//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
//
using Microsoft.SqlTools.EditorServices.Protocol.LanguageServer;
using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol.Channel;
using Microsoft.SqlTools.EditorServices.Session;
using System.Threading.Tasks;
using Microsoft.SqlTools.EditorServices.Utility;
using System.Collections.Generic;
using System.Text;

namespace Microsoft.SqlTools.EditorServices.Protocol.Server
{
    public class LanguageServer : LanguageServerBase
    {
        private EditorSession editorSession;

        /// <param name="hostDetails">
        /// Provides details about the host application.
        /// </param>
        public LanguageServer(HostDetails hostDetails, ProfilePaths profilePaths)
            : base(new StdioServerChannel())
        {
            this.editorSession = new EditorSession();
            this.editorSession.StartSession(hostDetails, profilePaths);
        }

        protected override void Initialize()
        {
            // Register all supported message types
            this.SetRequestHandler(InitializeRequest.Type, this.HandleInitializeRequest);
            this.SetEventHandler(DidChangeTextDocumentNotification.Type, this.HandleDidChangeTextDocumentNotification);
            this.SetEventHandler(DidOpenTextDocumentNotification.Type, this.HandleDidOpenTextDocumentNotification);
            this.SetEventHandler(DidCloseTextDocumentNotification.Type, this.HandleDidCloseTextDocumentNotification);
            this.SetEventHandler(DidChangeConfigurationNotification<LanguageServerSettingsWrapper>.Type, this.HandleDidChangeConfigurationNotification);

            this.SetRequestHandler(DefinitionRequest.Type, this.HandleDefinitionRequest);
            this.SetRequestHandler(ReferencesRequest.Type, this.HandleReferencesRequest);
            this.SetRequestHandler(CompletionRequest.Type, this.HandleCompletionRequest);
            this.SetRequestHandler(CompletionResolveRequest.Type, this.HandleCompletionResolveRequest);
            this.SetRequestHandler(SignatureHelpRequest.Type, this.HandleSignatureHelpRequest);
            this.SetRequestHandler(DocumentHighlightRequest.Type, this.HandleDocumentHighlightRequest);
            this.SetRequestHandler(HoverRequest.Type, this.HandleHoverRequest);
            this.SetRequestHandler(DocumentSymbolRequest.Type, this.HandleDocumentSymbolRequest);
            this.SetRequestHandler(WorkspaceSymbolRequest.Type, this.HandleWorkspaceSymbolRequest);               
        }

        protected override async Task Shutdown()
        {
            Logger.Write(LogLevel.Normal, "Language service is shutting down...");

            if (this.editorSession != null)
            {
                this.editorSession.Dispose();
                this.editorSession = null;
            }

            await Task.FromResult(true);
        }

        protected async Task HandleInitializeRequest(
            InitializeRequest initializeParams,
            RequestContext<InitializeResult> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDidChangeTextDocumentNotification");

            // Grab the workspace path from the parameters
           //editorSession.Workspace.WorkspacePath = initializeParams.RootPath;

            await requestContext.SendResult(
                new InitializeResult
                {
                    Capabilities = new ServerCapabilities
                    {
                        TextDocumentSync = TextDocumentSyncKind.Incremental,
                        DefinitionProvider = true,
                        ReferencesProvider = true,
                        DocumentHighlightProvider = true,
                        DocumentSymbolProvider = true,
                        WorkspaceSymbolProvider = true,
                        HoverProvider = true,
                        CompletionProvider = new CompletionOptions
                        {
                            ResolveProvider = true,
                            TriggerCharacters = new string[] { ".", "-", ":", "\\" }
                        },
                        SignatureHelpProvider = new SignatureHelpOptions
                        {
                            TriggerCharacters = new string[] { " " } // TODO: Other characters here?
                        }
                    }
                });
        }

        /// <summary>
        /// Handles text document change events
        /// </summary>
        /// <param name="textChangeParams"></param>
        /// <param name="eventContext"></param>
        /// <returns></returns>
        protected Task HandleDidChangeTextDocumentNotification(
            DidChangeTextDocumentParams textChangeParams,
            EventContext eventContext)
        {
            StringBuilder msg = new StringBuilder();
            msg.Append("HandleDidChangeTextDocumentNotification"); 
            List<ScriptFile> changedFiles = new List<ScriptFile>();

            // A text change notification can batch multiple change requests
            foreach (var textChange in textChangeParams.ContentChanges)
            {
                string fileUri = textChangeParams.TextDocument.Uri;
                msg.AppendLine();
                msg.Append("  File: ");
                msg.Append(fileUri);

                ScriptFile changedFile = editorSession.Workspace.GetFile(fileUri);

                // changedFile.ApplyChange(
                //     GetFileChangeDetails(
                //         textChange.Range.Value,
                //         textChange.Text));

                // changedFiles.Add(changedFile);
            }

            Logger.Write(LogLevel.Normal, msg.ToString());

            // // TODO: Get all recently edited files in the workspace
            // this.RunScriptDiagnostics(
            //     changedFiles.ToArray(),
            //     editorSession,
            //     eventContext);

            return Task.FromResult(true);
        }

        protected Task HandleDidOpenTextDocumentNotification(
            DidOpenTextDocumentNotification openParams,
            EventContext eventContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDidOpenTextDocumentNotification");
            return Task.FromResult(true);
        }

         protected Task HandleDidCloseTextDocumentNotification(
            TextDocumentIdentifier closeParams,
            EventContext eventContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDidCloseTextDocumentNotification");
            return Task.FromResult(true);
        }

        protected async Task HandleDidChangeConfigurationNotification(
            DidChangeConfigurationParams<LanguageServerSettingsWrapper> configChangeParams,
            EventContext eventContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDidChangeConfigurationNotification");
            await Task.FromResult(true);
        }

        protected async Task HandleDefinitionRequest(
            TextDocumentPosition textDocumentPosition,
            RequestContext<Location[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDefinitionRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleReferencesRequest(
            ReferencesParams referencesParams,
            RequestContext<Location[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleReferencesRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleCompletionRequest(
            TextDocumentPosition textDocumentPosition,
            RequestContext<CompletionItem[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleCompletionRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleCompletionResolveRequest(
            CompletionItem completionItem,
            RequestContext<CompletionItem> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleCompletionResolveRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleSignatureHelpRequest(
            TextDocumentPosition textDocumentPosition,
            RequestContext<SignatureHelp> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleSignatureHelpRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleDocumentHighlightRequest(
            TextDocumentPosition textDocumentPosition,
            RequestContext<DocumentHighlight[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDocumentHighlightRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleHoverRequest(
            TextDocumentPosition textDocumentPosition,
            RequestContext<Hover> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleHoverRequest");
            await Task.FromResult(true);
        }

        protected async Task HandleDocumentSymbolRequest(
            TextDocumentIdentifier textDocumentIdentifier,
            RequestContext<SymbolInformation[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleDocumentSymbolRequest");
            await Task.FromResult(true);     
        }

        protected async Task HandleWorkspaceSymbolRequest(
            WorkspaceSymbolParams workspaceSymbolParams,
            RequestContext<SymbolInformation[]> requestContext)
        {
            Logger.Write(LogLevel.Normal, "HandleWorkspaceSymbolRequest");
            await Task.FromResult(true);
        }    
    }
}