From e47d92f2a992b1276774d845dd59460a01d0d04c Mon Sep 17 00:00:00 2001
From: CismonX <admin@cismon.net>
Date: Thu, 8 Oct 2020 07:09:21 +0800
Subject: [PATCH] implementing completion

---
 src/completion.ts | 73 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 1 deletion(-)

diff --git a/src/completion.ts b/src/completion.ts
index 21a3ae5..12a58bb 100644
--- a/src/completion.ts
+++ b/src/completion.ts
@@ -9,12 +9,83 @@ import * as vscode from 'vscode';
 
 export class CompletionItemProvider implements vscode.CompletionItemProvider {
 
+    private readonly completionItems: vscode.CompletionItem[] = [
+        {
+            label: 'header',
+            kind: vscode.CompletionItemKind.Snippet,
+            detail: 'Start/end of header',
+            sortText: 'c1',
+            filterText: 'c',
+            insertText: 'c %**',
+        },
+        {
+            label: '@setfilename',
+            kind: vscode.CompletionItemKind.Function,
+            detail: 'Set output file name',
+            sortText: 'setfilename',
+            filterText: 'setfilename',
+            insertText: 'setfilename ',
+        },
+        {
+            label: '@settitle',
+            kind: vscode.CompletionItemKind.Function,
+            detail: 'Set document title',
+            sortText: 'settitle',
+            filterText: 'settitle',
+            insertText: 'settitle ',
+        },
+        {
+            label: '@copying',
+            kind: vscode.CompletionItemKind.Function,
+            detail: 'declare copying permissions',
+            sortText: 'copying1',
+            filterText: 'copying',
+            insertText: 'copying',
+        },
+        {
+            label: 'copying',
+            kind: vscode.CompletionItemKind.Snippet,
+            detail: 'declare copying permissions',
+            sortText: 'copying0',
+            filterText: 'copying',
+            insertText: new vscode.SnippetString('copying\n$1\n@end copying\n'),
+        },
+        {
+            label: '@copyright',
+            kind: vscode.CompletionItemKind.Function,
+            detail: 'The \'©\' symbol',
+            sortText: 'copyright',
+            filterText: 'copyright',
+            insertText: 'copyright{} '
+        },
+    ];
+
     provideCompletionItems(
         document: vscode.TextDocument,
         position: vscode.Position,
         token: vscode.CancellationToken,
         context: vscode.CompletionContext
     ) {
-        return <vscode.CompletionItem[]>[];
+        if (context.triggerKind === vscode.CompletionTriggerKind.Invoke) {
+            const wordRange = document.getWordRangeAtPosition(position);
+            if (wordRange === undefined) {
+                return undefined;
+            }
+            position = wordRange.start;
+            if (document.getText(new vscode.Range(position.translate(0, -1), position)) !== '@') {
+                // Current word is not a command.
+                return undefined;
+            }
+        }
+        if (position.character === 1) {
+            // Start of line.
+            return this.completionItems;
+        }
+        if (document.getText(new vscode.Range(position.translate(0, -2), position.translate(0, -1))) === '@') {
+            // The '@' character is escaped.
+            return undefined;
+        } else {
+            return this.completionItems;
+        }
     }
 }