From e21944b4a4efc2ec17405d1484b184a952fa003f Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Thu, 22 Feb 2024 14:57:12 -0500
Subject: [PATCH] Add incremental (character by character) search functionality

---
 justfile               |  6 +--
 src/common/all_test.ts | 13 +++++++
 src/common/editor.ts   | 88 ++++++++++++++++++++++++++++++------------
 src/common/types.ts    | 15 +++++--
 4 files changed, 91 insertions(+), 31 deletions(-)

diff --git a/justfile b/justfile
index 98432e3..b338e7d 100644
--- a/justfile
+++ b/justfile
@@ -50,11 +50,11 @@ bun-run file="":
 # Lint code and check types
 deno-check:
 	deno lint
-	deno check --unstable  --all -c deno.jsonc ./src/deno/*.ts ./src/common/*.ts
+	deno check --unstable-ffi  --all -c deno.jsonc ./src/deno/*.ts ./src/common/*.ts
 
 # Test with deno
 deno-test:
-	deno test --allow-all --unstable
+	deno test --allow-all --unstable-ffi
 
 # Create test coverage report with deno
 deno-coverage:
@@ -62,4 +62,4 @@ deno-coverage:
 
 # Run with deno
 deno-run file="":
-	deno run --allow-all --allow-ffi --deny-hrtime --unstable ./src/scroll.ts {{file}}
+	deno run --allow-all --allow-ffi --deny-hrtime --unstable-ffi ./src/scroll.ts {{file}}
diff --git a/src/common/all_test.ts b/src/common/all_test.ts
index 8b0c3a9..57e98c1 100644
--- a/src/common/all_test.ts
+++ b/src/common/all_test.ts
@@ -138,6 +138,19 @@ testSuite({
 			assertEquals(p.x, 5);
 			assertEquals(p.y, 7);
 		},
+		'.from': () => {
+			const p1 = Position.at(1, 2);
+			const p2 = Position.from(p1);
+
+			p1.x = 2;
+			p1.y = 4;
+
+			assertEquals(p1.x, 2);
+			assertEquals(p1.y, 4);
+
+			assertEquals(p2.x, 1);
+			assertEquals(p2.y, 2);
+		},
 	},
 	Row: {
 		'.default': () => {
diff --git a/src/common/editor.ts b/src/common/editor.ts
index 17692d4..6b5ac14 100644
--- a/src/common/editor.ts
+++ b/src/common/editor.ts
@@ -231,10 +231,18 @@ class Editor {
 		return true;
 	}
 
-	public async prompt(p: string): Promise<string | null> {
+	public async prompt(
+		p: string,
+		callback?: (query: string, char: string) => void,
+	): Promise<string | null> {
 		const { term } = await getRuntime();
 
 		let res = '';
+		const maybeCallback = (query: string, char: string) => {
+			if (callback !== undefined) {
+				callback(query, char);
+			}
+		};
 
 		outer: while (true) {
 			if (p.includes('%s')) {
@@ -250,26 +258,38 @@ class Editor {
 					continue;
 				}
 
-				// End the prompt
-				if (char === KeyCommand.Enter) {
-					this.setStatusMessage('');
-					if (res.length === 0) {
+				switch (char) {
+					// Remove the last character from the prompt input
+					case KeyCommand.Backspace:
+					case KeyCommand.Delete:
+						res = truncate(res, res.length - 1);
+						maybeCallback(res, char);
+						continue outer;
+
+					// End the prompt
+					case KeyCommand.Escape:
+						this.setStatusMessage('');
+						maybeCallback(res, char);
+
 						return null;
-					}
 
-					return res;
+					// Return the input and end the prompt
+					case KeyCommand.Enter:
+						if (res.length > 0) {
+							this.setStatusMessage('');
+							maybeCallback(res, char);
+							return res;
+						}
+						break;
+
+					// Add to the prompt result
+					default:
+						if (!isControl(char)) {
+							res += char;
+						}
 				}
 
-				// Allow backspacing
-				if (char === KeyCommand.Backspace || char === KeyCommand.Delete) {
-					res = truncate(res, res.length - 1);
-					continue outer;
-				}
-
-				// Add to the prompt result
-				if (!isControl(char!)) {
-					res += char;
-				}
+				maybeCallback(res, char);
 			}
 		}
 	}
@@ -278,14 +298,32 @@ class Editor {
 	 * Find text within the document
 	 */
 	public async find(): Promise<void> {
-		const res = await this.prompt('Search: %s (ESC to cancel)');
-		if (res !== null && res.length > 0) {
-			const pos = this.#document.find(res);
-			if (pos !== null) {
-				this.#cursor = pos;
-			} else {
-				this.setStatusMessage('Not found');
-			}
+		const savedCursor = Position.from(this.#cursor);
+		const savedOffset = Position.from(this.#offset);
+
+		const query = await this.prompt(
+			'Search: %s (ESC to cancel)',
+			(query: string, key: string) => {
+				if (key === KeyCommand.Enter || key === KeyCommand.Escape) {
+					return;
+				}
+
+				if (query !== null && query.length > 0) {
+					const pos = this.#document.find(query);
+					if (pos !== null) {
+						this.#cursor = pos;
+					} else {
+						this.setStatusMessage('Not found');
+					}
+				}
+			},
+		);
+
+		// Return to document position before search
+		// when you cancel the search (press the escape key)
+		if (query !== null) {
+			this.#cursor = Position.from(savedCursor);
+			this.#offset = Position.from(savedOffset);
 		}
 	}
 
diff --git a/src/common/types.ts b/src/common/types.ts
index d7953a6..271a26c 100644
--- a/src/common/types.ts
+++ b/src/common/types.ts
@@ -139,7 +139,7 @@ export class Position {
 	public x: number;
 	public y: number;
 
-	private constructor(x: number, y: number) {
+	private constructor(x: number = 0, y: number = 0) {
 		this.x = x;
 		this.y = y;
 	}
@@ -148,9 +148,18 @@ export class Position {
 		return new Position(x, y);
 	}
 
-	public static default(): Position {
-		return new Position(0, 0);
+	public static from(p: Position): Position {
+		return new Position(p.x, p.y);
 	}
+
+	public static default(): Position {
+		return new Position();
+	}
+}
+
+export enum SearchDirection {
+	Forward = 1,
+	Backward = -1,
 }
 
 // ----------------------------------------------------------------------------