import { Platform, Dimensions } from 'react-native'
import { getConfig, isInitialized, getUserId } from '@xuqm/rn-common'
import { LogQueue } from './queue/LogQueue'
import { ErrorCapture } from './capture/ErrorCapture'
import { HttpInterceptor } from './interceptor/HttpInterceptor'
import { computeFingerprint } from './fingerprint'
import { FunnelTracker } from './funnel/FunnelTracker'
import type {
  LogLevel,
  Environment,
  IssueEvent,
  LogEvent,
  BugCollectEvent,
  BreadcrumbItem,
  DeviceInfo,
  Level,
} from './types'

// ─── Internal state ───────────────────────────────────────────────────────────

const SDK_NAME = 'bugcollect.rn'
const SDK_VERSION = '0.2.0'
const MAX_BREADCRUMBS = 100

let _logLevel: LogLevel = 'warn'
let _environment: Environment = 'production'
let _queue: LogQueue | null = null
let _errorCaptureStarted = false
let _httpInterceptorStarted = false
let _breadcrumbs: BreadcrumbItem[] = []

// ─── 上报频率控制 / 采样（降低服务端存储与流量压力）───────────────────────────
// 同一指纹在滑动窗口内最多上报 N 次，避免相同错误刷屏；fatal 不受限、不抽样。
const RATE_WINDOW_MS = 60_000
const RATE_MAX_PER_FINGERPRINT = 5
let _sampleRate = 1 // 1=全量；0~1 对非致命事件抽样
const _fingerprintHits = new Map<string, number[]>()

function _isFatal(event: BugCollectEvent): boolean {
  return event.type === 'issue' && event.level === 'fatal'
}

function _eventKey(event: BugCollectEvent): string {
  return event.type === 'issue' ? event.fingerprint : `event:${event.name}`
}

/** 是否允许上报：fatal 必报；否则先采样、再按指纹滑动窗口限频。 */
function _shouldReport(event: BugCollectEvent): boolean {
  if (_isFatal(event)) return true
  if (_sampleRate < 1 && Math.random() > _sampleRate) return false
  const key = _eventKey(event)
  const now = Date.now()
  const hits = (_fingerprintHits.get(key) ?? []).filter(t => now - t < RATE_WINDOW_MS)
  if (hits.length >= RATE_MAX_PER_FINGERPRINT) {
    _fingerprintHits.set(key, hits)
    return false
  }
  hits.push(now)
  _fingerprintHits.set(key, hits)
  return true
}

const _sessionId: string = _generateSessionId()

function _generateSessionId(): string {
  return 'xxxx-xxxx-xxxx'.replace(/x/g, () => ((Math.random() * 16) | 0).toString(16))
}

function _levelNum(level: LogLevel): number {
  return { debug: 0, info: 1, warn: 2, error: 3 }[level]
}

function _getPlatform(): 'ios' | 'android' | 'harmonyos' | 'web' | 'react-native' {
  switch (Platform.OS) {
    case 'ios': return 'ios'
    case 'android': return 'android'
    // @ts-expect-error HarmonyOS is not in the official RN types
    case 'harmony': return 'harmonyos'
    default: return 'react-native'
  }
}

function _getAppVersion(): string {
  const constants = Platform.constants as Record<string, unknown>
  const v = constants['appVersion'] ?? constants['Version']
  return typeof v === 'string' ? v : String(v ?? '0.0.0')
}

function _getDeviceInfo(): DeviceInfo {
  const constants = Platform.constants as Record<string, unknown>
  const { width, height } = Dimensions.get('screen')
  return {
    model: typeof constants['Model'] === 'string' ? constants['Model'] : undefined,
    brand: typeof constants['Brand'] === 'string' ? constants['Brand'] : undefined,
    manufacturer: typeof constants['Manufacturer'] === 'string' ? constants['Manufacturer'] : undefined,
    osName: Platform.OS,
    osVersion: typeof Platform.Version === 'string' ? Platform.Version : String(Platform.Version),
    sdkVersion: Platform.OS === 'android' && typeof constants['Release'] === 'string'
      ? constants['Release']
      : undefined,
    screenWidth: width,
    screenHeight: height,
  }
}

function _enqueue(event: BugCollectEvent): void {
  if (!_queue) {
    const cfg = getConfig()
    if (!cfg.bugCollectApiUrl || !cfg.bugCollectEnabled) return
    _queue = new LogQueue({ bugCollectApiUrl: cfg.bugCollectApiUrl, appKey: cfg.appKey })
  }
  if (!_shouldReport(event)) return
  void _queue.push(event)
}

function _buildIssue(level: Level, error: unknown, metadata?: Record<string, unknown>): IssueEvent {
  const err = error instanceof Error ? error : new Error(String(error))
  return {
    type: 'issue',
    level,
    platform: _getPlatform(),
    fingerprint: computeFingerprint(level, err.message, err.stack),
    timestamp: Date.now(),
    appKey: getConfig().appKey,
    release: _getAppVersion(),
    environment: _environment,
    exception: {
      type: err.name ?? 'Error',
      value: err.message,
      stacktrace: err.stack,
    },
    breadcrumbs: _breadcrumbs.length > 0 ? [..._breadcrumbs] : undefined,
    userId: getUserId() ?? undefined,
    sessionId: _sessionId,
    tags: metadata,
    device: _getDeviceInfo(),
    sdk: { name: SDK_NAME, version: SDK_VERSION },
  }
}

// ─── BugCollect public API ────────────────────────────────────────────────────

export const BugCollect = {
  setLogLevel(level: LogLevel): void {
    _logLevel = level
  },

  setEnvironment(env: Environment): void {
    _environment = env
  },

  /** 设置非致命事件的采样率（0~1，默认 1=全量）。fatal 始终全量上报。 */
  setSampleRate(rate: number): void {
    _sampleRate = Math.max(0, Math.min(1, rate))
  },

  /** Add a breadcrumb to the in-memory circular buffer (max 100). */
  addBreadcrumb(item: Omit<BreadcrumbItem, 'timestamp'> & { timestamp?: number }): void {
    const crumb: BreadcrumbItem = { ...item, timestamp: item.timestamp ?? Date.now() }
    if (_breadcrumbs.length >= MAX_BREADCRUMBS) _breadcrumbs.shift()
    _breadcrumbs.push(crumb)
  },

  /** Record a custom analytics event (funnel analysis, behaviour tracking). */
  event(name: string, properties?: Record<string, unknown>): void {
    if (!isInitialized()) return
    const event: LogEvent = {
      type: 'event',
      name,
      properties,
      timestamp: Date.now(),
      userId: getUserId() ?? undefined,
      sessionId: _sessionId,
      appKey: getConfig().appKey,
      platform: _getPlatform(),
      release: _getAppVersion(),
      environment: _environment,
      device: _getDeviceInfo(),
      sdk: { name: SDK_NAME, version: SDK_VERSION },
    }
    _enqueue(event)
    FunnelTracker.track(name, properties)
  },

  /** Upload a JS exception as an error-level issue. */
  captureError(error: unknown, metadata?: Record<string, unknown>): void {
    if (!isInitialized()) return
    _enqueue(_buildIssue('error', error, metadata))
  },

  /** Upload a JS exception as a fatal-level issue (persisted across restarts). */
  captureFatal(error: unknown, metadata?: Record<string, unknown>): void {
    if (!isInitialized()) return
    _enqueue(_buildIssue('fatal', error, metadata))
  },

  /** Log a warning (if log level allows). */
  warn(message: string, metadata?: Record<string, unknown>): void {
    if (_levelNum(_logLevel) > _levelNum('warn')) return
    if (!isInitialized()) return
    const issue: IssueEvent = {
      type: 'issue',
      level: 'warning',
      platform: _getPlatform(),
      fingerprint: computeFingerprint('warning', message),
      timestamp: Date.now(),
      appKey: getConfig().appKey,
      release: _getAppVersion(),
      environment: _environment,
      exception: { type: 'Warning', value: message },
      breadcrumbs: _breadcrumbs.length > 0 ? [..._breadcrumbs] : undefined,
      userId: getUserId() ?? undefined,
      sessionId: _sessionId,
      tags: metadata,
      sdk: { name: SDK_NAME, version: SDK_VERSION },
    }
    _enqueue(issue)
  },

  /** Log an informational event (if log level allows). */
  info(message: string, metadata?: Record<string, unknown>): void {
    if (_levelNum(_logLevel) > _levelNum('info')) return
    if (!isInitialized()) return
    const issue: IssueEvent = {
      type: 'issue',
      level: 'info',
      platform: _getPlatform(),
      fingerprint: computeFingerprint('info', message),
      timestamp: Date.now(),
      appKey: getConfig().appKey,
      release: _getAppVersion(),
      environment: _environment,
      exception: { type: 'Info', value: message },
      userId: getUserId() ?? undefined,
      sessionId: _sessionId,
      tags: metadata,
      sdk: { name: SDK_NAME, version: SDK_VERSION },
    }
    _enqueue(issue)
  },

  /**
   * Enable automatic capture of JS global errors and unhandled Promise rejections,
   * plus HTTP/接口报错 自动上报（包裹 global.fetch）。
   * Call once at app startup after XuqmSDK.initialize().
   */
  startCapture(): void {
    if (!_errorCaptureStarted) {
      _errorCaptureStarted = true
      ErrorCapture.start(BugCollect.captureError.bind(BugCollect))
    }
    if (!_httpInterceptorStarted) {
      _httpInterceptorStarted = true
      HttpInterceptor.start(BugCollect.captureError.bind(BugCollect))
    }
  },

  defineFunnel: FunnelTracker.define.bind(FunnelTracker),
  getFunnelProgress: FunnelTracker.getProgress.bind(FunnelTracker),

  async flush(): Promise<void> {
    if (_queue) await _queue.flush()
  },

  destroy(): void {
    if (_queue) {
      _queue.destroy()
      _queue = null
    }
    if (_httpInterceptorStarted) {
      HttpInterceptor.stop()
      _httpInterceptorStarted = false
    }
    _fingerprintHits.clear()
    _breadcrumbs = []
  },
}