package com.android.trisolarisserver.controller

import com.android.trisolarisserver.component.PropertyAccess
import com.android.trisolarisserver.component.RoomBoardEvents
import com.android.trisolarisserver.controller.dto.BookingCancelRequest
import com.android.trisolarisserver.controller.dto.BookingCheckInRequest
import com.android.trisolarisserver.controller.dto.BookingCheckOutRequest
import com.android.trisolarisserver.controller.dto.BookingNoShowRequest
import com.android.trisolarisserver.controller.dto.RoomStayPreAssignRequest
import com.android.trisolarisserver.db.repo.BookingRepo
import com.android.trisolarisserver.models.booking.BookingStatus
import com.android.trisolarisserver.models.booking.TransportMode
import com.android.trisolarisserver.models.room.RoomStay
import com.android.trisolarisserver.models.property.Role
import com.android.trisolarisserver.repo.AppUserRepo
import com.android.trisolarisserver.repo.RoomRepo
import com.android.trisolarisserver.repo.RoomStayRepo
import com.android.trisolarisserver.security.MyPrincipal
import org.springframework.http.HttpStatus
import org.springframework.security.core.annotation.AuthenticationPrincipal
import org.springframework.transaction.annotation.Transactional
import org.springframework.web.bind.annotation.PathVariable
import org.springframework.web.bind.annotation.PostMapping
import org.springframework.web.bind.annotation.RequestBody
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.ResponseStatus
import org.springframework.web.bind.annotation.RestController
import org.springframework.web.server.ResponseStatusException
import java.time.OffsetDateTime
import java.util.UUID

@RestController
@RequestMapping("/properties/{propertyId}/bookings")
class BookingFlow(
    private val propertyAccess: PropertyAccess,
    private val bookingRepo: BookingRepo,
    private val roomRepo: RoomRepo,
    private val roomStayRepo: RoomStayRepo,
    private val appUserRepo: AppUserRepo,
    private val roomBoardEvents: RoomBoardEvents
) {

    @PostMapping("/{bookingId}/check-in")
    @ResponseStatus(HttpStatus.CREATED)
    @Transactional
    fun checkIn(
        @PathVariable propertyId: UUID,
        @PathVariable bookingId: UUID,
        @AuthenticationPrincipal principal: MyPrincipal?,
        @RequestBody request: BookingCheckInRequest
    ) {
        val actor = requireActor(propertyId, principal)

        val roomIds = request.roomIds.distinct()
        if (roomIds.isEmpty()) {
            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "roomIds required")
        }
        val booking = requireBooking(propertyId, bookingId)
        if (booking.status != BookingStatus.OPEN) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Booking not open")
        }

        val now = OffsetDateTime.now()
        val checkInAt = parseOffset(request.checkInAt) ?: now

        val rooms = roomIds.map { roomId ->
            val room = roomRepo.findByIdAndPropertyId(roomId, propertyId)
                ?: throw ResponseStatusException(HttpStatus.NOT_FOUND, "Room not found")
            if (!room.active || room.maintenance) {
                throw ResponseStatusException(HttpStatus.CONFLICT, "Room not available")
            }
            room
        }

        val occupied = roomStayRepo.findActiveRoomIds(propertyId, rooms.mapNotNull { it.id })
        if (occupied.isNotEmpty()) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Room already occupied")
        }

        rooms.forEach { room ->
            val stay = RoomStay(
                property = booking.property,
                booking = booking,
                room = room,
                fromAt = checkInAt,
                toAt = null,
                createdBy = actor
            )
            roomStayRepo.save(stay)
        }

        booking.status = BookingStatus.CHECKED_IN
        booking.checkinAt = checkInAt
        booking.transportMode = request.transportMode?.let {
            val mode = parseTransportMode(it)
            if (!isTransportModeAllowed(booking.property, mode)) {
                throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Transport mode disabled")
            }
            mode
        }
        booking.transportVehicleNumber = request.transportVehicleNumber
        if (request.notes != null) booking.notes = request.notes
        booking.updatedAt = now
        bookingRepo.save(booking)
        roomBoardEvents.emit(propertyId)
    }

    @PostMapping("/{bookingId}/check-out")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    @Transactional
    fun checkOut(
        @PathVariable propertyId: UUID,
        @PathVariable bookingId: UUID,
        @AuthenticationPrincipal principal: MyPrincipal?,
        @RequestBody request: BookingCheckOutRequest
    ) {
        requireActor(propertyId, principal)
        val booking = requireBooking(propertyId, bookingId)
        if (booking.status != BookingStatus.CHECKED_IN) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Booking not checked in")
        }
        val now = OffsetDateTime.now()
        val checkOutAt = parseOffset(request.checkOutAt) ?: now

        val stays = roomStayRepo.findActiveByBookingId(bookingId)
        stays.forEach { it.toAt = checkOutAt }
        roomStayRepo.saveAll(stays)

        booking.status = BookingStatus.CHECKED_OUT
        booking.checkoutAt = checkOutAt
        if (request.notes != null) booking.notes = request.notes
        booking.updatedAt = now
        bookingRepo.save(booking)
        roomBoardEvents.emit(propertyId)
    }

    @PostMapping("/{bookingId}/cancel")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    @Transactional
    fun cancel(
        @PathVariable propertyId: UUID,
        @PathVariable bookingId: UUID,
        @AuthenticationPrincipal principal: MyPrincipal?,
        @RequestBody request: BookingCancelRequest
    ) {
        requireActor(propertyId, principal)
        val booking = requireBooking(propertyId, bookingId)
        if (booking.status == BookingStatus.CHECKED_IN) {
            val active = roomStayRepo.findActiveByBookingId(bookingId)
            if (active.isNotEmpty()) {
                throw ResponseStatusException(HttpStatus.CONFLICT, "Cannot cancel checked-in booking")
            }
        }
        booking.status = BookingStatus.CANCELLED
        if (request.reason != null) booking.notes = request.reason
        booking.updatedAt = OffsetDateTime.now()
        bookingRepo.save(booking)
    }

    @PostMapping("/{bookingId}/no-show")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    @Transactional
    fun noShow(
        @PathVariable propertyId: UUID,
        @PathVariable bookingId: UUID,
        @AuthenticationPrincipal principal: MyPrincipal?,
        @RequestBody request: BookingNoShowRequest
    ) {
        requireActor(propertyId, principal)
        val booking = requireBooking(propertyId, bookingId)
        if (booking.status != BookingStatus.OPEN) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Booking not open")
        }
        booking.status = BookingStatus.NO_SHOW
        if (request.reason != null) booking.notes = request.reason
        booking.updatedAt = OffsetDateTime.now()
        bookingRepo.save(booking)
    }

    @PostMapping("/{bookingId}/room-stays")
    @ResponseStatus(HttpStatus.CREATED)
    @Transactional
    fun preAssignRoom(
        @PathVariable propertyId: UUID,
        @PathVariable bookingId: UUID,
        @AuthenticationPrincipal principal: MyPrincipal?,
        @RequestBody request: RoomStayPreAssignRequest
    ) {
        val actor = requireActor(propertyId, principal)
        val booking = requireBooking(propertyId, bookingId)
        if (booking.status == BookingStatus.CANCELLED || booking.status == BookingStatus.NO_SHOW || booking.status == BookingStatus.CHECKED_OUT) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Booking closed")
        }

        val room = roomRepo.findByIdAndPropertyId(request.roomId, propertyId)
            ?: throw ResponseStatusException(HttpStatus.NOT_FOUND, "Room not found")
        if (!room.active || room.maintenance) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Room not available")
        }

        val fromAt = parseOffset(request.fromAt)
            ?: throw ResponseStatusException(HttpStatus.BAD_REQUEST, "fromAt required")
        val toAt = parseOffset(request.toAt)
            ?: throw ResponseStatusException(HttpStatus.BAD_REQUEST, "toAt required")
        if (!toAt.isAfter(fromAt)) {
            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid date range")
        }

        if (roomStayRepo.existsOverlap(propertyId, request.roomId, fromAt, toAt)) {
            throw ResponseStatusException(HttpStatus.CONFLICT, "Room already reserved/occupied for range")
        }

        val stay = RoomStay(
            property = booking.property,
            booking = booking,
            room = room,
            fromAt = fromAt,
            toAt = toAt,
            createdBy = actor
        )
        roomStayRepo.save(stay)
    }

    private fun requireBooking(propertyId: UUID, bookingId: UUID): com.android.trisolarisserver.models.booking.Booking {
        val booking = bookingRepo.findById(bookingId).orElseThrow {
            ResponseStatusException(HttpStatus.NOT_FOUND, "Booking not found")
        }
        if (booking.property.id != propertyId) {
            throw ResponseStatusException(HttpStatus.NOT_FOUND, "Booking not found for property")
        }
        return booking
    }

    private fun requireActor(propertyId: UUID, principal: MyPrincipal?): com.android.trisolarisserver.models.property.AppUser {
        requirePrincipal(principal)
        propertyAccess.requireMember(propertyId, principal!!.userId)
        propertyAccess.requireAnyRole(propertyId, principal.userId, Role.ADMIN, Role.MANAGER, Role.STAFF)
        return appUserRepo.findById(principal.userId).orElseThrow {
            ResponseStatusException(HttpStatus.UNAUTHORIZED, "User not found")
        }
    }

    private fun parseOffset(value: String?): OffsetDateTime? {
        if (value.isNullOrBlank()) return null
        return try {
            OffsetDateTime.parse(value.trim())
        } catch (_: Exception) {
            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid timestamp")
        }
    }

    private fun parseTransportMode(value: String): TransportMode {
        return try {
            TransportMode.valueOf(value)
        } catch (_: IllegalArgumentException) {
            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Unknown transport mode")
        }
    }

    private fun isTransportModeAllowed(
        property: com.android.trisolarisserver.models.property.Property,
        mode: TransportMode
    ): Boolean {
        val allowed = if (property.allowedTransportModes.isNotEmpty()) {
            property.allowedTransportModes
        } else {
            TransportMode.entries.toSet()
        }
        return allowed.contains(mode)
    }

    private fun requirePrincipal(principal: MyPrincipal?) {
        if (principal == null) {
            throw ResponseStatusException(HttpStatus.UNAUTHORIZED, "Missing principal")
        }
    }
}