package web_test

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"code.severnaya.net/kordophone-mock/v2/data"
	"code.severnaya.net/kordophone-mock/v2/model"
	"code.severnaya.net/kordophone-mock/v2/server"
	"code.severnaya.net/kordophone-mock/v2/web"
	"golang.org/x/net/websocket"
)

func TestVersion(t *testing.T) {
	s := httptest.NewServer(web.NewMockHTTPServer(web.MockHTTPServerConfiguration{}))

	resp, err := http.Get(s.URL + "/version")
	if err != nil {
		t.Fatalf("TestVersion error: %s", err)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	if string(body) != server.VERSION {
		t.Fatalf("Unexpected return value: %s (expected %s)", body, "1.0")
	}
}

func TestStatus(t *testing.T) {
	s := httptest.NewServer(web.NewMockHTTPServer(web.MockHTTPServerConfiguration{}))

	resp, err := http.Get(s.URL + "/status")
	if err != nil {
		t.Fatalf("TestStatus error: %s", err)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	if string(body) != "OK" {
		t.Fatalf("Unexpected return value: %s (expected %s)", body, "OK")
	}
}

func TestConversations(t *testing.T) {
	server := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{})
	httpServer := httptest.NewServer(server)

	conversation := model.Conversation{
		Date:               time.Now(),
		Participants:       []string{"Alice", "Bob"},
		UnreadCount:        1,
		LastMessagePreview: "Hello world",
		Guid:               "1234567890",
	}

	server.Server.AddConversation(conversation)

	resp, err := http.Get(httpServer.URL + "/conversations")
	if err != nil {
		t.Fatalf("TestConversations error: %s", err)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	var convos []model.Conversation
	err = json.Unmarshal(body, &convos)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s", err)
	}

	if len(convos) != 1 {
		t.Fatalf("Unexpected number of conversations: %d (expected %d)", len(convos), 1)
	}

	testConversation := &convos[0]
	if testConversation.Equal(&conversation) != true {
		t.Fatalf("Unexpected conversation: %v (expected %v)", convos[0], conversation)
	}
}

func TestMessages(t *testing.T) {
	server := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{})
	httpServer := httptest.NewServer(server)

	const sender = "Alice"
	const text = "This is a test."

	conversation := model.Conversation{
		Date:         time.Now(),
		Participants: []string{sender},
		UnreadCount:  1,
		Guid:         "1234567890",
	}

	server.Server.AddConversation(conversation)

	message := model.Message{
		Text:   text,
		Sender: &conversation.Participants[0],
		Date:   time.Now(),
	}

	server.Server.AppendMessageToConversation(&conversation, message)

	resp, err := http.Get(httpServer.URL + "/messages?guid=" + *&conversation.Guid)
	if err != nil {
		t.Fatalf("TestMessages error: %s", err)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	var messages []model.Message
	err = json.Unmarshal(body, &messages)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s", err)
	}

	if len(messages) != 1 {
		t.Fatalf("Unexpected num messages: %d (expected %d)", len(messages), 1)
	}

	fetchedMessage := messages[0]
	if fetchedMessage.Text != message.Text {
		t.Fatalf("Unexpected message text: %s (expected %s)", fetchedMessage.Text, message.Text)
	}

	if *fetchedMessage.Sender != *message.Sender {
		t.Fatalf("Unexpected message sender: %s (expected %s)", *fetchedMessage.Sender, *message.Sender)
	}
}

func TestAuthentication(t *testing.T) {
	s := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{AuthEnabled: true})
	httpServer := httptest.NewServer(s)

	// First, try authenticated request and make sure it fails
	resp, err := http.Get(httpServer.URL + "/status")
	if err != nil {
		t.Fatalf("TestAuthentication status error: %s", err)
	}

	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusUnauthorized)
	}

	tryAuthenticate := func(username string, password string) *http.Response {
		authRequest := web.AuthenticationRequest{
			Username: username,
			Password: password,
		}

		authRequestJSON, err := json.Marshal(authRequest)
		if err != nil {
			t.Fatalf("Error marshalling JSON: %s", err)
		}

		resp, err := http.Post(httpServer.URL+"/authenticate", "application/json", io.NopCloser(bytes.NewReader(authRequestJSON)))
		if err != nil {
			t.Fatalf("TestAuthentication error: %s", err)
		}

		return resp
	}

	// Send authentication request with bad credentials
	resp = tryAuthenticate("bad", "credentials")
	if resp.StatusCode == http.StatusOK {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusUnauthorized)
	}

	// Now try good credentials
	resp = tryAuthenticate(server.AUTH_USERNAME, server.AUTH_PASSWORD)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusOK)
	}

	// Decode the token from the body.
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	var authToken model.AuthToken
	err = json.Unmarshal(body, &authToken)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s, body: %s", err, body)
	}

	if authToken.SignedToken == "" {
		t.Fatalf("Unexpected empty signed token")
	}

	// Send a request with the signed token
	req, err := http.NewRequest(http.MethodGet, httpServer.URL+"/status", nil)
	if err != nil {
		t.Fatalf("Error creating request: %s", err)
	}

	req.Header.Set("Authorization", "Bearer "+authToken.SignedToken)

	resp, err = http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("Error sending request: %s", err)
	}

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusUnauthorized)
	}

	body, err = io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	if string(body) != "OK" {
		t.Fatalf("Unexpected body: %s (expected %s)", body, "OK")
	}
}

func TestUpdates(t *testing.T) {
	s := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{AuthEnabled: true})
	httpServer := httptest.NewServer(s)

	messageSeq := 0

	// Mock conversation
	guid := "1234567890"
	conversation := model.Conversation{
		Date:         time.Now(),
		Participants: []string{"Alice"},
		UnreadCount:  0,
		Guid:         guid,
	}
	s.Server.AddConversation(conversation)

	// Receive a message
	message := model.Message{
		Text:   "This is a test.",
		Sender: &conversation.Participants[0],
		Date:   time.Now(),
	}

	// This should enqueue an update item
	s.Server.ReceiveMessage(&conversation, message)

	resp, err := http.Get(httpServer.URL + fmt.Sprintf("/pollUpdates?seq=%d", messageSeq))
	if err != nil {
		t.Fatalf("TestUpdates error: %s", err)
	}

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusOK)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	var updates []model.UpdateItem
	err = json.Unmarshal(body, &updates)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s", err)
	}

	if len(updates) != 1 {
		t.Fatalf("Unexpected num updates: %d (expected %d)", len(updates), 1)
	}

	update := updates[0]

	// Message seq should be >= messageSeq
	messageSeq = update.MessageSequenceNumber
	if messageSeq != 1 {
		t.Fatalf("Unexpected message seq: %d (expected >= 0)", messageSeq)
	}

	if update.Conversation.Guid != conversation.Guid {
		t.Fatalf("Unexpected conversation guid: %s (expected %s)", update.Conversation.Guid, conversation.Guid)
	}

	if update.Message.Text != message.Text {
		t.Fatalf("Unexpected message text: %s (expected %s)", update.Message.Text, message.Text)
	}
}

type MessageUpdateError struct {
	Message string
}

func (e MessageUpdateError) Error() string {
	return e.Message
}

func TestUpdatesWebsocket(t *testing.T) {
	s := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{AuthEnabled: true})
	httpServer := httptest.NewServer(s)

	// Mock conversation
	guid := "1234567890"
	conversation := model.Conversation{
		Date:         time.Now(),
		Participants: []string{"Alice"},
		UnreadCount:  0,
		Guid:         guid,
	}
	s.Server.AddConversation(conversation)

	// Receive a message
	message := model.Message{
		Text:   "This is a test.",
		Sender: &conversation.Participants[0],
		Date:   time.Now(),
	}

	// Open websocket connection
	wsURL := "ws" + strings.TrimPrefix(httpServer.URL, "http") + "/updates"
	ws, err := websocket.Dial(wsURL, "ws", httpServer.URL)
	if err != nil {
		t.Fatalf("Error opening websocket: %s", err)
	}

	// Await messages on the websocket
	messageReceived := make(chan bool)
	errorEncountered := make(chan error)
	go func() {
		// Read from websocket
		var updates []model.UpdateItem
		err := websocket.JSON.Receive(ws, &updates)

		if err != nil {
			errorEncountered <- err
			return
		} else {
			if len(updates) != 1 {
				errorEncountered <- MessageUpdateError{
					fmt.Sprintf("Unexpected num updates: %d (expected %d)", len(updates), 1),
				}
				return
			}

			update := updates[0]
			if update.Conversation.Guid != conversation.Guid {
				errorEncountered <- MessageUpdateError{
					fmt.Sprintf("Unexpected conversation guid: %s (expected %s)", update.Conversation.Guid, conversation.Guid),
				}
				return
			}

			if update.Message.Text != message.Text {
				errorEncountered <- MessageUpdateError{
					fmt.Sprintf("Unexpected message text: %s (expected %s)", update.Message.Text, message.Text),
				}
				return
			}

			messageReceived <- true
		}

	}()

	// sleep for a bit to allow the websocket to connect
	time.Sleep(100 * time.Millisecond)

	// This should enqueue an update item
	s.Server.ReceiveMessage(&conversation, message)

	// Await expectation
	select {
	case <-messageReceived:
		// COOL
	case err := <-errorEncountered:
		t.Fatalf("Error encountered reading from websocket: %s", err)
	case <-time.After(1 * time.Second):
		t.Fatalf("Timed out waiting for websocket message")
	}
}

func TestMarkConversation(t *testing.T) {
	s := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{AuthEnabled: true})
	httpServer := httptest.NewServer(s)

	// Mock conversation
	guid := "1234567890"
	conversation := model.Conversation{
		Date:         time.Now(),
		Participants: []string{"Alice"},
		UnreadCount:  0,
		Guid:         guid,
	}

	s.Server.AddConversation(conversation)

	// Receive message to mark as unread
	message := model.Message{
		Text:   "This is a test.",
		Sender: &conversation.Participants[0],
		Date:   time.Now(),
	}

	s.Server.ReceiveMessage(&conversation, message)

	if convo, _ := s.Server.ConversationForGUID(guid); convo.UnreadCount != 1 {
		t.Fatalf("Unexpected unread count: %d (expected %d)", convo.UnreadCount, 1)
	}

	// Mark conversation as read
	resp, err := http.Post(httpServer.URL+"/markConversation?guid="+guid, "", nil)
	if err != nil {
		t.Fatalf("TestMarkConversation error: %s", err)
	}

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("Unexpected status code: %d (expected %d)", resp.StatusCode, http.StatusOK)
	}

	if convo, _ := s.Server.ConversationForGUID(guid); convo.UnreadCount != 0 {
		t.Fatalf("Unexpected unread count: %d (expected %d)", convo.UnreadCount, 0)
	}
}

func TestMessageQueries(t *testing.T) {
	s := web.NewMockHTTPServer(web.MockHTTPServerConfiguration{AuthEnabled: true})
	httpServer := httptest.NewServer(s)

	// Mock conversation
	guid := "1234567890"
	conversation := model.Conversation{
		Date:         time.Now(),
		Participants: []string{"Alice"},
		UnreadCount:  0,
		Guid:         guid,
	}

	s.Server.AddConversation(conversation)

	// Mock messages
	numMessages := 20
	for i := 0; i < numMessages; i++ {
		message := data.GenerateRandomMessage(conversation.Participants)
		s.Server.AppendMessageToConversation(&conversation, message)
	}

	// Pick a pivot message from the sorted list
	sortedMessages := s.Server.MessagesForConversation(&conversation)
	pivotMessage := sortedMessages[len(sortedMessages)/2]

	// Query messages before the pivot, test limit also
	limitMessageCount := 5
	resp, err := http.Get(httpServer.URL + fmt.Sprintf("/messages?guid=%s&beforeMessageGUID=%s&limit=%d", guid, pivotMessage.Guid, limitMessageCount))
	if err != nil {
		t.Fatalf("TestMessageQueries error: %s", err)
	}

	// Decode response
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	var messages []model.Message
	err = json.Unmarshal(body, &messages)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s", err)
	}

	if len(messages) != limitMessageCount {
		t.Fatalf("Unexpected num messages: %d (expected %d)", len(messages), limitMessageCount)
	}

	// Make sure before query is exclusive of the pivot message
	for _, message := range messages {
		if message.Guid == pivotMessage.Guid {
			t.Fatalf("Found pivot guid in before query: %s (expected != %s)", message.Guid, pivotMessage.Guid)
		}
	}

	// Make sure messages are actually before the pivot
	for _, message := range messages {
		if message.Date.After(pivotMessage.Date) {
			t.Fatalf("Unexpected message date: %s (expected before %s)", message.Date, pivotMessage.Date)
		}
	}

	// Query messages after the pivot
	resp, err = http.Get(httpServer.URL + fmt.Sprintf("/messages?guid=%s&afterMessageGUID=%s", guid, pivotMessage.Guid))
	if err != nil {
		t.Fatalf("TestMessageQueries error: %s", err)
	}

	// Decode response
	body, err = io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("Error decoding body: %s", body)
	}

	messages = []model.Message{}
	err = json.Unmarshal(body, &messages)
	if err != nil {
		t.Fatalf("Error unmarshalling JSON: %s", err)
	}

	// Make sure after query is exclusive of the pivot message
	for _, message := range messages {
		if message.Guid == pivotMessage.Guid {
			t.Fatalf("Found pivot guid in after query: %s (expected != %s)", message.Guid, pivotMessage.Guid)
		}
	}

	// Make sure messages are actually after the pivot
	for _, message := range messages {
		if message.Date.Before(pivotMessage.Date) {
			t.Fatalf("Unexpected message date: %s (expected after %s)", message.Date, pivotMessage.Date)
		}
	}

}