package starnet

import (
	"io"
	"net/http"
	"net/url"
	"strings"
	"sync/atomic"
	"testing"
)

type stateRoundTripperFunc func(*http.Request) (*http.Response, error)

func (fn stateRoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
	return fn(req)
}

func TestSetContextNilUsesBackground(t *testing.T) {
	req := NewSimpleRequest("http://example.com", http.MethodGet)
	req.client = &Client{client: &http.Client{
		Transport: stateRoundTripperFunc(func(r *http.Request) (*http.Response, error) {
			if r.Context() == nil {
				t.Fatal("request context is nil")
			}
			return &http.Response{
				StatusCode: http.StatusOK,
				Header:     make(http.Header),
				Body:       io.NopCloser(strings.NewReader("ok")),
				Request:    r,
			}, nil
		}),
	}}

	resp, err := req.SetContext(nil).Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	if req.Context() == nil {
		t.Fatal("request Context() is nil")
	}
}

func TestWithContextNilRetryPathDoesNotPanic(t *testing.T) {
	var hits int32
	req, err := NewRequest("http://example.com", http.MethodGet, WithContext(nil))
	if err != nil {
		t.Fatalf("NewRequest() error: %v", err)
	}
	req.client = &Client{client: &http.Client{
		Transport: stateRoundTripperFunc(func(r *http.Request) (*http.Response, error) {
			if r.Context() == nil {
				t.Fatal("retry request context is nil")
			}
			if atomic.AddInt32(&hits, 1) == 1 {
				return &http.Response{
					StatusCode: http.StatusServiceUnavailable,
					Header:     make(http.Header),
					Body:       io.NopCloser(strings.NewReader("retry")),
					Request:    r,
				}, nil
			}
			return &http.Response{
				StatusCode: http.StatusOK,
				Header:     make(http.Header),
				Body:       io.NopCloser(strings.NewReader("ok")),
				Request:    r,
			}, nil
		}),
	}}

	resp, err := req.
		SetTimeout(DefaultTimeout).
		SetRetry(1, WithRetryBackoff(0, 0, 1), WithRetryJitter(0)).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	if got := atomic.LoadInt32(&hits); got != 2 {
		t.Fatalf("hits=%d; want 2", got)
	}
}

func TestCloneRawRequestCreatesIndependentCopy(t *testing.T) {
	rawReq, err := http.NewRequest(http.MethodPost, "http://example.com/upload", strings.NewReader("payload"))
	if err != nil {
		t.Fatalf("NewRequest() error: %v", err)
	}
	rawReq.Header.Set("X-Test", "one")

	req := NewSimpleRequest("", http.MethodPost).SetRawRequest(rawReq)
	cloned := req.Clone()

	if cloned.Err() != nil {
		t.Fatalf("Clone() err = %v", cloned.Err())
	}
	if cloned.RawRequest() == rawReq {
		t.Fatal("raw request pointer reused")
	}

	cloned.RawRequest().Header.Set("X-Test", "two")
	if rawReq.Header.Get("X-Test") != "one" {
		t.Fatalf("original header mutated: %q", rawReq.Header.Get("X-Test"))
	}

	body, err := cloned.RawRequest().GetBody()
	if err != nil {
		t.Fatalf("GetBody() error: %v", err)
	}
	defer body.Close()

	data, err := io.ReadAll(body)
	if err != nil {
		t.Fatalf("ReadAll() error: %v", err)
	}
	if string(data) != "payload" {
		t.Fatalf("body=%q; want payload", string(data))
	}
}

func TestCloneRawRequestWithNonReplayableBodyFailsExplicitly(t *testing.T) {
	rawReq := &http.Request{
		Method: http.MethodPost,
		URL:    mustParseURL(t, "http://example.com/upload"),
		Header: make(http.Header),
		Body:   io.NopCloser(io.MultiReader(strings.NewReader("payload"))),
	}

	req := NewSimpleRequest("", http.MethodPost).SetRawRequest(rawReq)
	cloned := req.Clone()

	if cloned.Err() == nil {
		t.Fatal("Clone() should fail for non-replayable raw body")
	}
	if !strings.Contains(cloned.Err().Error(), "non-replayable") {
		t.Fatalf("Clone() err=%v; want non-replayable body error", cloned.Err())
	}
}

func TestDisableRawModeAfterSetRawRequestReturnsError(t *testing.T) {
	rawReq, err := http.NewRequest(http.MethodGet, "http://example.com", nil)
	if err != nil {
		t.Fatalf("NewRequest() error: %v", err)
	}

	req := NewSimpleRequest("", http.MethodGet).SetRawRequest(rawReq).DisableRawMode()
	if req.Err() == nil {
		t.Fatal("DisableRawMode() should set error")
	}
	if !strings.Contains(req.Err().Error(), "cannot disable raw mode") {
		t.Fatalf("DisableRawMode() err=%v", req.Err())
	}
	if !req.doRaw {
		t.Fatal("request should remain in raw mode")
	}
}

func mustParseURL(t *testing.T, raw string) *url.URL {
	t.Helper()
	parsed, err := url.Parse(raw)
	if err != nil {
		t.Fatalf("url.Parse() error: %v", err)
	}
	return parsed
}