import assert from "node:assert/strict";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import { afterEach, describe, it } from "vitest";

import { evaluateTargets, formatSummary, walk } from "./verify-test-density.mjs";

const tempRoots = [];

function makeRoot() {
  const root = fs.mkdtempSync(path.join(os.tmpdir(), "verify-test-density-"));
  tempRoots.push(root);
  return root;
}

function writeFile(root, filePath, contents = "export {};") {
  const fullPath = path.join(root, filePath);
  fs.mkdirSync(path.dirname(fullPath), { recursive: true });
  fs.writeFileSync(fullPath, contents, "utf8");
}

afterEach(() => {
  for (const root of tempRoots.splice(0)) {
    fs.rmSync(root, { force: true, recursive: true });
  }
});

describe("verify-test-density", () => {
  it("counts source and test files while ignoring generated and declaration files", () => {
    const root = makeRoot();
    writeFile(root, "src/index.ts");
    writeFile(root, "src/component.tsx");
    writeFile(root, "src/component.test.tsx");
    writeFile(root, "src/types.d.ts");
    writeFile(root, "src/generated/client.ts");
    writeFile(root, "src/.react-router/types.ts");
    writeFile(root, "src/node_modules/pkg/source.ts");

    assert.deepEqual(walk(path.join(root, "src")), { source: 2, test: 1 });
  });

  it("passes, fails, and skips targets using stable report lines", () => {
    const root = makeRoot();
    writeFile(root, "well/a.ts");
    writeFile(root, "well/a.test.ts");
    writeFile(root, "weak/a.ts");
    writeFile(root, "weak/b.ts");

    const result = evaluateTargets(
      [
        { name: "well-covered", root: "well", minRatio: 0.5 },
        { name: "under-covered", root: "weak", minRatio: 0.5 },
        { name: "empty", root: "missing", minRatio: 0.5 },
      ],
      root
    );

    assert.deepEqual(result.passes, [
      "PASS well-covered source=1 tests=1 ratio=1.000 min=0.500",
      "SKIP empty no source files",
    ]);
    assert.deepEqual(result.failures, ["FAIL under-covered source=2 tests=0 ratio=0.000 min=0.500 (drift=-0.500)"]);
    assert.equal(formatSummary(result), "Summary: 2 passed, 0 observed, 1 failed");
  });
});