import test from "node:test";
import assert from "node:assert/strict";

import { DEFAULT_SETTINGS } from "../lib/defaults.js";
import { buildChatGptUrl, MAX_URL_CHARS } from "../lib/build-url.js";

const withSettings = (overrides) => ({ ...DEFAULT_SETTINGS, ...overrides });
const queryOf = (url) => new URL(url).searchParams.get("q");
const paramsOf = (url) => [...new URL(url).searchParams.keys()];

test("defaults produce only the q parameter on the root path", () => {
  assert.equal(
    buildChatGptUrl(DEFAULT_SETTINGS, "hello"),
    "https://chatgpt.com/?q=hello",
  );
});

test("an empty or whitespace-only query omits q entirely", () => {
  for (const raw of ["", "   ", "\n\t", null, undefined]) {
    const url = buildChatGptUrl(DEFAULT_SETTINGS, raw);
    assert.equal(paramsOf(url).includes("q"), false, `raw=${JSON.stringify(raw)}`);
    assert.equal(url, "https://chatgpt.com/");
  }
});

test("model is sent only when non-empty after trimming", () => {
  assert.equal(queryOf(buildChatGptUrl(withSettings({ model: "auto" }), "hi")), "hi");
  assert.equal(new URL(buildChatGptUrl(withSettings({ model: "auto" }), "hi")).searchParams.get("model"), "auto");
  assert.equal(new URL(buildChatGptUrl(withSettings({ model: "  auto  " }), "hi")).searchParams.get("model"), "auto");
  for (const model of ["", "   "]) {
    assert.equal(paramsOf(buildChatGptUrl(withSettings({ model }), "hi")).includes("model"), false);
  }
});

test("temporaryChat and webSearch each appear only when enabled", () => {
  assert.equal(paramsOf(buildChatGptUrl(DEFAULT_SETTINGS, "hi")).includes("temporary-chat"), false);
  assert.equal(paramsOf(buildChatGptUrl(DEFAULT_SETTINGS, "hi")).includes("hints"), false);

  const temp = new URL(buildChatGptUrl(withSettings({ temporaryChat: true }), "hi"));
  assert.equal(temp.searchParams.get("temporary-chat"), "true");

  const search = new URL(buildChatGptUrl(withSettings({ webSearch: true }), "hi"));
  assert.equal(search.searchParams.get("hints"), "search");
});

test("all four URL-affecting settings combine, q first", () => {
  const url = buildChatGptUrl(
    withSettings({
      model: "auto",
      temporaryChat: true,
      webSearch: true,
      promptTemplate: "Explain: {query}",
    }),
    "entropy",
  );
  assert.deepEqual(paramsOf(url), ["q", "model", "temporary-chat", "hints"]);
  assert.equal(queryOf(url), "Explain: entropy");
});

test("openIn never influences the URL", () => {
  const base = buildChatGptUrl(DEFAULT_SETTINGS, "hi");
  for (const openIn of ["new-tab", "background-tab", "new-window"]) {
    assert.equal(buildChatGptUrl(withSettings({ openIn }), "hi"), base);
  }
});

test("special characters survive encoding round-trip", () => {
  const raw = 'a & b # c ? d = e + f "g" <h> 100% 😀 日本語\nnewline';
  const url = buildChatGptUrl(DEFAULT_SETTINGS, raw);
  assert.equal(queryOf(url), raw);
  assert.equal(url.includes(" "), false);
  assert.equal(url.includes("#"), false);
});

test("the template replaces every {query} occurrence", () => {
  const url = buildChatGptUrl(withSettings({ promptTemplate: "{query} / {query}" }), "x");
  assert.equal(queryOf(url), "x / x");
});

test("a template without {query} is treated as a prefix, never dropping the query", () => {
  const url = buildChatGptUrl(withSettings({ promptTemplate: "Be concise:" }), "why");
  assert.equal(queryOf(url), "Be concise: why");
});

test("an empty or whitespace-only template yields the bare query", () => {
  for (const promptTemplate of ["", "   "]) {
    assert.equal(queryOf(buildChatGptUrl(withSettings({ promptTemplate }), "why")), "why");
  }
});

test("a non-string template degrades to the bare query", () => {
  assert.equal(queryOf(buildChatGptUrl(withSettings({ promptTemplate: null }), "why")), "why");
});

test("an over-long prompt is truncated to fit the URL budget", () => {
  const url = buildChatGptUrl(DEFAULT_SETTINGS, "x".repeat(20000));
  assert.ok(url.length <= MAX_URL_CHARS, `length was ${url.length}`);
  assert.ok(queryOf(url).length > 0);
  assert.ok(queryOf(url).length < 20000);
});

test("truncation accounts for the other parameters", () => {
  const settings = withSettings({ model: "some-long-model-slug", temporaryChat: true, webSearch: true });
  const url = buildChatGptUrl(settings, "x".repeat(20000));
  assert.ok(url.length <= MAX_URL_CHARS, `length was ${url.length}`);
  assert.equal(new URL(url).searchParams.get("model"), "some-long-model-slug");
  assert.equal(new URL(url).searchParams.get("hints"), "search");
});

test("truncation never splits a surrogate pair", () => {
  const url = buildChatGptUrl(DEFAULT_SETTINGS, "😀".repeat(9000));
  assert.ok(url.length <= MAX_URL_CHARS);
  const lonelySurrogate = /[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]/;
  assert.equal(lonelySurrogate.test(queryOf(url)), false);
});

test("truncation never leaves a severed percent-escape", () => {
  const url = buildChatGptUrl(DEFAULT_SETTINGS, "😀 ".repeat(9000));
  assert.equal(/%[0-9A-Fa-f]?$/.test(url), false);
  assert.doesNotThrow(() => decodeURIComponent(new URL(url).search.slice(3)));
});

test("truncation prefers a whitespace boundary, so no word is cut in half", () => {
  const url = buildChatGptUrl(DEFAULT_SETTINGS, "lorem ipsum ".repeat(2000));
  const tokens = queryOf(url).trim().split(/\s+/);
  assert.ok(tokens.length > 1);
  for (const token of tokens) {
    assert.ok(token === "lorem" || token === "ipsum", `truncated mid-word: ${token}`);
  }
});

test("a query needing no truncation is left byte-identical", () => {
  const raw = "a modest question about thermodynamics";
  assert.equal(queryOf(buildChatGptUrl(DEFAULT_SETTINGS, raw)), raw);
});