'use client';

import type { UserProfile, SPFPassport } from './auth/types';

/**
 * WASM module interface with proper TypeScript typing
 */
interface PassportWASM {
  parse_spf_file(data: Uint8Array, password: string): Promise<SPFPassport>;
  get_profiles_from_passport(data: Uint8Array, password: string): Promise<UserProfile[]>;
  validate_spf_signature(data: Uint8Array, signature: Uint8Array): Promise<boolean>;
}

/**
 * WASM loader class for managing the WASM module
 */
export class PassportWASMLoader {
  private module: PassportWASM | null = null;
  private isLoading: boolean = false;
  private loadPromise: Promise<PassportWASM> | null = null;

  /**
   * Initialize the WASM module
   */
  async init(): Promise<PassportWASM> {
    if (this.module) {
      return this.module;
    }

    if (this.loadPromise) {
      return this.loadPromise;
    }

    this.isLoading = true;
    this.loadPromise = this.loadWASMModule();

    try {
      this.module = await this.loadPromise;
      return this.module;
    } catch (error) {
      this.loadPromise = null;
      this.isLoading = false;
      throw error;
    }
  }

  /**
   * Load the WASM module dynamically
   */
  private async loadWASMModule(): Promise<PassportWASM> {
    if (typeof window === 'undefined') {
      throw new Error('WASM module can only be loaded in browser environment');
    }

    try {
      // Dynamically import the WASM bindings
      // With bundler target, the module is automatically initialized on import
      // but we need to ensure the WASM memory is ready before calling functions
      const wasmModule = await import('./wasm-pkg/sharenet_passport_wasm');

      // Test that the WASM module is properly initialized by checking if
      // the wasm memory is accessible through a simple property access
      // This ensures the WASM module is fully loaded before we use it
      if (!wasmModule || typeof wasmModule.parse_spf_file !== 'function') {
        throw new Error('WASM module exports not properly loaded');
      }

      // Create wrapper functions with proper typing
      const wasmWrapper: PassportWASM = {
        parse_spf_file: async (data: Uint8Array, password: string): Promise<SPFPassport> => {
          const result = wasmModule.parse_spf_file(data, password);
          // The WASM function returns a JsValue that we need to convert
          // For now, we'll assume it returns the correct structure
          return result as unknown as SPFPassport;
        },

        get_profiles_from_passport: async (data: Uint8Array, password: string): Promise<UserProfile[]> => {
          const result = wasmModule.get_profiles_from_passport(data, password);
          return result as unknown as UserProfile[];
        },

        validate_spf_signature: async (data: Uint8Array, signature: Uint8Array): Promise<boolean> => {
          return wasmModule.validate_spf_signature(data, signature);
        },
      };

      return wasmWrapper;
    } catch (error) {
      console.error('Failed to load WASM module:', error);
      throw new Error(`Failed to load WASM module: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  /**
   * Check if the module is loaded
   */
  isLoaded(): boolean {
    return this.module !== null;
  }

  /**
   * Check if the module is currently loading
   */
  getIsLoading(): boolean {
    return this.isLoading;
  }

  /**
   * Get the loaded module (throws if not loaded)
   */
  getModule(): PassportWASM {
    if (!this.module) {
      throw new Error('WASM module not loaded. Call init() first.');
    }
    return this.module;
  }
}

// Create a singleton instance
export const passportWASM = new PassportWASMLoader();