package starnet

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

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

	var mu sync.Mutex
	events := map[string]int{}
	hooks := &TraceHooks{
		GetConn: func(info TraceGetConnInfo) {
			mu.Lock()
			events["get_conn"]++
			mu.Unlock()
		},
		GotConn: func(info TraceGotConnInfo) {
			mu.Lock()
			events["got_conn"]++
			mu.Unlock()
		},
		TLSHandshakeStart: func(info TraceTLSHandshakeStartInfo) {
			mu.Lock()
			events["tls_start"]++
			mu.Unlock()
		},
		TLSHandshakeDone: func(info TraceTLSHandshakeDoneInfo) {
			mu.Lock()
			events["tls_done"]++
			mu.Unlock()
			if info.Err != nil {
				t.Errorf("unexpected tls handshake error: %v", info.Err)
			}
		},
		WroteHeaders: func() {
			mu.Lock()
			events["wrote_headers"]++
			mu.Unlock()
		},
		WroteRequest: func(info TraceWroteRequestInfo) {
			mu.Lock()
			events["wrote_request"]++
			mu.Unlock()
			if info.Err != nil {
				t.Errorf("unexpected write error: %v", info.Err)
			}
		},
		GotFirstResponseByte: func() {
			mu.Lock()
			events["first_byte"]++
			mu.Unlock()
		},
	}

	resp, err := NewSimpleRequest(server.URL, http.MethodGet).
		SetSkipTLSVerify(true).
		SetTraceHooks(hooks).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	for _, key := range []string{"get_conn", "got_conn", "tls_start", "tls_done", "wrote_headers", "wrote_request", "first_byte"} {
		if events[key] == 0 {
			t.Fatalf("expected trace event %q", key)
		}
	}
}

func TestTraceHooksDynamicHTTPSPathDoesNotDuplicateTLSHandshake(t *testing.T) {
	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	var mu sync.Mutex
	tlsStartCount := 0
	tlsDoneCount := 0
	var lastInfo TraceTLSHandshakeDoneInfo
	hooks := &TraceHooks{
		TLSHandshakeStart: func(info TraceTLSHandshakeStartInfo) {
			mu.Lock()
			tlsStartCount++
			mu.Unlock()
		},
		TLSHandshakeDone: func(info TraceTLSHandshakeDoneInfo) {
			mu.Lock()
			tlsDoneCount++
			lastInfo = info
			mu.Unlock()
		},
	}

	resp, err := NewSimpleRequest(server.URL, http.MethodGet).
		SetSkipTLSVerify(true).
		SetDialTimeout(1500 * time.Millisecond).
		SetTraceHooks(hooks).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	if tlsStartCount != 1 {
		t.Fatalf("tlsStartCount=%d", tlsStartCount)
	}
	if tlsDoneCount != 1 {
		t.Fatalf("tlsDoneCount=%d", tlsDoneCount)
	}
	if lastInfo.Err != nil {
		t.Fatalf("unexpected tls handshake error: %v", lastInfo.Err)
	}
	if lastInfo.ConnectionState.Version == 0 {
		t.Fatal("expected tls connection state")
	}
}

func TestTraceHooksCustomLookupFuncEmitsDNSEvents(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	addr, err := net.ResolveTCPAddr("tcp", server.Listener.Addr().String())
	if err != nil {
		t.Fatalf("ResolveTCPAddr() error: %v", err)
	}

	var mu sync.Mutex
	dnsStartCount := 0
	dnsDoneCount := 0
	var dnsStartHost string
	hooks := &TraceHooks{
		DNSStart: func(info TraceDNSStartInfo) {
			mu.Lock()
			dnsStartCount++
			dnsStartHost = info.Host
			mu.Unlock()
		},
		DNSDone: func(info TraceDNSDoneInfo) {
			mu.Lock()
			dnsDoneCount++
			mu.Unlock()
			if info.Err != nil {
				t.Errorf("unexpected dns error: %v", info.Err)
			}
		},
	}

	url := "http://trace.example.test:" + strconv.Itoa(addr.Port)
	resp, err := NewSimpleRequest(url, http.MethodGet).
		SetLookupFunc(func(ctx context.Context, host string) ([]net.IPAddr, error) {
			return []net.IPAddr{{IP: addr.IP}}, nil
		}).
		SetTraceHooks(hooks).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	if dnsStartCount != 1 {
		t.Fatalf("dnsStartCount=%d", dnsStartCount)
	}
	if dnsDoneCount != 1 {
		t.Fatalf("dnsDoneCount=%d", dnsDoneCount)
	}
	if dnsStartHost != "trace.example.test" {
		t.Fatalf("dnsStartHost=%q", dnsStartHost)
	}
}

func TestTraceHooksCustomDialFuncEmitsConnectEvents(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	var mu sync.Mutex
	connectStartCount := 0
	connectDoneCount := 0
	hooks := &TraceHooks{
		ConnectStart: func(info TraceConnectStartInfo) {
			mu.Lock()
			connectStartCount++
			mu.Unlock()
		},
		ConnectDone: func(info TraceConnectDoneInfo) {
			mu.Lock()
			connectDoneCount++
			mu.Unlock()
			if info.Err != nil {
				t.Errorf("unexpected connect error: %v", info.Err)
			}
		},
	}

	resp, err := NewSimpleRequest(server.URL, http.MethodGet).
		SetDialFunc(func(ctx context.Context, network, addr string) (net.Conn, error) {
			var dialer net.Dialer
			return dialer.DialContext(context.Background(), network, addr)
		}).
		SetTraceHooks(hooks).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	if connectStartCount != 1 {
		t.Fatalf("connectStartCount=%d", connectStartCount)
	}
	if connectDoneCount != 1 {
		t.Fatalf("connectDoneCount=%d", connectDoneCount)
	}
}

func TestTraceHooksRetryEvents(t *testing.T) {
	var hits int
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		hits++
		if hits == 1 {
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	var mu sync.Mutex
	starts := 0
	dones := 0
	backoffs := 0
	var finalDone TraceRetryAttemptDoneInfo
	hooks := &TraceHooks{
		RetryAttemptStart: func(info TraceRetryAttemptStartInfo) {
			mu.Lock()
			starts++
			mu.Unlock()
		},
		RetryAttemptDone: func(info TraceRetryAttemptDoneInfo) {
			mu.Lock()
			dones++
			finalDone = info
			mu.Unlock()
		},
		RetryBackoff: func(info TraceRetryBackoffInfo) {
			mu.Lock()
			backoffs++
			mu.Unlock()
		},
	}

	resp, err := NewSimpleRequest(server.URL, http.MethodGet).
		SetRetry(1, WithRetryBackoff(time.Millisecond, time.Millisecond, 1), WithRetryJitter(0)).
		SetTraceHooks(hooks).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	if starts != 2 {
		t.Fatalf("starts=%d", starts)
	}
	if dones != 2 {
		t.Fatalf("dones=%d", dones)
	}
	if backoffs != 1 {
		t.Fatalf("backoffs=%d", backoffs)
	}
	if finalDone.WillRetry {
		t.Fatal("expected final attempt not to retry")
	}
	if finalDone.StatusCode != http.StatusOK {
		t.Fatalf("final status=%d", finalDone.StatusCode)
	}
}

func TestTraceHooksCustomLookupFuncPropagatesDNSError(t *testing.T) {
	var gotErr error
	hooks := &TraceHooks{
		DNSDone: func(info TraceDNSDoneInfo) {
			gotErr = info.Err
		},
	}

	_, err := NewSimpleRequest("http://trace.example.test:80", http.MethodGet).
		SetLookupFunc(func(ctx context.Context, host string) ([]net.IPAddr, error) {
			return nil, errors.New("lookup failed")
		}).
		SetTraceHooks(hooks).
		Do()
	if err == nil {
		t.Fatal("expected request error")
	}
	if gotErr == nil || gotErr.Error() != "lookup failed" {
		t.Fatalf("gotErr=%v", gotErr)
	}
}