/**
 * Compression control decorators (@Compress, @NoCompress)
 *
 * These decorators allow per-route control over compression:
 * - @Compress(options?) - Force compression with optional settings
 * - @NoCompress() - Disable compression for this route (useful for SSE, streaming)
 */

import { getControllerMetadata } from './decorators.metadata.js';
import type { IRouteCompressionOptions } from './decorators.types.js';

/**
 * Set compression options for a route
 */
function setRouteCompression(
  target: any,
  methodName: string | symbol,
  options: IRouteCompressionOptions
): void {
  const metadata = getControllerMetadata(target.constructor);

  let route = metadata.routes.get(methodName);
  if (!route) {
    // Create placeholder route (will be completed by @Get/@Post/etc.)
    route = {
      method: 'GET',
      path: '',
      methodName,
      interceptors: [],
      options: {},
    };
    metadata.routes.set(methodName, route);
  }

  route.compression = options;
}

/**
 * @Compress decorator - Force compression on a route with optional settings
 *
 * @example
 * ```typescript
 * @Controller('/api')
 * class ApiController {
 *   @Get('/heavy-data')
 *   @Compress({ level: 11 })  // Max brotli compression
 *   getHeavyData() {
 *     return massiveJsonData;
 *   }
 *
 *   @Get('/data')
 *   @Compress()  // Use default settings
 *   getData() {
 *     return jsonData;
 *   }
 * }
 * ```
 */
export function Compress(options?: { level?: number }) {
  return function <This, Args extends any[], Return>(
    target: (this: This, ...args: Args) => Return,
    context: ClassMethodDecoratorContext<This, (this: This, ...args: Args) => Return>
  ) {
    context.addInitializer(function (this: This) {
      setRouteCompression(this, context.name, {
        enabled: true,
        level: options?.level,
      });
    });
    return target;
  };
}

/**
 * @NoCompress decorator - Disable compression for a route
 *
 * Useful for:
 * - Server-Sent Events (SSE)
 * - Streaming responses
 * - Already-compressed content
 * - Real-time data where latency is critical
 *
 * @example
 * ```typescript
 * @Controller('/api')
 * class EventController {
 *   @Get('/events')
 *   @NoCompress()  // SSE should not be compressed
 *   getEvents() {
 *     return new Response(eventStream, {
 *       headers: { 'Content-Type': 'text/event-stream' }
 *     });
 *   }
 *
 *   @Get('/video/:id')
 *   @NoCompress()  // Already compressed media
 *   getVideo() {
 *     return videoStream;
 *   }
 * }
 * ```
 */
export function NoCompress() {
  return function <This, Args extends any[], Return>(
    target: (this: This, ...args: Args) => Return,
    context: ClassMethodDecoratorContext<This, (this: This, ...args: Args) => Return>
  ) {
    context.addInitializer(function (this: This) {
      setRouteCompression(this, context.name, {
        enabled: false,
      });
    });
    return target;
  };
}