package starnet

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

func TestWithRetrySmokeGet(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := atomic.AddInt32(&hits, 1)
		if n <= 2 {
			w.WriteHeader(http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	}))
	defer s.Close()

	resp, err := Get(s.URL,
		WithRetry(2,
			WithRetryBackoff(0, 0, 1),
			WithRetryJitter(0),
		),
	)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status=%d want=%d", resp.StatusCode, http.StatusOK)
	}
	if atomic.LoadInt32(&hits) != 3 {
		t.Fatalf("hits=%d want=3", hits)
	}
}

func TestWithRetryResponseRequestPointerStable(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := atomic.AddInt32(&hits, 1)
		if n == 1 {
			w.WriteHeader(http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodGet).
		SetRetry(1, WithRetryBackoff(0, 0, 1), WithRetryJitter(0))
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.Request() != req {
		t.Fatal("response request pointer should point to original request")
	}
}

func TestWithRetryNoRetryForNonReplayableBodyReader(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hits, 1)
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodPost).
		SetBodyReader(strings.NewReader("payload")).
		SetRetry(3,
			WithRetryIdempotentOnly(false),
			WithRetryBackoff(0, 0, 1),
			WithRetryJitter(0),
		)
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.StatusCode != http.StatusServiceUnavailable {
		t.Fatalf("status=%d want=%d", resp.StatusCode, http.StatusServiceUnavailable)
	}
	if atomic.LoadInt32(&hits) != 1 {
		t.Fatalf("hits=%d want=1", hits)
	}
}

func TestWithRetryPostWhenIdempotentDisabled(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := atomic.AddInt32(&hits, 1)
		_, _ = io.Copy(io.Discard, r.Body)
		if n == 1 {
			w.WriteHeader(http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodPost).
		SetBodyString("hello").
		SetRetry(1,
			WithRetryIdempotentOnly(false),
			WithRetryBackoff(0, 0, 1),
			WithRetryJitter(0),
		)
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status=%d want=%d", resp.StatusCode, http.StatusOK)
	}
	if atomic.LoadInt32(&hits) != 2 {
		t.Fatalf("hits=%d want=2", hits)
	}
}

func TestWithRetryRawWithoutGetBodyNoRetry(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hits, 1)
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	defer s.Close()

	rawReq, _ := http.NewRequest(http.MethodPost, s.URL, io.MultiReader(strings.NewReader("raw")))
	if rawReq.GetBody != nil {
		t.Fatal("raw request GetBody should be nil in this test")
	}

	req := NewSimpleRequest("", http.MethodPost, WithRawRequest(rawReq)).
		SetRetry(2,
			WithRetryIdempotentOnly(false),
			WithRetryBackoff(0, 0, 1),
			WithRetryJitter(0),
		)
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if atomic.LoadInt32(&hits) != 1 {
		t.Fatalf("hits=%d want=1", hits)
	}
}

func TestWithRetryRespectsTotalTimeoutBudget(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hits, 1)
		time.Sleep(80 * time.Millisecond)
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodGet).
		SetTimeout(120*time.Millisecond).
		SetRetry(3,
			WithRetryBackoff(0, 0, 1),
			WithRetryJitter(0),
		)

	_, err := req.Do()
	if err == nil {
		t.Fatal("expected timeout error")
	}
	if !errors.Is(err, context.DeadlineExceeded) {
		t.Fatalf("expected context deadline exceeded, got: %v", err)
	}
	if h := atomic.LoadInt32(&hits); h > 2 {
		t.Fatalf("hits=%d want<=2 under tight timeout budget", h)
	}
}

func TestSetRetryInvalidMax(t *testing.T) {
	req := NewSimpleRequest("http://example.com", http.MethodGet).SetRetry(-1)
	if req.Err() == nil {
		t.Fatal("expected error for negative retry max")
	}
}

func TestSetRetrySeriesSmokeGet(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := atomic.AddInt32(&hits, 1)
		if n <= 2 {
			w.WriteHeader(http.StatusTooManyRequests)
			return
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodGet).
		SetRetry(2).
		SetRetryBackoff(0, 0, 1).
		SetRetryJitter(0).
		SetRetryStatuses(http.StatusTooManyRequests)
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status=%d want=%d", resp.StatusCode, http.StatusOK)
	}
	if h := atomic.LoadInt32(&hits); h != 3 {
		t.Fatalf("hits=%d want=3", h)
	}
}

func TestSetRetryIdempotentOnlyWithPost(t *testing.T) {
	var hits int32
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := atomic.AddInt32(&hits, 1)
		_, _ = io.Copy(io.Discard, r.Body)
		if n == 1 {
			w.WriteHeader(http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer s.Close()

	req := NewSimpleRequest(s.URL, http.MethodPost).
		SetBodyString("hello").
		SetRetry(1).
		SetRetryIdempotentOnly(false).
		SetRetryBackoff(0, 0, 1).
		SetRetryJitter(0)
	resp, err := req.Do()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer resp.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status=%d want=%d", resp.StatusCode, http.StatusOK)
	}
	if h := atomic.LoadInt32(&hits); h != 2 {
		t.Fatalf("hits=%d want=2", h)
	}
}

func TestSetRetryOnErrorOverridesDefault(t *testing.T) {
	var dials int32
	dialErr := errors.New("dial failed")

	req := NewSimpleRequest("http://example.com", http.MethodGet).
		SetDialFunc(func(ctx context.Context, network, addr string) (net.Conn, error) {
			atomic.AddInt32(&dials, 1)
			return nil, dialErr
		}).
		SetRetry(1).
		SetRetryBackoff(0, 0, 1).
		SetRetryJitter(0).
		SetRetryOnError(func(err error) bool {
			return true
		})

	_, err := req.Do()
	if err == nil {
		t.Fatal("expected error")
	}
	if h := atomic.LoadInt32(&dials); h != 2 {
		t.Fatalf("dial attempts=%d want=2", h)
	}
}

func TestSetRetryOptionRequireEnableRetry(t *testing.T) {
	req := NewSimpleRequest("http://example.com", http.MethodGet).SetRetryBackoff(10*time.Millisecond, 100*time.Millisecond, 2)
	if req.Err() == nil {
		t.Fatal("expected error when setting retry options before SetRetry")
	}
	if !strings.Contains(req.Err().Error(), "call SetRetry first") {
		t.Fatalf("unexpected error: %v", req.Err())
	}
}