import { describe, it, expect } from "vitest";
import { readdirSync, readFileSync } from "node:fs";
import { join } from "node:path";

/**
 * Guards against the "two Zavřít buttons" bug class.
 *
 * The shared <Modal> (src/admin/ui/Modal.tsx) ALWAYS renders a primary submit
 * button (text = `submitText`) and — unless `hideCancel` is set — a secondary
 * cancel button (text = `cancelText`, default "Zrušit"). A close-only modal
 * therefore sets `submitText="Zavřít"`; if it ALSO leaves the cancel button on,
 * the user sees two buttons that both just close the dialog — and when
 * `cancelText` is "Zavřít" too, two literally-identical "Zavřít" buttons
 * (the production bug found on the "paid received invoice" detail modal).
 *
 * Rule enforced: any <Modal> whose `submitText` is a "Zavřít…" label (i.e. its
 * only action is to close) MUST pass `hideCancel`. Close-only modals get a
 * single button. See PlanCellModal / PlanCategoriesModal for the correct shape.
 */

const ADMIN_DIR = join(__dirname, "..", "admin");

function tsxFiles(dir: string): string[] {
  const out: string[] = [];
  for (const entry of readdirSync(dir, { withFileTypes: true })) {
    const full = join(dir, entry.name);
    if (entry.isDirectory()) out.push(...tsxFiles(full));
    else if (entry.name.endsWith(".tsx")) out.push(full);
  }
  return out;
}

/**
 * Extract every `<Modal …>` opening-tag substring from a source string.
 * Brace- and string-aware so arrow functions (`=>`) and conditional props
 * (`{cond ? "a" : "b"}`) inside the tag don't terminate it early.
 */
function modalOpeningTags(src: string): string[] {
  const tags: string[] = [];
  let i = 0;
  while ((i = src.indexOf("<Modal", i)) !== -1) {
    const after = src[i + 6];
    // Must be the <Modal> component, not <ModalSomething>.
    if (after && !/[\s>/]/.test(after)) {
      i += 6;
      continue;
    }
    let depth = 0;
    let quote: string | null = null;
    let j = i + 6;
    for (; j < src.length; j++) {
      const c = src[j];
      if (quote) {
        if (c === quote && src[j - 1] !== "\\") quote = null;
        continue;
      }
      if (c === '"' || c === "'" || c === "`") quote = c;
      else if (c === "{") depth++;
      else if (c === "}") depth--;
      else if (c === ">" && depth === 0) break;
    }
    tags.push(src.slice(i, j + 1));
    i = j + 1;
  }
  return tags;
}

/** Value of a JSX prop: `name="..."`, `name={...}` (balanced), or boolean. */
function propValue(tag: string, name: string): string | null {
  const re = new RegExp(`\\b${name}\\b`);
  const m = re.exec(tag);
  if (!m) return null;
  let k = m.index + m[0].length;
  while (k < tag.length && /\s/.test(tag[k])) k++;
  if (tag[k] !== "=") return ""; // boolean prop (e.g. `hideCancel`)
  k++;
  while (k < tag.length && /\s/.test(tag[k])) k++;
  if (tag[k] === '"' || tag[k] === "'") {
    const q = tag[k];
    const end = tag.indexOf(q, k + 1);
    return tag.slice(k + 1, end);
  }
  if (tag[k] === "{") {
    let depth = 0;
    for (let p = k; p < tag.length; p++) {
      if (tag[p] === "{") depth++;
      else if (tag[p] === "}" && --depth === 0) return tag.slice(k, p + 1);
    }
  }
  return null;
}

describe("Modal close-only buttons", () => {
  const offenders: string[] = [];

  for (const file of tsxFiles(ADMIN_DIR)) {
    const src = readFileSync(file, "utf8");
    for (const tag of modalOpeningTags(src)) {
      const submit = propValue(tag, "submitText");
      const isCloseOnly = submit != null && submit.includes("Zavřít");
      const hasHideCancel = propValue(tag, "hideCancel") != null;
      if (isCloseOnly && !hasHideCancel) {
        const title = propValue(tag, "title") ?? "(no title)";
        offenders.push(`${file.replace(ADMIN_DIR, "admin")} — ${title}`);
      }
    }
  }

  it("close-only modals (submitText='Zavřít') set hideCancel — no duplicate close button", () => {
    expect(
      offenders,
      `These <Modal>s render a close-only 'Zavřít' submit alongside a redundant ` +
        `cancel button (two buttons that both just close). Add hideCancel:\n` +
        offenders.map((o) => `  • ${o}`).join("\n"),
    ).toEqual([]);
  });
});