chat/chat/state/events.py

from __future__ import annotations
import json
from sqlite3 import Connection

from chat.eventlog.projector import on
from chat.eventlog.log import Event


_TERMINAL_STATUSES = {"completed", "cancelled", "expired"}


@on("event_planned")
def _apply_event_planned(conn: Connection, e: Event) -> None:
    p = e.payload
    conn.execute(
        "INSERT OR IGNORE INTO events "
        "(event_id, chat_id, kind, status, props_json, planned_for) "
        "VALUES (?, ?, ?, 'planned', ?, ?)",
        (
            p["event_id"],
            p["chat_id"],
            p["kind"],
            json.dumps(p.get("props", {})),
            p.get("planned_for"),
        ),
    )


@on("event_started")
def _apply_event_started(conn: Connection, e: Event) -> None:
    p = e.payload
    # Idempotent: only transition from non-terminal status.
    conn.execute(
        "UPDATE events SET status = 'active', started_at = ?, updated_at = datetime('now') "
        "WHERE event_id = ? AND status NOT IN ('completed','cancelled','expired')",
        (p.get("started_at"), p["event_id"]),
    )


@on("event_completed")
def _apply_event_completed(conn: Connection, e: Event) -> None:
    p = e.payload
    conn.execute(
        "UPDATE events SET status = 'completed', completed_at = ?, updated_at = datetime('now') "
        "WHERE event_id = ? AND status NOT IN ('completed','cancelled','expired')",
        (p.get("completed_at"), p["event_id"]),
    )


@on("event_cancelled")
def _apply_event_cancelled(conn: Connection, e: Event) -> None:
    p = e.payload
    conn.execute(
        "UPDATE events SET status = 'cancelled', completed_at = ?, updated_at = datetime('now') "
        "WHERE event_id = ? AND status NOT IN ('completed','cancelled','expired')",
        (p.get("completed_at"), p["event_id"]),
    )


@on("event_expired")
def _apply_event_expired(conn: Connection, e: Event) -> None:
    p = e.payload
    conn.execute(
        "UPDATE events SET status = 'expired', completed_at = ?, updated_at = datetime('now') "
        "WHERE event_id = ? AND status NOT IN ('completed','cancelled','expired')",
        (p.get("completed_at"), p["event_id"]),
    )


@on("event_status_reverted")
def _apply_event_status_reverted(conn: Connection, e: Event) -> None:
    """T114.2: Revert an event row's status to ``prior_status``.

    Emitted by ``regenerate_assistant_turn`` when a superseded turn had
    triggered a lifecycle transition (event_started / event_completed /
    event_cancelled). The rollback step needs an inverse projection that
    sets the row's status back to whatever it was *before* the now-
    superseded transition fired.

    Unlike the forward transitions (which guard against terminal-status
    overwrites) this handler is unconditional — the entire purpose is to
    reverse a transition, including reverting from a terminal status
    (completed/cancelled) back to a non-terminal one.
    """
    p = e.payload
    conn.execute(
        "UPDATE events SET status = ?, updated_at = datetime('now') "
        "WHERE event_id = ?",
        (p["prior_status"], p["event_id"]),
    )


def get_event(conn: Connection, event_id: str) -> dict | None:
    row = conn.execute(
        "SELECT event_id, chat_id, kind, status, props_json, planned_for, "
        "started_at, completed_at, created_at, updated_at "
        "FROM events WHERE event_id = ?",
        (event_id,),
    ).fetchone()
    if not row:
        return None
    return {
        "event_id": row[0],
        "chat_id": row[1],
        "kind": row[2],
        "status": row[3],
        "props": json.loads(row[4]),
        "planned_for": row[5],
        "started_at": row[6],
        "completed_at": row[7],
        "created_at": row[8],
        "updated_at": row[9],
    }


def list_active_events(conn: Connection, chat_id: str) -> list[dict]:
    rows = conn.execute(
        "SELECT event_id, chat_id, kind, status, props_json, planned_for, "
        "started_at, completed_at, created_at, updated_at "
        "FROM events WHERE chat_id = ? AND status IN ('planned','active') "
        "ORDER BY id ASC",
        (chat_id,),
    ).fetchall()
    return [
        {
            "event_id": r[0], "chat_id": r[1], "kind": r[2], "status": r[3],
            "props": json.loads(r[4]),
            "planned_for": r[5], "started_at": r[6], "completed_at": r[7],
            "created_at": r[8], "updated_at": r[9],
        }
        for r in rows
    ]


def list_events_in_status(conn: Connection, chat_id: str, status: str) -> list[dict]:
    rows = conn.execute(
        "SELECT event_id, chat_id, kind, status, props_json, planned_for, "
        "started_at, completed_at, created_at, updated_at "
        "FROM events WHERE chat_id = ? AND status = ? ORDER BY id ASC",
        (chat_id, status),
    ).fetchall()
    return [
        {
            "event_id": r[0], "chat_id": r[1], "kind": r[2], "status": r[3],
            "props": json.loads(r[4]),
            "planned_for": r[5], "started_at": r[6], "completed_at": r[7],
            "created_at": r[8], "updated_at": r[9],
        }
        for r in rows
    ]