import { afterEach, describe, expect, it, vi } from 'vitest';
import {
  ApiClientError,
  buildPreviewUrl,
  createPrivateLink,
  deletePrivateLink,
  deletePublicLink,
  listPrivateLinks,
  listPublicLinks,
  updatePrivateLink,
} from '../src/lib/api';

const originalFetch = globalThis.fetch;

function mockFetch(responder: (input: RequestInfo | URL, init?: RequestInit) => {
  status?: number;
  body?: unknown;
  statusText?: string;
}) {
  const calls: { path: string; init?: RequestInit }[] = [];
  const fetchMock = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const path = typeof input === 'string' ? input : new URL(input.toString()).pathname;
    calls.push({ path, init });
    const { status = 200, body = {}, statusText = 'OK' } = responder(input, init);
    return new Response(JSON.stringify(body), {
      status,
      statusText,
      headers: { 'content-type': 'application/json' },
    });
  });
  globalThis.fetch = fetchMock as unknown as typeof fetch;
  return {
    calls,
    fetchMock,
  };
}

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

/** Like mockFetch but returns a bodyless response (for 204 / empty 200). */
function mockFetchNoBody(responder: (input: RequestInfo | URL, init?: RequestInit) => {
  status?: number;
  statusText?: string;
}) {
  const calls: { path: string; init?: RequestInit }[] = [];
  const fetchMock = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const path = typeof input === 'string' ? input : new URL(input.toString()).pathname;
    calls.push({ path, init });
    const { status = 204, statusText = 'No Content' } = responder(input, init);
    return new Response(null, { status, statusText });
  });
  globalThis.fetch = fetchMock as unknown as typeof fetch;
  return { calls, fetchMock };
}

describe('api client', () => {
  it('listPrivateLinks sends GET with credentials to /api/links/private', async () => {
    const { calls } = mockFetch(() => ({
      body: { links: [{ id: 'link_1', alias: 'docs', scope: 'private', linkType: 'redirect' }] },
    }));

    const result = await listPrivateLinks();

    expect(calls).toHaveLength(1);
    expect(calls[0].path).toBe('/api/links/private');
    expect(calls[0].init?.method).toBeUndefined();
    expect(calls[0].init?.credentials).toBe('include');
    expect(result.links).toHaveLength(1);
    expect(result.links[0].alias).toBe('docs');
  });

  it('createPrivateLink POSTs a normalized JSON body', async () => {
    const { calls } = mockFetch((_input, init) => ({
      status: 201,
      body: { link: { id: 'new', alias: 'docs', scope: 'private', linkType: 'redirect' } },
    }));

    const result = await createPrivateLink({
      alias: 'Docs',
      linkType: 'redirect',
      targetUrl: 'https://example.com',
      description: '  spaced  ',
    });

    expect(calls[0].init?.method).toBe('POST');
    expect(calls[0].init?.credentials).toBe('include');
    const body = JSON.parse(calls[0].init?.body as string);
    expect(body).toEqual({
      alias: 'Docs',
      linkType: 'redirect',
      targetUrl: 'https://example.com',
      contentMarkdown: null,
      description: '  spaced  ',
    });
    expect(result.link.id).toBe('new');
  });

  it('updatePrivateLink targets the link id with PATCH', async () => {
    const { calls } = mockFetch(() => ({
      body: { link: { id: 'link_1', alias: 'renamed', scope: 'private', linkType: 'custom' } },
    }));

    await updatePrivateLink('link_1', { alias: 'renamed', linkType: 'custom', contentMarkdown: '# Hi' });

    expect(calls[0].path).toBe('/api/links/private/link_1');
    expect(calls[0].init?.method).toBe('PATCH');
    const body = JSON.parse(calls[0].init?.body as string);
    expect(body.linkType).toBe('custom');
    expect(body.targetUrl).toBeNull();
    expect(body.contentMarkdown).toBe('# Hi');
  });

  it('deletePrivateLink issues a DELETE request', async () => {
    const { calls } = mockFetch(() => ({ body: { ok: true } }));

    const result = await deletePrivateLink('link_1');

    expect(calls[0].path).toBe('/api/links/private/link_1');
    expect(calls[0].init?.method).toBe('DELETE');
    expect(result.ok).toBe(true);
  });

  it('deletePrivateLink normalizes a 204 No Content response to { ok: true }', async () => {
    const { calls } = mockFetchNoBody(() => ({ status: 204 }));

    const result = await deletePrivateLink('link_1');

    expect(calls[0].path).toBe('/api/links/private/link_1');
    expect(calls[0].init?.method).toBe('DELETE');
    expect(result).toEqual({ ok: true });
  });

  it('deletePublicLink normalizes a 204 No Content response to { ok: true }', async () => {
    const { calls } = mockFetchNoBody(() => ({ status: 204 }));

    const result = await deletePublicLink('link_1');

    expect(calls[0].path).toBe('/api/admin/public-links/link_1');
    expect(calls[0].init?.method).toBe('DELETE');
    expect(result).toEqual({ ok: true });
  });

  it('deletePrivateLink normalizes an empty 200 body to { ok: true }', async () => {
    mockFetchNoBody(() => ({ status: 200 }));

    const result = await deletePrivateLink('link_1');

    expect(result).toEqual({ ok: true });
  });

  it('listPublicLinks reads /api/links/public', async () => {
    const { calls } = mockFetch(() => ({ body: { links: [] } }));

    await listPublicLinks();

    expect(calls[0].path).toBe('/api/links/public');
  });

  it('encodes link ids containing special path segments', async () => {
    const { calls } = mockFetch(() => ({ body: { ok: true } }));

    await deletePrivateLink('link/with/slash');

    expect(calls[0].path).toBe('/api/links/private/link%2Fwith%2Fslash');
  });

  it('throws ApiClientError with the server error message on non-ok responses', async () => {
    mockFetch(() => ({ status: 409, body: { error: 'Alias already exists' } }));

    await expect(createPrivateLink({ alias: 'dup', linkType: 'redirect', targetUrl: 'https://x' }))
      .rejects.toMatchObject({ name: 'ApiClientError', status: 409, message: 'Alias already exists' });
  });

  it('falls back to status text when the body has no error field', async () => {
    mockFetch(() => ({ status: 500, body: {}, statusText: 'Internal Server Error' }));

    await expect(listPrivateLinks()).rejects.toMatchObject({
      name: 'ApiClientError',
      status: 500,
      message: '500 Internal Server Error',
    });
  });
});

describe('buildPreviewUrl', () => {
  it('returns null for empty target URLs', () => {
    expect(buildPreviewUrl(null)).toBeNull();
    expect(buildPreviewUrl('')).toBeNull();
  });

  it('substitutes known template placeholders with encoded values', () => {
    const url = 'https://example.com/search?q={query}&lang={lang}';
    expect(buildPreviewUrl(url, { query: 'go links', lang: 'en' }))
      .toBe('https://example.com/search?q=go%20links&lang=en');
  });

  it('replaces leftover placeholders with a readable token', () => {
    expect(buildPreviewUrl('https://example.com/{region}/view')).toBe('https://example.com/example/view');
  });
});