import test from "node:test";
import assert from "node:assert/strict";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";

const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-combo-test-route-"));
process.env.DATA_DIR = TEST_DATA_DIR;

const core = await import("../../src/lib/db/core.ts");
const combosDb = await import("../../src/lib/db/combos.ts");
const route = await import("../../src/app/api/combos/test/route.ts");

const originalFetch = globalThis.fetch;

async function resetStorage() {
  core.resetDbInstance();
  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
}

async function createTestCombo(models = ["openrouter/openai/gpt-5.4"]) {
  return combosDb.createCombo({
    name: "strict-live-test",
    models,
    strategy: "priority",
  });
}

function makeRequest(comboName = "strict-live-test") {
  return new Request("http://localhost/api/combos/test", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ comboName }),
  });
}

test.beforeEach(async () => {
  globalThis.fetch = originalFetch;
  await resetStorage();
});

test.afterEach(() => {
  globalThis.fetch = originalFetch;
});

test.after(() => {
  globalThis.fetch = originalFetch;
  core.resetDbInstance();
  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
});

test("combo test route marks a model healthy only when it returns assistant text", async () => {
  await createTestCombo();

  const fetchCalls = [];
  globalThis.fetch = async (url, init = {}) => {
    fetchCalls.push({ url: String(url), init });
    return new Response(
      JSON.stringify({
        choices: [
          {
            message: {
              role: "assistant",
              content: "OK",
            },
          },
        ],
      }),
      {
        status: 200,
        headers: { "content-type": "application/json" },
      }
    );
  };

  const response = await route.POST(makeRequest());
  const body = await response.json();
  const forwardedBody = JSON.parse(fetchCalls[0].init.body);

  assert.equal(response.status, 200);
  assert.equal(fetchCalls.length, 1);
  assert.equal(fetchCalls[0].url, "http://localhost/v1/chat/completions");
  assert.equal(fetchCalls[0].init.headers["X-Internal-Test"], "combo-health-check");
  assert.equal(fetchCalls[0].init.headers["X-OmniRoute-No-Cache"], "true");
  assert.match(fetchCalls[0].init.headers["X-Request-Id"], /^combo-test-/);
  assert.equal(forwardedBody.model, "openrouter/openai/gpt-5.4");
  assert.equal(forwardedBody.messages[0].content, "Reply with OK only.");
  assert.equal(forwardedBody.max_tokens, 64);
  assert.equal(forwardedBody.temperature, 0);
  assert.equal(body.resolvedBy, "openrouter/openai/gpt-5.4");
  assert.equal(body.results[0].status, "ok");
  assert.equal(body.results[0].responseText, "OK");
});

test("combo test route treats empty successful responses as failures", async () => {
  await createTestCombo();

  globalThis.fetch = async () =>
    new Response(
      JSON.stringify({
        choices: [
          {
            message: {
              role: "assistant",
              content: "",
            },
          },
        ],
      }),
      {
        status: 200,
        headers: { "content-type": "application/json" },
      }
    );

  const response = await route.POST(makeRequest());
  const body = await response.json();

  assert.equal(response.status, 200);
  assert.equal(body.resolvedBy, null);
  assert.equal(body.results[0].status, "error");
  assert.equal(body.results[0].statusCode, 200);
  assert.match(body.results[0].error, /no text content/i);
});

test("combo test route accepts reasoning-only completions as healthy smoke-test responses", async () => {
  await createTestCombo();

  globalThis.fetch = async () =>
    new Response(
      JSON.stringify({
        choices: [
          {
            finish_reason: "length",
            message: {
              role: "assistant",
              content: "",
            },
          },
        ],
        usage: {
          prompt_tokens: 6,
          completion_tokens: 12,
          total_tokens: 18,
          completion_tokens_details: {
            reasoning_tokens: 12,
          },
        },
      }),
      {
        status: 200,
        headers: { "content-type": "application/json" },
      }
    );

  const response = await route.POST(makeRequest());
  const body = await response.json();

  assert.equal(response.status, 200);
  assert.equal(body.resolvedBy, "openrouter/openai/gpt-5.4");
  assert.equal(body.results[0].status, "ok");
  assert.equal(body.results[0].responseText, "[reasoning-only completion]");
});

test("combo test route surfaces provider errors instead of downgrading them to reachability", async () => {
  await createTestCombo();

  globalThis.fetch = async () =>
    new Response(
      JSON.stringify({
        error: {
          message: "Upstream rejected this request shape",
        },
      }),
      {
        status: 422,
        headers: { "content-type": "application/json" },
      }
    );

  const response = await route.POST(makeRequest());
  const body = await response.json();

  assert.equal(response.status, 200);
  assert.equal(body.resolvedBy, null);
  assert.equal(body.results[0].status, "error");
  assert.equal(body.results[0].statusCode, 422);
  assert.equal(body.results[0].error, "Upstream rejected this request shape");
  assert.equal("probeMethod" in body.results[0], false);
});

test("combo test route launches model probes concurrently while preserving combo order", async () => {
  await createTestCombo(["provider/first", "provider/second", "provider/third"]);

  const fetchCalls = [];
  const resolvers = [];
  globalThis.fetch = (url, init = {}) =>
    new Promise((resolve) => {
      fetchCalls.push({ url: String(url), init });
      resolvers.push(resolve);
    });

  const responsePromise = route.POST(makeRequest());
  await new Promise((resolve) => setTimeout(resolve, 0));

  assert.equal(fetchCalls.length, 3);
  assert.deepEqual(
    fetchCalls.map(({ init }) => JSON.parse(init.body).model),
    ["provider/first", "provider/second", "provider/third"]
  );

  resolvers[2](
    new Response(
      JSON.stringify({
        choices: [{ message: { role: "assistant", content: "THIRD" } }],
      }),
      { status: 200, headers: { "content-type": "application/json" } }
    )
  );
  resolvers[1](
    new Response(
      JSON.stringify({
        choices: [{ message: { role: "assistant", content: "SECOND" } }],
      }),
      { status: 200, headers: { "content-type": "application/json" } }
    )
  );
  resolvers[0](
    new Response(
      JSON.stringify({
        choices: [{ message: { role: "assistant", content: "FIRST" } }],
      }),
      { status: 200, headers: { "content-type": "application/json" } }
    )
  );

  const response = await responsePromise;
  const body = await response.json();

  assert.equal(response.status, 200);
  assert.equal(body.resolvedBy, "provider/first");
  assert.deepEqual(
    body.results.map((result) => ({
      model: result.model,
      status: result.status,
      responseText: result.responseText,
    })),
    [
      { model: "provider/first", status: "ok", responseText: "FIRST" },
      { model: "provider/second", status: "ok", responseText: "SECOND" },
      { model: "provider/third", status: "ok", responseText: "THIRD" },
    ]
  );
});