import { HttpError } from "../errors.js";
import { and, eq, sql } from "drizzle-orm";
import { agentWakeupRequests, type Db } from "@paperclipai/db";
import { notifyDeferredExecutionWork } from "./deferred-execution-notifications.js";
import { persistActivity, publishActivity, type ActivityPublication } from "./activity-log.js";

/** Admission has saved this refusal on the caller's durable deferred receipt.
 * HTTP callers still receive the existing 409; receipt recovery waits for its
 * owning gate producer instead of treating the refusal as infrastructure debt. */
export class PersistedExecutionWaitRefusal extends HttpError {
  constructor(message: string, details?: unknown) { super(409, message, details); }
}

/**
 * Save why a deferred request cannot start yet. When the reason changes, the
 * request's task also records an `issue.execution_waiting` activity. Its live
 * event refreshes an open task page, so a person who just pressed Retry sees
 * the kept failure and the named wait (for example the budget) without
 * reloading. Pass `publications` when the caller's transaction is still open;
 * they must be published after it commits.
 */
export async function writeDeferredExecutionWait(db: Db, scope: { companyId: string; requestId: string },
  condition: Record<string, unknown>, options: { replace?: boolean; publications?: ActivityPublication[] } = {}) {
  const pending: ActivityPublication[] = [];
  const saved = await db.transaction(async tx => {
    const [current] = await tx.select({ payload: agentWakeupRequests.payload, agentId: agentWakeupRequests.agentId }).from(agentWakeupRequests)
      .where(and(eq(agentWakeupRequests.companyId, scope.companyId), eq(agentWakeupRequests.id, scope.requestId),
        eq(agentWakeupRequests.status, "deferred_issue_execution"))).for("update");
    if (!current) return false;
    const previous = current.payload?.executionWait;
    const previousReason = previous && typeof previous === "object" && !Array.isArray(previous)
      ? (previous as Record<string, unknown>).reason : undefined;
    const reasonChanged = !previous || previousReason !== condition.reason;
    if (reasonChanged) await notifyDeferredExecutionWork(tx, scope);
    const [saved] = await tx.update(agentWakeupRequests).set({
      payload: sql`jsonb_set(coalesce(${agentWakeupRequests.payload}, '{}'::jsonb), '{executionWait}',
        ${options.replace ? sql`'{}'::jsonb` : sql`coalesce(${agentWakeupRequests.payload}->'executionWait', '{}'::jsonb)`}
          || ${JSON.stringify(condition)}::jsonb)`,
      updatedAt: new Date(),
    }).where(and(eq(agentWakeupRequests.companyId, scope.companyId), eq(agentWakeupRequests.id, scope.requestId),
      eq(agentWakeupRequests.status, "deferred_issue_execution"))).returning({ id: agentWakeupRequests.id });
    const issueId = current.payload?.issueId;
    if (saved && reasonChanged && typeof issueId === "string" && issueId && typeof condition.reason === "string") {
      const { publication } = await persistActivity(tx as unknown as Db, { companyId: scope.companyId, actorType: "system",
        actorId: "execution-admission", action: "issue.execution_waiting", entityType: "issue", entityId: issueId,
        agentId: current.agentId, details: { requestId: scope.requestId, reason: condition.reason } });
      pending.push(publication);
    }
    return Boolean(saved);
  });
  if (options.publications) options.publications.push(...pending);
  else for (const publication of pending) publishActivity(publication);
  return saved;
}