fork(fix): Clone AMLL 并修复 BUG

- 将AMLL Clone到本以地进行修复和优化(emm虽然这很不优雅但是暂时无时间做子模块和Fork)
- 修复在当前播放歌词行不可见的视口Seek会出现滚动偏移的问题

amll-local/packages/lyric/test/lyl.test.ts

@@ -0,0 +1,129 @@
+import { describe, expect, it } from "vitest";
+import { parseLyl, stringifyLyl } from "../src/formats/lyl";
+
+describe("lyl", () => {
+	it("parses basic line-timestamped lines", () => {
+		const lines = parseLyl("[1000,2000]Hello\n[3000,4000]World");
+
+		expect(lines).toHaveLength(2);
+		expect(lines[0].startTime).toBe(1000);
+		expect(lines[0].endTime).toBe(2000);
+		expect(lines[0].words[0].word).toBe("Hello");
+		expect(lines[1].startTime).toBe(3000);
+		expect(lines[1].endTime).toBe(4000);
+		expect(lines[1].words[0].word).toBe("World");
+	});
+
+	it("handles CRLF and ignores non-lyric lines", () => {
+		const lines = parseLyl(
+			"[type:LyricifyLines]\r\n#comment\r\n{meta:true}\r\nno timestamp\r\n[1000,2000]Hello",
+		);
+
+		expect(lines).toHaveLength(1);
+		expect(lines[0].startTime).toBe(1000);
+		expect(lines[0].endTime).toBe(2000);
+		expect(lines[0].words[0].word).toBe("Hello");
+	});
+
+	it("ignores lines with bad timestamps", () => {
+		const lines = parseLyl(
+			"[1000,2000]Hello\n[invalid,2000]Bad\n[-1,2000]Bad\n[NaN,NaN]Bad\n[3000,4000]World",
+		);
+
+		expect(lines).toHaveLength(2);
+		expect(lines[0].startTime).toBe(1000);
+		expect(lines[0].endTime).toBe(2000);
+		expect(lines[0].words[0].word).toBe("Hello");
+		expect(lines[1].startTime).toBe(3000);
+		expect(lines[1].endTime).toBe(4000);
+		expect(lines[1].words[0].word).toBe("World");
+	});
+
+	it("identifies background lines with parentheses", () => {
+		const lines = parseLyl(
+			"[1000,2000](Hello)\n[3000,4000]（Hi）\n[5000,6000]World",
+		);
+
+		expect(lines).toHaveLength(3);
+		expect(lines[0].isBG).toBe(true);
+		expect(lines[0].words[0].word).toBe("Hello");
+		expect(lines[1].isBG).toBe(true);
+		expect(lines[1].words[0].word).toBe("Hi");
+		expect(lines[2].isBG).toBe(false);
+		expect(lines[2].words[0].word).toBe("World");
+	});
+
+	it("trims whitespace from lines and ignore empty lines", () => {
+		const lines = parseLyl(
+			"[0,500]\n[600,1000]   \n[1000,2000]   Hello   \n\n[3000,4000] World \n[5000,6000]   \n",
+		);
+		expect(lines).toHaveLength(2);
+		expect(lines[0].words[0].word).toBe("Hello");
+		expect(lines[1].words[0].word).toBe("World");
+	});
+
+	it("stringifies with header and bg markers", () => {
+		const result = stringifyLyl([
+			{
+				startTime: 1000,
+				endTime: 2000,
+				words: [
+					{ startTime: 1000, endTime: 2000, word: "Hello", romanWord: "" },
+				],
+				translatedLyric: "",
+				romanLyric: "",
+				isBG: true,
+				isDuet: false,
+			},
+			{
+				startTime: 3000,
+				endTime: 4000,
+				words: [
+					{ startTime: 3000, endTime: 4000, word: "World", romanWord: "" },
+				],
+				translatedLyric: "",
+				romanLyric: "",
+				isBG: false,
+				isDuet: false,
+			},
+		]);
+
+		expect(result).toBe(
+			"[type:LyricifyLines]\n[1000,2000](Hello)\n[3000,4000]World",
+		);
+	});
+
+	it("normalizes invalid timestamps when stringifying", () => {
+		const result = stringifyLyl([
+			{
+				startTime: Number.NaN,
+				endTime: Number.POSITIVE_INFINITY,
+				words: [{ startTime: 0, endTime: 0, word: "Hello", romanWord: "" }],
+				translatedLyric: "",
+				romanLyric: "",
+				isBG: false,
+				isDuet: false,
+			},
+			{
+				startTime: -1,
+				endTime: -2,
+				words: [{ startTime: 0, endTime: 0, word: "World", romanWord: "" }],
+				translatedLyric: "",
+				romanLyric: "",
+				isBG: false,
+				isDuet: false,
+			},
+		]);
+
+		expect(result).toBe("[type:LyricifyLines]\n[0,0]Hello\n[0,0]World");
+	});
+
+	it("keeps parse -> stringify -> parse stable for content and timing", () => {
+		const input = "[1000,2000]Hello\n[3000,4000](World)";
+		const first = parseLyl(input);
+		const text = stringifyLyl(first);
+		const second = parseLyl(text);
+
+		expect(second).toEqual(first);
+	});
+});