import { after, afterEach, beforeEach, describe, 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 previousQuotaDataDirectory = process.env.OPENCHAMBER_DATA_DIR;
const temporaryQuotaDataDirectory = fs.mkdtempSync(path.join(os.tmpdir(), 'openchamber-vscode-quota-'));
process.env.OPENCHAMBER_DATA_DIR = temporaryQuotaDataDirectory;

// readAuthFile reads ~/.local/share/opencode/auth.json via fs.readFileSync.
// Stub fs to serve a known auth entry so the providers treat themselves as
// configured and proceed straight to fetch.
const ORIGINAL_FS = { ...fs };
const AUTH = JSON.stringify({
  openai: { access: 'test-token' },
  crof: { key: 'test-token' },
  neuralwatt: { key: 'test-token' },
  'opencode-go': { key: 'test-token' },
  'zai-coding-plan': { key: 'test-token' },
  deepseek: { key: 'test-token' },
  'github-copilot': { access: 'test-token' },
  anthropic: { access: 'test-token', refresh: 'test-refresh' },
});
((fs as unknown) as { existsSync: () => boolean }).existsSync = () => true;
((fs as unknown) as { readFileSync: () => string }).readFileSync = () => AUTH;

import { fetchQuotaForProvider } from './quotaProviders';

type MockResponseInit = { ok?: boolean; status?: number };

after(() => {
  if (previousQuotaDataDirectory === undefined) delete process.env.OPENCHAMBER_DATA_DIR;
  else process.env.OPENCHAMBER_DATA_DIR = previousQuotaDataDirectory;
  fs.rmSync(temporaryQuotaDataDirectory, { recursive: true, force: true });
});

const mockResponse = (body: unknown, init: MockResponseInit = {}): Response => ({
  ok: 'ok' in init ? init.ok! : true,
  status: init.status ?? 200,
  json: async () => body,
} as unknown as Response);

// Documented NeuralWatt payload from https://portal.neuralwatt.com/docs/api/quota.
// plan="standard", kwh_included=20.0, kwh_used=13.9023.
const DOCUMENTED_SUBSCRIPTION_PAYLOAD = {
  snapshot_at: '2026-04-16T18:30:00Z',
  balance: { credits_remaining_usd: 32.6774, total_credits_usd: 52.34, credits_used_usd: 19.6626, accounting_method: 'energy' },
  usage: {
    lifetime: { cost_usd: 243.9145, requests: 37801, tokens: 1235477176, energy_kwh: 15.6009 },
    current_month: { cost_usd: 160.1463, requests: 23902, tokens: 1116658995, energy_kwh: 9.7278 },
  },
  limits: { overage_limit_usd: null, rate_limit_tier: 'standard' },
  subscription: {
    plan: 'standard',
    status: 'active',
    billing_interval: 'year',
    current_period_start: '2026-04-11T05:05:25Z',
    current_period_end: '2027-04-11T05:05:25Z',
    auto_renew: true,
    kwh_included: 20.0,
    kwh_used: 13.9023,
    kwh_remaining: 6.0977,
    in_overage: false,
  },
  key: { name: 'my-production-key', allowance: null },
} as const;

let ORIGINAL_FETCH: typeof globalThis.fetch;

beforeEach(() => {
  ORIGINAL_FETCH = globalThis.fetch;
});

afterEach(() => {
  globalThis.fetch = ORIGINAL_FETCH;
});

const stubFetchReturning = (resolver: () => Promise<unknown>): void => {
  globalThis.fetch = (async () => resolver()) as typeof fetch;
};

const stubFetchFailing = (json: () => Promise<unknown>, init: MockResponseInit): void => {
  globalThis.fetch = (async () => ({ json, ...init }) as unknown as Response) as typeof fetch;
};

describe('OpenCode Go quota provider (VS Code parity)', () => {
  test('uses the opencode-go key from auth.json', async () => {
    let request: RequestInit | undefined;
    const legacyPath = path.join(temporaryQuotaDataDirectory, 'quota', 'opencode-go.json');
    fs.mkdirSync(path.dirname(legacyPath), { recursive: true });
    fs.writeFileSync(legacyPath, '{not valid json');
    globalThis.fetch = (async (_url: string, init?: RequestInit) => {
      request = init;
      return mockResponse({ usage: { rolling: { percent: 25, resetsAt: '2026-08-12T12:00:00.000Z' } } });
    }) as typeof fetch;

    const result = await fetchQuotaForProvider('opencode-go');

    assert.equal(result.ok, true);
    assert.equal((request?.headers as Record<string, string>).Authorization, 'Bearer test-token');
    assert.equal(result.usage!.windows['5h']!.usedPercent, 25);
    assert.throws(() => fs.statSync(legacyPath));
  });
});


describe('Crof quota provider (VS Code parity)', () => {
  test('reports credits balance as valueLabel with null percent', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({ usable_requests: 450, credits: 12.3456 })));

    const result = await fetchQuotaForProvider('crof');

    assert.equal(result.ok, true);
    assert.equal(result.providerId, 'crof');
    assert.equal(result.usage!.windows.credits!.usedPercent, null);
    assert.equal(result.usage!.windows.credits!.valueLabel, '$12.35');
  });

  test('tolerates missing credits field', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({ usable_requests: 0 })));

    const result = await fetchQuotaForProvider('crof');

    assert.equal(result.ok, true);
    assert.equal(result.usage!.windows.credits!.valueLabel, undefined);
    assert.equal(result.usage!.windows.credits!.usedPercent, null);
  });

  test('maps 401 to session-expired with CrofAI branding', async () => {
    stubFetchFailing(async () => ({}), { ok: false, status: 401 });

    const result = await fetchQuotaForProvider('crof');

    assert.equal(result.ok, false);
    assert.equal(result.configured, true);
    assert.equal(result.error, 'Session expired — please re-authenticate with CrofAI');
  });

  test('reports invalid-response on JSON parse failure', async () => {
    globalThis.fetch = (async () => ({
      ok: true,
      status: 200,
      json: async () => { throw new SyntaxError('Unexpected token'); },
    }) as unknown as Response) as typeof fetch;

    const result = await fetchQuotaForProvider('crof');

    assert.equal(result.ok, false);
    assert.equal(result.error, 'Invalid response from provider');
  });
});

describe('Codex quota provider (VS Code parity)', () => {
  test('coalesces concurrent refreshes for the same provider', async () => {
    let resolveResponse: ((response: Response) => void) | undefined;
    let requestCount = 0;
    globalThis.fetch = (() => {
      requestCount += 1;
      return new Promise<Response>((resolve) => {
        resolveResponse = resolve;
      });
    }) as typeof fetch;

    const first = fetchQuotaForProvider('codex');
    const second = fetchQuotaForProvider('codex');
    resolveResponse?.(mockResponse({ rate_limit: null }));

    const [firstResult, secondResult] = await Promise.all([first, second]);

    assert.equal(firstResult.ok, true);
    assert.equal(secondResult.ok, true);
    assert.equal(requestCount, 1);
  });

  test('surfaces spend_control individual limit for business accounts', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      plan_type: 'business',
      rate_limit: null,
      credits: { has_credits: true, unlimited: false, balance: null },
      spend_control: {
        individual_limit: {
          limit: '7500',
          used: '2674.8724080324173',
          remaining: '4825.127591967583',
          used_percent: 36,
          remaining_percent: 64,
        },
      },
    })));

    const result = await fetchQuotaForProvider('codex');

    assert.equal(result.ok, true);
    assert.equal(result.usage!.windows.credits!.usedPercent, 36);
    assert.equal(result.usage!.windows.credits!.valueLabel, '2675 / 7500 used');
  });
});

describe('GitHub Copilot quota provider (VS Code parity)', () => {
  test('exposes only premium interactions as the primary usage window', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      quota_reset_date: '2026-09-01T00:00:00Z',
      quota_snapshots: {
        chat: { entitlement: 100, remaining: 80 },
        completions: { entitlement: 1000, remaining: 900 },
        premium_interactions: { entitlement: 300, remaining: 225 },
      },
    })));

    const result = await fetchQuotaForProvider('github-copilot');

    assert.equal(result.ok, true);
    assert.deepEqual(Object.keys(result.usage!.windows), ['premium_interactions']);
    assert.equal(result.usage!.windows.premium_interactions!.usedPercent, 25);
    assert.equal(result.usage!.windows.premium_interactions!.valueLabel, '225 / 300 left');
  });

  test('add-on path mirrors the primary window shaping', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      quota_reset_date: '2026-09-01T00:00:00Z',
      quota_snapshots: {
        premium_interactions: { entitlement: 300, remaining: 225 },
      },
    })));

    const result = await fetchQuotaForProvider('github-copilot-addon');

    assert.equal(result.ok, true);
    assert.deepEqual(Object.keys(result.usage!.windows), ['premium_interactions']);
    assert.equal(result.usage!.windows.premium_interactions!.usedPercent, 25);
  });

  test('reports unlimited plans without a percent', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      quota_reset_date: '2026-09-01T00:00:00Z',
      quota_snapshots: {
        premium_interactions: { unlimited: true, entitlement: -1, remaining: -1 },
      },
    })));

    const result = await fetchQuotaForProvider('github-copilot');

    assert.equal(result.ok, true);
    assert.equal(result.usage!.windows.premium_interactions!.usedPercent, null);
    assert.equal(result.usage!.windows.premium_interactions!.valueLabel, 'Unlimited');
  });

  test('falls back to percent_remaining when entitlement is unusable', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      quota_reset_date: '2026-09-01T00:00:00Z',
      quota_snapshots: {
        premium_interactions: { entitlement: 0, remaining: 0, percent_remaining: 75.5 },
      },
    })));

    const result = await fetchQuotaForProvider('github-copilot');

    assert.equal(result.ok, true);
    assert.ok(Math.abs(result.usage!.windows.premium_interactions!.usedPercent! - 24.5) < 1e-9);
    assert.equal(result.usage!.windows.premium_interactions!.valueLabel, undefined);
  });
});

describe('Claude quota provider (VS Code parity)', () => {
  test('parses current limits, model-scoped limits, and extra usage', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      limits: [
        { kind: 'session', percent: 12, resets_at: '2026-08-20T12:00:00Z', scope: null },
        { kind: 'weekly_all', percent: 34, resets_at: '2026-08-24T12:00:00Z', scope: null },
        { kind: 'weekly_scoped', percent: 56, resets_at: '2026-08-24T12:00:00Z', scope: { model: { display_name: 'Sonnet' } } },
      ],
      spend: {
        enabled: true,
        percent: 25,
        used: { amount_minor: 2500, exponent: 2, currency: 'USD' },
        limit: { amount_minor: 10000, exponent: 2, currency: 'USD' },
      },
    })));

    const result = await fetchQuotaForProvider('claude');

    assert.equal(result.ok, true);
    assert.equal(result.usage?.windows['5h']?.usedPercent, 12);
    assert.equal(result.usage?.windows['7d']?.usedPercent, 34);
    assert.equal(result.usage?.models?.Sonnet?.windows['7d']?.usedPercent, 56);
    assert.equal(result.usage?.windows.extra_usage?.valueLabel, '$25.00 / $100.00');
  });

  test('keeps serving the last good values while Anthropic rate limits', async () => {
    const responses = [
      mockResponse({ five_hour: { utilization: 12, resets_at: '2026-08-20T12:00:00Z' } }),
      {
        ok: false,
        status: 429,
        headers: new Headers({ 'retry-after': '120' }),
        json: async () => ({}),
      } as Response,
    ];
    let requestCount = 0;
    globalThis.fetch = (async () => {
      const response = responses[requestCount];
      requestCount += 1;
      return response;
    }) as typeof fetch;

    const initial = await fetchQuotaForProvider('claude');
    const rateLimited = await fetchQuotaForProvider('claude');
    const duringCooldown = await fetchQuotaForProvider('claude');

    assert.equal(initial.ok, true);
    assert.equal(rateLimited.ok, true);
    assert.equal(duringCooldown.ok, true);
    assert.equal(duringCooldown.usage?.windows['5h']?.usedPercent, 12);
    assert.equal(requestCount, 2);
  });
});

describe('Z.ai quota provider (VS Code parity)', () => {
  test('surfaces 5-hour, weekly, and MCP quota windows', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      data: {
        limits: [
          { type: 'TOKENS_LIMIT', unit: 3, number: 5, percentage: 0 },
          { type: 'TOKENS_LIMIT', unit: 6, number: 1, percentage: 100, nextResetTime: 1785659659993 },
          { type: 'TIME_LIMIT', unit: 5, number: 1, percentage: 0, nextResetTime: 1787128459979 },
        ],
      },
    })));

    const result = await fetchQuotaForProvider('zai-coding-plan');
    const windows = result.usage!.windows;

    assert.equal(result.ok, true);
    assert.equal(windows['5h']!.usedPercent, 0);
    assert.equal(windows['5h']!.windowSeconds, 5 * 60 * 60);
    assert.equal(windows.weekly!.usedPercent, 100);
    assert.equal(windows.weekly!.windowSeconds, 7 * 24 * 60 * 60);
    assert.equal(windows.weekly!.resetAt, 1785659659993);
    assert.equal(windows['MCP Tools']!.usedPercent, 0);
    assert.equal(windows['MCP Tools']!.windowSeconds, 30 * 24 * 60 * 60);
    assert.equal(windows['MCP Tools']!.resetAt, 1787128459979);
  });

  test('maps CREDIT_LIMIT entries to windows with credit value labels and plan level', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      code: 200,
      data: {
        limits: [
          { type: 'CREDIT_LIMIT', unit: 3, number: 5, usage: 12000, currentValue: 65, remaining: 11934, percentage: 1, nextResetTime: 1787257978907 },
          { type: 'CREDIT_LIMIT', unit: 6, number: 1, usage: 60000, currentValue: 65, remaining: 59934, percentage: 1, nextResetTime: 1787844668997 },
        ],
        level: 'pro',
      },
    })));

    const result = await fetchQuotaForProvider('zai-coding-plan');
    const windows = result.usage!.windows;

    assert.equal(result.ok, true);
    assert.equal(result.planLabel, 'pro');
    assert.equal(windows['5h']!.usedPercent, 1);
    assert.equal(windows['5h']!.windowSeconds, 5 * 60 * 60);
    assert.equal(windows['5h']!.resetAt, 1787257978907);
    assert.equal(windows['5h']!.valueLabel, '65 / 12k credits');
    assert.equal(windows.weekly!.usedPercent, 1);
    assert.equal(windows.weekly!.windowSeconds, 7 * 24 * 60 * 60);
    assert.equal(windows.weekly!.resetAt, 1787844668997);
    assert.equal(windows.weekly!.valueLabel, '65 / 60k credits');
  });
});

describe('NeuralWatt quota provider (VS Code parity)', () => {
  test('builds subscription window keyed by plan name (windowSeconds null)', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse(DOCUMENTED_SUBSCRIPTION_PAYLOAD)));

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.equal(result.ok, true);
    assert.equal(result.providerId, 'neuralwatt');

    // Subscription window is keyed by the plan name; windowSeconds is null
    // because the API exposes no kWh window start to derive duration from.
    const window = result.usage!.windows.standard;
    assert.ok(window, 'subscription window should be defined');
    assert.ok(Math.abs((window.usedPercent as number) - (13.9023 / 20.0) * 100) < 1e-2);
    assert.equal(window.windowSeconds, null);
    assert.equal(window.resetAt, Date.parse('2027-04-11T05:05:25Z'));

    // allowance is null → credits_balance also surfaced
    assert.ok(result.usage!.windows.credits_balance, 'credits_balance should be defined');
    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '$32.68');
  });

  test('falls back to plan_limit title when plan is missing', async () => {
    const payload = {
      ...DOCUMENTED_SUBSCRIPTION_PAYLOAD,
      subscription: { ...DOCUMENTED_SUBSCRIPTION_PAYLOAD.subscription, plan: null },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.ok(result.usage!.windows.plan_limit);
    assert.ok(Math.abs((result.usage!.windows.plan_limit!.usedPercent as number) - (13.9023 / 20.0) * 100) < 1e-2);
  });

  test('marks in-overage subscription as 100%, still shows credits', async () => {
    const payload = {
      ...DOCUMENTED_SUBSCRIPTION_PAYLOAD,
      subscription: { ...DOCUMENTED_SUBSCRIPTION_PAYLOAD.subscription, in_overage: true, kwh_used: 25.0 },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.standard;
    assert.ok(window);
    assert.equal(window!.usedPercent, 100);
    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '$32.68');
  });

  test('surfaces subscription and allowance windows (allowance keyed by period, key name in valueLabel)', async () => {
    const payload = {
      ...DOCUMENTED_SUBSCRIPTION_PAYLOAD,
      balance: { credits_remaining_usd: 200 },
      key: {
        name: 'Prod',
        allowance: { limit_usd: 100, period: 'monthly', spent_usd: 25, blocked: false, reset_at: '2026-08-01T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const subWindow = result.usage!.windows.standard;
    assert.ok(subWindow);
    assert.ok(Math.abs((subWindow!.usedPercent as number) - (13.9023 / 20.0) * 100) < 1e-2);

    // Allowance window is keyed by the localized period label ("monthly");
    // key name flows through valueLabel for identification.
    const allowWindow = result.usage!.windows.monthly;
    assert.ok(allowWindow);
    assert.equal(allowWindow!.usedPercent, 25);
    assert.equal(allowWindow!.valueLabel, 'Prod');
    assert.equal(allowWindow!.resetAt, Date.parse('2026-08-01T00:00:00Z'));

    assert.equal(result.usage!.windows.credits_balance, undefined);
  });

  test('uses allowance effective limit = min(limit, credits_remaining + spent)', async () => {
    const payload = {
      balance: { credits_remaining_usd: 30 },
      subscription: null,
      key: {
        name: 'prod-key',
        allowance: { limit_usd: 100, period: 'monthly', spent_usd: 25, blocked: false, reset_at: '2026-08-01T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.monthly;
    assert.ok(window);
    // effectiveLimit = min(100, 30+25) = 55; usedPercent = 25/55 * 100 ≈ 45.4545
    assert.ok(Math.abs((window!.usedPercent as number) - (25 / 55) * 100) < 1e-2);
    assert.equal(window!.windowSeconds, 30 * 86400);
    assert.equal(window!.resetAt, Date.parse('2026-08-01T00:00:00Z'));
    assert.equal(window!.valueLabel, 'prod-key');
    assert.equal(result.usage!.windows.credits_balance, undefined);
  });

  test('binds allowance ceiling to limit when limit < credits_remaining + spent', async () => {
    const payload = {
      balance: { credits_remaining_usd: 200 },
      subscription: null,
      key: {
        name: 'prod-key',
        allowance: { limit_usd: 100, period: 'monthly', spent_usd: 25, blocked: false, reset_at: '2026-08-01T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.monthly;
    assert.ok(window);
    assert.equal(window!.usedPercent, 25);
  });

  test('uses weekly as the allowance key when period is weekly', async () => {
    const payload = {
      balance: { credits_remaining_usd: 200 },
      subscription: null,
      key: {
        name: 'Prod',
        allowance: { limit_usd: 100, period: 'weekly', spent_usd: 20, blocked: false, reset_at: '2026-07-04T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.weekly;
    assert.ok(window);
    assert.equal(window!.windowSeconds, 604800);
    assert.equal(window!.resetAt, Date.parse('2026-07-04T00:00:00Z'));
    assert.equal(window!.valueLabel, 'Prod');
  });

  test('uses daily as the allowance key when period is daily', async () => {
    const payload = {
      balance: { credits_remaining_usd: 200 },
      subscription: null,
      key: {
        name: 'Prod',
        allowance: { limit_usd: 10, period: 'daily', spent_usd: 2, blocked: false, reset_at: '2026-07-04T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.daily;
    assert.ok(window);
    assert.equal(window!.windowSeconds, 86400);
    assert.equal(window!.resetAt, Date.parse('2026-07-04T00:00:00Z'));
  });

  test('falls back to billing_cycle when allowance period is missing or unknown', async () => {
    const payload = {
      balance: { credits_remaining_usd: 200 },
      subscription: null,
      key: {
        name: 'Prod',
        allowance: { limit_usd: 100, period: 'fortnightly', spent_usd: 25, blocked: false, reset_at: '2026-08-01T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.billing_cycle;
    assert.ok(window);
    assert.equal(window!.usedPercent, 25);
  });

  test('marks blocked allowance as 100% with valueLabel set', async () => {
    const payload = {
      balance: { credits_remaining_usd: 30 },
      subscription: null,
      key: {
        name: 'sample',
        allowance: { limit_usd: 50, period: 'monthly', spent_usd: 10, blocked: true, reset_at: '2026-08-01T00:00:00Z' },
      },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    const window = result.usage!.windows.monthly;
    assert.ok(window);
    assert.equal(window!.usedPercent, 100);
    assert.equal(window!.valueLabel, 'sample');
  });

  test('falls back to credits_balance when neither subscription nor allowance exists', async () => {
    const payload = {
      balance: { credits_remaining_usd: 32.6774 },
      subscription: null,
      key: { name: 'sample', allowance: null },
    };
    stubFetchReturning(() => Promise.resolve(mockResponse(payload)));

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '$32.68');
    assert.equal(result.usage!.windows.credits_balance!.usedPercent, null);
  });

  test('maps 401 to session-expired', async () => {
    stubFetchFailing(async () => ({}), { ok: false, status: 401 });

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.equal(result.ok, false);
    assert.equal(result.error, 'Session expired — please re-authenticate with NeuralWatt');
  });

  test('reports invalid-response on JSON parse failure', async () => {
    globalThis.fetch = (async () => ({
      ok: true,
      status: 200,
      json: async () => { throw new SyntaxError('Unexpected token'); },
    }) as unknown as Response) as typeof fetch;

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.equal(result.ok, false);
    assert.equal(result.error, 'Invalid response from provider');
  });

  test('returns no-quota-data on a 200 payload with no usable windows', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      balance: { credits_remaining_usd: null },
      subscription: null,
      key: { name: 'sample', allowance: null },
    })));

    const result = await fetchQuotaForProvider('neuralwatt');

    assert.equal(result.ok, false);
    assert.equal(result.configured, true);
    assert.equal(result.error, 'No quota data in response');
    assert.equal(result.usage, null);
  });

  // Restore fs so other test files (which use the real auth file) are unaffected.
  test('teardown: restore fs', () => {
    const fsMock = fs as unknown as { existsSync: unknown; readFileSync: unknown };
    fsMock.existsSync = ORIGINAL_FS.existsSync;
    fsMock.readFileSync = ORIGINAL_FS.readFileSync;
  });
});

describe('DeepSeek quota provider (VS Code parity)', () => {
  beforeEach(() => {
    const fsMock = fs as unknown as { existsSync: () => boolean; readFileSync: () => string };
    fsMock.existsSync = () => true;
    fsMock.readFileSync = () => AUTH;
  });

  test('builds credits_balance window from documented USD payload (string balance)', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      is_available: true,
      balance_infos: [
        { currency: 'USD', total_balance: '7.54', granted_balance: '0.00', topped_up_balance: '7.54' },
      ],
    })));

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, true);
    assert.equal(result.providerId, 'deepseek');
    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '$7.54');
    assert.equal(result.usage!.windows.credits_balance!.usedPercent, null);
    assert.equal(result.usage!.windows.credits_balance!.windowSeconds, null);
    assert.equal(result.usage!.windows.credits_balance!.resetAt, null);
  });

  test('falls back to CNY entry with ¥ symbol when no USD entry is present', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      is_available: true,
      balance_infos: [
        { currency: 'CNY', total_balance: '100.00', granted_balance: '0.00', topped_up_balance: '100.00' },
      ],
    })));

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, true);
    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '¥100.00');
  });

  test('maps 401 to session-expired', async () => {
    stubFetchFailing(async () => ({}), { ok: false, status: 401 });

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, false);
    assert.equal(result.error, 'Session expired — please re-authenticate with DeepSeek');
  });

  test('reports a normalized timeout error', async () => {
    stubFetchReturning(() => Promise.reject(new DOMException('The operation timed out.', 'TimeoutError')));

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, false);
    assert.equal(result.error, 'Request timed out');
  });

  test('returns no-quota-data on a 200 payload with no usable balance', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      is_available: true,
      balance_infos: [{ currency: 'USD', total_balance: '', granted_balance: '0.00', topped_up_balance: '0.00' }],
    })));

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, false);
    assert.equal(result.configured, true);
    assert.equal(result.error, 'No quota data in response');
    assert.equal(result.usage, null);
  });

  test('keeps a literal zero balance as a valid valueLabel', async () => {
    stubFetchReturning(() => Promise.resolve(mockResponse({
      is_available: true,
      balance_infos: [{ currency: 'USD', total_balance: '0.00', granted_balance: '0.00', topped_up_balance: '0.00' }],
    })));

    const result = await fetchQuotaForProvider('deepseek');

    assert.equal(result.ok, true);
    assert.equal(result.usage!.windows.credits_balance!.valueLabel, '$0.00');
  });

  test('teardown: restore fs', () => {
    const fsMock = fs as unknown as { existsSync: unknown; readFileSync: unknown };
    fsMock.existsSync = ORIGINAL_FS.existsSync;
    fsMock.readFileSync = ORIGINAL_FS.readFileSync;
  });
});