Automatically generate API Docs

.gitignore

@@ -10,4 +10,6 @@
 *.egg-info
 
 # magic environments
-.magic
+.magic
+
+.lightbug

README.md

@@ -95,14 +95,58 @@ Once you have a Mojo project set up locally,
     fn main() raises:
         var app = App()
 
-        app.get("/", hello)
-        app.post("/", printer)
+        app.get("/", hello, "hello")
+        app.post("/printer", printer, "printer")
 
         app.start_server()
    ```
 7. Excellent 😈. Your app is now listening on the selected port. 
    You've got yourself a pure-Mojo API! 🔥
 
+## API Docs
+Lightbug serves API docs for your app automatically at `/docs` by default.
+To disable this, add the `docs_enabled=False` flag when creating a new app instance: `App(docs_enabled=False)`.
+To describe your routes, add Mojo docstring annotations like below:
+
+```mojo
+
+@always_inline
+fn printer(req: HTTPRequest) -> HTTPResponse:
+        """Prints the request body and returns it.
+
+        Args:
+            req: Any arbitrary HTTP request with a body.
+
+        Returns:
+                HTTPResponse: 200 OK with the request body.
+        """
+        print("Got a request on ", req.uri.path, " with method ", req.method)
+        return OK(req.body_raw)
+
+@always_inline
+fn hello(req: HTTPRequest) -> HTTPResponse:
+        """Simple hello world function.
+
+        Args:
+            req: Any arbitrary HTTP request.
+
+        Returns:
+                HTTPResponse: 200 OK with a Hello World message.
+
+        Tags:
+                hello.
+        """
+        return OK("Hello 🔥!", "text/plain; charset=utf-8")
+
+fn main() raises:
+    var app = App()
+
+    app.get("/", hello, "hello")
+    app.post("/printer", printer, "printer")
+
+    app.start_server()
+```
+
 
 <!-- MARKDOWN LINKS & IMAGES -->
 <!-- https://www.markdownguide.org/basic-syntax/#reference-style-links -->

lightbug.🔥

@@ -1,19 +1,39 @@
-from lightbug_api import App
+from lightbug_api.app import App
 from lightbug_http import HTTPRequest, HTTPResponse, OK
 
 @always_inline
 fn printer(req: HTTPRequest) -> HTTPResponse:
+        """Prints the request body and returns it.
+
+        Args:
+            req: Any arbitrary HTTP request with a body.
+
+        Returns:
+                HTTPResponse: 200 OK with the request body.
+        """
         print("Got a request on ", req.uri.path, " with method ", req.method)
         return OK(req.body_raw)
 
 @always_inline
 fn hello(req: HTTPRequest) -> HTTPResponse:
-        return OK("Hello 🔥!")
+        """Simple hello world function.
+
+        Args:
+            req: Any arbitrary HTTP request.
+
+        Returns:
+                HTTPResponse: 200 OK with a Hello World message.
+
+        Tags:
+                hello.
+        """
+        return OK("Hello 🔥!", "text/plain; charset=utf-8")
 
 fn main() raises:
-    var app = App()
+    var app = App[docs_enabled=True]()
 
-    app.get("/", hello)
-    app.post("/", printer)
+    app.get("/", hello, "hello")
+    app.post("/printer", printer, "printer")
 
     app.start_server()
+

lightbug_api/__init__.mojo

@@ -1,27 +0,0 @@
-from lightbug_http import HTTPRequest, HTTPResponse, SysServer, NotFound
-from lightbug_api.routing import Router
-
-
-@value
-struct App:
-    var router: Router
-
-    fn __init__(inout self):
-        self.router = Router()
-
-    fn func(self, req: HTTPRequest) raises -> HTTPResponse:
-        for route_ptr in self.router.routes:
-            var route = route_ptr[]
-            if route.path == req.uri.path and route.method == req.method:
-                return route.handler(req)
-        return NotFound(req.uri.path)
-
-    fn get(inout self, path: String, handler: fn (HTTPRequest) -> HTTPResponse):
-        self.router.add_route(path, "GET", handler)
-
-    fn post(inout self, path: String, handler: fn (HTTPRequest) -> HTTPResponse):
-        self.router.add_route(path, "POST", handler)
-
-    fn start_server(inout self, address: StringLiteral = "0.0.0.0:8080") raises:
-        var server = SysServer()
-        server.listen_and_serve(address, self)

lightbug_api/app.mojo

@@ -0,0 +1,94 @@
+from os import mkdir
+from os.path import exists
+from pathlib import Path
+from sys.ffi import external_call
+from lightbug_http import HTTPRequest, HTTPResponse, Server, NotFound
+from lightbug_http.utils import logger
+from emberjson import JSON, Array, Object, Value, to_string
+from lightbug_api.openapi.generate import OpenAPIGenerator
+from lightbug_api.routing import Router
+from lightbug_api.docs import DocsApp
+
+
+@value
+struct App[docs_enabled: Bool = False]:
+    var router: Router
+    var lightbug_dir: Path
+
+    fn __init__(out self) raises:
+        self.router = Router()
+        self.lightbug_dir = Path()
+
+    fn set_lightbug_dir(mut self, lightbug_dir: Path):
+        self.lightbug_dir = lightbug_dir
+
+    fn func(mut self, req: HTTPRequest) raises -> HTTPResponse:
+        if docs_enabled and req.uri.path == "/docs" and req.method == "GET":
+            var openapi_spec = self.generate_openapi_spec()
+            var docs = DocsApp(to_string(openapi_spec))
+            return docs.func(req)
+        for route_ptr in self.router.routes:
+            var route = route_ptr[]
+            if route.path == req.uri.path and route.method == req.method:
+                return route.handler(req)
+        return NotFound(req.uri.path)
+
+    fn get(mut self, path: String, handler: fn (HTTPRequest) -> HTTPResponse, operation_id: String):
+        self.router.add_route(path, "GET", handler, operation_id)
+
+    fn post(mut self, path: String, handler: fn (HTTPRequest) -> HTTPResponse, operation_id: String):
+        self.router.add_route(path, "POST", handler, operation_id)
+
+    fn put(mut self, path: String, handler: fn (HTTPRequest) -> HTTPResponse, operation_id: String):
+        self.router.add_route(path, "PUT", handler, operation_id)
+
+    fn delete(mut self, path: String, handler: fn (HTTPRequest) -> HTTPResponse, operation_id: String):
+        self.router.add_route(path, "DELETE", handler, operation_id)
+
+    fn update_temporary_files(mut self) raises:
+        var routes_obj = Object()
+        var routes = List[Value]()
+
+        for route_ptr in self.router.routes:
+            var route = route_ptr[]
+            var route_obj = Object()
+            route_obj["path"] = route.path
+            route_obj["method"] = route.method
+            route_obj["handler"] = route.operation_id
+            routes.append(route_obj)
+
+        routes_obj["routes"] = Array.from_list(routes)
+        var cwd = Path()
+        var lightbug_dir = cwd / ".lightbug"
+        self.set_lightbug_dir(lightbug_dir)
+
+        if not exists(lightbug_dir):
+            logger.info("Creating .lightbug directory")
+            mkdir(lightbug_dir)
+
+        with open((lightbug_dir / "routes.json"), "w") as f:
+            f.write(to_string[pretty=True](routes_obj))
+
+        var mojodoc_status = external_call["system", UInt8](
+            "magic run mojo doc ./lightbug.🔥 -o " + str(lightbug_dir) + "/mojodoc.json"
+        )
+        if mojodoc_status != 0:
+            logger.error("Failed to generate mojodoc.json")
+            return
+
+    fn generate_openapi_spec(self) raises -> JSON:
+        var generator = OpenAPIGenerator()
+
+        var mojo_doc_json = generator.read_mojo_doc(str(self.lightbug_dir / "mojodoc.json"))
+        var router_metadata_json = generator.read_router_metadata(str(self.lightbug_dir / "routes.json"))
+
+        var openapi_spec = generator.generate_spec(mojo_doc_json, router_metadata_json)
+        generator.save_spec(openapi_spec, str(self.lightbug_dir / "openapi_spec.json"))
+        return openapi_spec
+
+    fn start_server(mut self, address: StringLiteral = "0.0.0.0:8080") raises:
+        if docs_enabled:
+            logger.info("API Docs ready at: " + "http://" + String(address) + "/docs")
+        self.update_temporary_files()
+        var server = Server()
+        server.listen_and_serve(address, self)

lightbug_api/docs.mojo

@@ -0,0 +1,40 @@
+from lightbug_http import Server, HTTPRequest, HTTPResponse, OK
+from lightbug_http.utils import logger
+
+
+@value
+struct DocsApp:
+    var openapi_spec: String
+
+    fn func(mut self, req: HTTPRequest) raises -> HTTPResponse:
+        var html_response = String(
+            """
+        <!doctype html>
+<html>
+  <head>
+    <title>Scalar API Reference</title>
+    <meta charset="utf-8" />
+    <meta
+      name="viewport"
+      content="width=device-width, initial-scale=1" />
+  </head>
+  <body>
+    <script
+  id="api-reference"
+  type="application/json">
+  {}
+</script>
+<script src="https://cdn.jsdelivr.net/npm/@scalar/api-reference"></script>
+  </body>
+</html>
+        """
+        ).format(self.openapi_spec)
+        return OK(html_response, "text/html; charset=utf-8")
+
+    fn set_openapi_spec(mut self, openapi_spec: String):
+        self.openapi_spec = openapi_spec
+
+    fn start_docs_server(mut self, address: StringLiteral = "0.0.0.0:8888") raises:
+        logger.info("Starting docs at " + String(address))
+        var server = Server()
+        server.listen_and_serve(address, self)