import { ref, type Ref } from 'vue'
import type { FightData, FightBot, FightArenaInfo } from '../game/fight/types'

export interface LiveLogItem {
  type: string
  round: number
  text: string
  color: string
}

export interface LiveFightData {
  botA: FightBot | null
  botB: FightBot | null
  arena: string
  arenaInfo?: FightArenaInfo | null
  mode?: string
  potSats?: number
}

interface SSEListenerEntry {
  event: string
  handler: EventListener
}

export function useFightPolling(fightId: Ref<string>) {
  const isLive = ref(false)
  const isLoading = ref(true)
  const liveRounds = ref(0)
  const fightError = ref('')
  const fight = ref<FightData | null>(null)
  const liveFightData = ref<LiveFightData | null>(null)
  const spectatorCount = ref(0)
  const currentChallengeInfo = ref<{ type: string; label: string } | null>(null)
  const pendingSSEEvents = ref<{ type: string; data: any }[]>([])

  let pollHandle: ReturnType<typeof setInterval> | null = null
  let pollCount = 0
  let eventSource: EventSource | null = null
  let sseRetries = 0
  const sseListeners: SSEListenerEntry[] = []

  // --- Load fight data ---
  async function loadFight(): Promise<string | null> {
    try {
      const res = await fetch(`/api/fights/${fightId.value}`)
      if (res.status === 429) return null // Rate limited, skip this poll
      if (res.ok) {
        const data = await res.json()
        liveRounds.value = data.rounds?.length || 0

        if (!liveFightData.value && data.botA && data.botB) {
          liveFightData.value = data
        }

        if (data.status === 'finished') {
          fight.value = data
        }
        return data.status
      }
    } catch (err) {
      console.warn('[FightPolling] loadFight failed:', err)
    }
    return null
  }

  function startPolling(callbacks?: {
    onFinished?: () => void
    onTimeout?: () => void
    keepLive?: boolean  // Don't set isLive=false (human fights manage lifecycle via SSE)
  }) {
    pollCount = 0
    pollHandle = setInterval(async () => {
      pollCount++
      const s = await loadFight()
      if (s === 'finished') {
        if (!eventSource) {
          if (!callbacks?.keepLive) isLive.value = false
          disconnectSSE()
          stopPolling()
          callbacks?.onFinished?.()
        }
      } else if (pollCount > 120) {
        isLive.value = false
        fightError.value = 'Fight took too long. Try refreshing.'
        stopPolling()
        callbacks?.onTimeout?.()
      }
    }, 1500)
  }

  function stopPolling() {
    if (pollHandle) { clearInterval(pollHandle); pollHandle = null }
  }

  // --- SSE ---
  function addSSEListener(es: EventSource, event: string, handler: (e: MessageEvent) => void) {
    es.addEventListener(event, handler as EventListener)
    sseListeners.push({ event, handler: handler as EventListener })
  }

  function connectSSE(handlers: {
    onRoundStart?: (data: any) => void
    onRoundEnd?: (data: any) => void
    onFightEnd?: (data: any) => void
    onHumanChallenge?: (data: any) => void
    onReaction?: (data: any) => void
  }) {
    // Close any existing SSE connection before opening a new one
    disconnectSSE()
    eventSource = new EventSource(`/api/fights/${fightId.value}/stream`)

    addSSEListener(eventSource, 'spectator_count', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        if (typeof data.count === 'number') spectatorCount.value = data.count
      } catch (err) {
        console.warn('[SSE] spectator_count parse error:', err)
      }
    })

    addSSEListener(eventSource, 'ping', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        if (typeof data.spectators === 'number') spectatorCount.value = data.spectators
      } catch (err) {
        console.warn('[SSE] ping parse error:', err)
      }
    })

    addSSEListener(eventSource, 'reaction', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        handlers.onReaction?.(data)
      } catch (err) {
        console.warn('[SSE] reaction parse error:', err)
      }
    })

    addSSEListener(eventSource, 'round_start', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        if (!data.challenge || !data.round) return
        currentChallengeInfo.value = { type: data.challenge.type, label: data.challenge.label }
        handlers.onRoundStart?.(data)
      } catch (err) {
        console.warn('[SSE] round_start parse error:', err)
      }
    })

    addSSEListener(eventSource, 'human_challenge', async (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        handlers.onHumanChallenge?.(data)
      } catch (err) {
        console.warn('[SSE] human_challenge parse error:', err)
      }
    })

    addSSEListener(eventSource, 'round_end', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        if (data.spectators !== undefined) spectatorCount.value = data.spectators
        handlers.onRoundEnd?.(data)
      } catch (err) {
        console.warn('[SSE] round_end parse error:', err)
      }
    })

    addSSEListener(eventSource, 'fight_end', (e) => {
      try {
        if (!e.data) return
        const data = JSON.parse(e.data)
        if (data.spectators !== undefined) spectatorCount.value = data.spectators
        handlers.onFightEnd?.(data)
      } catch (err) {
        console.warn('[SSE] fight_end parse error:', err)
      }
    })

    eventSource.onerror = () => {
      sseRetries++
      if (eventSource) {
        eventSource.close()
        eventSource = null
      }
      // Always reconnect if fight isn't finished, regardless of isLive
      if (fight.value?.status === 'finished') return
      const delay = Math.min(1000 * 2 ** (sseRetries - 1), 8000) // 1s, 2s, 4s, 8s max
      setTimeout(() => {
        if (!eventSource && fight.value?.status !== 'finished') connectSSE(handlers)
      }, delay)
    }
    eventSource.onopen = () => { sseRetries = 0 }
  }

  function disconnectSSE() {
    if (eventSource) {
      for (const { event, handler } of sseListeners) {
        eventSource.removeEventListener(event, handler)
      }
      sseListeners.length = 0
      eventSource.close()
      eventSource = null
    }
    spectatorCount.value = 0
  }

  function cleanup() {
    stopPolling()
    disconnectSSE()
  }

  return {
    isLive,
    isLoading,
    liveRounds,
    fightError,
    fight,
    liveFightData,
    spectatorCount,
    currentChallengeInfo,
    pendingSSEEvents,
    loadFight,
    startPolling,
    stopPolling,
    connectSSE,
    disconnectSSE,
    cleanup,
  }
}