import assert from "node:assert/strict";
import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { test } from "node:test";
import { computeLineHash } from "../core/hash.ts";
import { DEFAULT_CONFIG } from "../pi/config.ts";
import { parseFileHeader } from "../pi/grep-output.ts";
import { makeGrepOverrideWithBackend } from "../pi/grep-tool.ts";
import { reportOf } from "../pi/report.ts";
import { callTool } from "../pi/tool-call.testing.ts";

test("repeated real-rg query with increasing limits → stable traversal order and a growing row prefix", async (t) => {
  const dir = await mkdtemp(join(tmpdir(), "hl-grep-order-integration-"));
  t.after(() => rm(dir, { recursive: true, force: true }));
  await mkdir(join(dir, "sub"));
  await writeFile(join(dir, ".ignore"), "a-ignored.txt\n");
  const names = ["z.txt", "sub/b.txt", "sub.txt", "a.txt", "sub/a-ignored.txt"];
  const sourceLine = (name: string, line: number) => `needle ${name} ${line}`;
  for (const name of names) {
    await writeFile(join(dir, name), `${sourceLine(name, 1)}\n${sourceLine(name, 2)}\n`);
  }
  const tool = makeGrepOverrideWithBackend(dir, DEFAULT_CONFIG, {});
  for (const [roots, expectedNames] of [
    [["."], ["a.txt", "sub/b.txt", "sub.txt", "z.txt"]],
    [
      ["z.txt", "sub", "a.txt"],
      ["z.txt", "sub/b.txt", "a.txt"],
    ],
    [
      ["sub", ".", "sub/a-ignored.txt"],
      ["sub/b.txt", "a.txt", "sub.txt", "z.txt", "sub/a-ignored.txt"],
    ],
    [
      ["sub/a-ignored.txt", ".", "a.txt"],
      ["sub/a-ignored.txt", "a.txt", "sub/b.txt", "sub.txt", "z.txt"],
    ],
  ]) {
    const expected = expectedNames.flatMap((name) =>
      [1, 2].map((line) => {
        const source = sourceLine(name, line);
        return `${name}\n${line}#${computeLineHash(line, source, DEFAULT_CONFIG.hashLen)}│${source}`;
      }),
    );
    for (const multiline of [false, true]) {
      await t.test(JSON.stringify({ roots, multiline }), async () => {
        let previous: string[] = [];
        for (const limit of [1, 3, expected.length]) {
          const query = {
            path: roots.map((root) => join(dir, root)),
            pattern: "needle",
            literal: true,
            multiline,
            limit,
          };
          const first = await callTool(tool, query);
          const second = await callTool(tool, query);
          for (const result of [first, second]) {
            assert.equal(result.isError, undefined, JSON.stringify(reportOf(result, "grep")));
          }
          assert.deepEqual(first.content, second.content);
          const body = first.content[0];
          assert.ok(body.type === "text");
          const rows: string[] = [];
          let path = "";
          for (const line of body.text.split("\n")) {
            const header = parseFileHeader(line);
            if (header) path = header.path;
            else if (/^\d+#[0-9A-Z]+│/.test(line)) rows.push(`${path}\n${line}`);
          }
          assert.deepEqual(rows, expected.slice(0, limit));
          assert.deepEqual(rows.slice(0, previous.length), previous);
          previous = rows;
        }
      });
    }
  }
});