/** Machine-readable live-log markers stored in event.remarks (locale-independent). */
export const LIVE_EVENT_CODES = {
  MOTOR_START: '__live:motor_start',
  MOTOR_STOP: '__live:motor_stop',
  CAST_OFF: '__live:cast_off',
  MOOR: '__live:moor',
  POSITION: '__live:position',
  AUTO_POSITION: '__live:auto_position',
  COURSE: '__live:course',
  WIND: '__live:wind',
  PRESSURE: '__live:pressure',
  SEA_STATE: '__live:sea_state',
  VISIBILITY: '__live:visibility'
} as const

/** @deprecated Stored in older log entries; still recognized when reading events. */
export const LEGACY_LIVE_POSITION_REMARK = '__live:fix'

export type LiveEventCode = (typeof LIVE_EVENT_CODES)[keyof typeof LIVE_EVENT_CODES]

export function liveSailsRemark(sails: string): string {
  return `__live:sails:${sails}`
}

export function liveCommentRemark(text: string): string {
  return `__live:comment:${text}`
}

export function liveTempRemark(tempC: string): string {
  return `__live:temp:${tempC}`
}

export function livePrecipRemark(text: string): string {
  return `__live:precip:${text}`
}

export function liveFuelRemark(liters: string): string {
  return `__live:fuel:${liters}`
}

export function liveWaterRemark(liters: string): string {
  return `__live:water:${liters}`
}

export function livePhotoRemark(caption?: string): string {
  const text = caption?.trim()
  return text ? `__live:photo:${text}` : '__live:photo'
}

export function parseLivePhotoRemark(remarks: string): string | null {
  if (remarks === '__live:photo') return ''
  const prefix = '__live:photo:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

const VOICE_UUID_RE =
  /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i

export function liveVoiceRemark(audioId: string): string {
  return `__live:voice:${audioId}`
}

export function parseLiveVoiceRemark(remarks: string): string | null {
  const trimmed = remarks.trim()
  const prefix = '__live:voice:'
  if (!trimmed.startsWith(prefix)) return null
  const id = trimmed.slice(prefix.length)
  return VOICE_UUID_RE.test(id) ? id : null
}

export function liveSogRemark(speedKn: string): string {
  return `__live:sog:${speedKn}`
}

export function liveStwRemark(speedKn: string): string {
  return `__live:stw:${speedKn}`
}

export function parseLiveSailsRemark(remarks: string): string | null {
  const prefix = '__live:sails:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveCommentRemark(remarks: string): string | null {
  const prefix = '__live:comment:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveTempRemark(remarks: string): string | null {
  const prefix = '__live:temp:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLivePrecipRemark(remarks: string): string | null {
  const prefix = '__live:precip:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveFuelRemark(remarks: string): string | null {
  const prefix = '__live:fuel:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveWaterRemark(remarks: string): string | null {
  const prefix = '__live:water:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveSogRemark(remarks: string): string | null {
  const prefix = '__live:sog:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

export function parseLiveStwRemark(remarks: string): string | null {
  const prefix = '__live:stw:'
  return remarks.startsWith(prefix) ? remarks.slice(prefix.length) : null
}

/** Derive motor running state from event history (survives reload). */
export function isMotorRunningFromEvents(
  events: Array<{ remarks: string }>,
  motorStartCode: string = LIVE_EVENT_CODES.MOTOR_START,
  motorStopCode: string = LIVE_EVENT_CODES.MOTOR_STOP
): boolean {
  for (let i = events.length - 1; i >= 0; i--) {
    const code = events[i].remarks.trim()
    if (code === motorStartCode) return true
    if (code === motorStopCode) return false
  }
  return false
}

export function eventTimestampMs(date: string, time: string): number | null {
  const normalized = time.trim().match(/^(\d{1,2}):(\d{2})/)
  if (!normalized || !date) return null
  const hours = parseInt(normalized[1], 10)
  const minutes = parseInt(normalized[2], 10)
  if (hours > 23 || minutes > 59) return null
  const parsed = new Date(`${date}T${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}:00`)
  return Number.isNaN(parsed.getTime()) ? null : parsed.getTime()
}

export function getLastAutoPositionMs(
  events: Array<{ remarks: string; time: string }>,
  entryDate: string
): number | null {
  for (let i = events.length - 1; i >= 0; i--) {
    if (events[i].remarks.trim() !== LIVE_EVENT_CODES.AUTO_POSITION) continue
    return eventTimestampMs(entryDate, events[i].time)
  }
  return null
}

/** Max age of a logged position for OpenWeatherMap lookups in live log. */
export const LIVE_LOG_WEATHER_POSITION_MAX_AGE_MS = 6 * 60 * 60 * 1000

export type LiveLogPositionSource = 'position' | 'auto_position'

export interface LiveLogPosition {
  lat: string
  lng: string
  loggedAtMs: number
  source: LiveLogPositionSource
}

export function isManualPositionEventCode(code: string): boolean {
  return code === LIVE_EVENT_CODES.POSITION || code === LEGACY_LIVE_POSITION_REMARK
}

function isPositionEventCode(code: string): boolean {
  return isManualPositionEventCode(code) || code === LIVE_EVENT_CODES.AUTO_POSITION
}

/** Latest manual or auto-position event with GPS coordinates (any age). */
export function getLatestLoggedPosition(
  events: Array<{ remarks: string; time: string; gpsLat?: string; gpsLng?: string }>,
  entryDate: string
): LiveLogPosition | null {
  for (let i = events.length - 1; i >= 0; i--) {
    const event = events[i]
    const code = event.remarks.trim()
    if (!isPositionEventCode(code)) continue
    const lat = event.gpsLat?.trim()
    const lng = event.gpsLng?.trim()
    if (!lat || !lng) continue
    const loggedAtMs = eventTimestampMs(entryDate, event.time)
    if (loggedAtMs == null) continue
    return {
      lat,
      lng,
      loggedAtMs,
      source: isManualPositionEventCode(code) ? 'position' : 'auto_position'
    }
  }
  return null
}

/** Logged position for weather if recorded within `maxAgeMs` (default 6 h). */
export function getLastLoggedPositionWithin(
  events: Array<{ remarks: string; time: string; gpsLat?: string; gpsLng?: string }>,
  entryDate: string,
  maxAgeMs: number = LIVE_LOG_WEATHER_POSITION_MAX_AGE_MS,
  nowMs: number = Date.now()
): LiveLogPosition | null {
  const latest = getLatestLoggedPosition(events, entryDate)
  if (!latest) return null
  if (nowMs - latest.loggedAtMs > maxAgeMs) return null
  return latest
}