From 01f1f7ae227af29abcac7556e62563bdedc97583 Mon Sep 17 00:00:00 2001
From: KernelDeimos <eric@centos1.rack1.local>
Date: Wed, 24 May 2023 17:40:51 -0400
Subject: [PATCH] Add tab completion

---
 src/ansi-shell/readline.js                   | 66 +++++++++++++++++++-
 src/ansi-shell/rl_comprehend.js              |  2 +
 src/puter-shell/PuterANSIShell.js            | 11 +++-
 src/puter-shell/completers/file_completer.js | 31 +++++++++
 4 files changed, 107 insertions(+), 3 deletions(-)
 create mode 100644 src/puter-shell/completers/file_completer.js

diff --git a/src/ansi-shell/readline.js b/src/ansi-shell/readline.js
index 01ee60f..a0877d8 100644
--- a/src/ansi-shell/readline.js
+++ b/src/ansi-shell/readline.js
@@ -1,4 +1,5 @@
 import { Context } from "../context/context";
+import { FileCompleter } from "../puter-shell/completers/file_completer";
 import { Uint8List } from "../util/bytes";
 import { Log } from "../util/log";
 import { StatefulProcessorBuilder } from "../util/statemachine";
@@ -34,6 +35,7 @@ const ReadlineProcessorBuilder = builder => builder
     .external('in_', { required: true })
     .external('history', { required: true })
     .external('prompt', { required: true })
+    .external('commandCtx', { required: true })
     .beforeAll('get-byte', async ctx => {
         const { locals, externs } = ctx;
 
@@ -72,6 +74,65 @@ const ReadlineProcessorBuilder = builder => builder
             }));
             // NEXT: get tab completer for input state
             console.log('input state', inputState);
+            
+            let completer = null;
+            if ( inputState.$ === 'redirect' ) {
+                completer = new FileCompleter();
+            }
+
+            // TODO: try to get a completer from the command
+            if ( inputState.$ === 'command' ) {
+                completer = new FileCompleter();
+            }
+
+            if ( completer === null ) return;
+            
+            const completions = await completer.getCompetions(
+                externs.commandCtx,
+                inputState,
+            );
+            
+            const applyCompletion = txt => {
+                const p1 = vars.result.slice(0, vars.cursor);
+                const p2 = vars.result.slice(vars.cursor);
+                console.log({ p1, p2 });
+                vars.result = p1 + txt + p2;
+                vars.cursor += txt.length;
+                externs.out.write(txt);
+            };
+
+            if ( completions.length === 0 ) return;
+
+            if ( completions.length === 1 ) {
+                applyCompletion(completions[0]);
+            }
+
+            if ( completions.length > 1 ) {
+                let inCommon = '';
+                for ( let i=0 ; true ; i++ ) {
+                    if ( ! completions.every(completion => {
+                        return completion.length > i;
+                    }) ) break;
+
+                    let matches = true;
+
+                    const chrFirst = completions[0][i];
+                    for ( let ci=1 ; ci < completions.length ; ci++ ) {
+                        const chrOther = completions[ci][i];
+                        if ( chrFirst !== chrOther ) {
+                            matches = false;
+                            break;
+                        }
+                    }
+                
+                    if ( ! matches ) break;
+                    inCommon += chrFirst;
+                }
+
+                if ( inCommon.length > 0 ) {
+                    applyCompletion(inCommon);
+                }
+            }
             return;
         }
 
@@ -239,7 +300,7 @@ class Readline {
         this.history = new HistoryManager();
     }
 
-    async readline (prompt) {
+    async readline (prompt, commandCtx) {
         const out = this.internal_.out;
         const in_ = this.internal_.in;
 
@@ -250,7 +311,8 @@ class Readline {
         } = await ReadlineProcessor.run({
             prompt,
             out, in_,
-            history: this.history
+            history: this.history,
+            commandCtx,
         });
 
         this.history.save(result);
diff --git a/src/ansi-shell/rl_comprehend.js b/src/ansi-shell/rl_comprehend.js
index 1b68083..a2c1263 100644
--- a/src/ansi-shell/rl_comprehend.js
+++ b/src/ansi-shell/rl_comprehend.js
@@ -108,6 +108,8 @@ export const readline_comprehend = (ctx) => {
         $: 'command',
         id: tokens[0],
         tokens: argTokens,
+        input: endsWithWhitespace ?
+            '' : argTokens[argTokens.length - 1],
         endsWithWhitespace,
     };
 };
diff --git a/src/puter-shell/PuterANSIShell.js b/src/puter-shell/PuterANSIShell.js
index 4a87f38..b4c55ab 100644
--- a/src/puter-shell/PuterANSIShell.js
+++ b/src/puter-shell/PuterANSIShell.js
@@ -62,8 +62,17 @@ export class PuterANSIShell extends EventTarget {
     async doPromptIteration() {
         console.log('prompt iteration');
         const { readline } = this.ctx.externs;
+        // DRY: created the same way in runPipeline
+        const executionCtx = this.ctx.sub({
+            vars: this.variables,
+            env: this.env,
+            locals: {
+                pwd: this.variables.pwd,
+            }
+        });
         const input = await readline(
-            this.expandPromptString(this.env.PS1)
+            this.expandPromptString(this.env.PS1),
+            executionCtx,
         );
         
         await this.runPipeline(input);
diff --git a/src/puter-shell/completers/file_completer.js b/src/puter-shell/completers/file_completer.js
new file mode 100644
index 0000000..30cefd3
--- /dev/null
+++ b/src/puter-shell/completers/file_completer.js
@@ -0,0 +1,31 @@
+import path_ from "path-browserify";
+
+// DRY: also done in many other places
+const resolve = (ctx, relPath) => {
+    if ( relPath.startsWith('/') ) {
+        return relPath;
+    }
+    console.log('wrong context?', ctx);
+    return path_.resolve(ctx.vars.pwd, relPath);
+}
+
+export class FileCompleter {
+    async getCompetions (ctx, inputState) {
+        const { puterShell } = ctx.externs;
+
+        let path = resolve(ctx, inputState.input);
+        let dir = path_.dirname(path);
+        let base = path_.basename(path);
+
+        const completions = [];
+
+        const result = await puterShell.command('list', { path: dir });
+        for ( const item of result ) {
+            if ( item.name.startsWith(base) ) {
+                completions.push(item.name.slice(base.length));
+            }
+        }
+        
+        return completions;
+    }
+}