package main

import (
	"context"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
	"time"
)

func TestRunSendsConcurrentRequestsAcrossTargets(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(response http.ResponseWriter, _ *http.Request) {
		response.WriteHeader(http.StatusOK)
		_, _ = response.Write([]byte("ok"))
	}))
	defer server.Close()

	requestTargets, err := targets(server.URL, "/,/transactions")
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
	defer cancel()
	result := run(ctx, server.Client(), requestTargets, 4)

	if result.Requests == 0 || result.Errors != 0 || result.Non2xx != 0 {
		t.Fatalf("unexpected load result: %+v", result)
	}
	if len(result.Latency) != int(result.Requests) {
		t.Fatalf("expected one latency per request, got %d for %d", len(result.Latency), result.Requests)
	}
}

func TestTargetsRejectsExternalAndRelativePaths(t *testing.T) {
	for _, paths := range []string{"relative", "https://example.com/"} {
		if _, err := targets("http://localhost:8080", paths); err == nil {
			t.Fatalf("expected %q to be rejected", paths)
		}
	}
}

func TestPercentileUsesNearestRank(t *testing.T) {
	values := []time.Duration{time.Millisecond, 4 * time.Millisecond, 2 * time.Millisecond, 3 * time.Millisecond}
	if got := percentile(values, 95); got != 4*time.Millisecond {
		t.Fatalf("unexpected p95: %s", got)
	}
}

func TestRunDrainsInflightRequestAfterDuration(t *testing.T) {
	var canceled atomic.Bool
	server := httptest.NewServer(http.HandlerFunc(func(response http.ResponseWriter, request *http.Request) {
		time.Sleep(20 * time.Millisecond)
		if request.Context().Err() != nil {
			canceled.Store(true)
		}
		response.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Millisecond)
	defer cancel()
	result := run(ctx, server.Client(), []string{server.URL}, 1)

	if result.Requests != 1 || result.Errors != 0 || canceled.Load() {
		t.Fatalf("in-flight request was not drained cleanly: %+v", result)
	}
}