package starnet

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

func TestRequestProxyWithCustomIPFallbackTriesNextResolvedTarget(t *testing.T) {
	tlsServer := newIPv4TLSServer(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer tlsServer.Close()

	_, port, err := net.SplitHostPort(tlsServer.Listener.Addr().String())
	if err != nil {
		t.Fatalf("split tls server addr: %v", err)
	}

	firstTarget := net.JoinHostPort("127.0.0.2", port)
	secondTarget := net.JoinHostPort("127.0.0.1", port)

	var (
		mu             sync.Mutex
		connectTargets []string
	)
	proxyServer := newIPv4Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodConnect {
			http.Error(w, "connect required", http.StatusMethodNotAllowed)
			return
		}

		mu.Lock()
		connectTargets = append(connectTargets, r.Host)
		mu.Unlock()

		if r.Host == firstTarget {
			http.Error(w, "first target failed", http.StatusBadGateway)
			return
		}

		targetConn, err := net.Dial("tcp", r.Host)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadGateway)
			return
		}

		hijacker, ok := w.(http.Hijacker)
		if !ok {
			targetConn.Close()
			t.Fatal("proxy response writer is not a hijacker")
		}

		clientConn, rw, err := hijacker.Hijack()
		if err != nil {
			targetConn.Close()
			t.Fatalf("hijack proxy conn: %v", err)
		}
		if _, err := rw.WriteString("HTTP/1.1 200 Connection Established\r\n\r\n"); err != nil {
			clientConn.Close()
			targetConn.Close()
			t.Fatalf("write connect response: %v", err)
		}
		if err := rw.Flush(); err != nil {
			clientConn.Close()
			targetConn.Close()
			t.Fatalf("flush connect response: %v", err)
		}

		relayProxyConns(clientConn, targetConn)
	}))
	defer proxyServer.Close()

	reqURL := fmt.Sprintf("https://proxy-fallback.test:%s", port)
	resp, err := NewSimpleRequest(reqURL, http.MethodGet).
		SetProxy(proxyServer.URL).
		SetCustomIP([]string{"127.0.0.2", "127.0.0.1"}).
		SetSkipTLSVerify(true).
		Do()
	if err != nil {
		t.Fatalf("Do() error: %v", err)
	}
	defer resp.Close()

	mu.Lock()
	defer mu.Unlock()
	if len(connectTargets) != 2 {
		t.Fatalf("connect target attempts=%d; want 2 (%v)", len(connectTargets), connectTargets)
	}
	if connectTargets[0] != firstTarget {
		t.Fatalf("first connect target=%q; want %q", connectTargets[0], firstTarget)
	}
	if connectTargets[1] != secondTarget {
		t.Fatalf("second connect target=%q; want %q", connectTargets[1], secondTarget)
	}
}

func TestTraceHooksDefaultResolverEmitsDNSEvents(t *testing.T) {
	server := newIPv4Server(t, 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 int
		dnsDoneCount  int
		lastHost      string
	)
	hooks := &TraceHooks{
		DNSStart: func(info TraceDNSStartInfo) {
			mu.Lock()
			dnsStartCount++
			lastHost = 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)
			}
		},
	}

	reqURL := "http://localhost:" + strconv.Itoa(addr.Port)
	resp, err := NewSimpleRequest(reqURL, http.MethodGet).
		SetDialTimeout(DefaultDialTimeout + 200*time.Millisecond).
		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 lastHost != "localhost" {
		t.Fatalf("lastHost=%q; want localhost", lastHost)
	}
}

func TestRequestHeadersReturnsCopy(t *testing.T) {
	req := NewSimpleRequest("http://example.com", http.MethodGet).
		SetHeader("X-Test", "one").
		SetHost("origin.example")

	headers := req.Headers()
	headers.Set("X-Test", "two")
	headers.Set("Host", "mutated.example")

	if got := req.GetHeader("X-Test"); got != "one" {
		t.Fatalf("request header=%q; want one", got)
	}
	if got := req.Host(); got != "origin.example" {
		t.Fatalf("request host=%q; want origin.example", got)
	}
}

func TestRequestCookiesIsolation(t *testing.T) {
	req := NewSimpleRequest("http://example.com", http.MethodGet)
	source := []*http.Cookie{{
		Name:  "session",
		Value: "one",
		Path:  "/",
	}}

	req.SetCookies(source)
	source[0].Value = "mutated-outside"

	got := req.Cookies()
	if len(got) != 1 || got[0].Value != "one" {
		t.Fatalf("cookies after SetCookies=%v", got)
	}

	got[0].Value = "mutated-copy"
	if latest := req.Cookies()[0].Value; latest != "one" {
		t.Fatalf("internal cookie mutated via getter, got %q", latest)
	}

	cookie := &http.Cookie{Name: "auth", Value: "token"}
	req.ResetCookies().AddCookie(cookie)
	cookie.Value = "changed"

	latest := req.Cookies()
	if len(latest) != 1 || latest[0].Value != "token" {
		t.Fatalf("cookies after AddCookie=%v", latest)
	}
}

func TestTraceHooksLookupFuncStillEmitsDNSEvents(t *testing.T) {
	server := newIPv4Server(t, 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 dnsStartCount int
	var dnsDoneCount int
	hooks := &TraceHooks{
		DNSStart: func(info TraceDNSStartInfo) {
			dnsStartCount++
		},
		DNSDone: func(info TraceDNSDoneInfo) {
			dnsDoneCount++
		},
	}

	resp, err := NewSimpleRequest("http://lookup-copy.test:"+strconv.Itoa(addr.Port), 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()

	if dnsStartCount != 1 || dnsDoneCount != 1 {
		t.Fatalf("dns trace counts start=%d done=%d", dnsStartCount, dnsDoneCount)
	}
}