import { describe, it } from "vitest";
import { RuleTester } from "eslint";
import path from "node:path";
import os from "node:os";
import fs from "node:fs";
import rule from "./no-undeclared-rate-limit.js";

function makeFixture({ manifestRateLimit, useCaseBody }) {
  const repoRoot = fs.mkdtempSync(path.join(os.tmpdir(), "nurl-"));
  const featureDir = path.join(repoRoot, "packages", "demo");
  fs.mkdirSync(path.join(featureDir, "src", "application", "use-cases"), {
    recursive: true,
  });
  const rateLimitField =
    manifestRateLimit.length > 0
      ? `, rateLimit: [${manifestRateLimit.map((b) => `"${b}"`).join(", ")}]`
      : "";
  fs.writeFileSync(
    path.join(featureDir, "src", "feature.manifest.ts"),
    `export const demoManifest = defineFeature({
  name: "demo",
  requiredCores: [],
  useCases: {
    signUp: { mutates: true, audits: [], publishes: [], consumes: []${rateLimitField} },
  },
  realtimeChannels: [],
  jobs: [],
} as const);`,
  );
  const useCaseFile = path.join(
    featureDir,
    "src",
    "application",
    "use-cases",
    "sign-up.use-case.ts",
  );
  fs.writeFileSync(useCaseFile, useCaseBody);
  return { repoRoot, useCaseFile };
}

const tester = new RuleTester({
  languageOptions: {
    parser: await import("@typescript-eslint/parser"),
    ecmaVersion: "latest",
    sourceType: "module",
  },
});

describe("no-undeclared-rate-limit", () => {
  it("passes when rateLimit.consume budget matches manifest rateLimit[]", () => {
    const { repoRoot, useCaseFile } = makeFixture({
      manifestRateLimit: ["signUp.ip"],
      useCaseBody: `export const signUpUseCase = (rateLimit) => async (input) => { await rateLimit.consume("signUp.ip", input.ip); };`,
    });
    tester.run("no-undeclared-rate-limit", rule, {
      valid: [
        {
          filename: useCaseFile,
          code: fs.readFileSync(useCaseFile, "utf8"),
          options: [{ repoRoot }],
        },
      ],
      invalid: [],
    });
  });

  it("fires when rateLimit.consume budget is not declared in manifest", () => {
    const { repoRoot, useCaseFile } = makeFixture({
      manifestRateLimit: [],
      useCaseBody: `export const signUpUseCase = (rateLimit) => async (input) => { await rateLimit.consume("signUp.ip", input.ip); };`,
    });
    tester.run("no-undeclared-rate-limit", rule, {
      valid: [],
      invalid: [
        {
          filename: useCaseFile,
          code: fs.readFileSync(useCaseFile, "utf8"),
          options: [{ repoRoot }],
          errors: [
            {
              messageId: "undeclared",
              data: { budget: "signUp.ip", useCase: "signUp" },
            },
          ],
        },
      ],
    });
  });

  it("fires when a declared budget is never consumed in the use-case body", () => {
    const { repoRoot, useCaseFile } = makeFixture({
      manifestRateLimit: ["signUp.ip"],
      useCaseBody: `export const signUpUseCase = () => async () => { return { ok: true }; };`,
    });
    tester.run("no-undeclared-rate-limit", rule, {
      valid: [],
      invalid: [
        {
          filename: useCaseFile,
          code: fs.readFileSync(useCaseFile, "utf8"),
          options: [{ repoRoot }],
          errors: [
            {
              messageId: "unusedDeclaration",
              data: { budget: "signUp.ip", useCase: "signUp" },
            },
          ],
        },
      ],
    });
  });

  it("passes when rateLimit.consume budget matches a RateLimitBudget object in manifest rateLimit[]", () => {
    const repoRoot = fs.mkdtempSync(path.join(os.tmpdir(), "nurl-obj-"));
    const featureDir = path.join(repoRoot, "packages", "demo");
    fs.mkdirSync(path.join(featureDir, "src", "application", "use-cases"), {
      recursive: true,
    });
    fs.writeFileSync(
      path.join(featureDir, "src", "feature.manifest.ts"),
      `export const demoManifest = defineFeature({
  name: "demo",
  requiredCores: [],
  useCases: {
    signUp: { mutates: true, audits: [], publishes: [], consumes: [], rateLimit: [{ name: "ip", window: "1m", budget: 5 }, { name: "account", window: "1h", budget: 10 }] },
  },
  realtimeChannels: [],
  jobs: [],
} as const);`,
    );
    const useCaseFile = path.join(
      featureDir,
      "src",
      "application",
      "use-cases",
      "sign-up.use-case.ts",
    );
    fs.writeFileSync(
      useCaseFile,
      `export const signUpUseCase = (rateLimit) => async (input) => {
  await rateLimit.consume("ip", input.clientIp);
  await rateLimit.consume("account", input.username);
};`,
    );
    tester.run("no-undeclared-rate-limit", rule, {
      valid: [
        {
          filename: useCaseFile,
          code: fs.readFileSync(useCaseFile, "utf8"),
          options: [{ repoRoot }],
        },
      ],
      invalid: [],
    });
  });

  it("is a no-op for non-use-case files", () => {
    const { repoRoot } = makeFixture({
      manifestRateLimit: ["signUp.ip"],
      useCaseBody: `export const signUpUseCase = (rateLimit) => async (input) => { await rateLimit.consume("signUp.ip", input.ip); };`,
    });
    const serviceFile = path.join(
      repoRoot,
      "packages",
      "demo",
      "src",
      "application",
      "services",
      "sign-up.service.ts",
    );
    fs.mkdirSync(path.dirname(serviceFile), { recursive: true });
    fs.writeFileSync(
      serviceFile,
      `export function doWork(rateLimit) { rateLimit.consume("undeclared", "x"); }`,
    );
    tester.run("no-undeclared-rate-limit", rule, {
      valid: [
        {
          filename: serviceFile,
          code: fs.readFileSync(serviceFile, "utf8"),
          options: [{ repoRoot }],
        },
      ],
      invalid: [],
    });
  });
});