package station_test

import (
	"context"
	"net"
	"os"
	"testing"
	"time"

	"gitea.neitzel.de/konrad/funknetz/station"
)

func TestVersionErrorFallsBackWhenTheMaximumIs2(t *testing.T) {
	for _, msg := range []string{
		"Unsupported protocol version 3.0. May be at most 2.0.",
		"Unsupported protocol version 3.0. May be at most 2.5.",
	} {
		t.Run(msg, func(t *testing.T) {
			refl := newReflector(t)
			path := writeConfigFile(t, configJSON(t, "127.0.0.1", refl.port, "DL1ABC", "key", 20))
			clock := newFakeClock()
			st, err := station.New(station.Options{ConfigPath: path, Clock: clock})
			if err != nil {
				t.Fatal(err)
			}
			ctx, cancel := context.WithCancel(t.Context())
			defer cancel()
			go func() {
				// Run's error is observed through State, which is the station seam.
				_ = st.Run(ctx)
			}()
			refl.accept(t)
			typ, body := refl.readFrame(t)
			if typ != 5 || !versionIs(body, 3, 0) {
				t.Fatalf("type %d body %v", typ, body)
			}
			refl.writeFrame(t, 13, appendStr(nil, msg))
			refl.accept(t)
			typ, body = refl.readFrame(t)
			if typ != 5 || !versionIs(body, 2, 0) {
				t.Fatalf("fallback type %d body %v", typ, body)
			}
		})
	}
}

func TestVersionErrorBelow2Stops(t *testing.T) {
	for _, msg := range []string{
		"Unsupported protocol version 3.0. May be at most 1.9.",
		"Unsupported protocol version 3.0. May be at most 0.6.",
	} {
		t.Run(msg, func(t *testing.T) {
			refl := newReflector(t)
			path := writeConfigFile(t, configJSON(t, "127.0.0.1", refl.port, "DL1ABC", "key", 20))
			clock := newFakeClock()
			st, err := station.New(station.Options{ConfigPath: path, Clock: clock})
			if err != nil {
				t.Fatal(err)
			}
			ctx, cancel := context.WithCancel(t.Context())
			defer cancel()
			go func() {
				// Run's error is observed through State, which is the station seam.
				_ = st.Run(ctx)
			}()
			refl.accept(t)
			refl.readFrame(t)
			refl.writeFrame(t, 13, appendStr(nil, msg))
			got, err := st.Wait(ctx, func(s station.State) bool { return s.Detail == msg })
			if err != nil {
				t.Fatal(err)
			}
			if got.Connection != "Disconnected" || got.Protocol != "" {
				t.Fatalf("State = %+v", got)
			}
			clock.Advance(2 * time.Second)
			refl.ln.(*net.TCPListener).SetDeadline(time.Now().Add(150 * time.Millisecond))
			if conn, err := refl.ln.Accept(); err == nil {
				conn.Close()
				t.Fatal("retried")
			}
		})
	}
}

func TestDowngradeOtherThan2Stops(t *testing.T) {
	for _, tc := range []struct {
		major, minor uint16
		want         string
	}{
		{1, 0, "Unsupported protocol version 1.0"},
		{4, 2, "Unsupported protocol version 4.2"},
	} {
		t.Run(tc.want, func(t *testing.T) {
			refl := newReflector(t)
			path := writeConfigFile(t, configJSON(t, "127.0.0.1", refl.port, "DL1ABC", "key", 20))
			clock := newFakeClock()
			st, err := station.New(station.Options{ConfigPath: path, Clock: clock})
			if err != nil {
				t.Fatal(err)
			}
			ctx, cancel := context.WithCancel(t.Context())
			defer cancel()
			go func() {
				// Run's error is observed through State, which is the station seam.
				_ = st.Run(ctx)
			}()
			refl.accept(t)
			refl.readFrame(t)
			refl.writeFrame(t, 6, versionWire(tc.major, tc.minor))
			got, err := st.Wait(ctx, func(s station.State) bool { return s.Detail == tc.want })
			if err != nil {
				t.Fatal(err)
			}
			if got.Protocol != "" || got.Connection != "Disconnected" {
				t.Fatalf("State = %+v", got)
			}
			clock.Advance(2 * time.Second)
			refl.ln.(*net.TCPListener).SetDeadline(time.Now().Add(150 * time.Millisecond))
			if conn, err := refl.ln.Accept(); err == nil {
				conn.Close()
				t.Fatal("retried")
			}
		})
	}
}

func TestDowngradeDoesNotCreateTheCertificateDirectory(t *testing.T) {
	refl := newReflector(t)
	dir := t.TempDir()
	path := dir + "/funknetz.json"
	body := configWithDir(t, "127.0.0.1", refl.port, "DL1ABC", "key", 20, "./funknetz", "")
	if err := os.WriteFile(path, []byte(body), 0o600); err != nil {
		t.Fatal(err)
	}
	clock := newFakeClock()
	st, err := station.New(station.Options{ConfigPath: path, Clock: clock})
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithCancel(t.Context())
	defer cancel()
	go func() {
		// Run's error is observed through State, which is the station seam.
		_ = st.Run(ctx)
	}()
	refl.accept(t)
	declineTo2(t, refl)
	if _, err := os.Stat(dir + "/funknetz"); err == nil {
		t.Fatal("created the certificate directory on a 2.0 fallback")
	}
}