import { useTorchStore } from '../stores/torch'
import { getWebMCP, autoConnect } from './webmcp'
import { endpoints } from '../config/endpoints'

const API_BASE = endpoints.api

let pollingInterval: number | null = null
let clientId: string | null = null

/**
 * Register this browser as a torch client
 */
export async function registerClient(): Promise<string | null> {
  try {
    const res = await fetch(`${API_BASE}/torch/register`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        userAgent: navigator.userAgent,
        hostname: window.location.hostname
      })
    })

    if (!res.ok) {
      console.error('[Torch] Failed to register:', res.status)
      return null
    }

    const data = await res.json()
    clientId = data.id

    const torchStore = useTorchStore()
    torchStore.setClientId(data.id)

    console.log(`[Torch] Registered as ${data.id}, hasTorch: ${data.hasTorch}`)

    // If we have the torch, connect to MCP
    if (data.hasTorch) {
      torchStore.setTorchState(data.id)
      await connectToMCP()
    }

    return data.id
  } catch (e) {
    console.error('[Torch] Error registering:', e)
    return null
  }
}

/**
 * Unregister this browser
 */
export async function unregisterClient(): Promise<void> {
  if (!clientId) return

  try {
    await fetch(`${API_BASE}/torch/client/${clientId}`, {
      method: 'DELETE'
    })
    console.log('[Torch] Unregistered')
  } catch (e) {
    console.error('[Torch] Error unregistering:', e)
  }

  clientId = null
}

/**
 * Request the torch
 */
export async function requestTorch(): Promise<boolean> {
  if (!clientId) {
    console.error('[Torch] Not registered')
    return false
  }

  const torchStore = useTorchStore()
  torchStore.setRequesting(true)

  try {
    const res = await fetch(`${API_BASE}/torch/request`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ clientId })
    })

    if (!res.ok) {
      console.error('[Torch] Failed to request:', res.status)
      torchStore.setRequesting(false)
      return false
    }

    const data = await res.json()
    console.log('[Torch] Torch granted!')

    // Update state and connect to MCP
    torchStore.setTorchState(clientId)
    torchStore.setRequesting(false)
    await connectToMCP()

    return true
  } catch (e) {
    console.error('[Torch] Error requesting:', e)
    torchStore.setRequesting(false)
    return false
  }
}

/**
 * Release the torch
 */
export async function releaseTorch(): Promise<boolean> {
  if (!clientId) {
    console.error('[Torch] Not registered')
    return false
  }

  const torchStore = useTorchStore()

  if (!torchStore.hasTorch) {
    console.warn('[Torch] Cannot release - do not have torch')
    return false
  }

  try {
    const res = await fetch(`${API_BASE}/torch/release`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ clientId })
    })

    if (!res.ok) {
      console.error('[Torch] Failed to release:', res.status)
      return false
    }

    console.log('[Torch] Torch released')

    // Update state and disconnect from MCP
    torchStore.setTorchState(null)
    disconnectFromMCP()

    return true
  } catch (e) {
    console.error('[Torch] Error releasing:', e)
    return false
  }
}

/**
 * Fetch current torch state from server
 */
export async function fetchTorchState(): Promise<void> {
  try {
    const res = await fetch(`${API_BASE}/torch`)
    if (!res.ok) return

    const data = await res.json()
    const torchStore = useTorchStore()

    torchStore.setClients(data.clients)

    // Check if torch holder changed
    const hadTorch = torchStore.hasTorch
    const hasTorchNow = data.holderId === clientId

    if (hadTorch && !hasTorchNow) {
      // We lost the torch - disconnect
      console.log('[Torch] Lost torch, disconnecting from MCP')
      torchStore.setTorchState(data.holderId)
      disconnectFromMCP()
    } else if (!hadTorch && hasTorchNow) {
      // We got the torch - connect
      console.log('[Torch] Got torch, connecting to MCP')
      torchStore.setTorchState(data.holderId)
      await connectToMCP()
    } else {
      torchStore.setTorchState(data.holderId)
    }
  } catch (e) {
    // Silently ignore polling errors
  }
}

/**
 * Start polling for torch state changes
 */
export function startTorchPolling(intervalMs: number = 2000) {
  if (pollingInterval) return

  console.log('[Torch] Starting polling...')
  pollingInterval = window.setInterval(fetchTorchState, intervalMs)
}

/**
 * Stop polling
 */
export function stopTorchPolling() {
  if (pollingInterval) {
    window.clearInterval(pollingInterval)
    pollingInterval = null
    console.log('[Torch] Polling stopped')
  }
}

/**
 * Connect to MCP (when we have the torch)
 */
async function connectToMCP(): Promise<void> {
  const webmcp = getWebMCP()
  if (!webmcp) {
    console.error('[Torch] WebMCP not initialized')
    return
  }

  if (webmcp.isConnected) {
    console.log('[Torch] Already connected to MCP')
    return
  }

  console.log('[Torch] Connecting to MCP...')
  const success = await autoConnect()
  if (success) {
    console.log('[Torch] Connected to MCP')
  } else {
    console.error('[Torch] Failed to connect to MCP')
  }
}

/**
 * Disconnect from MCP (when we lose the torch)
 */
function disconnectFromMCP(): void {
  const webmcp = getWebMCP()
  if (!webmcp) return

  if (webmcp.isConnected && typeof webmcp.disconnect === 'function') {
    console.log('[Torch] Disconnecting from MCP...')
    webmcp.disconnect()
  }
}

/**
 * Initialize torch system
 */
export async function initTorch(): Promise<void> {
  // Register this client
  await registerClient()

  // Start polling for state changes
  startTorchPolling()

  // Cleanup on page unload
  window.addEventListener('beforeunload', () => {
    stopTorchPolling()
    // Note: unregisterClient is async, may not complete before unload
    // Server should handle stale clients via timeout
  })
}

/**
 * Cleanup torch system
 */
export async function destroyTorch(): Promise<void> {
  stopTorchPolling()
  await unregisterClient()

  const torchStore = useTorchStore()
  torchStore.reset()
}