refactor: start implementing InputBuffer

Author: fraxken

README.md

@@ -44,13 +44,13 @@ console.log(`input data: ${data}`);
 
 ## API
 
-### stdin(query: null | string, options?: StdinOptions): Promise< string >
+### stdin(title: null | string, options?: StdinOptions): Promise< string >
 Query paramaters can be set to `null` to disable the title. Options is described by the following TypeScript interface:
 
 ```ts
 interface StdinOptions {
-    history?: string[];
-    autocomplete?: string[];
+  history?: string[];
+  autocomplete?: string[];
 }
 ```
 

src/class/Completion.class.ts

@@ -21,7 +21,7 @@ export class Completion {
     this.choices = choices.slice(0);
   }
 
-  clear(
+  clearHint(
     force = false
   ) {
     if (this.hint.length > 0) {
@@ -33,22 +33,21 @@ export class Completion {
     }
   }
 
-  lookFor(
-    rawStr: string,
-    str?: string,
+  findHint(
+    rawInput: string,
+    currentInput?: string,
     forceNextMatch = false
   ) {
     if (this.choices.length === 0) {
       return true;
     }
-    const localMatch = localMatchOf(this.choices, rawStr, forceNextMatch);
+    const localMatch = localMatchOf(this.choices, rawInput, forceNextMatch);
 
-    this.clear();
-    if (localMatch !== null && localMatch !== "") {
+    this.clearHint();
+    if (localMatch) {
       this.hint.setValue(localMatch);
-
       this.output.write(
-        this.hint.prefix(str)
+        this.hint.prefix(currentInput)
       );
       this.output.moveCursor(
         -this.hint.length,

src/class/Cursor.class.ts

@@ -0,0 +1,37 @@
+// Import Node.js Dependencies
+import * as TTY from "node:tty";
+
+export class Cursor {
+  position = 0;
+  offset = 0;
+
+  private output: TTY.WriteStream;
+
+  constructor(
+    output: TTY.WriteStream
+  ) {
+    this.output = output;
+  }
+
+  left() {
+    if (this.position > 0) {
+      this.output.moveCursor(-1, 0);
+      this.position--;
+
+      return true;
+    }
+
+    return false;
+  }
+
+  right() {
+    if (this.position < this.offset) {
+      process.stdout.moveCursor(1, 0);
+      this.position++;
+
+      return true;
+    }
+
+    return false;
+  }
+}

src/class/History.class.ts

@@ -2,13 +2,28 @@ export class History {
   #commands: string[] = [];
   #index = 0;
 
+  private isOriginal = true;
+
   constructor(
     commands: string[] = []
   ) {
     this.#commands = commands;
     this.#index = this.#commands.length;
   }
 
+  keep(
+    command: string
+  ) {
+    if (this.isOriginal) {
+      this.push(command);
+      this.isOriginal = false;
+
+      return true;
+    }
+
+    return false;
+  }
+
   push(
     command: string,
     noDuplicateCheck = false

src/class/InputBuffer.class.ts

@@ -0,0 +1,111 @@
+// Import Node.js Dependencies
+import * as TTY from "node:tty";
+
+// Import Internal Dependencies
+import { Cursor } from "./Cursor.class.js";
+
+export interface ReplaceOptions {
+  clearOutput?: boolean;
+}
+
+export class InputBuffer {
+  cursor: Cursor;
+
+  private output: TTY.WriteStream;
+  private value: string = "";
+
+  constructor(
+    output: TTY.WriteStream
+  ) {
+    this.output = output;
+    this.cursor = new Cursor(this.output);
+  }
+
+  clear() {
+    this.output.moveCursor(this.cursor.offset - this.cursor.position, 0);
+    this.output.moveCursor(-this.value.length, 0);
+    this.output.clearLine(1);
+  }
+
+  cursorIsAtEnd() {
+    return this.cursor.position === this.value.length;
+  }
+
+  append(
+    input: string
+  ): string {
+    this.output.write(input);
+
+    return this.appendValue(input);
+  }
+
+  appendAtCursor(
+    input: string
+  ): string {
+    const rightSideOfValue = this.value.slice(
+      this.cursor.position
+    );
+
+    this.replaceValue(
+      `${this.value.slice(0, this.cursor.position)}${input}${rightSideOfValue}`,
+      ++this.cursor.position
+    );
+
+    this.output.write(`${input}${rightSideOfValue}`);
+    this.output.moveCursor(-rightSideOfValue.length, 0);
+
+    return this.value;
+  }
+
+  appendValue(
+    input: string,
+    cursorLength: number = input.length
+  ): string {
+    this.value += input;
+    this.cursor.position += cursorLength;
+
+    return this.value;
+  }
+
+  appendChar(
+    char: string
+  ): { autocomplete: boolean; } {
+    if (this.cursorIsAtEnd()) {
+      this.appendValue(char);
+
+      return { autocomplete: true };
+    }
+
+    this.appendAtCursor(char);
+
+    return { autocomplete: false };
+  }
+
+  replace(
+    input: string,
+    options: ReplaceOptions = {}
+  ): string {
+    const { clearOutput = false } = options;
+
+    if (clearOutput) {
+      this.clear();
+    }
+    this.output.write(input);
+
+    return this.replaceValue(input);
+  }
+
+  replaceValue(
+    input: string,
+    cursorLength: number = input.length
+  ): string {
+    this.value = input;
+    this.cursor.position = cursorLength;
+
+    return this.value;
+  }
+
+  toString() {
+    return this.value;
+  }
+}