import type { IUIAdapter, PaywallHandle, FlowNavigationOptions } from '@namiml/sdk-core';
import type { IPaywall } from '@namiml/sdk-core';
import type { NamiPaywallLaunchContext } from '@namiml/sdk-core';

type PaywallListener = (paywall: IPaywall, context: NamiPaywallLaunchContext) => void;
type ReRenderListener = () => void;
type FlowNavListener = (paywall: IPaywall, options: FlowNavigationOptions) => void;

/**
 * Expo UI adapter.
 * Uses a listener pattern so the Expo PaywallView component can register
 * itself to receive create/reRender/flowNav events from the core SDK.
 */
export class ExpoUIAdapter implements IUIAdapter {
  private paywallListener: PaywallListener | null = null;
  private reRenderListener: ReRenderListener | null = null;
  private flowNavListener: FlowNavListener | null = null;

  onPaywallRequested(listener: PaywallListener): () => void {
    this.paywallListener = listener;
    return () => { this.paywallListener = null; };
  }

  onReRenderRequested(listener: ReRenderListener): () => void {
    this.reRenderListener = listener;
    return () => { this.reRenderListener = null; };
  }

  onFlowNavigationRequested(listener: FlowNavListener): () => void {
    this.flowNavListener = listener;
    return () => { this.flowNavListener = null; };
  }

  createPaywall(
    type: string | undefined,
    value: string,
    context: NamiPaywallLaunchContext
  ): PaywallHandle {
    // In Expo, we don't create a DOM element. Instead, we notify the
    // registered PaywallView component to present the paywall.
    // The PaywallView resolves the paywall data using the same core logic.
    if (this.paywallListener) {
      // Build minimal paywall info for navigation
      const paywallInfo = { type, value, context };
      this.paywallListener(paywallInfo as any, context);
    }
    return { type, value, context };
  }

  reRenderPaywall(): void {
    this.reRenderListener?.();
  }

  flowNavigateToScreen(paywall: IPaywall, options: FlowNavigationOptions): void {
    this.flowNavListener?.(paywall, options);
  }

  /**
   * Drop all registered listener refs. Called from `Nami.reset()` via the
   * IUIAdapter contract so the singleton adapter doesn't hold stale
   * closures from a pre-reset NamiView/PaywallView mount. If a NamiView
   * is still mounted when reset runs, it will re-register its listeners
   * on the next effect cycle.
   */
  onReset(): void {
    this.paywallListener = null;
    this.reRenderListener = null;
    this.flowNavListener = null;
  }
}