import { describe, expect, it } from "vitest";
import {
  createProviderUsageFetch,
  makeResponse,
} from "../../src/test-utils/provider-usage-fetch.js";
import { fetchCopilotUsage } from "./usage.js";

describe("fetchCopilotUsage", () => {
  it("returns HTTP errors for failed requests", async () => {
    const mockFetch = createProviderUsageFetch(async () => makeResponse(500, "boom"));
    const result = await fetchCopilotUsage("token", 5000, mockFetch);

    expect(result.error).toBe("HTTP 500");
    expect(result.windows).toHaveLength(0);
  });

  it("parses premium/chat usage from remaining percentages", async () => {
    const mockFetch = createProviderUsageFetch(async (_url, init) => {
      const headers = (init?.headers as Record<string, string> | undefined) ?? {};
      expect(headers.Authorization).toBe("token token");
      expect(headers["X-Github-Api-Version"]).toBe("2025-04-01");

      return makeResponse(200, {
        quota_snapshots: {
          premium_interactions: { percent_remaining: 20 },
          chat: { percent_remaining: 75 },
        },
        copilot_plan: "pro",
      });
    });

    const result = await fetchCopilotUsage("token", 5000, mockFetch);

    expect(result.plan).toBe("pro");
    expect(result.windows).toEqual([
      { label: "Premium", usedPercent: 80 },
      { label: "Chat", usedPercent: 25 },
    ]);
  });

  it("defaults missing snapshot values and clamps invalid remaining percentages", async () => {
    const mockFetch = createProviderUsageFetch(async () =>
      makeResponse(200, {
        quota_snapshots: {
          premium_interactions: { percent_remaining: null },
          chat: { percent_remaining: 140 },
        },
      }),
    );

    const result = await fetchCopilotUsage("token", 5000, mockFetch);

    expect(result.windows).toEqual([
      { label: "Premium", usedPercent: 100 },
      { label: "Chat", usedPercent: 0 },
    ]);
    expect(result.plan).toBeUndefined();
  });

  it("returns an empty window list when quota snapshots are missing", async () => {
    const mockFetch = createProviderUsageFetch(async () =>
      makeResponse(200, {
        copilot_plan: "free",
      }),
    );

    const result = await fetchCopilotUsage("token", 5000, mockFetch);

    expect(result).toEqual({
      provider: "github-copilot",
      displayName: "Copilot",
      windows: [],
      plan: "free",
    });
  });
});