import { assert, assertEquals } from "@std/assert";
import { withDom } from "@berry/util/dom.ts";
import { TERMINAL_PALETTE } from "@berry/util/palette.ts";
import { ansiOutput } from "./ansi-view.ts";

Deno.test("coloured output appends in place and resets for replacement snapshots", async (t) => {
  await withDom(async () => {
    const element = document.createElement("pre");
    const show = ansiOutput(element);
    const colour = (value: string) => {
      const span = document.createElement("span");
      span.style.color = value;
      return span.style.color;
    };
    await t.step("colour arrives as soon as a split escape is completed", () => {
      assertEquals(element.hidden, true);
      show("start\x1b[38;2;12;");
      assertEquals(element.textContent, "start");
      const first = element.firstChild;
      show("start\x1b[38;2;12;34;56mred");
      assertEquals(element.textContent, "startred");
      assertEquals(element.firstChild, first);
      assertEquals(
        (element.lastElementChild as HTMLElement).style.color,
        colour("rgb(12, 34, 56)"),
      );
      const red = element.lastChild!;
      const text = red.firstChild;
      show("start\x1b[38;2;12;34;56mredder\x1b[0mplain");
      assertEquals(element.textContent, "startredderplain");
      assertEquals(element.childNodes[1], red);
      assertEquals(red.firstChild, text);
      assertEquals(red.textContent, "redder");
      assertEquals((element.lastElementChild as HTMLElement).style.color, "");
    });
    await t.step("a truncated or replaced result resets text, style and pending controls", () => {
      show("\x1b[31mold\x1b]unfinished");
      show("replacement");
      assertEquals(element.textContent, "replacement");
      assertEquals((element.firstElementChild as HTMLElement).style.color, "");
      show("");
      assertEquals(element.hidden, true);
      assertEquals(element.childNodes.length, 0);
      show("new\x1b[32mgreen");
      assertEquals(element.textContent, "newgreen");
      assertEquals(
        (element.lastElementChild as HTMLElement).style.color,
        colour(TERMINAL_PALETTE[2]),
      );
    });
    await t.step("output stays literal text rather than markup", () => {
      show('<script>alert("x")</script>\x1b[31m<a>red</a>');
      assertEquals(element.textContent, '<script>alert("x")</script><a>red</a>');
      assertEquals(element.querySelector("script, a"), null);
    });
    await t.step("large outputs bound individual text-node edits without splitting emoji", () => {
      show("");
      const text = "x".repeat(16383) + "😀" + "y".repeat(50000);
      show(text);
      assertEquals(element.textContent, text);
      for (const span of element.children) {
        assert(span.textContent!.length < 20000);
        assert(!/[\ud800-\udbff]$/.test(span.textContent!));
        assert(!/^[\udc00-\udfff]/.test(span.textContent!));
      }
      const first = element.firstChild;
      show(text + "end");
      assertEquals(element.firstChild, first);
      assertEquals(element.textContent, text + "end");
    });
  });
});