package starnet

import (
	"crypto/tls"
	"net"
	"net/http"
	"strconv"
	"sync"
	"testing"
	"time"
)

func TestTransportDynamicCacheReusesSafeProfile(t *testing.T) {
	transport := &Transport{base: newBaseHTTPTransport()}

	first := transport.getDynamicTransport(&RequestContext{
		Proxy:         "http://127.0.0.1:8080",
		DialTimeout:   2 * time.Second,
		CustomIP:      []string{"127.0.0.1"},
		TLSServerName: "cache.test",
	}, nil)
	second := transport.getDynamicTransport(&RequestContext{
		Proxy:         "http://127.0.0.1:8080",
		DialTimeout:   2 * time.Second,
		CustomIP:      []string{"127.0.0.1"},
		TLSServerName: "cache.test",
	}, nil)

	if first != second {
		t.Fatal("expected cached dynamic transport to be reused")
	}
	if got := len(transport.dynamicCache); got != 1 {
		t.Fatalf("dynamic cache size=%d; want 1", got)
	}
}

func TestTransportDynamicCacheSeparatesTLSServerName(t *testing.T) {
	transport := &Transport{base: newBaseHTTPTransport()}

	first := transport.getDynamicTransport(&RequestContext{
		CustomIP:      []string{"127.0.0.1"},
		TLSServerName: "first.test",
	}, nil)
	second := transport.getDynamicTransport(&RequestContext{
		CustomIP:      []string{"127.0.0.1"},
		TLSServerName: "second.test",
	}, nil)

	if first == second {
		t.Fatal("expected distinct tls server names to use different transports")
	}
	if got := len(transport.dynamicCache); got != 2 {
		t.Fatalf("dynamic cache size=%d; want 2", got)
	}
}

func TestTransportDynamicCacheSkipsUserTLSConfig(t *testing.T) {
	transport := &Transport{base: newBaseHTTPTransport()}
	reqCtx := &RequestContext{
		CustomIP:  []string{"127.0.0.1"},
		TLSConfig: &tls.Config{InsecureSkipVerify: true},
	}

	first := transport.getDynamicTransport(reqCtx, nil)
	second := transport.getDynamicTransport(reqCtx, nil)

	if first == second {
		t.Fatal("expected user tls config to bypass dynamic transport cache")
	}
	if got := len(transport.dynamicCache); got != 0 {
		t.Fatalf("dynamic cache size=%d; want 0", got)
	}
}

func TestTransportDynamicCacheResetOnDefaultTLSChange(t *testing.T) {
	client := NewClientNoErr()
	transport, ok := client.HTTPClient().Transport.(*Transport)
	if !ok {
		t.Fatalf("transport type=%T; want *Transport", client.HTTPClient().Transport)
	}

	reqCtx := &RequestContext{CustomIP: []string{"127.0.0.1"}}
	first := transport.getDynamicTransport(reqCtx, nil)
	if got := len(transport.dynamicCache); got != 1 {
		t.Fatalf("dynamic cache size=%d; want 1 before reset", got)
	}

	client.SetDefaultSkipTLSVerify(true)
	if got := len(transport.dynamicCache); got != 0 {
		t.Fatalf("dynamic cache size=%d; want 0 after reset", got)
	}

	second := transport.getDynamicTransport(reqCtx, nil)
	if first == second {
		t.Fatal("expected cache reset after default tls change")
	}
}

func TestDynamicTransportCacheReusesConnectionForCustomIP(t *testing.T) {
	server := newIPv4Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	}))
	defer server.Close()

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

	client := NewClientNoErr()
	targetURL := "http://cache-reuse.test:" + strconv.Itoa(addr.Port)

	runRequest := func() bool {
		var (
			mu      sync.Mutex
			gotConn bool
			reused  bool
		)

		resp, err := client.NewSimpleRequest(targetURL, http.MethodGet).
			SetCustomIP([]string{"127.0.0.1"}).
			SetTraceHooks(&TraceHooks{
				GotConn: func(info TraceGotConnInfo) {
					mu.Lock()
					gotConn = true
					reused = info.Reused
					mu.Unlock()
				},
			}).
			Do()
		if err != nil {
			t.Fatalf("Do() error: %v", err)
		}
		defer resp.Close()

		if _, err := resp.Body().Bytes(); err != nil {
			t.Fatalf("Body().Bytes() error: %v", err)
		}

		mu.Lock()
		defer mu.Unlock()
		if !gotConn {
			t.Fatal("expected GotConn trace event")
		}
		return reused
	}

	if runRequest() {
		t.Fatal("first request unexpectedly reused a connection")
	}
	if !runRequest() {
		t.Fatal("second request did not reuse cached dynamic transport connection")
	}

	transport, ok := client.HTTPClient().Transport.(*Transport)
	if !ok {
		t.Fatalf("transport type=%T; want *Transport", client.HTTPClient().Transport)
	}
	if got := len(transport.dynamicCache); got != 1 {
		t.Fatalf("dynamic cache size=%d; want 1", got)
	}
}

func TestPrepareProxyTargetRequestSingleTargetRewritesExecRequest(t *testing.T) {
	req, err := http.NewRequest(http.MethodGet, "https://proxy-single.test:8443/path", nil)
	if err != nil {
		t.Fatalf("http.NewRequest() error: %v", err)
	}
	req.Host = req.URL.Host

	execReq, execReqCtx, targetAddrs, err := prepareProxyTargetRequest(req, &RequestContext{
		Proxy:    "http://127.0.0.1:8080",
		CustomIP: []string{"127.0.0.1"},
	}, nil)
	if err != nil {
		t.Fatalf("prepareProxyTargetRequest() error: %v", err)
	}

	if execReq == req {
		t.Fatal("expected cloned request for proxy target preparation")
	}
	if got := execReq.URL.Host; got != "127.0.0.1:8443" {
		t.Fatalf("execReq.URL.Host=%q; want %q", got, "127.0.0.1:8443")
	}
	if got := req.URL.Host; got != "proxy-single.test:8443" {
		t.Fatalf("original req.URL.Host=%q; want %q", got, "proxy-single.test:8443")
	}
	if len(targetAddrs) != 0 {
		t.Fatalf("targetAddrs=%v; want empty after single target rewrite", targetAddrs)
	}
	if execReqCtx == nil || execReqCtx.TLSConfig == nil {
		t.Fatal("expected synthesized tls config for single target proxy request")
	}
	if got := execReqCtx.TLSConfig.ServerName; got != "proxy-single.test" {
		t.Fatalf("tls server name=%q; want %q", got, "proxy-single.test")
	}
}

func TestPrepareProxyTargetRequestMultiTargetPreservesFallbackList(t *testing.T) {
	req, err := http.NewRequest(http.MethodGet, "https://proxy-multi.test:9443/path", nil)
	if err != nil {
		t.Fatalf("http.NewRequest() error: %v", err)
	}
	req.Host = req.URL.Host

	execReq, _, targetAddrs, err := prepareProxyTargetRequest(req, &RequestContext{
		Proxy:    "http://127.0.0.1:8080",
		CustomIP: []string{"127.0.0.1", "127.0.0.2"},
	}, nil)
	if err != nil {
		t.Fatalf("prepareProxyTargetRequest() error: %v", err)
	}

	if got := execReq.URL.Host; got != "proxy-multi.test:9443" {
		t.Fatalf("execReq.URL.Host=%q; want original host", got)
	}
	if len(targetAddrs) != 2 {
		t.Fatalf("targetAddrs=%v; want 2 targets", targetAddrs)
	}
	if targetAddrs[0] != "127.0.0.1:9443" || targetAddrs[1] != "127.0.0.2:9443" {
		t.Fatalf("targetAddrs=%v; want ordered fallback targets", targetAddrs)
	}
}