import { config } from '../config.js'

function appwriteHeaders() {
  return {
    'Content-Type': 'application/json',
    'X-Appwrite-Project': config.appwrite.projectId,
  }
}

async function appwriteFetch(path, { method = 'GET', body } = {}) {
  const url = `${config.appwrite.endpoint}${path}`
  const response = await fetch(url, {
    method,
    headers: appwriteHeaders(),
    body: body ? JSON.stringify(body) : undefined,
  })

  let data = null
  const text = await response.text()
  if (text) {
    try {
      data = JSON.parse(text)
    } catch {
      data = { message: text }
    }
  }

  if (!response.ok) {
    const error = new Error(data?.message || `Appwrite ${response.status}`)
    error.status = response.status
    error.code = data?.code
    error.type = data?.type
    if (response.status === 429 || data?.type === 'general_rate_limit_exceeded') {
      error.message =
        'Zu viele Anmeldeversuche. Bitte warte einige Minuten, bevor du es erneut versuchst.'
      error.status = 429
    }
    throw error
  }

  return data
}

/**
 * Login via Appwrite Auth REST. userId kommt aus der Session – kein users.read nötig.
 */
let appwriteLoginBlockedUntil = 0
const APPWRITE_LOGIN_COOLDOWN_MS = 5 * 60 * 1000
const APPWRITE_RATE_LIMIT_COOLDOWN_MS = 15 * 60 * 1000

export function getLoginCooldownRemainingSec() {
  const left = appwriteLoginBlockedUntil - Date.now()
  return left > 0 ? Math.ceil(left / 1000) : 0
}

export function clearLoginCooldown() {
  appwriteLoginBlockedUntil = 0
}

export async function loginWithAppwrite(email, password) {
  const now = Date.now()
  if (now < appwriteLoginBlockedUntil) {
    const waitSec = Math.ceil((appwriteLoginBlockedUntil - now) / 1000)
    const error = new Error(
      `Zu viele Anmeldeversuche. Bitte warte noch ${waitSec} Sekunden.`
    )
    error.status = 429
    throw error
  }

  let session
  try {
    session = await appwriteFetch('/account/sessions/email', {
      method: 'POST',
      body: { email, password },
    })
  } catch (err) {
    if (err.status === 429) {
      appwriteLoginBlockedUntil = Date.now() + APPWRITE_RATE_LIMIT_COOLDOWN_MS
    }
    const error = new Error(err.message || 'Anmeldung fehlgeschlagen')
    error.status = err.status || 401
    throw error
  }

  if (!session?.userId) {
    const error = new Error('Appwrite-Session ohne userId.')
    error.status = 500
    throw error
  }

  const user = { $id: session.userId, email, name: '' }

  clearLoginCooldown()
  return user
}