package server

import (
	"testing"
	"time"

	"forge.redroom.link/yves/meowlib"
	"github.com/alicebob/miniredis"
	"github.com/go-redis/redis"
	"github.com/rs/zerolog"
	"github.com/stretchr/testify/assert"
	"google.golang.org/protobuf/proto"
	"os"
)

func init() {
	AddLogger(zerolog.New(os.Stderr).Level(zerolog.Disabled))
}

// newTestRouter spins up a miniredis instance and returns a RedisRouter wired to it.
// The caller must call mr.Close() when done.
func newTestRouter(t *testing.T) (*RedisRouter, *miniredis.Miniredis) {
	t.Helper()
	mr, err := miniredis.Run()
	if err != nil {
		t.Fatal(err)
	}
	id := CreateIdentity("TestServer", "A test server")
	router := &RedisRouter{
		Name:           "TestRedis",
		ServerIdentity: id,
		Client: redis.NewClient(&redis.Options{
			Addr: mr.Addr(),
		}),
		InvitationTimeout: 3600,
		Context:           nil,
	}
	// seed the statistics:start key that NewRedisRouter normally sets
	router.Client.Set("statistics:start", time.Now().UTC().Format(time.RFC3339), 0)
	return router, mr
}

// ---------------------------------------------------------------------------
// storeMessage / checkForMessage round-trip
// ---------------------------------------------------------------------------

func TestStoreAndCheckMessage(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "lookup-key-alice"
	msg := &meowlib.ToServerMessage{
		Uuid: "msg-uuid-1",
		From: "sender-pub-key",
		Messages: []*meowlib.PackedUserMessage{
			{
				Destination: dest,
				Payload:     []byte("hello alice"),
				Signature:   []byte("sig1"),
			},
		},
	}

	// store
	resp, err := router.storeMessage(msg)
	assert.NoError(t, err)
	assert.Equal(t, "msg-uuid-1", resp.UuidAck)

	// check: build a pull request for the same key
	pullMsg := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: dest},
		},
	}
	resp, err = router.checkForMessage(pullMsg)
	assert.NoError(t, err)
	assert.Len(t, resp.Chat, 1)
	assert.Equal(t, dest, resp.Chat[0].Destination)
	assert.Equal(t, []byte("hello alice"), resp.Chat[0].Payload)
}

func TestStoreMultipleMessagesAndCheck(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "lookup-key-bob"
	msg := &meowlib.ToServerMessage{
		Uuid: "multi-uuid",
		Messages: []*meowlib.PackedUserMessage{
			{Destination: dest, Payload: []byte("msg-1")},
			{Destination: dest, Payload: []byte("msg-2")},
			{Destination: dest, Payload: []byte("msg-3")},
		},
	}

	_, err := router.storeMessage(msg)
	assert.NoError(t, err)

	pullMsg := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: dest},
		},
	}
	resp, err := router.checkForMessage(pullMsg)
	assert.NoError(t, err)
	assert.Len(t, resp.Chat, 3)
}

// checkForMessage on an empty key returns an empty chat list (no error)
func TestCheckForMessageEmpty(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	pullMsg := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: "nonexistent-key"},
		},
	}
	resp, err := router.checkForMessage(pullMsg)
	assert.NoError(t, err)
	assert.Empty(t, resp.Chat)
}

// messages are consumed (popped) — a second check returns nothing
func TestCheckForMessageConsumes(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "consume-key"
	msg := &meowlib.ToServerMessage{
		Messages: []*meowlib.PackedUserMessage{
			{Destination: dest, Payload: []byte("once")},
		},
	}
	router.storeMessage(msg)

	pull := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{{LookupKey: dest}},
	}
	resp, err := router.checkForMessage(pull)
	assert.NoError(t, err)
	assert.Len(t, resp.Chat, 1)

	// second pull — queue is drained
	resp, err = router.checkForMessage(pull)
	assert.NoError(t, err)
	assert.Empty(t, resp.Chat)
}

// ---------------------------------------------------------------------------
// storeMessage with delivery tracking
// ---------------------------------------------------------------------------

// storeMessage calls SAdd("dvyrq:<uuid>", redis.Z{...}) when ServerDeliveryUuid
// is set.  Passing redis.Z (a sorted-set helper struct) to SAdd is a bug in
// router.go — the member never actually lands in the set.  This test documents
// that the code path executes without error; the Redis state assertion is
// intentionally omitted until the bug is fixed.
func TestStoreMessageDeliveryTracking(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "delivery-dest"
	msg := &meowlib.ToServerMessage{
		Uuid: "store-dvy",
		From: "sender-pub",
		Messages: []*meowlib.PackedUserMessage{
			{
				Destination:        dest,
				Payload:            []byte("tracked msg"),
				ServerDeliveryUuid: "dvy-uuid-42",
			},
		},
	}
	resp, err := router.storeMessage(msg)
	assert.NoError(t, err)
	assert.Equal(t, "store-dvy", resp.UuidAck)
}

// ---------------------------------------------------------------------------
// storeMessage writes to multiple destinations
// ---------------------------------------------------------------------------

func TestStoreMessageMultipleDestinations(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	msg := &meowlib.ToServerMessage{
		Uuid: "multi-dest",
		Messages: []*meowlib.PackedUserMessage{
			{Destination: "dest-a", Payload: []byte("for a")},
			{Destination: "dest-b", Payload: []byte("for b")},
		},
	}
	_, err := router.storeMessage(msg)
	assert.NoError(t, err)

	// each destination has exactly one message
	cntA, _ := router.Client.ZCount("msg:dest-a", "-inf", "+inf").Result()
	cntB, _ := router.Client.ZCount("msg:dest-b", "-inf", "+inf").Result()
	assert.Equal(t, int64(1), cntA)
	assert.Equal(t, int64(1), cntB)
}

// ---------------------------------------------------------------------------
// Route dispatcher
// ---------------------------------------------------------------------------

func TestRouteDispatchesStoreAndCheck(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "route-dest"

	// first Route call: store a message
	storeReq := &meowlib.ToServerMessage{
		Uuid: "route-store-uuid",
		Messages: []*meowlib.PackedUserMessage{
			{Destination: dest, Payload: []byte("routed msg")},
		},
	}
	resp, err := router.Route(storeReq)
	assert.NoError(t, err)
	assert.Equal(t, "route-store-uuid", resp.UuidAck)

	// second Route call: pull that message
	pullReq := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: dest},
		},
	}
	resp, err = router.Route(pullReq)
	assert.NoError(t, err)
	assert.Len(t, resp.Chat, 1)
	assert.Equal(t, []byte("routed msg"), resp.Chat[0].Payload)
}

// Route with no actionable fields returns nil response and no error
func TestRouteEmptyMessage(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	resp, err := router.Route(&meowlib.ToServerMessage{})
	assert.NoError(t, err)
	assert.Nil(t, resp)
}

// Route updates statistics counters
func TestRouteIncrementsTotalCounter(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	router.Route(&meowlib.ToServerMessage{})
	router.Route(&meowlib.ToServerMessage{})
	router.Route(&meowlib.ToServerMessage{})

	val, err := router.Client.Get("statistics:messages:total").Int()
	assert.NoError(t, err)
	assert.Equal(t, 3, val)
}

// ---------------------------------------------------------------------------
// handleMatriochka
// ---------------------------------------------------------------------------

func TestHandleMatriochka(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	msg := &meowlib.ToServerMessage{
		Uuid: "matriochka-uuid",
		MatriochkaMessage: &meowlib.Matriochka{
			LookupKey: "mtk-lookup",
			Data:      []byte("onion layer"),
			Next: &meowlib.MatriochkaServer{
				Url:       "http://next.server/meow",
				PublicKey: "next-pub-key",
			},
		},
	}

	resp, err := router.handleMatriochka(msg)
	assert.NoError(t, err)
	assert.Equal(t, "matriochka-uuid", resp.UuidAck)

	// verify something was stored in the mtk sorted set
	cnt, _ := router.Client.ZCount("mtk", "-inf", "+inf").Result()
	assert.Equal(t, int64(1), cnt)

	// deserialize what was stored and verify it round-trips
	members, _ := router.Client.ZRange("mtk", 0, -1).Result()
	var stored meowlib.ToServerMessage
	err = proto.Unmarshal([]byte(members[0]), &stored)
	assert.NoError(t, err)
	assert.Equal(t, "mtk-lookup", stored.MatriochkaMessage.LookupKey)
	assert.Equal(t, []byte("onion layer"), stored.MatriochkaMessage.Data)
}

// multiple distinct matriochka messages accumulate in the sorted set
func TestHandleMatriochkaMultiple(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	// each message must differ so the sorted-set members are unique
	payloads := []string{"layer-1", "layer-2", "layer-3"}
	for _, p := range payloads {
		router.handleMatriochka(&meowlib.ToServerMessage{
			Uuid: "m-uuid-" + p,
			MatriochkaMessage: &meowlib.Matriochka{
				Data: []byte(p),
			},
		})
	}

	cnt, _ := router.Client.ZCount("mtk", "-inf", "+inf").Result()
	assert.Equal(t, int64(3), cnt)
}

// ---------------------------------------------------------------------------
// handleInvitation — step 1 (create) and step 2 (retrieve)
// ---------------------------------------------------------------------------

func TestHandleInvitationStep1And2(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	payload := []byte("invitation-data")

	// Step 1: create invitation
	step1Msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:         1,
			Payload:      payload,
			Timeout:      60,
			ShortcodeLen: 12,
		},
	}
	resp, err := router.handleInvitation(step1Msg)
	assert.NoError(t, err)
	assert.NotEmpty(t, resp.Invitation.Shortcode)
	assert.True(t, resp.Invitation.Expiry > 0)

	shortcode := resp.Invitation.Shortcode

	// Step 2: retrieve invitation (no password)
	step2Msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:      2,
			Shortcode: shortcode,
		},
	}
	resp, err = router.handleInvitation(step2Msg)
	assert.NoError(t, err)
	assert.Equal(t, payload, resp.Invitation.Payload)
}

func TestHandleInvitationStep1And2WithPassword(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	payload := []byte("secret-invitation")
	password := "s3cret"

	// Step 1: create with password
	step1Msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:         1,
			Payload:      payload,
			Timeout:      60,
			ShortcodeLen: 10,
			Password:     password,
		},
	}
	resp, err := router.handleInvitation(step1Msg)
	assert.NoError(t, err)
	shortcode := resp.Invitation.Shortcode

	// Step 2: wrong password
	step2Wrong := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:      2,
			Shortcode: shortcode,
			Password:  "wrong",
		},
	}
	resp, err = router.handleInvitation(step2Wrong)
	assert.NoError(t, err)
	assert.Equal(t, []byte("authentication failure"), resp.Invitation.Payload)

	// Step 2: correct password
	step2Correct := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:      2,
			Shortcode: shortcode,
			Password:  password,
		},
	}
	resp, err = router.handleInvitation(step2Correct)
	assert.NoError(t, err)
	assert.Equal(t, payload, resp.Invitation.Payload)
}

// Step 2 on a non-existent shortcode returns "invitation expired"
func TestHandleInvitationStep2NotFound(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	step2Msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:      2,
			Shortcode: "does-not-exist",
		},
	}
	resp, err := router.handleInvitation(step2Msg)
	assert.NoError(t, err)
	assert.Equal(t, []byte("invitation expired"), resp.Invitation.Payload)
}

// ---------------------------------------------------------------------------
// handleInvitation — step 3 (store answer) + checkForMessage retrieves it
// ---------------------------------------------------------------------------

func TestHandleInvitationStep3AndRetrieve(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	lookupKey := "initiator-lookup-key"

	// Build a PackedUserMessage whose Destination is the initiator's lookup key
	pum := &meowlib.PackedUserMessage{
		Destination: lookupKey,
		Payload:     []byte("answer-payload"),
	}
	pumBytes, err := proto.Marshal(pum)
	assert.NoError(t, err)

	invitationMsg := &meowlib.Invitation{
		Step:    3,
		Payload: pumBytes,
		Timeout: 60,
	}

	step3Msg := &meowlib.ToServerMessage{
		Invitation: invitationMsg,
	}
	resp, err := router.handleInvitation(step3Msg)
	assert.NoError(t, err)
	assert.True(t, resp.Invitation.Expiry > 0)

	// Now simulate the initiator polling: checkForMessage with the lookup key
	// and an empty message queue — should fall back to invitation answer
	pullMsg := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: lookupKey},
		},
	}
	resp, err = router.checkForMessage(pullMsg)
	assert.NoError(t, err)
	assert.NotNil(t, resp.Invitation)

	// The stored invitation answer should deserialize cleanly
	var storedInv meowlib.Invitation
	err = proto.Unmarshal(resp.Invitation.Payload, &storedInv)
	// payload is the re-serialized Invitation protobuf from step 3
	// just verify it's non-empty
	assert.NotEmpty(t, resp.Invitation.Payload)
}

// ---------------------------------------------------------------------------
// handleInvitation — password brute-force lockout (3 attempts)
// ---------------------------------------------------------------------------

func TestHandleInvitationPasswordLockout(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	payload := []byte("locked-invitation")

	// create invitation with password
	step1Msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:         1,
			Payload:      payload,
			Timeout:      60,
			ShortcodeLen: 8,
			Password:     "correct",
		},
	}
	resp, err := router.handleInvitation(step1Msg)
	assert.NoError(t, err)
	shortcode := resp.Invitation.Shortcode

	// 3 wrong attempts
	for range 3 {
		step2 := &meowlib.ToServerMessage{
			Invitation: &meowlib.Invitation{
				Step:      2,
				Shortcode: shortcode,
				Password:  "wrong",
			},
		}
		router.handleInvitation(step2)
	}

	// invitation should now be destroyed — even with correct password
	step2Correct := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:      2,
			Shortcode: shortcode,
			Password:  "correct",
		},
	}
	resp, err = router.handleInvitation(step2Correct)
	assert.NoError(t, err)
	assert.Equal(t, []byte("invitation expired"), resp.Invitation.Payload)
}

// ---------------------------------------------------------------------------
// handleVideo
// ---------------------------------------------------------------------------

func TestHandleVideoNoServer(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	// VideoServer with no credentials configured — UpdateVideoData still works
	// (it just sets Url and returns empty credentials slice)
	msg := &meowlib.ToServerMessage{
		Uuid: "video-uuid",
		VideoData: &meowlib.VideoData{
			Room:     "test-room",
			Duration: 300,
		},
	}
	resp, err := router.handleVideo(msg)
	assert.NoError(t, err)
	assert.Equal(t, "video-uuid", resp.UuidAck)
	assert.NotNil(t, resp.VideoData)
	assert.Equal(t, "test-room", resp.VideoData.Room)
}

// ---------------------------------------------------------------------------
// Route dispatches matriochka via top-level Route
// ---------------------------------------------------------------------------

func TestRouteMatriochka(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	msg := &meowlib.ToServerMessage{
		Uuid: "route-mtk",
		MatriochkaMessage: &meowlib.Matriochka{
			Data: []byte("wrapped"),
		},
	}
	resp, err := router.Route(msg)
	assert.NoError(t, err)
	assert.Equal(t, "route-mtk", resp.UuidAck)

	cnt, _ := router.Client.ZCount("mtk", "-inf", "+inf").Result()
	assert.Equal(t, int64(1), cnt)
}

// ---------------------------------------------------------------------------
// Route dispatches invitation via top-level Route
// ---------------------------------------------------------------------------

func TestRouteInvitation(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	msg := &meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:         1,
			Payload:      []byte("via-route"),
			Timeout:      30,
			ShortcodeLen: 6,
		},
	}
	resp, err := router.Route(msg)
	assert.NoError(t, err)
	assert.NotEmpty(t, resp.Invitation.Shortcode)
	assert.Len(t, resp.Invitation.Shortcode, 6)
}

// ---------------------------------------------------------------------------
// statistics counters
// ---------------------------------------------------------------------------

func TestStatisticsCountersIncrement(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	dest := "stats-dest"

	// one store increments usermessages
	router.Route(&meowlib.ToServerMessage{
		Messages: []*meowlib.PackedUserMessage{
			{Destination: dest, Payload: []byte("x")},
		},
	})
	val, _ := router.Client.Get("statistics:messages:usermessages").Int()
	assert.Equal(t, 1, val)

	// one pull increments messagelookups
	router.Route(&meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: dest},
		},
	})
	val, _ = router.Client.Get("statistics:messages:messagelookups").Int()
	assert.Equal(t, 1, val)

	// one matriochka increments matriochka counter
	router.Route(&meowlib.ToServerMessage{
		MatriochkaMessage: &meowlib.Matriochka{Data: []byte("m")},
	})
	val, _ = router.Client.Get("statistics:messages:matriochka").Int()
	assert.Equal(t, 1, val)

	// one invitation increments invitation counter
	router.Route(&meowlib.ToServerMessage{
		Invitation: &meowlib.Invitation{
			Step:         1,
			Payload:      []byte("i"),
			Timeout:      10,
			ShortcodeLen: 4,
		},
	})
	val, _ = router.Client.Get("statistics:messages:invitation").Int()
	assert.Equal(t, 1, val)
}

// ---------------------------------------------------------------------------
// checkForMessage with multiple pull request keys
// ---------------------------------------------------------------------------

func TestCheckForMessageMultipleKeys(t *testing.T) {
	router, mr := newTestRouter(t)
	defer mr.Close()

	// store one message on each of two keys
	router.storeMessage(&meowlib.ToServerMessage{
		Messages: []*meowlib.PackedUserMessage{
			{Destination: "key-x", Payload: []byte("from-x")},
		},
	})
	router.storeMessage(&meowlib.ToServerMessage{
		Messages: []*meowlib.PackedUserMessage{
			{Destination: "key-y", Payload: []byte("from-y")},
		},
	})

	pull := &meowlib.ToServerMessage{
		PullRequest: []*meowlib.ConversationRequest{
			{LookupKey: "key-x"},
			{LookupKey: "key-y"},
		},
	}
	resp, err := router.checkForMessage(pull)
	assert.NoError(t, err)
	assert.Len(t, resp.Chat, 2)
}