import type { Quote } from "../types.js";

export interface ToolConfirmationRequest {
  sessionId: string;
  toolCallId: string;
  toolName: string;
  args: unknown;
  quote?: Quote;
  confirmType?: string;
  payload?: unknown;
  expiresAt: number;
}

export interface ToolConfirmationDecision {
  approved: boolean;
  content?: string;
  reason?: string;
}

interface PendingConfirmation {
  resolve: (decision: ToolConfirmationDecision) => void;
  timer: NodeJS.Timeout;
  cleanup: () => void;
}

function keyOf(sessionId: string, toolCallId: string): string {
  return `${sessionId}:${toolCallId}`;
}

export class ToolConfirmationManager {
  private readonly pending = new Map<string, PendingConfirmation>();

  constructor(private readonly timeoutMs: number) {}

  request(
    input: Omit<ToolConfirmationRequest, "expiresAt">,
    onRequest: (request: ToolConfirmationRequest) => void,
    signal?: AbortSignal,
  ): Promise<ToolConfirmationDecision> {
    if (signal?.aborted) {
      return Promise.resolve({ approved: false, reason: "请求已中止" });
    }

    const key = keyOf(input.sessionId, input.toolCallId);
    if (this.pending.has(key)) {
      return Promise.resolve({ approved: false, reason: "该工具调用已在等待确认" });
    }

    const request: ToolConfirmationRequest = {
      ...input,
      expiresAt: Date.now() + this.timeoutMs,
    };

    return new Promise((resolve) => {
      let settled = false;
      const finish = (decision: ToolConfirmationDecision): void => {
        if (settled) return;
        settled = true;
        clearTimeout(timer);
        signal?.removeEventListener("abort", onAbort);
        this.pending.delete(key);
        resolve(decision);
      };
      const onAbort = (): void => finish({ approved: false, reason: "请求已中止" });
      const timer = setTimeout(
        () => finish({ approved: false, reason: "等待用户确认超时" }),
        this.timeoutMs,
      );
      timer.unref?.();

      this.pending.set(key, {
        resolve: finish,
        timer,
        cleanup: () => finish({ approved: false, reason: "会话已结束" }),
      });
      signal?.addEventListener("abort", onAbort, { once: true });
      try {
        onRequest(request);
      } catch (error) {
        finish({ approved: false, reason: error instanceof Error ? error.message : String(error) });
      }
    });
  }

  resolve(
    sessionId: string,
    toolCallId: string,
    decision: boolean | ToolConfirmationDecision,
    reason?: string,
  ): boolean {
    const pending = this.pending.get(keyOf(sessionId, toolCallId));
    if (!pending) return false;
    pending.resolve(typeof decision === "boolean" ? { approved: decision, reason } : decision);
    return true;
  }

  clearSession(sessionId: string): void {
    const prefix = `${sessionId}:`;
    for (const [key, pending] of this.pending) {
      if (key.startsWith(prefix)) pending.cleanup();
    }
  }

  count(): number {
    return this.pending.size;
  }
}