From 7368533e3ae2b3fd289add01f699836002b027e0 Mon Sep 17 00:00:00 2001
From: Emma Short <emma@cyborggrizzly.com>
Date: Sun, 10 Nov 2024 11:12:35 -0700
Subject: [PATCH] init

---
 .vscode/settings.json |   3 +
 deno.json             |  12 +++
 mod.ts                | 222 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)
 create mode 100644 .vscode/settings.json
 create mode 100644 deno.json
 create mode 100644 mod.ts

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..4b9fb22
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "deno.enable": true
+}
\ No newline at end of file
diff --git a/deno.json b/deno.json
new file mode 100644
index 0000000..cd278d8
--- /dev/null
+++ b/deno.json
@@ -0,0 +1,12 @@
+{
+  "name": "BearMetal Router",
+  "description": "A simple router for Deno",
+  "version": "0.1.0",
+  "stable": true,
+  "repository": "https://github.com/emmaos/bearmetal",
+  "files": [
+    "mod.ts",
+    "README.md",
+    "LICENSE"
+  ]
+}
diff --git a/mod.ts b/mod.ts
new file mode 100644
index 0000000..1451f3e
--- /dev/null
+++ b/mod.ts
@@ -0,0 +1,222 @@
+interface RouterContext {
+  url: URL;
+  params: Record<string, string | undefined>;
+  state: Record<string, unknown>;
+  pattern: URLPattern;
+  request: Request;
+}
+
+type Handler = (ctx: RouterContext) => Promise<Response> | Response;
+type Middleware = (ctx: RouterContext, next: () => Promise<Response>) => Promise<Response>;
+
+interface RouteConfig {
+  pattern: URLPattern;
+  handlers: { [method: string]: Handler };
+}
+
+interface MiddlewareConfig {
+  pattern: URLPattern;
+  handler: Middleware;
+}
+
+export class Router {
+  private routes: RouteConfig[] = [];
+  private middleware: MiddlewareConfig[] = [];
+
+  route(path: string) {
+    path = path.startsWith('/') ? path : `/${path}`;
+    
+    const pattern = new URLPattern({ pathname: path });
+    const routeConfig: RouteConfig = {
+      pattern,
+      handlers: {}
+    };
+    this.routes.push(routeConfig);
+
+    return {
+      get: (handler: Handler) => {
+        routeConfig.handlers['GET'] = handler;
+        return this;
+      },
+      post: (handler: Handler) => {
+        routeConfig.handlers['POST'] = handler;
+        return this;
+      },
+      put: (handler: Handler) => {
+        routeConfig.handlers['PUT'] = handler;
+        return this;
+      },
+      delete: (handler: Handler) => {
+        routeConfig.handlers['DELETE'] = handler;
+        return this;
+      },
+      patch: (handler: Handler) => {
+        routeConfig.handlers['PATCH'] = handler;
+        return this;
+      },
+      options: (handler: Handler) => {
+        routeConfig.handlers['OPTIONS'] = handler;
+        return this;
+      }
+    };
+  }
+
+  use(pathOrMiddleware: string | Middleware, middlewareOrRouter?: Middleware | Router) {
+    // Handle the case where only middleware is provided
+    if (typeof pathOrMiddleware === 'function') {
+      const pattern = new URLPattern({ pathname: '/*' });
+      this.middleware.push({
+        pattern,
+        handler: pathOrMiddleware
+      });
+      return this;
+    }
+
+    const path = pathOrMiddleware;
+    const middleware = middlewareOrRouter;
+
+    if (!middleware) {
+      throw new Error('Middleware or Router is required');
+    }
+
+    // Normalize the path
+    const normalizedPath = path.startsWith('/') ? path : `/${path}`;
+    // Only add wildcard if there isn't already a parameter or pattern at the end
+    const wildcardPath = normalizedPath.includes(':') || normalizedPath.includes('*') ? 
+      normalizedPath : 
+      `${normalizedPath.replace(/\/+$/, '')}/*`;
+
+    if (middleware instanceof Router) {
+      // Merge the nested router's routes
+      for (const nestedRoute of middleware.routes) {
+        const combinedPath = this.combinePaths(path, nestedRoute.pattern.pathname);
+        const newPattern = new URLPattern({ pathname: combinedPath });
+        
+        this.routes.push({
+          pattern: newPattern,
+          handlers: { ...nestedRoute.handlers }
+        });
+      }
+
+      // Merge the nested router's middleware
+      for (const nestedMiddleware of middleware.middleware) {
+        const combinedPath = this.combinePaths(path, nestedMiddleware.pattern.pathname);
+        const newPattern = new URLPattern({ pathname: combinedPath });
+        
+        this.middleware.push({
+          pattern: newPattern,
+          handler: nestedMiddleware.handler
+        });
+      }
+    } else {
+      // Handle regular middleware
+      const pattern = new URLPattern({ pathname: wildcardPath });
+      this.middleware.push({
+        pattern,
+        handler: middleware
+      });
+    }
+
+    return this;
+  }
+
+  handle = async (req: Request): Promise<Response> => {
+    const url = new URL(req.url);
+    const method = req.method;
+
+    // Find the matching route
+    const matchedRoute = this.findMatchingRoute(url);
+    if (!matchedRoute) {
+      return new Response('Not Found', { status: 404 });
+    }
+
+    const handler = matchedRoute.config.handlers[method];
+    if (!handler) {
+      return new Response('Method Not Allowed', { status: 405 });
+    }
+
+    // Get matching middleware with their parameters
+    const matchingMiddleware = this.getMatchingMiddleware(url);
+
+    // Create the base context object
+    const baseCtx: RouterContext = {
+      url,
+      params: {},
+      state: {},
+      pattern: matchedRoute.config.pattern,
+      request: req
+    };
+
+    // Combine route parameters with the base context
+    baseCtx.params = {
+      ...baseCtx.params,
+      ...matchedRoute.params
+    };
+
+    // Execute middleware chain
+    let index = 0;
+    const executeMiddleware = async (): Promise<Response> => {
+      if (index < matchingMiddleware.length) {
+        const { middleware, params } = matchingMiddleware[index++];
+        // Create a new context for each middleware with its specific parameters
+        const middlewareCtx: RouterContext = {
+          ...baseCtx,
+          params: { ...baseCtx.params, ...params },
+          pattern: middleware.pattern
+        };
+        return await middleware.handler(middlewareCtx, executeMiddleware);
+      }
+      // Final handler gets the accumulated parameters
+      return await handler(baseCtx);
+    };
+
+    try {
+      return await executeMiddleware();
+    } catch (error) {
+      console.error('Error handling request:', error);
+      return new Response('Internal Server Error', { status: 500 });
+    }
+  }
+
+  private findMatchingRoute(url: URL): { config: RouteConfig; params: Record<string, string | undefined> } | null {
+    for (const route of this.routes) {
+      const result = route.pattern.exec(url);
+      if (result) {
+        return {
+          config: route,
+          params: result.pathname.groups
+        };
+      }
+    }
+    return null;
+  }
+
+  private getMatchingMiddleware(url: URL): Array<{ 
+    middleware: MiddlewareConfig; 
+    params: Record<string, string> 
+  }> {
+    return this.middleware
+      .map(mw => {
+        const result = mw.pattern.exec(url);
+        if (result) {
+          return {
+            middleware: mw,
+            params: result.pathname.groups
+          };
+        }
+        return null;
+      })
+      .filter((item): item is { 
+        middleware: MiddlewareConfig; 
+        params: Record<string, string> 
+      } => item !== null);
+  }
+
+  private combinePaths(basePath: string, routePath: string): string {
+    const normalizedBase = basePath.replace(/\/+$/, '').replace(/^\/*/, '/');
+    const normalizedRoute = routePath.replace(/^\/*/, '');
+    return `${normalizedBase}/${normalizedRoute}`;
+  }
+}
+
+export default Router;
\ No newline at end of file