//go:build !windows

package plugins

import (
	"context"
	"crypto/sha256"

	"encoding/hex"
	"maps"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"sync"

	"github.com/gorilla/websocket"
	"github.com/navidrome/navidrome/conf"
	"github.com/navidrome/navidrome/conf/configtest"
	"github.com/navidrome/navidrome/model"
	"github.com/navidrome/navidrome/tests"
	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("WebSocketService", Ordered, func() {
	var (
		manager     *Manager
		tmpDir      string
		testService *testableWebSocketService
	)

	BeforeAll(func() {
		var err error
		tmpDir, err = os.MkdirTemp("", "websocket-test-*")
		Expect(err).ToNot(HaveOccurred())

		// Copy the test-websocket plugin
		srcPath := filepath.Join(testdataDir, "test-websocket"+PackageExtension)
		destPath := filepath.Join(tmpDir, "test-websocket"+PackageExtension)
		data, err := os.ReadFile(srcPath)
		Expect(err).ToNot(HaveOccurred())
		err = os.WriteFile(destPath, data, 0600)
		Expect(err).ToNot(HaveOccurred())

		// Compute SHA256 for the plugin
		hash := sha256.Sum256(data)
		hashHex := hex.EncodeToString(hash[:])

		// Setup config
		DeferCleanup(configtest.SetupConfig())
		conf.Server.Plugins.Enabled = true
		conf.Server.Plugins.Folder = tmpDir
		conf.Server.Plugins.AutoReload = false

		// Setup mock DataStore with pre-enabled plugin
		mockPluginRepo := tests.CreateMockPluginRepo()
		mockPluginRepo.Permitted = true
		mockPluginRepo.SetData(model.Plugins{{
			ID:      "test-websocket",
			Path:    destPath,
			SHA256:  hashHex,
			Enabled: true,
		}})
		dataStore := &tests.MockDataStore{MockedPlugin: mockPluginRepo}

		// Create and start manager
		manager = &Manager{
			plugins:        make(map[string]*plugin),
			ds:             dataStore,
			subsonicRouter: http.NotFoundHandler(),
			metrics:        noopMetricsRecorder{},
		}
		err = manager.Start(GinkgoT().Context())
		Expect(err).ToNot(HaveOccurred())

		// Get WebSocket service from plugin's closers and wrap it for testing
		service := findWebSocketService(manager, "test-websocket")
		Expect(service).ToNot(BeNil())
		testService = &testableWebSocketService{webSocketServiceImpl: service}

		DeferCleanup(func() {
			_ = manager.Stop()
			_ = os.RemoveAll(tmpDir)
		})
	})

	BeforeEach(func() {
		// Clean up any connections from previous tests
		testService.closeAllConnections()
	})

	Describe("Plugin Loading", func() {
		It("should detect WebSocket capability", func() {
			names := manager.PluginNames(string(CapabilityWebSocket))
			Expect(names).To(ContainElement("test-websocket"))
		})

		It("should register WebSocket service for plugin", func() {
			service := findWebSocketService(manager, "test-websocket")
			Expect(service).ToNot(BeNil())
		})
	})

	Describe("URL Validation", func() {
		It("should reject invalid URL schemes", func() {
			ctx := GinkgoT().Context()
			_, err := testService.Connect(ctx, "http://example.com", nil, "test-conn")
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("invalid URL scheme"))
		})

		It("should reject disallowed hosts", func() {
			ctx := GinkgoT().Context()
			_, err := testService.Connect(ctx, "wss://evil.com/socket", nil, "test-conn")
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("not allowed"))
		})

		It("should allow hosts matching wildcard patterns", func() {
			// test-websocket manifest allows *.example.com
			// The pattern *.example.com matches any host ending with .example.com
			ctx := context.Background()
			allowed := testService.isHostAllowed("api.example.com")
			Expect(allowed).To(BeTrue())

			// Deep subdomains also match (ends with .example.com)
			allowed = testService.isHostAllowed("sub.api.example.com")
			Expect(allowed).To(BeTrue())

			// But exact match without subdomain doesn't match *.example.com
			allowed = testService.isHostAllowed("example.com")
			Expect(allowed).To(BeFalse())
			_ = ctx
		})

		It("should allow exact host matches", func() {
			// test-websocket manifest allows echo.websocket.org
			allowed := testService.isHostAllowed("echo.websocket.org")
			Expect(allowed).To(BeTrue())

			allowed = testService.isHostAllowed("other.org")
			Expect(allowed).To(BeFalse())
		})

		It("should strip port before checking host", func() {
			// Implementation strips port before matching against patterns
			// test-websocket manifest has "localhost:*" which matches "localhost"
			// after port stripping
			// Note: The port wildcard pattern isn't actually implemented, but
			// since port is stripped, "localhost:*" is compared against "localhost"
			// which won't match. To make localhost work, we'd need exact "localhost"
			// in the allowed hosts list.

			// Testing that port is properly stripped
			// The pattern "localhost:*" won't match "localhost" due to exact match
			allowed := testService.isHostAllowed("localhost:8080")
			Expect(allowed).To(BeFalse())
		})
	})

	Describe("Connection Management", func() {
		var wsServer *httptest.Server
		var serverMessages []string
		var serverMu sync.Mutex

		BeforeEach(func() {
			serverMessages = nil

			upgrader := websocket.Upgrader{
				CheckOrigin: func(r *http.Request) bool { return true },
			}
			wsServer = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				conn, err := upgrader.Upgrade(w, r, nil)
				if err != nil {
					return
				}

				// Read messages until connection closes
				for {
					_, msg, err := conn.ReadMessage()
					if err != nil {
						break
					}
					serverMu.Lock()
					serverMessages = append(serverMessages, string(msg))
					serverMu.Unlock()
				}
			}))

			// Add the server's host to allowed hosts for testing
			// Since the implementation strips port before matching, we need to add
			// the host without port
			serverURL := strings.TrimPrefix(wsServer.URL, "http://")
			hostOnly := serverURL
			if idx := strings.LastIndex(serverURL, ":"); idx != -1 {
				hostOnly = serverURL[:idx]
			}
			testService.requiredHosts = append(testService.requiredHosts, hostOnly)
		})

		AfterEach(func() {
			testService.closeAllConnections()
			if wsServer != nil {
				wsServer.Close()
			}
		})

		It("should connect to WebSocket server", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			connID, err := testService.Connect(ctx, wsURL, nil, "test-conn")
			Expect(err).ToNot(HaveOccurred())
			Expect(connID).To(Equal("test-conn"))
			Expect(testService.getConnectionCount()).To(Equal(1))
		})

		It("should generate connection ID when not provided", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			connID, err := testService.Connect(ctx, wsURL, nil, "")
			Expect(err).ToNot(HaveOccurred())
			Expect(connID).ToNot(BeEmpty())
		})

		It("should reject duplicate connection IDs", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			_, err := testService.Connect(ctx, wsURL, nil, "dup-conn")
			Expect(err).ToNot(HaveOccurred())

			_, err = testService.Connect(ctx, wsURL, nil, "dup-conn")
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("already exists"))
		})

		It("should send text messages", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			connID, err := testService.Connect(ctx, wsURL, nil, "send-text-conn")
			Expect(err).ToNot(HaveOccurred())

			err = testService.SendText(ctx, connID, "hello world")
			Expect(err).ToNot(HaveOccurred())

			// Give server time to receive the message
			Eventually(func() []string {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverMessages
			}).Should(ContainElement("hello world"))
		})

		It("should send binary messages", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			connID, err := testService.Connect(ctx, wsURL, nil, "send-binary-conn")
			Expect(err).ToNot(HaveOccurred())

			binaryData := []byte{0x00, 0x01, 0x02, 0x03}
			err = testService.SendBinary(ctx, connID, binaryData)
			Expect(err).ToNot(HaveOccurred())

			// Give server time to receive the message
			Eventually(func() []string {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverMessages
			}).Should(ContainElement(string(binaryData)))
		})

		It("should close connections", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			connID, err := testService.Connect(ctx, wsURL, nil, "close-conn")
			Expect(err).ToNot(HaveOccurred())
			Expect(testService.getConnectionCount()).To(Equal(1))

			err = testService.CloseConnection(ctx, connID, 1000, "normal close")
			Expect(err).ToNot(HaveOccurred())
			Expect(testService.getConnectionCount()).To(Equal(0))
		})

		It("should return error for non-existent connection", func() {
			ctx := GinkgoT().Context()
			err := testService.SendText(ctx, "non-existent", "message")
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("not found"))
		})
	})

	Describe("Plugin Callbacks", func() {
		var wsServer *httptest.Server
		var serverConn *websocket.Conn
		var serverMessages []string
		var serverBinaryMessages [][]byte
		var serverMu sync.Mutex

		BeforeEach(func() {
			serverConn = nil
			serverMessages = nil
			serverBinaryMessages = nil

			upgrader := websocket.Upgrader{
				CheckOrigin: func(r *http.Request) bool { return true },
			}
			wsServer = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				conn, err := upgrader.Upgrade(w, r, nil)
				if err != nil {
					return
				}
				serverMu.Lock()
				serverConn = conn
				serverMu.Unlock()

				// Read and store messages
				for {
					msgType, msg, err := conn.ReadMessage()
					if err != nil {
						break
					}
					serverMu.Lock()
					if msgType == websocket.BinaryMessage {
						serverBinaryMessages = append(serverBinaryMessages, msg)
					} else {
						serverMessages = append(serverMessages, string(msg))
					}
					serverMu.Unlock()
				}
			}))

			serverURL := strings.TrimPrefix(wsServer.URL, "http://")
			hostOnly := serverURL
			if idx := strings.LastIndex(serverURL, ":"); idx != -1 {
				hostOnly = serverURL[:idx]
			}
			testService.requiredHosts = append(testService.requiredHosts, hostOnly)
		})

		AfterEach(func() {
			testService.closeAllConnections()
			if wsServer != nil {
				wsServer.Close()
			}
		})

		It("should invoke OnBinaryMessage callback when receiving binary", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			_, err := testService.Connect(ctx, wsURL, nil, "binary-cb-conn")
			Expect(err).ToNot(HaveOccurred())

			// Wait for server to have the connection
			Eventually(func() *websocket.Conn {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverConn
			}).ShouldNot(BeNil())

			// Send binary message from server to plugin
			binaryData := []byte{0xDE, 0xAD, 0xBE, 0xEF}
			serverMu.Lock()
			err = serverConn.WriteMessage(websocket.BinaryMessage, binaryData)
			serverMu.Unlock()
			Expect(err).ToNot(HaveOccurred())

			// Plugin echoes binary data back as a binary message
			Eventually(func() [][]byte {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverBinaryMessages
			}).Should(ContainElement(binaryData))
		})

		It("should invoke OnClose callback when server closes connection", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			_, err := testService.Connect(ctx, wsURL, nil, "close-cb-conn")
			Expect(err).ToNot(HaveOccurred())

			// Wait for server to have the connection
			Eventually(func() *websocket.Conn {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverConn
			}).ShouldNot(BeNil())

			// Close from server side
			serverMu.Lock()
			_ = serverConn.WriteMessage(websocket.CloseMessage,
				websocket.FormatCloseMessage(websocket.CloseNormalClosure, "goodbye"))
			serverConn.Close()
			serverMu.Unlock()

			// Connection should be removed after close callback
			Eventually(func() int {
				return testService.getConnectionCount()
			}).Should(Equal(0))
		})
	})

	Describe("Plugin Host Function Calls", func() {
		var wsServer *httptest.Server
		var serverConn *websocket.Conn
		var serverMessages []string
		var serverMu sync.Mutex

		BeforeEach(func() {
			serverMessages = nil
			serverConn = nil

			upgrader := websocket.Upgrader{
				CheckOrigin: func(r *http.Request) bool { return true },
			}
			wsServer = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				conn, err := upgrader.Upgrade(w, r, nil)
				if err != nil {
					return
				}
				serverMu.Lock()
				serverConn = conn
				serverMu.Unlock()

				// Read and store messages
				for {
					_, msg, err := conn.ReadMessage()
					if err != nil {
						break
					}
					serverMu.Lock()
					serverMessages = append(serverMessages, string(msg))
					serverMu.Unlock()
				}
			}))

			serverURL := strings.TrimPrefix(wsServer.URL, "http://")
			hostOnly := serverURL
			if idx := strings.LastIndex(serverURL, ":"); idx != -1 {
				hostOnly = serverURL[:idx]
			}
			testService.requiredHosts = append(testService.requiredHosts, hostOnly)
		})

		AfterEach(func() {
			testService.closeAllConnections()
			if wsServer != nil {
				wsServer.Close()
			}
		})

		It("should allow plugin to send messages via host function", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			_, err := testService.Connect(ctx, wsURL, nil, "host-send-conn")
			Expect(err).ToNot(HaveOccurred())

			// Wait for server to have the connection
			Eventually(func() *websocket.Conn {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverConn
			}).ShouldNot(BeNil())

			// Server sends "echo" message to trigger plugin to echo back
			serverMu.Lock()
			err = serverConn.WriteMessage(websocket.TextMessage, []byte("echo"))
			serverMu.Unlock()
			Expect(err).ToNot(HaveOccurred())

			// Plugin should have echoed back via host function
			Eventually(func() []string {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverMessages
			}).Should(ContainElement("echo:echo"))
		})

		It("should allow plugin to close connection via host function", func() {
			ctx := GinkgoT().Context()
			wsURL := "ws://" + strings.TrimPrefix(wsServer.URL, "http://")
			_, err := testService.Connect(ctx, wsURL, nil, "host-close-conn")
			Expect(err).ToNot(HaveOccurred())
			Expect(testService.getConnectionCount()).To(Equal(1))

			// Wait for server to have the connection
			Eventually(func() *websocket.Conn {
				serverMu.Lock()
				defer serverMu.Unlock()
				return serverConn
			}).ShouldNot(BeNil())

			// Server sends "close" message to trigger plugin to close connection
			serverMu.Lock()
			err = serverConn.WriteMessage(websocket.TextMessage, []byte("close"))
			serverMu.Unlock()
			Expect(err).ToNot(HaveOccurred())

			// Connection should be closed by plugin
			Eventually(func() int {
				return testService.getConnectionCount()
			}).Should(Equal(0))
		})
	})

	Describe("Plugin Unload", func() {
		It("should close all connections when plugin is unloaded", func() {
			// Create a fresh server for this test
			upgrader := websocket.Upgrader{
				CheckOrigin: func(r *http.Request) bool { return true },
			}
			wsServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				conn, err := upgrader.Upgrade(w, r, nil)
				if err != nil {
					return
				}
				// Keep alive
				for {
					_, _, err := conn.ReadMessage()
					if err != nil {
						break
					}
				}
			}))
			defer wsServer.Close()

			serverURL := strings.TrimPrefix(wsServer.URL, "http://")
			hostOnly := serverURL
			if idx := strings.LastIndex(serverURL, ":"); idx != -1 {
				hostOnly = serverURL[:idx]
			}
			testService.requiredHosts = append(testService.requiredHosts, hostOnly)

			ctx := GinkgoT().Context()
			wsURL := "ws://" + serverURL

			// Create multiple connections
			_, err := testService.Connect(ctx, wsURL, nil, "unload-conn-1")
			Expect(err).ToNot(HaveOccurred())
			_, err = testService.Connect(ctx, wsURL, nil, "unload-conn-2")
			Expect(err).ToNot(HaveOccurred())
			Expect(testService.getConnectionCount()).To(Equal(2))

			// Close the service (simulates plugin unload)
			err = testService.Close()
			Expect(err).ToNot(HaveOccurred())
			Expect(testService.getConnectionCount()).To(Equal(0))
		})
	})

	Describe("matchHostPattern", func() {
		It("should match exact hosts", func() {
			Expect(matchHostPattern("example.com", "example.com")).To(BeTrue())
			Expect(matchHostPattern("example.com", "other.com")).To(BeFalse())
		})

		It("should match wildcard patterns", func() {
			Expect(matchHostPattern("*.example.com", "api.example.com")).To(BeTrue())
			Expect(matchHostPattern("*.example.com", "example.com")).To(BeFalse())
			Expect(matchHostPattern("*.example.com", "deep.api.example.com")).To(BeTrue())
		})

		It("should match bare '*' as allow-all", func() {
			Expect(matchHostPattern("*", "anything.example.com")).To(BeTrue())
			Expect(matchHostPattern("*", "127.0.0.1")).To(BeTrue())
			Expect(matchHostPattern("*", "::1")).To(BeTrue())
		})

		It("should not match partial patterns", func() {
			Expect(matchHostPattern("*.example.com", "example.com.evil.org")).To(BeFalse())
		})
	})
})

// testableWebSocketService wraps webSocketServiceImpl with test helpers.
type testableWebSocketService struct {
	*webSocketServiceImpl
}

func (t *testableWebSocketService) getConnectionCount() int {
	t.mu.RLock()
	defer t.mu.RUnlock()
	return len(t.connections)
}

func (t *testableWebSocketService) closeAllConnections() {
	t.mu.Lock()
	conns := make(map[string]*wsConnection, len(t.connections))
	maps.Copy(conns, t.connections)
	t.connections = make(map[string]*wsConnection)
	t.mu.Unlock()

	for _, conn := range conns {
		conn.closeMu.Lock()
		conn.isClosed = true
		conn.closeMu.Unlock()
		_ = conn.conn.Close()
		close(conn.done)
	}
}

// findWebSocketService finds the WebSocket service from a plugin's closers.
func findWebSocketService(m *Manager, pluginName string) *webSocketServiceImpl {
	m.mu.RLock()
	instance, ok := m.plugins[pluginName]
	m.mu.RUnlock()
	if !ok {
		return nil
	}
	for _, closer := range instance.closers {
		if svc, ok := closer.(*webSocketServiceImpl); ok {
			return svc
		}
	}
	return nil
}
