"""Durable WorkflowRun — resume semantics, step state, idempotency (G-RUN, G-CTX).

Extends workflow_instances with resume_at, resume_reason, step_state,
idempotency_key, and lock_owner for durable/resumable workflow execution.

Revision ID: 0125
Revises: 0124
"""

from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects.postgresql import JSONB, UUID as PGUUID

revision = "0125"
down_revision = "0124"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # ── Add durable/resumable columns to workflow_instances ──────────────
    op.add_column(
        "workflow_instances",
        sa.Column("resume_at", sa.DateTime(timezone=True), nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("resume_reason", sa.String(50), nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("step_state", JSONB, nullable=False, server_default="{}"),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("idempotency_key", sa.String(255), nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("lock_owner", sa.String(100), nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("lock_expires_at", sa.DateTime(timezone=True), nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("error_message", sa.Text, nullable=True),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("retry_count", sa.Integer, nullable=False, server_default="0"),
    )
    op.add_column(
        "workflow_instances",
        sa.Column("max_retries", sa.Integer, nullable=False, server_default="3"),
    )

    # Index for finding workflows that need to be resumed
    op.create_index(
        "ix_wf_instances_resume",
        "workflow_instances",
        ["tenant_id", "status", "resume_at"],
    )
    # Index for idempotency key lookup
    op.create_index(
        "ix_wf_instances_idempotency",
        "workflow_instances",
        ["tenant_id", "idempotency_key"],
    )


def downgrade() -> None:
    op.drop_index("ix_wf_instances_idempotency", table_name="workflow_instances")
    op.drop_index("ix_wf_instances_resume", table_name="workflow_instances")
    op.drop_column("workflow_instances", "max_retries")
    op.drop_column("workflow_instances", "retry_count")
    op.drop_column("workflow_instances", "error_message")
    op.drop_column("workflow_instances", "lock_expires_at")
    op.drop_column("workflow_instances", "lock_owner")
    op.drop_column("workflow_instances", "idempotency_key")
    op.drop_column("workflow_instances", "step_state")
    op.drop_column("workflow_instances", "resume_reason")
    op.drop_column("workflow_instances", "resume_at")