refactor: move extension initialization logic to extension.ts

Initialization logic was spread along all files and now it is
centralized in extension.ts file.
This is intermediate step because there are lots of refactorings and
optimization in my list.

Author: ashenBlade

src/configuration.ts

@@ -2,6 +2,7 @@ import * as vscode from 'vscode';
 
 import * as vars from './variables';
 import * as utils from './utils';
+import { Log as logger } from './logger';
 
 export interface VariablesConfiguration {
     /* Array special members */
@@ -502,3 +503,97 @@ export function parseVariablesConfiguration(configFile: unknown): VariablesConfi
         };
     }
 }
+
+export async function readConfigFile(file: vscode.Uri) {
+    let document;
+    try {
+        document = await vscode.workspace.openTextDocument(file);
+    } catch {
+        /* the file might not exist, this is ok */
+        return;
+    }
+
+    let text;
+    try {
+        text = document.getText();
+    } catch (err: unknown) {
+        logger.error('could not read settings file %s', document.uri.fsPath, err);
+        return;
+    }
+
+    if (text.length === 0) {
+        /* JSON file can be used as activation event */
+        return;
+    }
+
+    let data;
+    try {
+        data = JSON.parse(text);
+    } catch (err: unknown) {
+        logger.error('could not parse JSON settings file %s', document.uri.fsPath, err);
+        return;
+    }
+    
+    return data;
+}
+
+let variablesConfig: VariablesConfiguration | undefined;
+let formatterConfig: PgindentConfiguration | undefined;
+
+/* Flag indicating that configuration file should be refreshed */
+let configDirty = true;
+
+export function getVariablesConfiguration(): VariablesConfiguration | undefined {
+    return variablesConfig;
+}
+
+export function getFormatterConfiguration(): PgindentConfiguration | undefined {
+    return formatterConfig;
+}
+
+export async function refreshVariablesConfiguration(file: vscode.Uri) {
+    if (!configDirty) {
+        return;
+    }
+
+    const config = await readConfigFile(file);
+    if (!config) {
+        return;
+    }
+    
+    variablesConfig = parseVariablesConfiguration(config);
+    configDirty = false;
+}
+
+export async function refreshFormatterConfiguration(file: vscode.Uri) {
+    if (!configDirty) {
+        return;
+    }
+
+    const config = await readConfigFile(file);
+    if (!config) {
+        return;
+    }
+
+    formatterConfig = parseFormatterConfiguration(config);
+    configDirty = false;
+}
+
+export async function refreshConfiguration(file: vscode.Uri) {
+    if (!configDirty) {
+        return;
+    }
+
+    const config = await readConfigFile(file);
+    if (!config) {
+        return;
+    }
+
+    formatterConfig = parseFormatterConfiguration(config);
+    variablesConfig = parseVariablesConfiguration(config);
+    configDirty = false;
+}
+
+export function markConfigFileDirty() {
+    configDirty = true;
+}

src/debugger.ts

@@ -1,7 +1,7 @@
 import * as vscode from 'vscode';
 import * as dap from "./dap";
 import { Features } from './utils';
-import { NodePreviewTreeViewProvider } from './extension';
+import { PgVariablesViewProvider } from './variables';
 import {EvaluationError} from './error';
 
 export interface IDebugVariable {
@@ -947,8 +947,8 @@ export function pointerIsNull(pointer: string) {
     return pointer === '0x0' || /0x0+/.test(pointer);
 }
 
-export function setupDebugger(variablesView: NodePreviewTreeViewProvider,
-                              context: vscode.ExtensionContext) {
+export function setupDebugger(context: vscode.ExtensionContext, 
+                              variablesView: PgVariablesViewProvider) {
     if (!Features.debugFocusEnabled()) {
         /* 
          * Prior to VS Code version 1.90 there is no debugFocus API - 

src/entrypoint.ts

@@ -1,10 +1,6 @@
 import * as vscode from 'vscode';
-import * as vars from './variables';
-import * as formatter from './formatter';
 import { Log as logger, initLogger } from './logger';
-import { setupDebugger } from './debugger';
 import {
-    NodePreviewTreeViewProvider as PgVariablesView,
     Configuration as config,
     setupExtension,
 } from './extension';
@@ -14,30 +10,12 @@ function setExtensionActive(status: boolean) {
     vscode.commands.executeCommand('setContext', context, status);
 }
 
-function createPostgresVariablesView(context: vscode.ExtensionContext,
-                                     nodeVars: vars.NodeVarRegistry) {
-    const nodesView = new PgVariablesView(nodeVars);
-    const nodesViewName = config.Views.NodePreviewTreeView;
-    const treeDisposable = vscode.window.registerTreeDataProvider(nodesViewName,
-                                                                  nodesView);
-    context.subscriptions.push(treeDisposable);
-    return nodesView;
-}
-
 export function activate(context: vscode.ExtensionContext) {
     initLogger(context);
     try {
         logger.info('Extension is activating');
-        const nodeVars = new vars.NodeVarRegistry();
-        const nodesView = createPostgresVariablesView(context, nodeVars);
-
-        setupExtension(context, nodeVars, nodesView);
-        setupDebugger(nodesView, context);
-
-        formatter.registerFormatting();
-
+        setupExtension(context);
         setExtensionActive(true);
-
         logger.info('Extension activated');
     } catch (error) {
         logger.error('Failed to activate extension', error);