import { randomUUID } from 'node:crypto'
import { config, WOMS_DATABASE_ID } from '../config.js'

function buildQueries(queries = []) {
  return queries.map((q) => {
    if (typeof q === 'string') return q
    return JSON.stringify(q)
  })
}

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

function formatRequestBody(body, method) {
  if (!body || method === 'GET' || method === 'DELETE') return body
  if (body.data !== undefined) return body
  const { documentId, ...fields } = body
  const payload = { data: fields }
  if (documentId) payload.documentId = documentId
  return payload
}

async function adminFetch(path, { method = 'GET', body, queries = [] } = {}) {
  if (!config.appwrite.apiKey) {
    const error = new Error('APPWRITE_API_KEY fehlt in .env')
    error.status = 500
    throw error
  }

  const url = new URL(`${config.appwrite.endpoint}${path}`)
  for (const q of buildQueries(queries)) {
    url.searchParams.append('queries[]', q)
  }

  const requestBody = formatRequestBody(body, method)

  const response = await fetch(url.toString(), {
    method,
    headers: adminHeaders(),
    body: requestBody ? JSON.stringify(requestBody) : undefined,
  })

  const text = await response.text()
  let data = null
  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 >= 500 ? 500 : response.status
    error.code = data?.code
    error.type = data?.type
    throw error
  }

  return data
}

/** Appwrite Query-Helper (kompatibel zu bisherigen Aufrufen) */
export const Query = {
  equal: (attribute, value) => ({
    method: 'equal',
    attribute,
    values: Array.isArray(value) ? value : [value],
  }),
  limit: (n) => ({ method: 'limit', values: [n] }),
  orderDesc: (attribute) => ({ method: 'orderDesc', attribute }),
  orderAsc: (attribute) => ({ method: 'orderAsc', attribute }),
}

export const ID = {
  unique: () => randomUUID(),
}

function collectionPath(collectionId) {
  return `/databases/${config.appwrite.databaseId}/collections/${collectionId}/documents`
}

export async function getUserById(userId) {
  return adminFetch(`/users/${userId}`)
}

export async function deleteUserSession(userId, sessionId) {
  return adminFetch(`/users/${userId}/sessions/${sessionId}`, { method: 'DELETE' })
}

export async function listDocuments(collectionId, queries = []) {
  const result = await adminFetch(collectionPath(collectionId), { queries })
  return result.documents
}

export async function getCustomerByAppwriteUserId(appwriteUserId) {
  const docs = await listDocuments(config.collections.customers, [
    Query.equal('appwriteUserId', appwriteUserId),
    Query.limit(1),
  ])
  return docs[0] || null
}

export async function getCustomerByEmail(email) {
  if (!email) return null
  const docs = await listDocuments(config.collections.customers, [
    Query.equal('email', email.trim()),
    Query.limit(1),
  ])
  return docs[0] || null
}

export async function getPortalAccessByCustomerId(customerId) {
  const docs = await listDocuments(config.collections.customerPortalAccess, [
    Query.equal('customerId', customerId),
    Query.limit(1),
  ])
  return docs[0] || null
}

export async function updateDocument(collectionId, documentId, data) {
  return adminFetch(`${collectionPath(collectionId)}/${documentId}`, {
    method: 'PATCH',
    body: data,
  })
}

export async function upsertWebsiteProjectByRepo(repoFullName, data) {
  const existing = await listDocuments(config.collections.websiteProjects, [
    Query.equal('repoFullName', repoFullName),
    Query.limit(1),
  ])

  const now = new Date().toISOString()
  const payload = { ...data, updatedAt: now }

  if (existing[0]) {
    return updateDocument(
      config.collections.websiteProjects,
      existing[0].$id,
      payload
    )
  }

  return adminFetch(collectionPath(config.collections.websiteProjects), {
    method: 'POST',
    body: { ...payload, createdAt: now, documentId: ID.unique() },
  })
}

export async function verifyDatabaseAccess() {
  if (!config.appwrite.apiKey) {
    return { ok: false, reason: 'APPWRITE_API_KEY fehlt' }
  }
  try {
    await listDocuments(config.collections.customers, [Query.limit(1)])
    return { ok: true }
  } catch (err) {
    return {
      ok: false,
      reason: err.message,
      code: err.code,
      type: err.type,
      status: err.status,
    }
  }
}

export function createAdminClient() {
  return { usesNativeFetch: true, databaseId: WOMS_DATABASE_ID }
}

export function createUserClient() {
  return { usesNativeFetch: true }
}