// @vitest-environment node
import http from 'node:http'
import type { AddressInfo } from 'node:net'
import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import path from 'node:path'
import { afterAll, beforeAll, beforeEach, describe, expect, it } from 'vitest'
import { parseConfig } from './config.ts'
import { createHub } from './server.ts'

/* A fake Technitium: answers `canned(path, query)` and records every request. */
interface Fake {
  server: http.Server
  url: string
  calls: { path: string; query: URLSearchParams }[]
  canned: (path: string, query: URLSearchParams) => unknown
  down: boolean
}

function fakeUpstream(canned: Fake['canned']): Promise<Fake> {
  return new Promise((resolve) => {
    const fake: Fake = { server: http.createServer(), url: '', calls: [], canned, down: false }
    fake.server.on('request', (req, res) => {
      if (fake.down) {
        req.socket.destroy()
        return
      }
      const url = new URL(req.url ?? '/', 'http://fake')
      const apiPath = url.pathname.replace(/^\/api\//, '')
      fake.calls.push({ path: apiPath, query: url.searchParams })
      res.setHeader('content-type', 'application/json')
      res.end(JSON.stringify({ status: 'ok', response: fake.canned(apiPath, url.searchParams) }))
    })
    fake.server.listen(0, '127.0.0.1', () => {
      fake.url = `http://127.0.0.1:${(fake.server.address() as AddressInfo).port}`
      resolve(fake)
    })
  })
}

const stats = (queries: number) => ({
  stats: { totalQueries: queries, totalBlocked: queries / 10 },
  mainChartData: { labels: ['a', 'b'], datasets: [{ label: 'Total', data: [queries, queries] }] },
  topDomains: [{ name: 'x.example', hits: queries }],
})

function logPage(prefix: string, stamps: string[], total: number) {
  return {
    pageNumber: 1,
    totalPages: 1,
    totalEntries: total,
    entries: stamps.map((timestamp, i) => ({ rowNumber: i + 1, timestamp, qname: `${prefix}${i}.example` })),
  }
}

function canned(queries: number, stamps: string[]): Fake['canned'] {
  return (apiPath, query) => {
    switch (apiPath) {
      case 'dashboard/stats/get':
        return stats(queries)
      case 'dashboard/stats/getTop':
        return { topDomains: [{ name: 'x.example', hits: queries }, { name: `only-${queries}.example`, hits: 1 }] }
      case 'logs/query':
        return logPage(`q${queries}-`, stamps.slice(0, Number(query.get('entriesPerPage') ?? 25)), stamps.length)
      case 'apps/list':
        return { apps: [{ name: 'Shared' }, { name: `App ${queries}` }] }
      case 'settings/get':
        return { enableBlocking: true, from: queries }
      default:
        return {}
    }
  }
}

let a: Fake
let b: Fake
let hub: http.Server
let base: string
let staticDir: string

function makeConfig(over: Record<string, string> = {}) {
  return parseConfig({
    HUB_SERVERS: `a=${a.url},b=${b.url}`,
    A_TOKEN: 'token-a',
    B_TOKEN: 'token-b',
    HUB_USER: 'admin',
    HUB_PASSWORD: 'secret',
    HUB_STATIC: staticDir,
    HUB_CACHE_SECONDS: '15',
    HUB_TIMEOUT_MS: '2000',
    ...over,
  })
}

async function listen(server: http.Server): Promise<string> {
  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve))
  return `http://127.0.0.1:${(server.address() as AddressInfo).port}`
}

async function call(apiPath: string, params: Record<string, string> = {}, token?: string, method = 'GET') {
  const query = new URLSearchParams(params)
  const url = `${base}/api/${apiPath}${method === 'GET' && params ? `?${query}` : ''}`
  const init: RequestInit = { method, headers: token ? { authorization: `Bearer ${token}` } : {} }
  if (method === 'POST') {
    init.body = query.toString()
    init.headers = { ...init.headers, 'content-type': 'application/x-www-form-urlencoded' }
  }
  const res = await fetch(url, init)
  return { code: res.status, body: (await res.json()) as Record<string, any> }
}

async function login(): Promise<string> {
  const { body } = await call('user/login', { user: 'admin', pass: 'secret', includeInfo: 'true' }, undefined, 'POST')
  return body.token as string
}

beforeAll(async () => {
  a = await fakeUpstream(canned(100, ['2026-01-01T10:00:04Z', '2026-01-01T10:00:02Z']))
  b = await fakeUpstream(canned(300, ['2026-01-01T10:00:03Z', '2026-01-01T10:00:01Z']))
  staticDir = mkdtempSync(path.join(tmpdir(), 'hub-static-'))
  writeFileSync(path.join(staticDir, 'index.html'), '<html>root</html>')
  mkdirSync(path.join(staticDir, 'logs', 'query-logs'), { recursive: true })
  writeFileSync(path.join(staticDir, 'logs', 'index.html'), '<html>logs</html>')
  mkdirSync(path.join(staticDir, 'assets'))
  writeFileSync(path.join(staticDir, 'assets', 'app.js'), 'export {}')
})

afterAll(() => {
  a.server.close()
  b.server.close()
  rmSync(staticDir, { recursive: true, force: true })
})

beforeEach(async () => {
  a.down = false
  b.down = false
  hub?.close()
  hub = createHub(makeConfig())
  base = await listen(hub)
  a.calls.length = 0
  b.calls.length = 0
})

describe('config', () => {
  it('refuses to start without credentials or a token', () => {
    const env = { HUB_SERVERS: 'a=http://x', A_TOKEN: 't' }
    expect(() => parseConfig(env)).toThrow(/HUB_USER/)
    expect(() => parseConfig({ ...env, HUB_USER: 'u', HUB_PASSWORD: 'p', A_TOKEN: '' })).toThrow(/A_TOKEN/)
  })

  it('derives the token variable from the id and applies defaults', () => {
    const c = parseConfig({ HUB_SERVERS: 'my-dns.1=http://x/', MY_DNS_1_TOKEN: 't', HUB_USER: 'u', HUB_PASSWORD: 'p' })
    expect(c.servers).toEqual([{ id: 'my-dns.1', url: 'http://x', token: 't' }])
    expect([c.port, c.cacheSeconds, c.timeoutMs, c.domain, c.staticDir]).toEqual([8080, 15, 8000, 'hub', './dist'])
  })
})

describe('session', () => {
  it('logs in and describes the servers as cluster nodes', async () => {
    const token = await login()
    expect(token).toMatch(/^[0-9a-f]{64}$/)
    const { body } = await call('user/session/get', {}, token)
    expect(body.status).toBe('ok')
    expect(body.info.hub).toBe(true)
    expect(body.info.clusterInitialized).toBe(true)
    expect(body.info.clusterNodes).toEqual([{ name: 'a', type: 'Primary' }, { name: 'b', type: 'Secondary' }])
    expect(body.info.permissions.Dashboard.canView).toBe(true)
    expect(body.info.permissions.Logs.canView).toBe(true)
    expect(body.info.permissions.Zones).toEqual({ canView: false, canModify: false, canDelete: false })
  })

  it('refuses a wrong password', async () => {
    const { body } = await call('user/login', { user: 'admin', pass: 'nope' }, undefined, 'POST')
    expect(body.status).toBe('error')
    expect(body.token).toBeUndefined()
  })

  it('answers invalid-token for a missing, unknown or logged-out token', async () => {
    expect((await call('dashboard/stats/get')).body.status).toBe('invalid-token')
    expect((await call('dashboard/stats/get', {}, 'bogus')).body.status).toBe('invalid-token')
    const token = await login()
    await call('user/logout', {}, token)
    expect((await call('user/session/get', {}, token)).body.status).toBe('invalid-token')
  })

  it('accepts the token as a parameter too', async () => {
    const token = await login()
    expect((await call('user/checkForUpdate', { token })).body.response.updateAvailable).toBe(false)
  })
})

describe('read-only', () => {
  it('refuses everything that is not a listed read', async () => {
    const token = await login()
    const { code, body } = await call('zones/delete', { zone: 'x' }, token, 'POST')
    expect(code).toBe(403)
    expect(body).toEqual({ status: 'error', errorMessage: 'The hub is read-only.' })
    expect(a.calls).toHaveLength(0)
  })
})

describe('single node', () => {
  it('forwards to that server with its token and without node', async () => {
    const token = await login()
    const { body } = await call('dashboard/stats/get', { type: 'LastDay', node: 'b' }, token)
    expect(body.response.stats.totalQueries).toBe(300)
    expect(a.calls).toHaveLength(0)
    expect(b.calls).toHaveLength(1)
    expect(b.calls[0].query.get('token')).toBe('token-b')
    expect(b.calls[0].query.has('node')).toBe(false)
    expect(b.calls[0].query.get('type')).toBe('LastDay')
    expect(body.hubWarnings).toBeUndefined()
  })

  it('reports an unreachable server by its id', async () => {
    const token = await login()
    a.down = true
    const { body } = await call('settings/get', { node: 'a' }, token)
    expect(body.status).toBe('error')
    expect(body.errorMessage).toMatch(/^a did not answer: /)
    expect(body.errorMessage).not.toContain('token-a')
  })

  it('rejects an unknown node', async () => {
    const token = await login()
    expect((await call('settings/get', { node: 'zzz' }, token)).body.status).toBe('error')
  })
})

describe('aggregate', () => {
  it('sums the stats of every server', async () => {
    const token = await login()
    for (const node of [undefined, 'cluster']) {
      const params: Record<string, string> = { type: 'LastDay' }
      if (node) params.node = node
      const { body } = await call('dashboard/stats/get', params, token)
      expect(body.response.stats.totalQueries).toBe(400)
      expect(body.response.mainChartData.datasets[0].data).toEqual([400, 400])
      expect(body.hubWarnings).toEqual([])
    }
  })

  it('merges the top lists by name', async () => {
    const token = await login()
    const { body } = await call('dashboard/stats/getTop', { type: 'LastDay', statsType: 'TopDomains', limit: '2' }, token)
    expect(body.response.topDomains).toEqual([
      { name: 'x.example', hits: 400 },
      { name: 'only-100.example', hits: 1 },
    ])
  })

  it('merges query logs across servers with node tags and pages', async () => {
    const token = await login()
    const page1 = await call('logs/query', { pageNumber: '1', entriesPerPage: '3', descendingOrder: 'true' }, token)
    expect(page1.body.response.totalEntries).toBe(4)
    expect(page1.body.response.totalPages).toBe(2)
    expect(page1.body.response.entries.map((e: any) => [e.node, e.timestamp])).toEqual([
      ['a', '2026-01-01T10:00:04Z'],
      ['b', '2026-01-01T10:00:03Z'],
      ['a', '2026-01-01T10:00:02Z'],
    ])
    // Each server was asked for the head of the list that page N needs.
    expect(a.calls[0].query.get('entriesPerPage')).toBe('3')
    expect(a.calls[0].query.get('pageNumber')).toBe('1')

    a.calls.length = 0
    const page2 = await call('logs/query', { pageNumber: '2', entriesPerPage: '3', descendingOrder: 'true' }, token)
    expect(a.calls[0].query.get('entriesPerPage')).toBe('6')
    expect(page2.body.response.entries.map((e: any) => [e.node, e.rowNumber])).toEqual([['b', 4]])

    const asc = await call('logs/query', { pageNumber: '1', entriesPerPage: '2', descendingOrder: 'false' }, token)
    expect(asc.body.response.entries.map((e: any) => e.timestamp)).toEqual(['2026-01-01T10:00:01Z', '2026-01-01T10:00:02Z'])
  })

  it('unions the apps by name and asks the first server for other reads', async () => {
    const token = await login()
    const apps = await call('apps/list', {}, token)
    expect(apps.body.response.apps.map((x: any) => x.name)).toEqual(['Shared', 'App 100', 'App 300'])
    const settings = await call('settings/get', {}, token)
    expect(settings.body.response.from).toBe(100)
    expect(b.calls).toHaveLength(1)
  })

  it('serves a repeated call from the cache', async () => {
    const token = await login()
    await call('dashboard/stats/get', { type: 'LastDay' }, token)
    await call('dashboard/stats/get', { type: 'LastDay' }, token)
    expect(a.calls).toHaveLength(1)
    await call('dashboard/stats/get', { type: 'LastWeek' }, token)
    expect(a.calls).toHaveLength(2)
  })

  it('answers with the other server and a warning when one is down', async () => {
    const token = await login()
    b.down = true
    const { body } = await call('dashboard/stats/get', { type: 'Warn' }, token)
    expect(body.status).toBe('ok')
    expect(body.response.stats.totalQueries).toBe(100)
    expect(body.hubWarnings).toHaveLength(1)
    expect(body.hubWarnings[0]).toMatch(/^b: /)
  })

  it('is an error when every server is down', async () => {
    const token = await login()
    a.down = true
    b.down = true
    const { body } = await call('dashboard/stats/get', { type: 'Dead' }, token)
    expect(body.status).toBe('error')
    expect(body.errorMessage).toMatch(/No server answered/)
  })
})

describe('static files', () => {
  it('serves files and the index of a folder, with the console headers on html', async () => {
    const root = await fetch(`${base}/`)
    expect(await root.text()).toBe('<html>root</html>')
    expect(root.headers.get('content-security-policy')).toBe("default-src 'self'; img-src 'self' data:; style-src 'self' 'unsafe-inline'")
    expect(root.headers.get('x-content-type-options')).toBe('nosniff')

    const logs = await fetch(`${base}/logs/`)
    expect(await logs.text()).toBe('<html>logs</html>')

    const js = await fetch(`${base}/assets/app.js`)
    expect(js.headers.get('content-type')).toMatch(/^text\/javascript/)
  })

  it('redirects a folder without the slash and 404s the rest', async () => {
    const redirect = await fetch(`${base}/logs`, { redirect: 'manual' })
    expect(redirect.status).toBe(301)
    expect(redirect.headers.get('location')).toBe('/logs/')
    expect((await fetch(`${base}/nope.js`)).status).toBe(404)
    // A folder with no index of its own is not a route.
    expect((await fetch(`${base}/assets`, { redirect: 'manual' })).status).toBe(404)
    expect((await fetch(`${base}/..%2f..%2fetc/passwd`)).status).toBeGreaterThanOrEqual(400)
  })

  it('answers the api under a sub path', async () => {
    const res = await fetch(`${base}/dashboard/api/status`)
    expect(((await res.json()) as { status: string }).status).toBe('ok')
  })
})