From f4d27689e76b0206e52432ca58812adafa31fbec Mon Sep 17 00:00:00 2001
From: NiseVoid <nisevoid@gmail.com>
Date: Fri, 3 Aug 2018 21:29:15 +0200
Subject: [PATCH] Initial commit

---
 context.go |  56 ++++++++++++++++++++
 router.go  | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+)
 create mode 100644 context.go
 create mode 100644 router.go

diff --git a/context.go b/context.go
new file mode 100644
index 0000000..4ca32f7
--- /dev/null
+++ b/context.go
@@ -0,0 +1,56 @@
+package router
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/julienschmidt/httprouter"
+)
+
+// Context is passed to handlers and middlewares
+type Context struct {
+	Request  *http.Request
+	Response http.ResponseWriter
+	Param    func(string) string
+	store    map[string]interface{}
+}
+
+func newContext(res http.ResponseWriter, req *http.Request, param httprouter.Params) *Context {
+	return &Context{req, res, param.ByName, make(map[string]interface{})}
+}
+
+// String returns the given status code and writes the bytes to the body
+func (c *Context) Bytes(code int, b []byte) error {
+	c.Response.WriteHeader(code)
+	_, err := c.Response.Write(b)
+	return err
+}
+
+// String returns the given status code and writes the string to the body
+func (c *Context) String(code int, s string) error {
+	c.Response.WriteHeader(code)
+	_, err := c.Response.Write([]byte(s))
+	return err
+}
+
+// NoContent returns the given status code without writing anything to the body
+func (c *Context) NoContent(code int) error {
+	c.Response.WriteHeader(code)
+	return nil
+}
+
+// JSON returns the given status code and writes JSON to the body
+func (c *Context) JSON(code int, data interface{}) error {
+	c.Response.WriteHeader(code)
+	return json.NewEncoder(c.Response).Encode(data) // TODO: Encode to buffer first to prevent partial responses on error
+}
+
+// Set sets a value in the context. Set is not safe to be used concurrently
+func (c *Context) Set(key string, value interface{}) {
+	c.store[key] = value
+}
+
+// Get retrieves a value from the context.
+func (c *Context) Get(key string) interface{} {
+	return c.store[key]
+}
diff --git a/router.go b/router.go
new file mode 100644
index 0000000..df9d566
--- /dev/null
+++ b/router.go
@@ -0,0 +1,148 @@
+package router
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"reflect"
+
+	"github.com/julienschmidt/httprouter"
+)
+
+type route struct {
+	Method string
+	Path   string
+	Handle interface{}
+}
+
+// GetHandle handles a request that doesn't receive a body
+type GetHandle func(*Context) error
+
+// Router is the router itself
+type Router struct {
+	routes []route
+	Port   int
+}
+
+// New returns a new Router
+func New() *Router {
+	return &Router{}
+}
+
+// GET adds a GET route
+func (r *Router) GET(path string, handle GetHandle) {
+	r.routes = append(r.routes, route{`GET`, path, handle})
+}
+
+// POST adds a POST route
+func (r *Router) POST(path string, handle interface{}) {
+	checkInterfaceHandle(handle)
+	r.routes = append(r.routes, route{`POST`, path, handle})
+}
+
+// DELETE adds a DELETE route
+func (r *Router) DELETE(path string, handle GetHandle) {
+	r.routes = append(r.routes, route{`DELETE`, path, handle})
+}
+
+// PUT adds a PUT route
+func (r *Router) PUT(path string, handle interface{}) {
+	checkInterfaceHandle(handle)
+	r.routes = append(r.routes, route{`PUT`, path, handle})
+}
+
+// PATCH adds a PATCH route
+func (r *Router) PATCH(path string, handle interface{}) {
+	checkInterfaceHandle(handle)
+	r.routes = append(r.routes, route{`PATCH`, path, handle})
+}
+
+// HEAD adds a HEAD route
+func (r *Router) HEAD(path string, handle GetHandle) {
+	r.routes = append(r.routes, route{`HEAD`, path, handle})
+}
+
+// OPTIONS adds a OPTIONS route
+func (r *Router) OPTIONS(path string, handle GetHandle) {
+	r.routes = append(r.routes, route{`OPTIONS`, path, handle})
+}
+
+// Start starts the web server and binds to the given address
+func (r *Router) Start(addr string) error {
+	httpr := r.getHttpr()
+
+	return http.ListenAndServe(addr, httpr)
+}
+
+func (r *Router) getHttpr() *httprouter.Router {
+	httpr := httprouter.New()
+
+	for _, v := range r.routes {
+		if handle, ok := v.Handle.(GetHandle); ok {
+			httpr.Handle(v.Method, v.Path, handleGET(handle))
+			continue
+		}
+
+		httpr.Handle(v.Method, v.Path, handlePOST(v.Handle))
+	}
+
+	return httpr
+}
+
+func checkInterfaceHandle(f interface{}) {
+	if _, ok := f.(GetHandle); ok {
+		return
+	}
+
+	rt := reflect.TypeOf(f)
+
+	if rt.Kind() != reflect.Func {
+		panic(`non-func handle`)
+	}
+
+	if rt.NumIn() != 2 {
+		panic(`handle should take 2 arguments`)
+	}
+
+	if rt.NumOut() != 1 || rt.Out(0).Name() != `error` {
+		panic(`handle should return only error`)
+	}
+
+	if rt.In(0) != reflect.TypeOf(&Context{}) {
+		panic(`handle should accept Context as first argument`)
+	}
+
+	return
+}
+
+func handlePOST(f interface{}) httprouter.Handle {
+	funcRv, inputRt := reflect.ValueOf(f), reflect.TypeOf(f).In(1)
+
+	return func(res http.ResponseWriter, req *http.Request, param httprouter.Params) {
+		c := newContext(res, req, param)
+
+		data := reflect.New(inputRt)
+		{
+			err := json.NewDecoder(req.Body).Decode(data.Interface())
+			req.Body.Close()
+			if err != nil {
+				c.NoContent(400) // TODO: send info about error (BindError)
+				return
+			}
+		}
+
+		out := funcRv.Call([]reflect.Value{reflect.ValueOf(c), data.Elem()})
+		err := out[0].Interface()
+		_ = err
+	}
+}
+
+func handleGET(f GetHandle) httprouter.Handle {
+	return func(res http.ResponseWriter, req *http.Request, param httprouter.Params) {
+		c := newContext(res, req, param)
+
+		err := f(c)
+
+		fmt.Println(err)
+	}
+}