import type { ApiRequest, ApiResponse } from '../_lib/types.js'
import { cors, withTelegramAuth } from '../_lib/auth.js'
import { questEventSchema } from '../_lib/validation.js'
import {
  findUserByTelegramId,
  createQuestEvent,
  getPointById,
  updatePointStatus,
  markPointArrived,
  updatePointContent,
  getActivePointForDay,
  getActiveDayForQuest,
  getActiveQuestForUser,
  updateDayStatus,
  getPointsForDay,
} from '../_lib/db.js'

async function handler(req: ApiRequest, res: ApiResponse) {
  cors(req, res)

  if (req.method === 'OPTIONS') {
    return res.status(200).end()
  }

  if (req.method !== 'POST') {
    return res.status(405).json({ error: 'Method not allowed' })
  }

  const telegramUser = req.telegramUser
  if (!telegramUser) {
    return res.status(401).json({ error: 'Not authenticated' })
  }

  const parsed = questEventSchema.safeParse(req.body)
  if (!parsed.success) {
    return res.status(400).json({ error: 'Invalid request', details: parsed.error.issues })
  }

  const { questId, pointId, eventType, payload } = parsed.data

  const user = await findUserByTelegramId(telegramUser.id)
  if (!user) {
    return res.status(404).json({ error: 'User not found' })
  }

  // Immediate state updates for UI responsiveness
  let nextAction: string = 'wait'
  let updatedPoint = null
  let shouldCreateEvent = true
  const currentPoint = pointId ? await getPointById(pointId) : null

  switch (eventType) {
    case 'arrived': {
      if (pointId) {
        if (currentPoint?.arrived_at) {
          shouldCreateEvent = false
          updatedPoint = currentPoint
        } else {
          await markPointArrived(pointId)
          updatedPoint = await getPointById(pointId)
        }
        nextAction = 'show_content'
      }
      break
    }
    case 'point_completed': {
      if (pointId) {
        if (currentPoint?.status === 'completed' || currentPoint?.status === 'skipped') {
          shouldCreateEvent = false
        } else {
          await updatePointStatus(pointId, 'completed')
        }
        // Check if there are more points in the day
        const quest = await getActiveQuestForUser(user.id)
        if (quest) {
          const day = await getActiveDayForQuest(quest.id)
          if (day) {
            const points = await getPointsForDay(day.id)
            const nextPoint = points.find((p: { status: string }) => p.status === 'hidden' || p.status === 'preview')
            if (nextPoint) {
              nextAction = 'next_point'
            } else {
              nextAction = 'day_complete'
            }
          }
        }
      }
      break
    }
    case 'skipped': {
      if (pointId) {
        if (currentPoint?.status === 'completed' || currentPoint?.status === 'skipped') {
          shouldCreateEvent = false
        } else {
          await updatePointStatus(pointId, 'skipped')
        }
        nextAction = 'next_point'
      }
      break
    }
    case 'finished_today': {
      const quest = await getActiveQuestForUser(user.id)
      if (quest) {
        const day = await getActiveDayForQuest(quest.id)
        if (day) {
          // Mark all remaining points as skipped
          const points = await getPointsForDay(day.id)
          for (const point of points) {
            if (point.status !== 'completed' && point.status !== 'skipped') {
              await updatePointStatus(point.id, 'skipped')
            }
          }
          await updateDayStatus(day.id, 'completed')
          nextAction = 'day_complete'
        }
      }
      break
    }
  }

  // Write event to DB (bot will process it asynchronously)
  if (shouldCreateEvent) {
    await createQuestEvent({
      quest_id: questId,
      user_id: user.id,
      point_id: pointId,
      event_type: eventType,
      payload,
    })
  }

  return res.json({
    success: true,
    updatedPoint,
    nextAction,
  })
}

export default withTelegramAuth(handler)