/**
 * Controller / gamepad-style navigation for Archipelago.
 * Supports Rii X8 (keyboard/d-pad) and standard gamepads.
 * - Arrow keys / d-pad: navigate between focusable elements
 * - Enter / A button: activate
 * - Escape / B button: back
 * - Game-like navigation sounds and visual feedback
 */

import { ref, onMounted, onBeforeUnmount, watch } from 'vue'
import { useControllerStore } from '@/stores/controller'
import { useSpotlightStore } from '@/stores/spotlight'

const FOCUSABLE_SELECTOR = [
  'a[href]',
  'button:not([disabled])',
  'input:not([disabled])',
  'select:not([disabled])',
  'textarea:not([disabled])',
  '[tabindex]:not([tabindex="-1"])',
  '[data-controller-focus]',
].join(', ')

function getFocusableElements(container: Document | HTMLElement = document): HTMLElement[] {
  return Array.from(container.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTOR)).filter(
    (el) => !el.hasAttribute('disabled') && el.offsetParent !== null
  )
}

function playNavSound(type: 'move' | 'select' | 'back' = 'move') {
  try {
    const ctx = new (window.AudioContext || (window as any).webkitAudioContext)()
    const osc = ctx.createOscillator()
    const gain = ctx.createGain()
    osc.connect(gain)
    gain.connect(ctx.destination)
    gain.gain.value = 0.08
    osc.frequency.value = type === 'select' ? 880 : type === 'back' ? 220 : 440
    osc.type = 'sine'
    osc.start()
    osc.stop(ctx.currentTime + 0.05)
  } catch {
    // Audio not supported or blocked
  }
}

export function useControllerNav(containerRef?: { value: HTMLElement | null }) {
  const store = useControllerStore()
  const isControllerActive = ref(false)
  const gamepadCount = ref(0)

  watch([isControllerActive, gamepadCount], () => {
    store.setActive(isControllerActive.value)
    store.setGamepadCount(gamepadCount.value)
  }, { immediate: true })
  let keyNavTimeout: ReturnType<typeof setTimeout> | null = null
  let pollIntervalId: ReturnType<typeof setInterval> | null = null

  function checkGamepads() {
    const gamepads = navigator.getGamepads?.()
    const count = gamepads ? Array.from(gamepads).filter((g) => g?.connected).length : 0
    if (count !== gamepadCount.value) {
      gamepadCount.value = count
      isControllerActive.value = count > 0
    }
  }

  function handleKeyDown(e: KeyboardEvent) {
    const navKeys = ['ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight', 'Enter', 'Escape']
    if (!navKeys.includes(e.key)) return

    // Ignore when typing in inputs
    const target = e.target as HTMLElement
    if (target.tagName === 'INPUT' || target.tagName === 'TEXTAREA') {
      if (e.key !== 'Escape') return
    }

    const root = containerRef?.value ?? document
    const focusable = getFocusableElements(root)
    const currentIndex = focusable.indexOf(document.activeElement as HTMLElement)

    if (e.key === 'Escape') {
      if (useSpotlightStore().isOpen) {
        useSpotlightStore().close()
        e.preventDefault()
        e.stopPropagation()
        return
      }
      playNavSound('back')
      window.history.back()
      e.preventDefault()
      return
    }

    if (e.key === 'Enter') {
      if (currentIndex >= 0 && focusable[currentIndex]) {
        playNavSound('select')
        ;(focusable[currentIndex] as HTMLElement).click()
      }
      e.preventDefault()
      return
    }

    if (['ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight'].includes(e.key)) {
      isControllerActive.value = true
      if (keyNavTimeout) clearTimeout(keyNavTimeout)
      keyNavTimeout = setTimeout(() => {
        isControllerActive.value = gamepadCount.value > 0
      }, 3000)

      let nextIndex = currentIndex
      const isForward = e.key === 'ArrowDown' || e.key === 'ArrowRight'

      if (focusable.length === 0) return

      if (currentIndex < 0) {
        nextIndex = isForward ? 0 : focusable.length - 1
      } else {
        nextIndex = isForward ? currentIndex + 1 : currentIndex - 1
        if (nextIndex < 0) nextIndex = focusable.length - 1
        if (nextIndex >= focusable.length) nextIndex = 0
      }

      const next = focusable[nextIndex]
      if (next) {
        playNavSound('move')
        next.focus()
        next.scrollIntoView({ block: 'nearest', behavior: 'smooth' })
        e.preventDefault()
      }
    }
  }

  function handleGamepadInput() {
    checkGamepads()
  }

  function handleGamepadConnected() {
    const gamepads = navigator.getGamepads?.()
    gamepadCount.value = gamepads ? Array.from(gamepads).filter((g) => g?.connected).length : 1
    isControllerActive.value = true
  }

  function handleGamepadDisconnected() {
    const gamepads = navigator.getGamepads?.()
    gamepadCount.value = gamepads ? Array.from(gamepads).filter((g) => g?.connected).length : 0
    isControllerActive.value = gamepadCount.value > 0
  }

  onMounted(() => {
    checkGamepads()
    window.addEventListener('keydown', handleKeyDown, true)
    window.addEventListener('gamepadconnected', handleGamepadConnected)
    window.addEventListener('gamepaddisconnected', handleGamepadDisconnected)
    pollIntervalId = setInterval(handleGamepadInput, 500)
  })

  onBeforeUnmount(() => {
    window.removeEventListener('keydown', handleKeyDown, true)
    window.removeEventListener('gamepadconnected', handleGamepadConnected)
    window.removeEventListener('gamepaddisconnected', handleGamepadDisconnected)
    if (pollIntervalId) clearInterval(pollIntervalId)
    if (keyNavTimeout) clearTimeout(keyNavTimeout)
  })

  return {
    isControllerActive,
    gamepadCount,
  }
}