/**
 * Unit tests for @sh-mcp/internal-data tools.
 *
 * Strategy:
 *   - All DynamoDB access is replaced by a typed mock that satisfies InternalDataClient.
 *   - AuthContext is a mock with the required `ops:read` scope (or deliberately wrong
 *     scopes for the scope-enforcement tests).
 *   - No AWS SDK, no network, no environment variables required.
 *
 * Coverage:
 *   - Happy path (record found)                for each tool
 *   - Empty result  (record not found → found=false)
 *   - Downstream error (client rejects)        → handler re-throws
 *   - Throttle / retry signal (ProvisionedThroughputExceededException)
 *   - Scope enforcement (missing ops:read)     → ScopeError thrown
 */

import { describe, it, expect, vi, beforeEach } from 'vitest';
import type { InternalDataClient, WorkOrderRecord, PurchaseOrderRecord, SiteRecord } from '../src/client.js';
import { makeTools } from '../src/tools.js';
import type { AuthContext } from '@sh-mcp/shared';

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

function makeCtx(scopes: string[] = ['ops:read']): AuthContext {
  return {
    sub: 'lauren@seahavenind.com',
    scopes: scopes as AuthContext['scopes'],
    aud: 'sh-mcp-ops',
  };
}

function makeMockClient(
  overrides: Partial<InternalDataClient> = {},
): InternalDataClient {
  return {
    getWorkOrder: vi.fn().mockResolvedValue(null),
    getPurchaseOrder: vi.fn().mockResolvedValue(null),
    getSite: vi.fn().mockResolvedValue(null),
    ...overrides,
  };
}

// Fixture records
const WORK_ORDER_RECORD: WorkOrderRecord = {
  workOrderId: 'WO-20240101-001',
  title: 'Replace HVAC filter – Building A',
  status: 'open',
  siteId: 'SITE-NYC-001',
  assignedTo: 'tech1@seahavenind.com',
  createdAt: '2024-01-01T10:00:00Z',
  updatedAt: '2024-01-02T08:00:00Z',
  description: 'Quarterly filter replacement per schedule.',
};

const PURCHASE_ORDER_RECORD: PurchaseOrderRecord = {
  purchaseOrderId: 'PO-2024-00123',
  vendor: 'Acme Supplies',
  status: 'approved',
  totalAmount: 1250.0,
  currency: 'USD',
  issuedAt: '2024-01-05T09:00:00Z',
  updatedAt: '2024-01-06T11:00:00Z',
  lineItems: [
    { description: 'HVAC filter 20x25', quantity: 10, unitPrice: 125.0 },
  ],
};

const SITE_RECORD: SiteRecord = {
  siteId: 'SITE-NYC-001',
  name: 'Sea Haven HQ – New York',
  address: '123 Main St, New York, NY 10001',
  region: 'northeast',
  status: 'active',
  assignedTechnicians: ['tech1@seahavenind.com'],
};

// ---------------------------------------------------------------------------
// Tests — lookup_work_order
// ---------------------------------------------------------------------------

describe('lookup_work_order', () => {
  let client: InternalDataClient;
  let tool: ReturnType<typeof makeTools>[0];

  beforeEach(() => {
    client = makeMockClient();
    [tool] = makeTools(client);
  });

  it('happy path: returns found=true with shaped output for a known work order', async () => {
    (client.getWorkOrder as ReturnType<typeof vi.fn>).mockResolvedValue(WORK_ORDER_RECORD);

    const result = await tool.handler({ workOrderId: 'WO-20240101-001' }, makeCtx());

    expect(result.found).toBe(true);
    expect(result.workOrder).toMatchObject({
      workOrderId: 'WO-20240101-001',
      title: 'Replace HVAC filter – Building A',
      status: 'open',
      siteId: 'SITE-NYC-001',
      assignedTo: 'tech1@seahavenind.com',
    });
    expect(client.getWorkOrder).toHaveBeenCalledWith('WO-20240101-001');
  });

  it('empty result: returns found=false when work order does not exist', async () => {
    (client.getWorkOrder as ReturnType<typeof vi.fn>).mockResolvedValue(null);

    const result = await tool.handler({ workOrderId: 'WO-NOTEXIST' }, makeCtx());

    expect(result.found).toBe(false);
    expect(result.workOrder).toBeUndefined();
  });

  it('error: re-throws when the DynamoDB client rejects', async () => {
    (client.getWorkOrder as ReturnType<typeof vi.fn>).mockRejectedValue(
      new Error('DynamoDB unavailable'),
    );

    await expect(tool.handler({ workOrderId: 'WO-20240101-001' }, makeCtx())).rejects.toThrow(
      'DynamoDB unavailable',
    );
  });

  it('throttle/retry: re-throws ProvisionedThroughputExceededException for the caller to retry', async () => {
    const throttleError = Object.assign(
      new Error('ProvisionedThroughputExceededException: Rate exceeded'),
      { name: 'ProvisionedThroughputExceededException' },
    );
    (client.getWorkOrder as ReturnType<typeof vi.fn>).mockRejectedValue(throttleError);

    await expect(tool.handler({ workOrderId: 'WO-20240101-001' }, makeCtx())).rejects.toMatchObject(
      { name: 'ProvisionedThroughputExceededException' },
    );
  });

  it('scope enforcement: throws when ops:read scope is missing', async () => {
    // The real shared requireScope throws a ScopeError; our mock honours the
    // same contract (imported from @sh-mcp/shared in the handler).
    await expect(
      tool.handler({ workOrderId: 'WO-20240101-001' }, makeCtx([])),
    ).rejects.toThrow();
  });
});

// ---------------------------------------------------------------------------
// Tests — lookup_purchase_order
// ---------------------------------------------------------------------------

describe('lookup_purchase_order', () => {
  let client: InternalDataClient;
  let tool: ReturnType<typeof makeTools>[1];

  beforeEach(() => {
    client = makeMockClient();
    [, tool] = makeTools(client);
  });

  it('happy path: returns found=true with shaped output for a known PO', async () => {
    (client.getPurchaseOrder as ReturnType<typeof vi.fn>).mockResolvedValue(PURCHASE_ORDER_RECORD);

    const result = await tool.handler({ purchaseOrderId: 'PO-2024-00123' }, makeCtx());

    expect(result.found).toBe(true);
    expect(result.purchaseOrder).toMatchObject({
      purchaseOrderId: 'PO-2024-00123',
      vendor: 'Acme Supplies',
      status: 'approved',
      totalAmount: 1250.0,
      currency: 'USD',
    });
    expect(result.purchaseOrder?.lineItems).toHaveLength(1);
    expect(client.getPurchaseOrder).toHaveBeenCalledWith('PO-2024-00123');
  });

  it('empty result: returns found=false when PO does not exist', async () => {
    (client.getPurchaseOrder as ReturnType<typeof vi.fn>).mockResolvedValue(null);

    const result = await tool.handler({ purchaseOrderId: 'PO-NOTEXIST' }, makeCtx());

    expect(result.found).toBe(false);
    expect(result.purchaseOrder).toBeUndefined();
  });

  it('error: re-throws when the DynamoDB client rejects', async () => {
    (client.getPurchaseOrder as ReturnType<typeof vi.fn>).mockRejectedValue(
      new Error('ResourceNotFoundException'),
    );

    await expect(
      tool.handler({ purchaseOrderId: 'PO-2024-00123' }, makeCtx()),
    ).rejects.toThrow('ResourceNotFoundException');
  });

  it('throttle/retry: re-throws ProvisionedThroughputExceededException', async () => {
    const throttleError = Object.assign(
      new Error('ProvisionedThroughputExceededException: Rate exceeded'),
      { name: 'ProvisionedThroughputExceededException' },
    );
    (client.getPurchaseOrder as ReturnType<typeof vi.fn>).mockRejectedValue(throttleError);

    await expect(
      tool.handler({ purchaseOrderId: 'PO-2024-00123' }, makeCtx()),
    ).rejects.toMatchObject({ name: 'ProvisionedThroughputExceededException' });
  });

  it('scope enforcement: throws when ops:read scope is missing', async () => {
    await expect(
      tool.handler({ purchaseOrderId: 'PO-2024-00123' }, makeCtx([])),
    ).rejects.toThrow();
  });
});

// ---------------------------------------------------------------------------
// Tests — lookup_site
// ---------------------------------------------------------------------------

describe('lookup_site', () => {
  let client: InternalDataClient;
  let tool: ReturnType<typeof makeTools>[2];

  beforeEach(() => {
    client = makeMockClient();
    [, , tool] = makeTools(client);
  });

  it('happy path: returns found=true with shaped output for a known site', async () => {
    (client.getSite as ReturnType<typeof vi.fn>).mockResolvedValue(SITE_RECORD);

    const result = await tool.handler({ siteId: 'SITE-NYC-001' }, makeCtx());

    expect(result.found).toBe(true);
    expect(result.site).toMatchObject({
      siteId: 'SITE-NYC-001',
      name: 'Sea Haven HQ – New York',
      address: '123 Main St, New York, NY 10001',
      region: 'northeast',
      status: 'active',
    });
    expect(result.site?.assignedTechnicians).toContain('tech1@seahavenind.com');
    expect(client.getSite).toHaveBeenCalledWith('SITE-NYC-001');
  });

  it('empty result: returns found=false when site does not exist', async () => {
    (client.getSite as ReturnType<typeof vi.fn>).mockResolvedValue(null);

    const result = await tool.handler({ siteId: 'SITE-NOTEXIST' }, makeCtx());

    expect(result.found).toBe(false);
    expect(result.site).toBeUndefined();
  });

  it('error: re-throws when the DynamoDB client rejects', async () => {
    (client.getSite as ReturnType<typeof vi.fn>).mockRejectedValue(
      new Error('Internal server error'),
    );

    await expect(
      tool.handler({ siteId: 'SITE-NYC-001' }, makeCtx()),
    ).rejects.toThrow('Internal server error');
  });

  it('throttle/retry: re-throws ProvisionedThroughputExceededException', async () => {
    const throttleError = Object.assign(
      new Error('ProvisionedThroughputExceededException: Rate exceeded'),
      { name: 'ProvisionedThroughputExceededException' },
    );
    (client.getSite as ReturnType<typeof vi.fn>).mockRejectedValue(throttleError);

    await expect(
      tool.handler({ siteId: 'SITE-NYC-001' }, makeCtx()),
    ).rejects.toMatchObject({ name: 'ProvisionedThroughputExceededException' });
  });

  it('scope enforcement: throws when ops:read scope is missing', async () => {
    await expect(
      tool.handler({ siteId: 'SITE-NYC-001' }, makeCtx([])),
    ).rejects.toThrow();
  });

  it('scope enforcement: throws when a finance scope is present but ops:read is absent', async () => {
    // A token from sh-mcp-finance has finance:read but no ops:read.
    await expect(
      tool.handler({ siteId: 'SITE-NYC-001' }, makeCtx(['finance:read'])),
    ).rejects.toThrow();
  });
});

// ---------------------------------------------------------------------------
// Tool metadata contract tests
// ---------------------------------------------------------------------------

describe('tool metadata', () => {
  it('all tools have required metadata fields', () => {
    const client = makeMockClient();
    const tools = makeTools(client);

    for (const tool of tools) {
      expect(tool.name).toBeTruthy();
      expect(tool.description).toBeTruthy();
      expect(tool.tier).toBe('ops');
      expect(tool.requiredScope).toBe('ops:read');
      expect(tool.inputSchema).toBeTruthy();
      expect(typeof tool.handler).toBe('function');
    }
  });

  it('tool names are the expected identifiers', () => {
    const client = makeMockClient();
    const tools = makeTools(client);
    const names = tools.map((t) => t.name);

    expect(names).toEqual(['lookup_work_order', 'lookup_purchase_order', 'lookup_site']);
  });

  it('input schemas declare required fields and disallow additional properties', () => {
    const client = makeMockClient();
    const [wo, po, site] = makeTools(client);

    expect((wo.inputSchema as { required: string[] }).required).toContain('workOrderId');
    expect((po.inputSchema as { required: string[] }).required).toContain('purchaseOrderId');
    expect((site.inputSchema as { required: string[] }).required).toContain('siteId');

    for (const tool of [wo, po, site]) {
      expect((tool.inputSchema as { additionalProperties: boolean }).additionalProperties).toBe(false);
    }
  });
});