package sux

import (
	"net/http"
	"net/http/httptest"
	"runtime"
	"testing"
)

// BenchmarkParameterOperations benchmarks the new parameter handling
func BenchmarkParameterOperations(b *testing.B) {
	params := Params{
		keys:   make([]string, 0, 4),
		values: make([]string, 0, 4),
	}

	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		params.Set("id", "123")
		params.Set("name", "test")
		_ = params.Get("id")
		_ = params.Get("name")
		params.Reset()
	}
}

// BenchmarkPathParsing compares old vs new path parsing
func BenchmarkPathParsingOld(b *testing.B) {
	path := "/users/123/posts/456/comments/789"
	
	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		_ = parsePath(path)
	}
}

func BenchmarkPathParsingNew(b *testing.B) {
	path := "/users/123/posts/456/comments/789"
	
	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		_ = parsePathZeroAlloc(path)
	}
}

// BenchmarkMemoryUsage tests memory efficiency under load
func BenchmarkMemoryUsage(b *testing.B) {
	router := New()

	// Add routes with different patterns
	router.GET("/", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	})
	router.GET("/users/:id", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("id")
		w.WriteHeader(http.StatusOK)
	})
	router.GET("/files/*path", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("path")
		w.WriteHeader(http.StatusOK)
	})

	requests := []struct {
		method string
		path   string
	}{
		{"GET", "/"},
		{"GET", "/users/123"},
		{"GET", "/files/docs/readme.txt"},
	}

	var reqs []*http.Request
	for _, req := range requests {
		for i := 0; i < 100; i++ {
			reqs = append(reqs, httptest.NewRequest(req.method, req.path, nil))
		}
	}

	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		w := httptest.NewRecorder()
		router.ServeHTTP(w, reqs[i%len(reqs)])
	}
}

// BenchmarkConcurrentAccess tests performance under high concurrency
func BenchmarkConcurrentAccess(b *testing.B) {
	router := New()
	router.GET("/test/:id", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("id")
		w.WriteHeader(http.StatusOK)
	})

	req := httptest.NewRequest("GET", "/test/123", nil)

	b.ResetTimer()
	b.ReportAllocs()

	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			w := httptest.NewRecorder()
			router.ServeHTTP(w, req)
		}
	})
}

// BenchmarkGCPressure measures GC pressure from allocations
func BenchmarkGCPressure(b *testing.B) {
	router := New()
	router.GET("/users/:id/posts/:postId", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("id") + params.Get("postId")
		w.WriteHeader(http.StatusOK)
	})

	req := httptest.NewRequest("GET", "/users/123/posts/456", nil)

	// Force GC before benchmark
	runtime.GC()

	var m1, m2 runtime.MemStats
	runtime.ReadMemStats(&m1)

	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		w := httptest.NewRecorder()
		router.ServeHTTP(w, req)
	}

	b.StopTimer()
	runtime.ReadMemStats(&m2)
	b.Logf("Allocs: %d, TotalAlloc: %d bytes", m2.Mallocs-m1.Mallocs, m2.TotalAlloc-m1.TotalAlloc)
}

// BenchmarkWildcardOptimization tests the wildcard parameter optimization
func BenchmarkWildcardOptimization(b *testing.B) {
	router := New()
	router.GET("/files/*path", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("path")
		w.WriteHeader(http.StatusOK)
	})

	// Test with varying path lengths
	paths := []string{
		"/files/file.txt",
		"/files/docs/readme.txt",
		"/files/docs/api/v1/users.json",
		"/files/very/deep/nested/path/with/many/segments/file.txt",
	}

	var reqs []*http.Request
	for _, path := range paths {
		for i := 0; i < 25; i++ {
			reqs = append(reqs, httptest.NewRequest("GET", path, nil))
		}
	}

	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		w := httptest.NewRecorder()
		router.ServeHTTP(w, reqs[i%len(reqs)])
	}
}

// BenchmarkPoolEfficiency tests the efficiency of our pooling strategy
func BenchmarkPoolEfficiency(b *testing.B) {
	router := New()
	router.GET("/test/:param", func(w http.ResponseWriter, r *http.Request) {
		params := ParamsFromContext(r)
		_ = params.Get("param")
		w.WriteHeader(http.StatusOK)
	})

	req := httptest.NewRequest("GET", "/test/value", nil)

	b.ResetTimer()
	b.ReportAllocs()

	// This should show minimal allocations due to pooling
	for i := 0; i < b.N; i++ {
		w := httptest.NewRecorder()
		router.ServeHTTP(w, req)
	}
}