/**
 * Analytics Admin Query Hooks
 *
 * React Query hooks for fetching analytics data from the backend.
 * These hooks use the analytics backend client and provide caching,
 * automatic refetching, and error handling.
 *
 * Supports mock mode when wrapped in MockDataProvider or when
 * MOCK_ANALYTICS environment variable is set.
 */

import { useState, useEffect, useCallback, useContext, createContext } from 'react'

// Mock data context - allows hooks to use mock data instead of real API calls
interface MockContextValue {
  enabled: boolean
  mockData: Record<string, unknown>
}

const MockContext = createContext<MockContextValue>({ enabled: false, mockData: {} })

export const useMockContext = () => useContext(MockContext)

// Provider for mock mode
export { MockContext }

// Types for API responses
interface QueryResult<T> {
  data: T | undefined
  isLoading: boolean
  isError: boolean
  error: Error | null
  refetch: () => void
}

// Simple query hook factory - in production, use @tanstack/react-query
function useQuery<T>(
  key: string,
  fetcher: () => Promise<T>,
  options?: { enabled?: boolean; refetchInterval?: number; mockData?: T }
): QueryResult<T> {
  const [data, setData] = useState<T | undefined>(undefined)
  const [isLoading, setIsLoading] = useState(true)
  const [isError, setIsError] = useState(false)
  const [error, setError] = useState<Error | null>(null)

  const enabled = options?.enabled ?? true
  const mockData = options?.mockData

  const fetchData = useCallback(async () => {
    if (!enabled) return

    setIsLoading(true)
    setIsError(false)
    setError(null)

    try {
      // If mock data is provided, use it instead of making API call
      if (mockData !== undefined) {
        // Small delay to simulate network
        await new Promise(resolve => setTimeout(resolve, 50))
        setData(mockData)
      } else {
        const result = await fetcher()
        setData(result)
      }
    } catch (err) {
      setIsError(true)
      setError(err instanceof Error ? err : new Error('Unknown error'))
    } finally {
      setIsLoading(false)
    }
  }, [enabled, fetcher, mockData])

  useEffect(() => {
    fetchData()
  }, [fetchData, key])

  useEffect(() => {
    if (options?.refetchInterval && enabled && !mockData) {
      const interval = setInterval(fetchData, options.refetchInterval)
      return () => clearInterval(interval)
    }
    return undefined
  }, [fetchData, options?.refetchInterval, enabled, mockData])

  return {
    data,
    isLoading,
    isError,
    error,
    refetch: fetchData,
  }
}

// Check if we should use mock data (env var or mock provider)
const USE_MOCK = typeof process !== 'undefined' && process.env?.MOCK_ANALYTICS === 'true'

// Base URL for analytics API - should be configured via environment
const API_BASE = typeof process !== 'undefined' && process.env?.ANALYTICS_API_URL
  ? process.env.ANALYTICS_API_URL
  : '/api/analytics'

async function fetchJson<T>(endpoint: string): Promise<T> {
  const response = await fetch(`${API_BASE}${endpoint}`)
  if (!response.ok) {
    throw new Error(`Failed to fetch ${endpoint}: ${response.statusText}`)
  }
  return response.json()
}

// Import mock data for fallback
import { mockData as MOCK_DATA } from '../providers/MockDataProvider'

// ============================================================================
// Revenue Hooks
// ============================================================================

export interface RevenueMetrics {
  totalRevenue: number
  monthlyRecurring: number
  oneTimeRevenue: number
  cryptoRevenue: number
  growthRate: number
  avgRevenuePerUser: number
}

export interface RevenueTrendPoint {
  date: string
  revenue: number
  recurring: number
  oneTime: number
}

export interface RevenueBreakdown {
  bySource: { source: string; amount: number; percentage: number }[]
  byProvider: { provider: string; amount: number; percentage: number }[]
}

export function useRevenueMetrics() {
  return useQuery<RevenueMetrics>(
    'revenue-metrics',
    () => fetchJson('/dashboard/revenue'),
    { mockData: USE_MOCK ? MOCK_DATA.revenueMetrics : undefined }
  )
}

export function useRevenueTrend() {
  return useQuery<RevenueTrendPoint[]>(
    'revenue-trend',
    () => fetchJson('/dashboard/revenue-chart'),
    { mockData: USE_MOCK ? MOCK_DATA.revenueTrend : undefined }
  )
}

export function useRevenueBreakdown() {
  return useQuery<RevenueBreakdown>(
    'revenue-breakdown',
    () => fetchJson('/dashboard/revenue-breakdown'),
    { mockData: USE_MOCK ? MOCK_DATA.revenueBreakdown : undefined }
  )
}

// ============================================================================
// Transactions Hooks
// ============================================================================

export interface Transaction {
  id: string
  timestamp: string
  type: string
  status: string
  amount: number
  cryptoAmount?: number
  cryptoCurrency?: string
  provider: string
}

export interface TransactionDetails extends Transaction {
  creator?: { name: string; id: string }
  subscriber?: { name: string; id: string }
  fees?: { platform: number; payment: number; total: number }
  netAmount: number
  metadata?: { ip: string; userAgent: string; referrer: string }
  errorReason?: string
}

export interface TransactionsResult {
  transactions: Transaction[]
  total: number
}

export function useTransactions(filters: {
  status?: string
  type?: string
  dateRange?: string
  provider?: string
  search?: string
}) {
  const queryString = new URLSearchParams(
    Object.entries(filters).filter(([, v]) => v && v !== 'all')
  ).toString()

  return useQuery<TransactionsResult>(
    `transactions-${queryString}`,
    () => fetchJson(`/transactions?${queryString}`),
    { mockData: USE_MOCK ? MOCK_DATA.transactions(filters) : undefined }
  )
}

export function useTransactionDetails(id: string) {
  return useQuery<TransactionDetails>(
    `transaction-${id}`,
    () => fetchJson(`/transactions/${id}`),
    { enabled: !!id, mockData: USE_MOCK ? MOCK_DATA.transactionDetails(id) : undefined }
  )
}

// ============================================================================
// P&L Hooks
// ============================================================================

export interface PnLStatement {
  revenue: { total: number; crypto: number }
  costs: { total: number }
  grossProfit: number
  operatingExpenses: number
  netIncome: number
  ebitda: number
  margins: { gross: number; net: number }
}

export interface PnLTrendPoint {
  date: string
  revenue: number
  costs: number
  netIncome: number
}

export interface ReserveProgress {
  target: number
  current: number
  percentage: number
  monthlyContribution: number
  projectedDate: string
}

export function usePnLStatement() {
  return useQuery<PnLStatement>(
    'pnl-statement',
    () => fetchJson('/reports/pnl'),
    { mockData: USE_MOCK ? MOCK_DATA.pnlStatement : undefined }
  )
}

export function usePnLTrend() {
  return useQuery<PnLTrendPoint[]>(
    'pnl-trend',
    () => fetchJson('/reports/pnl-trend'),
    { mockData: USE_MOCK ? MOCK_DATA.pnlTrend : undefined }
  )
}

export function useReserveProgress() {
  return useQuery<ReserveProgress>(
    'reserve-progress',
    () => fetchJson('/reports/reserve'),
    { mockData: USE_MOCK ? MOCK_DATA.reserveProgress : undefined }
  )
}

// ============================================================================
// Real-Time Hooks
// ============================================================================

export interface RealTimeMetrics {
  activeUsers: number
  activeCreators: number
  liveTransactions: number
  revenuePerMinute: number
  systemLoad: number
  responseTime: number
}

export interface RealTimeActivity {
  timestamp: string
  event: string
  user: string
  amount: number
}

export interface ActiveUserPoint {
  minute: string
  count: number
}

export function useRealTimeMetrics() {
  return useQuery<RealTimeMetrics>(
    'realtime-metrics',
    () => fetchJson('/realtime/metrics'),
    { refetchInterval: USE_MOCK ? undefined : 5000, mockData: USE_MOCK ? MOCK_DATA.realTimeMetrics : undefined }
  )
}

export function useRealTimeActivity() {
  return useQuery<RealTimeActivity[]>(
    'realtime-activity',
    () => fetchJson('/realtime/activity'),
    { refetchInterval: USE_MOCK ? undefined : 5000, mockData: USE_MOCK ? MOCK_DATA.realTimeActivity : undefined }
  )
}

export function useActiveUsers() {
  return useQuery<ActiveUserPoint[]>(
    'active-users',
    () => fetchJson('/realtime/active-users'),
    { refetchInterval: USE_MOCK ? undefined : 5000, mockData: USE_MOCK ? MOCK_DATA.activeUsers : undefined }
  )
}

// ============================================================================
// Costs Hooks
// ============================================================================

export interface CostMetrics {
  totalCosts: number
  fixedCosts: number
  variableCosts: number
  costPerTransaction: number
  costGrowthRate: number
  budgetUtilization: number
}

export interface CostBreakdown {
  byCategory: { category: string; amount: number; percentage: number }[]
  byType: { type: string; amount: number; percentage: number }[]
}

export interface BudgetComparison {
  totalBudget: number
  actualCosts: number
  remaining: number
  utilization: number
  byCategory: { category: string; budget: number; actual: number; variance: number }[]
}

export function useCostMetrics() {
  return useQuery<CostMetrics>(
    'cost-metrics',
    () => fetchJson('/dashboard/costs'),
    { mockData: USE_MOCK ? MOCK_DATA.costMetrics : undefined }
  )
}

export function useCostBreakdown() {
  return useQuery<CostBreakdown>(
    'cost-breakdown',
    () => fetchJson('/dashboard/costs-breakdown'),
    { mockData: USE_MOCK ? MOCK_DATA.costBreakdown : undefined }
  )
}

export function useBudgetComparison() {
  return useQuery<BudgetComparison>(
    'budget-comparison',
    () => fetchJson('/dashboard/budget'),
    { mockData: USE_MOCK ? MOCK_DATA.budgetComparison : undefined }
  )
}

// ============================================================================
// Performance Hooks
// ============================================================================

export interface PerformanceMetrics {
  avgResponseTime: number
  p50ResponseTime: number
  p95ResponseTime: number
  p99ResponseTime: number
  requestsPerSecond: number
  errorRate: number
  uptime: number
}

export interface EndpointMetrics {
  endpoint: string
  avgResponseTime: number
  requestCount: number
  errorRate: number
}

export function usePerformanceMetrics() {
  return useQuery<PerformanceMetrics>(
    'performance-metrics',
    () => fetchJson('/dashboard/performance'),
    { mockData: USE_MOCK ? MOCK_DATA.performanceMetrics : undefined }
  )
}

export function useEndpointMetrics() {
  return useQuery<EndpointMetrics[]>(
    'endpoint-metrics',
    () => fetchJson('/dashboard/endpoints'),
    { mockData: USE_MOCK ? MOCK_DATA.endpointMetrics : undefined }
  )
}

// ============================================================================
// Error Tracking Hooks
// ============================================================================

export interface ErrorMetrics {
  totalErrors: number
  errorRate: number
  criticalErrors: number
  resolvedErrors: number
  avgResolutionTime: number
}

export interface ErrorByType {
  type: string
  count: number
  percentage: number
}

export interface RecentError {
  id: string
  type: string
  message: string
  endpoint: string
  count: number
  lastOccurrence: string
  severity: string
  status: string
}

export function useErrorMetrics() {
  return useQuery<ErrorMetrics>(
    'error-metrics',
    () => fetchJson('/dashboard/errors'),
    { mockData: USE_MOCK ? MOCK_DATA.errorMetrics : undefined }
  )
}

export function useErrorsByType() {
  return useQuery<ErrorByType[]>(
    'errors-by-type',
    () => fetchJson('/dashboard/errors-by-type'),
    { mockData: USE_MOCK ? MOCK_DATA.errorsByType : undefined }
  )
}

export function useRecentErrors() {
  return useQuery<RecentError[]>(
    'recent-errors',
    () => fetchJson('/dashboard/recent-errors'),
    { mockData: USE_MOCK ? MOCK_DATA.recentErrors : undefined }
  )
}

// ============================================================================
// Bounce Rate Hooks
// ============================================================================

export interface BounceRateMetrics {
  overallBounceRate: number
  avgSessionDuration: number
  pagesPerSession: number
  exitRate: number
}

export interface BounceRateByPage {
  page: string
  bounceRate: number
  visits: number
}

export function useBounceRateMetrics() {
  return useQuery<BounceRateMetrics>(
    'bounce-rate-metrics',
    () => fetchJson('/dashboard/bounce-rate'),
    { mockData: USE_MOCK ? MOCK_DATA.bounceRateMetrics : undefined }
  )
}

export function useBounceRateByPage() {
  return useQuery<BounceRateByPage[]>(
    'bounce-rate-by-page',
    () => fetchJson('/dashboard/bounce-rate-by-page'),
    { mockData: USE_MOCK ? MOCK_DATA.bounceRateByPage : undefined }
  )
}

// ============================================================================
// Conversion Hooks
// ============================================================================

export interface ConversionMetrics {
  overallConversionRate: number
  signupToSubscriber: number
  visitorToSignup: number
  freeToTrial: number
  trialToPaid: number
  avgTimeToConversion: number
}

export interface FunnelStage {
  stage: string
  count: number
  rate: number
}

export interface ConversionBySource {
  source: string
  conversions: number
  rate: number
}

export function useConversionMetrics() {
  return useQuery<ConversionMetrics>(
    'conversion-metrics',
    () => fetchJson('/dashboard/conversions'),
    { mockData: USE_MOCK ? MOCK_DATA.conversionMetrics : undefined }
  )
}

export function useFunnelData() {
  return useQuery<FunnelStage[]>(
    'funnel-data',
    () => fetchJson('/funnel'),
    { mockData: USE_MOCK ? MOCK_DATA.funnelData : undefined }
  )
}

export function useConversionBySource() {
  return useQuery<ConversionBySource[]>(
    'conversion-by-source',
    () => fetchJson('/dashboard/conversions-by-source'),
    { mockData: USE_MOCK ? MOCK_DATA.conversionBySource : undefined }
  )
}

// ============================================================================
// A/B Testing Hooks
// ============================================================================

export interface ABTestMetrics {
  activeTests: number
  completedTests: number
  significantResults: number
  avgLiftPercent: number
}

export interface ABTest {
  id: string
  name: string
  status: 'running' | 'completed' | 'paused'
  variants: number
  participants: number
  conversionRateA: number
  conversionRateB: number
  significance: number
  startDate: string
  endDate?: string
  winner?: string
}

export function useABTestMetrics() {
  return useQuery<ABTestMetrics>(
    'ab-test-metrics',
    () => fetchJson('/ab-tests/metrics'),
    { mockData: USE_MOCK ? MOCK_DATA.abTestMetrics : undefined }
  )
}

export function useActiveTests() {
  return useQuery<ABTest[]>(
    'active-tests',
    () => fetchJson('/ab-tests'),
    { mockData: USE_MOCK ? MOCK_DATA.activeTests : undefined }
  )
}