# 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
- Implements `http.Handler` for direct integration
- 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("/", func(w router.Res, r router.Req, params []string) {
    fmt.Fprintf(w, "Root handler")
})

// Parameter routes
r.Get("/users/[id]", func(w router.Res, r router.Req, params []string) {
    userID := params[0]
    fmt.Fprintf(w, "User ID: %s", userID)
})

// Wildcard routes
r.Get("/files/*path", func(w router.Res, r router.Req, params []string) {
    filePath := params[0]
    fmt.Fprintf(w, "File path: %s", filePath)
})

// Standard http.HandlerFunc adapter
r.Get("/simple", router.StandardHandler(func(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Simple handler without params")
}))

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

// Or simply serve them
http.ListenAndServe(":8080", r)
```

### Middleware

```go
// Create logging middleware
func LoggingMiddleware(next router.Handler) router.Handler {
    return &router.simpleHandler{
        fn: 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)

http.ListenAndServe(":8080", r)
```

### 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.ListenAndServe(":8080", r)
```

## Benchmarks

Benchmark comparing Router to the standard `http.ServeMux`:

```
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
```

- 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!