From f9275a8e1a25493be6a223afdfc1a2fb1d3f82f9 Mon Sep 17 00:00:00 2001
From: Eric Amodio <eamodio@gmail.com>
Date: Mon, 26 Jun 2017 23:55:39 -0400
Subject: [PATCH] Reworks command structure with context

---
 src/commands/common.ts           | 92 +++++++++++++++++++++++++++++++++++++++-
 src/commands/diffWithPrevious.ts | 26 +++++++++---
 2 files changed, 110 insertions(+), 8 deletions(-)

diff --git a/src/commands/common.ts b/src/commands/common.ts
index 12698c2..2faf198 100644
--- a/src/commands/common.ts
+++ b/src/commands/common.ts
@@ -1,5 +1,5 @@
 'use strict';
-import { commands, Disposable, TextDocumentShowOptions, TextEditor, TextEditorEdit, Uri, window, workspace } from 'vscode';
+import { commands, Disposable, SourceControlResourceGroup, SourceControlResourceState, TextDocumentShowOptions, TextEditor, TextEditorEdit, Uri, window, workspace } from 'vscode';
 import { Logger } from '../logger';
 import { Telemetry } from '../telemetry';
 
@@ -86,6 +86,51 @@ export function getCommandUri(uri?: Uri, editor?: TextEditor): Uri | undefined {
     return editor.document.uri;
 }
 
+export interface ScmGroupsCommandContext {
+    type: 'scm-groups';
+    scmResourceGroups: SourceControlResourceGroup[];
+}
+
+export interface ScmStatesCommandContext {
+    type: 'scm-states';
+    scmResourceStates: SourceControlResourceState[];
+}
+
+export interface UnknownCommandContext {
+    type: 'unknown';
+    editor?: TextEditor;
+}
+
+export interface UriCommandContext {
+    type: 'uri';
+    editor?: TextEditor;
+    uri: Uri;
+}
+
+export type CommandContext = ScmGroupsCommandContext | ScmStatesCommandContext | UnknownCommandContext | UriCommandContext;
+
+function isScmResourceGroup(group: any): group is SourceControlResourceGroup {
+    if (group === undefined) return false;
+
+    return (group as SourceControlResourceGroup).id !== undefined && (group.handle !== undefined || (group as SourceControlResourceGroup).label !== undefined || (group as SourceControlResourceGroup).resourceStates !== undefined);
+}
+
+function isScmResourceState(state: any): state is SourceControlResourceState {
+    if (state === undefined) return false;
+
+    return (state as SourceControlResourceState).resourceUri !== undefined;
+}
+
+function isTextEditor(editor: any): editor is TextEditor {
+    if (editor === undefined) return false;
+
+    return editor.id !== undefined && ((editor as TextEditor).edit !== undefined || (editor as TextEditor).document !== undefined);
+}
+
+export interface Command {
+    run?(context: CommandContext, ...args: any[]): any;
+}
+
 export abstract class Command extends Disposable {
 
     private _disposable: Disposable;
@@ -101,6 +146,51 @@ export abstract class Command extends Disposable {
 
     protected _execute(...args: any[]): any {
         Telemetry.trackEvent(this.command);
+
+        if (typeof this.run === 'function') {
+            let editor: TextEditor | undefined = undefined;
+
+            let firstArg = args[0];
+            if (firstArg === undefined || isTextEditor(firstArg)) {
+                editor = firstArg;
+                args = args.slice(1);
+                firstArg = args[0];
+            }
+
+            if (firstArg instanceof Uri) {
+                const [uri, ...rest] = args;
+                return this.run({ type: 'uri', editor: editor, uri: uri }, ...rest);
+            }
+
+            if (isScmResourceState(firstArg)) {
+                const states = [];
+                let count = 0;
+                for (const arg of args) {
+                    if (!isScmResourceState(arg)) break;
+
+                    count++;
+                    states.push(arg);
+                }
+
+                return this.run({ type: 'scm-states', scmResourceStates: states }, ...args.slice(count));
+            }
+
+            if (isScmResourceGroup(firstArg)) {
+                const groups = [];
+                let count = 0;
+                for (const arg of args) {
+                    if (!isScmResourceGroup(arg)) break;
+
+                    count++;
+                    groups.push(arg);
+                }
+
+                return this.run({ type: 'scm-groups', scmResourceGroups: groups }, ...args.slice(count));
+            }
+
+            return this.run({ type: 'unknown', editor: editor }, ...args);
+        }
+
         return this.execute(...args);
     }
 
diff --git a/src/commands/diffWithPrevious.ts b/src/commands/diffWithPrevious.ts
index 6b1b210..0fd5e14 100644
--- a/src/commands/diffWithPrevious.ts
+++ b/src/commands/diffWithPrevious.ts
@@ -1,7 +1,7 @@
 'use strict';
 import { Iterables } from '../system';
 import { commands, Range, TextDocumentShowOptions, TextEditor, Uri, window } from 'vscode';
-import { ActiveEditorCommand, Commands, getCommandUri } from './common';
+import { ActiveEditorCommand, CommandContext, Commands, getCommandUri } from './common';
 import { BuiltInCommands, GlyphChars } from '../constants';
 import { DiffWithWorkingCommandArgs } from './diffWithWorking';
 import { GitCommit, GitService, GitUri } from '../gitService';
@@ -22,15 +22,27 @@ export class DiffWithPreviousCommand extends ActiveEditorCommand {
         super(Commands.DiffWithPrevious);
     }
 
-    async execute(editor: TextEditor, uri?: Uri, args: DiffWithPreviousCommandArgs = {}): Promise<any> {
+    async run(context: CommandContext, args: DiffWithPreviousCommandArgs = {}): Promise<any> {
+        // Since we can change the args and they could be cached -- make a copy
+        switch (context.type) {
+            case 'uri':
+                return this.execute(context.editor, context.uri, { ...args });
+            case 'scm-states':
+                const resource = context.scmResourceStates[0];
+                return this.execute(undefined, resource.resourceUri, { ...args });
+            case 'scm-groups':
+                return undefined;
+            default:
+                return this.execute(context.editor, undefined, { ...args });
+        }
+    }
+
+    async execute(editor: TextEditor | undefined, uri?: Uri, args: DiffWithPreviousCommandArgs = {}): Promise<any> {
         uri = getCommandUri(uri, editor);
         if (uri === undefined) return undefined;
 
-        if (args.commit !== undefined && args.commit.type !== 'file') {
-            args.line = 0;
-        }
-        else {
-            args.line = args.line || (editor === undefined ? 0 : editor.selection.active.line);
+        if (args.line === undefined) {
+            args.line = editor === undefined ? 0 : editor.selection.active.line;
         }
 
         if (args.commit === undefined || args.commit.type !== 'file' || args.range !== undefined) {