
    op.add_column(
        "automation_agent_definitions",
        sa.Column(
            "ai_use_case_metadata",
            JSONB,
            nullable=False,
            server_default=sa.text("'{}'::jsonb"),
        ),
    )


def downgrade() -> None:
    op.drop_column("automation_agent_definitions", "ai_use_case_metadata")
    op.drop_column("automation_agent_definitions", "trigger_config")
    op.drop_column("automation_agent_definitions", "skill_ids")
    op.drop_column("automation_agent_definitions", "trace_mode")
    op.drop_column("automation_agent_definitions", "max_steps")
    op.drop_column("automation_agent_definitions", "max_tokens")
    op.drop_column("automation_agent_definitions", "temperature")