/**
 * MultiAgentSchedulerHandle — runtime façade that backs the public
 * `harborforge_calendar_*` tools when the plugin runs in multi-agent sync
 * mode.
 *
 * Background
 * ----------
 * The old single-agent path used `CalendarScheduler` which kept a "current
 * slot" cursor and exposed `isRunning() / completeCurrentSlot() / abortCurrentSlot() / …`.
 * In multi-agent mode the plugin doesn't own a single cursor — one plugin
 * instance services every agent on the claw — so the previous code stubbed the
 * `calendarScheduler` variable to `{ stop() }`. That made every tool fail
 * with `calendarScheduler.<method> is not a function`.
 *
 * This handle restores the same surface area (`isRunning / getCurrentSlot /
 * completeCurrentSlot / …`) but resolves the "current slot" per caller via
 * the agentId/sessionKey supplied by the OpenClaw tool-factory context. The
 * scheduler records the slot it just dispatched to each agent in
 * {@link recordWoken}; the tool resolves the caller, looks up the last woken
 * slot, and PATCHes the backend via the shared bridge.
 *
 * Tools must pass the calling agentId (from `OpenClawPluginToolContext.agentId`)
 * into every method. The handle does not consult `process.env.AGENT_ID` — the
 * gateway sets that to the host's primary agent which is meaningless in
 * multi-agent mode.
 */

import type { CalendarBridgeClient } from './calendar-bridge.js';
import type { MultiAgentScheduleCache, CachedSlot } from './schedule-cache.js';
import { SlotStatus } from './types.js';

export interface MultiAgentSchedulerHandleParams {
  bridge: CalendarBridgeClient;
  cache: MultiAgentScheduleCache;
  /** setInterval handles cleared on stop() */
  syncHandle: ReturnType<typeof setInterval>;
  checkHandle: ReturnType<typeof setInterval>;
  logger: {
    info: (...args: unknown[]) => void;
    warn: (...args: unknown[]) => void;
    error: (...args: unknown[]) => void;
  };
}

/** Last slot we dispatched to an agent. Used as the implicit "current slot". */
export interface WokenSlot {
  agentId: string;
  slotId: number | null;
  virtualId: string | null;
  scheduledAt: string | null;
  slotType: string | null;
  estimatedDuration: number | null;
  wokenAt: string;
}

/** Public surface — mirrors the relevant subset of the old single-agent scheduler. */
export class MultiAgentSchedulerHandle {
  private readonly bridge: CalendarBridgeClient;
  private readonly cache: MultiAgentScheduleCache;
  private readonly syncHandle: ReturnType<typeof setInterval>;
  private readonly checkHandle: ReturnType<typeof setInterval>;
  private readonly logger: MultiAgentSchedulerHandleParams['logger'];
  private readonly woken: Map<string, WokenSlot> = new Map();
  private stopped = false;

  constructor(params: MultiAgentSchedulerHandleParams) {
    this.bridge = params.bridge;
    this.cache = params.cache;
    this.syncHandle = params.syncHandle;
    this.checkHandle = params.checkHandle;
    this.logger = params.logger;
  }

  // ---------- lifecycle ----------

  /** True while the sync/check intervals are still ticking. */
  isRunning(): boolean {
    return !this.stopped;
  }

  /** Always false in multi-agent mode — there is no per-instance work queue. */
  isProcessing(): boolean {
    return false;
  }

  stop(): void {
    if (this.stopped) return;
    this.stopped = true;
    clearInterval(this.syncHandle);
    clearInterval(this.checkHandle);
    this.logger.info('Calendar scheduler stopped (multi-agent mode)');
  }

  // ---------- wake bookkeeping ----------

  /** Record that we just dispatched a slot to `agentId`. */
  recordWoken(agentId: string, slot: CachedSlot): void {
    this.woken.set(agentId, {
      agentId,
      slotId: typeof slot.id === 'number' ? slot.id : null,
      virtualId: typeof slot.virtual_id === 'string' ? slot.virtual_id : null,
      scheduledAt: typeof slot.scheduled_at === 'string' ? slot.scheduled_at : null,
      slotType: typeof slot.slot_type === 'string' ? slot.slot_type : null,
      estimatedDuration:
        typeof slot.estimated_duration === 'number' ? slot.estimated_duration : null,
      wokenAt: new Date().toISOString(),
    });
  }

  // ---------- per-agent reads ----------

  /**
   * The slot most recently dispatched to `agentId`, or null if we never woke
   * them (e.g. tool called outside a wakeup). Callers can fall back to
   * scanning {@link cachedSlotsFor} for `not_started`/`deferred` slots if they
   * want a heuristic "current".
   */
  getWokenSlot(agentId: string | null | undefined): WokenSlot | null {
    if (!agentId) return null;
    return this.woken.get(agentId) ?? null;
  }

  /** Today's cached slots for an agent (whatever runSync last pulled). */
  cachedSlotsFor(agentId: string | null | undefined): CachedSlot[] {
    if (!agentId) return [];
    return this.cache.getAgentSlots(agentId);
  }

  /**
   * Implicit "current" slot: the last woken slot if we know about it,
   * otherwise the highest-priority `not_started`/`deferred`/`ongoing` cached
   * slot for the agent (so a tool called between sync windows still finds
   * something sensible).
   */
  resolveCurrentSlot(agentId: string | null | undefined): WokenSlot | null {
    const woken = this.getWokenSlot(agentId);
    if (woken) return woken;
    if (!agentId) return null;
    const slots = this.cache.getAgentSlots(agentId)
      .filter((s) => s.status === 'not_started' || s.status === 'deferred' || s.status === 'ongoing')
      .sort((a, b) => (b.priority ?? 0) - (a.priority ?? 0));
    const top = slots[0];
    if (!top) return null;
    return {
      agentId,
      slotId: typeof top.id === 'number' ? top.id : null,
      virtualId: typeof top.virtual_id === 'string' ? top.virtual_id : null,
      scheduledAt: typeof top.scheduled_at === 'string' ? top.scheduled_at : null,
      slotType: typeof top.slot_type === 'string' ? top.slot_type : null,
      estimatedDuration:
        typeof top.estimated_duration === 'number' ? top.estimated_duration : null,
      wokenAt: 'inferred-from-cache',
    };
  }

  // ---------- per-agent writes ----------

  async completeSlot(agentId: string, actualDurationMinutes: number): Promise<SlotMutationResult> {
    return this.transition(agentId, SlotStatus.FINISHED, { actual_duration: actualDurationMinutes });
  }

  async abortSlot(agentId: string, reason?: string): Promise<SlotMutationResult> {
    if (reason) this.logger.info(`Aborting slot for ${agentId}: ${reason}`);
    return this.transition(agentId, SlotStatus.ABORTED);
  }

  async pauseSlot(agentId: string): Promise<SlotMutationResult> {
    return this.transition(agentId, SlotStatus.PAUSED);
  }

  /** Resume puts the slot back into `ongoing` so it isn't picked up as `not_started`. */
  async resumeSlot(agentId: string): Promise<SlotMutationResult> {
    return this.transition(agentId, SlotStatus.ONGOING);
  }

  private async transition(
    agentId: string,
    status: SlotStatus,
    extra: { actual_duration?: number } = {}
  ): Promise<SlotMutationResult> {
    const slot = this.resolveCurrentSlot(agentId);
    if (!slot) {
      return { ok: false, error: `No tracked slot for agent '${agentId}'` };
    }
    if (slot.slotId == null && slot.virtualId == null) {
      return { ok: false, error: 'Resolved slot has neither id nor virtual_id' };
    }
    const update = { status, ...extra };
    try {
      if (slot.slotId != null) {
        const ok = await this.bridge.updateSlotAs(agentId, slot.slotId, update);
        if (!ok) return { ok: false, error: `Backend rejected slot ${slot.slotId} → ${status}` };
        // Clear the wake cursor only on terminal transitions so re-wakes don't
        // re-trigger the same slot mutation.
        if (status === SlotStatus.FINISHED || status === SlotStatus.ABORTED) {
          this.woken.delete(agentId);
        }
        return { ok: true, slot, status };
      }
      // virtual slot path: bridge has updateVirtualSlot
      const materialised = await this.bridge.updateVirtualSlot(slot.virtualId!, update);
      if (!materialised) {
        return { ok: false, error: `Backend rejected virtual slot ${slot.virtualId}` };
      }
      if (status === SlotStatus.FINISHED || status === SlotStatus.ABORTED) {
        this.woken.delete(agentId);
      }
      return { ok: true, slot, status, materialised };
    } catch (err: unknown) {
      const msg = (err as { message?: string } | undefined)?.message ?? String(err);
      return { ok: false, error: msg };
    }
  }

  // ---------- gateway-restart parity (no-op in multi-agent mode) ----------

  /** Multi-agent scheduler does not persist a `ScheduledGatewayRestart` flag. */
  isRestartPending(): boolean {
    return false;
  }
  getStateFilePath(): string | null {
    return null;
  }
  getState(): { mode: 'multi-agent'; agents: number; lastWoken: WokenSlot[] } {
    return {
      mode: 'multi-agent',
      agents: this.cache.getStatus().agentCount,
      lastWoken: Array.from(this.woken.values()),
    };
  }
}

export interface SlotMutationResult {
  ok: boolean;
  error?: string;
  status?: SlotStatus;
  slot?: WokenSlot;
  /** Present only when a virtual slot was materialised. */
  materialised?: unknown;
}