/**
 * Controller registry - stores all registered controllers
 */

import type { IControllerMetadata, IRegisteredController, ICompiledRoute } from './decorators.types.js';
import type { IRequestContext, IInterceptOptions, THttpMethod } from '../core/smartserve.interfaces.js';
import { getControllerMetadata, combinePaths } from './decorators.metadata.js';

/**
 * Global registry of all controllers
 */
export class ControllerRegistry {
  private static controllers: Map<Function, IControllerMetadata> = new Map();
  private static instances: Map<Function, any> = new Map();
  private static compiledRoutes: ICompiledRoute[] = [];
  private static routesCompiled = false;

  /**
   * Register a controller class
   */
  static registerClass(target: Function): void {
    const metadata = getControllerMetadata(target);
    metadata.target = target as new (...args: any[]) => any;
    this.controllers.set(target, metadata);
    this.routesCompiled = false;
  }

  /**
   * Register a controller instance
   */
  static registerInstance(instance: any): void {
    const constructor = instance.constructor;
    const metadata = getControllerMetadata(constructor);

    // Store instance
    this.instances.set(constructor, instance);

    // Register class if not already registered
    if (!this.controllers.has(constructor)) {
      this.registerClass(constructor);
    }

    this.routesCompiled = false;
  }

  /**
   * Get all registered controllers
   */
  static getControllers(): IRegisteredController[] {
    const result: IRegisteredController[] = [];

    for (const [constructor, metadata] of this.controllers) {
      // Get or create instance
      let instance = this.instances.get(constructor);
      if (!instance && metadata.target) {
        instance = new metadata.target();
        this.instances.set(constructor, instance);
      }

      if (instance) {
        result.push({ instance, metadata });
      }
    }

    return result;
  }

  /**
   * Compile all routes for fast matching
   */
  static compileRoutes(): ICompiledRoute[] {
    if (this.routesCompiled) {
      return this.compiledRoutes;
    }

    this.compiledRoutes = [];

    for (const { instance, metadata } of this.getControllers()) {
      for (const [methodName, route] of metadata.routes) {
        const fullPath = combinePaths(metadata.basePath, route.path);
        const { regex, paramNames } = this.pathToRegex(fullPath);

        // Combine class and method interceptors
        const interceptors: IInterceptOptions[] = [
          ...metadata.classInterceptors,
          ...route.interceptors,
        ];

        // Create bound handler
        const handler = async (ctx: IRequestContext): Promise<any> => {
          const method = instance[methodName];
          if (typeof method !== 'function') {
            throw new Error(`Method ${String(methodName)} not found on controller`);
          }
          return method.call(instance, ctx);
        };

        this.compiledRoutes.push({
          pattern: fullPath,
          regex,
          paramNames,
          method: route.method,
          handler,
          interceptors,
        });
      }
    }

    // Sort routes by specificity (more specific paths first)
    this.compiledRoutes.sort((a, b) => {
      // Routes without wildcards come first
      const aHasWildcard = a.pattern.includes('*');
      const bHasWildcard = b.pattern.includes('*');
      if (aHasWildcard !== bHasWildcard) return aHasWildcard ? 1 : -1;

      // Routes with more segments come first
      const aSegments = a.pattern.split('/').length;
      const bSegments = b.pattern.split('/').length;
      if (aSegments !== bSegments) return bSegments - aSegments;

      // Routes without params come first
      const aParams = a.paramNames.length;
      const bParams = b.paramNames.length;
      return aParams - bParams;
    });

    this.routesCompiled = true;
    return this.compiledRoutes;
  }

  /**
   * Match a request to a compiled route
   */
  static matchRoute(path: string, method: THttpMethod): {
    route: ICompiledRoute;
    params: Record<string, string>;
  } | null {
    const routes = this.compileRoutes();

    for (const route of routes) {
      // Check method match
      if (route.method !== 'ALL' && route.method !== method) {
        continue;
      }

      // Check path match
      const match = route.regex.exec(path);
      if (match) {
        // Extract params
        const params: Record<string, string> = {};
        route.paramNames.forEach((name, index) => {
          params[name] = match[index + 1];
        });

        return { route, params };
      }
    }

    return null;
  }

  /**
   * Convert path pattern to regex
   * Supports :param and * wildcard
   */
  private static pathToRegex(path: string): { regex: RegExp; paramNames: string[] } {
    const paramNames: string[] = [];

    let regexStr = path
      // Escape special regex chars (except : and *)
      .replace(/[.+?^${}()|[\]\\]/g, '\\$&')
      // Convert :param to capture group
      .replace(/:([a-zA-Z_][a-zA-Z0-9_]*)/g, (_, name) => {
        paramNames.push(name);
        return '([^/]+)';
      })
      // Convert * to wildcard
      .replace(/\*/g, '(.*)');

    // Anchor the regex
    regexStr = `^${regexStr}$`;

    return {
      regex: new RegExp(regexStr),
      paramNames,
    };
  }

  /**
   * Clear all registered controllers (useful for testing)
   */
  static clear(): void {
    this.controllers.clear();
    this.instances.clear();
    this.compiledRoutes = [];
    this.routesCompiled = false;
  }
}