import type {
  ClassProvider,
  DynamicModule,
  ExistingProvider,
  FactoryProvider,
  InjectionToken,
  OptionalFactoryDependency,
  ValueProvider,
} from '@nestjs/common';
import type { Resource, ResourceExtractor } from '@rsdk/metadata';
import {
  PLATFORM_RAW_GLOBAL_METADATA_SCOPE,
  RsdkMetadata,
} from '@rsdk/metadata';
import { Assert, NestDefinition } from '@rsdk/nest-tools';

import { Config, PlatformConfigModule } from '../config';

/**
 * @private
 */
export class ConfigMetadataExtractor implements ResourceExtractor {
  extract(
    value:
      | DynamicModule
      | ClassProvider<any>
      | ValueProvider<any>
      | FactoryProvider<any>
      | ExistingProvider<any>
      | InjectionToken,
  ): Resource<unknown>[] {
    if (!Assert.isObjectOrCtor(value)) {
      return [];
    }

    if ('useExisting' in value) {
      return this.handle(value.useExisting);
    }

    /**
     * Получаем аргументы конструктора
     */
    const args = NestDefinition.extractDeps(value);

    /**
     * Если их нет, просто возвращаем пустой массив
     */
    if (!Array.isArray(args)) {
      return [];
    }
    return args.flatMap(this.handle);
  }

  private handle(
    arg: InjectionToken | OptionalFactoryDependency,
  ): Resource<any>[] {
    if (!Assert.isObjectOrCtor(arg)) {
      return [];
    }
    const isConfigSection = Config.isConfigSection(arg);

    if (!isConfigSection) {
      return [];
    }
    const rs: Resource<DynamicModule> = <Resource<DynamicModule>>{
      value: PlatformConfigModule.createConfigProvider(arg),
      key: arg,
      scope: PLATFORM_RAW_GLOBAL_METADATA_SCOPE,
    };

    const configs = RsdkMetadata.get(arg);

    return [rs, ...(configs ?? [])];
  }
}