import assert from "node:assert";
import { after, describe, it } from "node:test";

import { buildApp } from "./server.js";
import { setServers } from "node:dns";

describe("API endpoints", () => {
  const app = buildApp();

  after(async () => {
    await app.close();
  });

  it("GET /health returns 200 and status ok", async () => {
    const response = await app.inject({
      method: "GET",
      url: "/health",
    });

    assert.equal(response.statusCode, 200);
    assert.deepEqual(response.json(), {
      status: "ok",
    });
  });

  it("GET /ready returns 200 and dependency status", async () => {
    const app = buildApp(undefined, async () => true);

    try {
      const response = await app.inject({
        method: "GET",
        url: "/ready",
      });

      assert.equal(response.statusCode, 200);
      assert.deepEqual(response.json(), {
        status: "ready",
        dependencies: {
          ollama: "available",
        },
      });
    } finally {
      await app.close();
    }
  });

  it("GET /ready returns 503 when Ollama is unavailable", async () => {
    const app = buildApp(undefined, async () => false);

    try {
      const response = await app.inject({
        method: "GET",
        url: "/ready",
      });

      assert.equal(response.statusCode, 503);
      assert.deepEqual(response.json(), {
        status: "not-ready",
        dependencies: {
          ollama: "unavailable",
        },
      });
    } finally {
      await app.close();
    }
  });

  it("POST /echo returns the validated message", async () => {
    const response = await app.inject({
      method: "POST",
      url: "/echo",
      payload: {
        message: "Hello, world!",
      },
    });

    assert.equal(response.statusCode, 200);
    assert.deepEqual(response.json(), {
      message: "Hello, world!",
    });
  });

  it("POST /echo accepts a 500-character message", async () => {
    const message = "a".repeat(500);

    const response = await app.inject({
      method: "POST",
      url: "/echo",
      payload: { message },
    });

    assert.equal(response.statusCode, 200);
    assert.deepEqual(response.json(), { message });
  });

  it("POST /generate returns generated text", async () => {
    const app = buildApp(async (prompt) => {
      assert.equal(prompt, "Explain a REST API.");
      return "A REST API enables software systems to communicate.";
    });

    try {
      const response = await app.inject({
        method: "POST",
        url: "/generate",
        payload: {
          message: "Explain a REST API.",
        },
      });

      assert.equal(response.statusCode, 200);
      assert.deepEqual(response.json(), {
        response: "A REST API enables software systems to communicate.",
      });
    } finally {
      await app.close();
    }
  });

  it("POST /generate returns 503 when generation fails", async () => {
    const app = buildApp(async () => {
      throw new Error("Ollama is unavailable");
    });

    try {
      const response = await app.inject({
        method: "POST",
        url: "/generate",
        payload: {
          message: "Explain a REST API.",
        },
      });

      assert.equal(response.statusCode, 503);
      assert.deepEqual(response.json(), {
        error: "Generation service unavailable",
      });
      assert.equal(response.body.includes("Ollama is unavailable"), false);
    } finally {
      await app.close();
    }
  });

  it("POST /echo rejects an empty message", async () => {
    const response = await app.inject({
      method: "POST",
      url: "/echo",
      payload: {
        message: "",
      },
    });

    assert.equal(response.statusCode, 400);
    assert.deepEqual(response.json(), {
      error: "Invalid request body",
    });
  });

  it("POST /echo rejects a message longer than 500 characters", async () => {
    const message = "a".repeat(501);

    const response = await app.inject({
      method: "POST",
      url: "/echo",
      payload: { message },
    });

    assert.equal(response.statusCode, 400);
    assert.deepEqual(response.json(), {
      error: "Invalid request body",
    });
  });

  it("POST /echo rejects a non-string message", async () => {
    const message = "a".repeat(501);

    const response = await app.inject({
      method: "POST",
      url: "/echo",
      payload: {
        message: 123,
      },
    });

    assert.equal(response.statusCode, 400);
    assert.deepEqual(response.json(), {
      error: "Invalid request body",
    });
  });

  it("returns 404 for an unknown endpoint", async () => {
    const response = await app.inject({
      method: "GET",
      url: "/does-not-exist",
    });

    assert.equal(response.statusCode, 404);
    assert.deepEqual(response.json(), {
      error: "Not Found",
    });
  });

  it("returns a generic 500 response for unexpected error", async () => {
    const response = await app.inject({
      method: "GET",
      url: "/test-error",
    });

    assert.equal(response.statusCode, 500);
    assert.deepEqual(response.json(), {
      error: "Internal Server Error",
    });
    assert.equal(response.body.includes("Sensitive internal detail"), false);
  });
});