import { assertEquals } from "@std/assert";
import { TERMINAL_PALETTE } from "@berry/util/palette.ts";
import { ansiParser, type AnsiRun, ansiRuns } from "./ansi.ts";

Deno.test("ANSI output preserves literal text, whitespace, and newlines", () => {
  const text = '  <script>alert("&")</script>\n\tend\n';
  assertEquals(ansiRuns(text), [{ text, style: {} }]);
  assertEquals(ansiRuns(""), []);
});

Deno.test("ANSI colours and emphasis persist across lines until reset", () => {
  assertEquals(ansiRuns("before\x1b[1;31mred\nline\x1b[22m normal\x1b[39m after"), [
    { text: "before", style: {} },
    { text: "red\nline", style: { color: TERMINAL_PALETTE[1], "font-weight": "bold" } },
    { text: " normal", style: { color: TERMINAL_PALETTE[1] } },
    { text: " after", style: {} },
  ]);
  assertEquals(ansiRuns("\x1b[2;94;103mdim\x1b[mplain"), [
    {
      text: "dim",
      style: {
        color: TERMINAL_PALETTE[12],
        "background-color": TERMINAL_PALETTE[11],
        opacity: "0.5",
      },
    },
    { text: "plain", style: {} },
  ]);
});

Deno.test("ANSI extended colours support the palette, cube, grayscale, and RGB", () => {
  assertEquals(
    ansiRuns("\x1b[38;5;2mpalette\x1b[38;5;196mcube\x1b[48;5;244mgray\x1b[38;2;12;34;56mrgb"),
    [
      { text: "palette", style: { color: TERMINAL_PALETTE[2] } },
      { text: "cube", style: { color: "rgb(255, 0, 0)" } },
      {
        text: "gray",
        style: { color: "rgb(255, 0, 0)", "background-color": "rgb(128, 128, 128)" },
      },
      {
        text: "rgb",
        style: { color: "rgb(12, 34, 56)", "background-color": "rgb(128, 128, 128)" },
      },
    ],
  );
});

Deno.test("ANSI resets foreground and background independently and clears decorations", () => {
  assertEquals(ansiRuns("\x1b[3;4;9;32;41mstyled\x1b[39mbackground\x1b[49;23;24;29mplain"), [
    {
      text: "styled",
      style: {
        color: TERMINAL_PALETTE[2],
        "background-color": TERMINAL_PALETTE[1],
        "font-style": "italic",
        "text-decoration": "underline line-through",
      },
    },
    {
      text: "background",
      style: {
        "background-color": TERMINAL_PALETTE[1],
        "font-style": "italic",
        "text-decoration": "underline line-through",
      },
    },
    { text: "plain", style: {} },
  ]);
});

Deno.test("ANSI reverse video uses defaults and can be turned off", () => {
  assertEquals(ansiRuns("\x1b[7mreverse\x1b[27mplain"), [
    { text: "reverse", style: { color: "var(--panel)", "background-color": "var(--text)" } },
    { text: "plain", style: {} },
  ]);
});

Deno.test("unsupported terminal controls and OSC links keep their visible text", () => {
  const text =
    "\x1b[?25l\x1b[2K\x1b[H\x1b]0;title\x07\x1b]8;;https://example.com\x1b\\link\x1b]8;;\x07\x1b[999m end";
  assertEquals(ansiRuns(text).map((run) => run.text).join(""), "link end");
});

Deno.test("incomplete streaming escapes stay hidden and render once complete", () => {
  const partial = "start\x1b[38;2;12;";
  assertEquals(ansiRuns(partial), [{ text: "start", style: {} }]);
  assertEquals(ansiRuns(partial + "34;56mend"), [
    { text: "start", style: {} },
    { text: "end", style: { color: "rgb(12, 34, 56)" } },
  ]);
  assertEquals(ansiRuns("text\x1b]unfinished title"), [{ text: "text", style: {} }]);
});

Deno.test("malformed extended colours do not consume their components as SGR styles", () => {
  assertEquals(ansiRuns("\x1b[38;2;999;1;2mtext\x1b[48;5;999mend"), [
    { text: "text", style: {} },
    { text: "end", style: {} },
  ]);
});

Deno.test("ANSI streaming preserves styles and hides escapes at every chunk boundary", () => {
  const sources = [
    "before\x1b[1;31mred\nline\x1b[22m normal\x1b[39m after",
    "\x1b[38;2;12;34;56mrgb\x1b[48;5;244mgray\x1b[0mplain",
    "\x1b]8;;https://example.com\x1b\\link\x1b]8;;\x07 end",
    "\x1b[?25l\x1b[2K\x1b[H\x1b]0;title\x07text\x1b(B end",
    "text\x1b[38;2;1;",
  ];
  const characters = (runs: AnsiRun[]) =>
    runs.flatMap(({ text, style }) => [...text].map((text) => ({ text, style })));
  for (const source of sources) {
    const expected = characters(ansiRuns(source));
    for (let split = 0; split <= source.length; split++) {
      const parser = ansiParser();
      assertEquals(
        characters([
          ...parser.write(source.slice(0, split)),
          ...parser.write(source.slice(split)),
        ]),
        expected,
        `split at ${split}`,
      );
    }
    const parser = ansiParser();
    assertEquals(characters([...source].flatMap((char) => parser.write(char))), expected);
  }
});

Deno.test("ANSI streaming discards long control payloads without leaking them or losing later styles", () => {
  const parser = ansiParser();
  assertEquals(parser.write("\x1b]0;"), []);
  for (let i = 0; i < 100; i++) assertEquals(parser.write("x".repeat(10000)), []);
  assertEquals(parser.write("\x1b"), []);
  assertEquals(parser.write("\\\x1b[32mgreen"), [
    { text: "green", style: { color: TERMINAL_PALETTE[2] } },
  ]);
  assertEquals(parser.write("\x1b[" + "1;".repeat(10000)), []);
  assertEquals(parser.write("mstill green\x1b[mplain"), [
    { text: "still green", style: { color: TERMINAL_PALETTE[2] } },
    { text: "plain", style: {} },
  ]);
});