# Router

A high-performance router for Go with support for path parameters, wildcards, middleware, and route grouping. Sports an incredibly simple API over the top of a prefix tree data structure. Minimal allocations and, dare we say, 🔥*blazingly* fast🔥.

## Features
- Zero dependencies
- Fast path matching with radix tree structure
- Support for path parameters (`[id]`) and wildcards (`*path`)
- Middleware support for request processing pipelines
- Route grouping with shared prefixes and middleware
- Adapters for net/http and fasthttp (optional)
- Up to 15x faster than `http.ServeMux` for dynamic routes
- Zero allocations for static routes

## Installation

```shell
go get git.sharkk.net/Go/Router
```

## Usage

### Basic Routing

```go
// Create a new router
r := router.New()

// Static routes
r.Get("/", router.FuncHandler(func(params []string) {
    fmt.Println("Root handler")
}))

// Parameter routes
r.Get("/users/[id]", router.FuncHandler(func(params []string) {
    userID := params[0]
    fmt.Printf("User ID: %s\n", userID)
}))

// Wildcard routes
r.Get("/files/*path", router.FuncHandler(func(params []string) {
    filePath := params[0]
    fmt.Printf("File path: %s\n", filePath)
}))

// Lookup routes
if handler, params, ok := r.Lookup("GET", "/users/123"); ok {
    handler.Serve(params)
}
```

### Middleware

```go
// Create logging middleware
func LoggingMiddleware(next router.Handler) router.Handler {
    return router.FuncHandler(func(params []string) {
        fmt.Println("Request started")
        next.Serve(params)
        fmt.Println("Request completed")
    })
}

// Apply middleware globally
r := router.New()
r.Use(LoggingMiddleware)

// Apply middleware to specific routes
r.WithMiddleware(AuthMiddleware).Get("/admin", adminHandler)
```

### Route Groups

```go
// Create a router
r := router.New()

// Create an API group
api := r.Group("/api")
api.Get("/users", listUsersHandler)  // matches /api/users

// Nested groups
v1 := api.Group("/v1")
v1.Get("/products", listProductsHandler)  // matches /api/v1/products

// Group with middleware
admin := api.Group("/admin")
admin.Use(AuthMiddleware)
admin.Get("/stats", statsHandler)  // matches /api/admin/stats
```

### HTTP Integration

```go
// Standard net/http integration
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    // Find the matching handler
    handler, params, found := router.Lookup(r.Method, r.URL.Path)
    if !found {
        http.NotFound(w, r)
        return
    }

    // Create an HTTP-compatible handler
    httpHandler := router.NewHTTP(w, r, func(w http.ResponseWriter, r *http.Request, params []string) {
        fmt.Fprintf(w, "Hello, user %s", params[0])
    })

    // Execute the handler
    httpHandler.Serve(params)
})
```

### FastHTTP Integration (Optional)

Build with `-tags fasthttp` to enable FastHTTP support:

```go
// FastHTTP integration
fastHandler := func(ctx *fasthttp.RequestCtx) {
    path := string(ctx.Path())
    method := string(ctx.Method())

    handler, params, found := router.Lookup(method, path)
    if !found {
        ctx.Error("Not found", fasthttp.StatusNotFound)
        return
    }

    // Create a FastHTTP-compatible handler
    fastHandler := router.NewFastHTTP(ctx, func(ctx *fasthttp.RequestCtx, params []string) {
        fmt.Fprintf(ctx, "Hello, user %s", params[0])
    })

    // Execute the handler
    fastHandler.Serve(params)
}
```

## Benchmarks

Benchmark results comparing our router to the standard `http.ServeMux` on AMD Ryzen 9 7950X:

```
cpu: AMD Ryzen 9 7950X 16-Core Processor

BenchmarkComparison/root_path
Router:     2.098 ns/op     0 B/op   0 allocs/op
ServeMux:  32.010 ns/op     0 B/op   0 allocs/op

BenchmarkComparison/static_path
Router:    16.050 ns/op     0 B/op   0 allocs/op
ServeMux:  67.980 ns/op     0 B/op   0 allocs/op

BenchmarkComparison/dynamic_path
Router:    39.170 ns/op    16 B/op   1 allocs/op
ServeMux: 174.000 ns/op    48 B/op   3 allocs/op

BenchmarkComparison/not_found
Router:    10.580 ns/op     0 B/op   0 allocs/op
ServeMux: 178.100 ns/op    56 B/op   3 allocs/op
```

Key Performance Points:
- Root path lookups are 15x faster
- Static paths are 4x faster with zero allocations
- Dynamic paths are 4.4x faster with fewer allocations
- Not found paths are 16.8x faster with zero allocations

## License

[Sharkk Minimal License](LICENSE); do what you like!