import { NOTIFICATION_EVENTS } from '../../../shared/constants/notification-events.js'
import { asyncHandler } from '../lib/async-handler.js'
import { isDeliveryCarrier } from '../lib/delivery-carrier.js'
import { findUserOrder } from '../lib/find-user-order.js'
import { prisma } from '../lib/prisma.js'

export async function registerUserOrderRoutes(fastify) {
  // ---- Создание заказа (checkout) ----

  fastify.post('/api/me/orders', { preHandler: [fastify.authenticate] }, async (request, reply) => {
    const userId = request.user.sub
    const deliveryTypeRaw = request.body?.deliveryType
    const deliveryType =
      deliveryTypeRaw === undefined || deliveryTypeRaw === null || deliveryTypeRaw === ''
        ? 'delivery'
        : String(deliveryTypeRaw).trim()

    const addressId = String(request.body?.addressId || '').trim()
    const commentRaw = request.body?.comment
    const comment = commentRaw === null || commentRaw === undefined ? null : String(commentRaw).trim()

    const paymentMethodRaw = request.body?.paymentMethod
    const paymentMethod =
      paymentMethodRaw === undefined || paymentMethodRaw === null || paymentMethodRaw === ''
        ? 'online'
        : String(paymentMethodRaw).trim()
    if (paymentMethod !== 'online' && paymentMethod !== 'on_pickup') {
      return reply.code(400).send({ error: 'paymentMethod должен быть online | on_pickup' })
    }

    if (deliveryType !== 'delivery' && deliveryType !== 'pickup') {
      return reply.code(400).send({ error: 'deliveryType должен быть delivery | pickup' })
    }

    const carrierRaw = request.body?.deliveryCarrier
    let deliveryCarrier = null
    if (deliveryType === 'delivery') {
      const carrierStr =
        carrierRaw === undefined || carrierRaw === null || carrierRaw === '' ? '' : String(carrierRaw).trim()
      if (!isDeliveryCarrier(carrierStr)) {
        return reply.code(400).send({
          error: 'deliveryCarrier обязателен для доставки: RUSSIAN_POST | OZON_PVZ | YANDEX_PVZ | FIVE_POST | WB_PVZ',
        })
      }
      deliveryCarrier = carrierStr
    }

    if (paymentMethod === 'on_pickup' && deliveryType !== 'pickup') {
      return reply.code(400).send({
        error: 'Оплата при получении доступна только для самовывоза',
      })
    }

    let address = null
    if (deliveryType === 'delivery') {
      if (!addressId) return reply.code(400).send({ error: 'Выберите адрес доставки' })
      address = await prisma.shippingAddress.findFirst({
        where: { id: addressId, userId },
      })
      if (!address) return reply.code(404).send({ error: 'Адрес не найден' })
    }

    const cartItems = await prisma.cartItem.findMany({
      where: { userId },
      include: { product: true },
    })
    if (cartItems.length === 0) return reply.code(400).send({ error: 'Корзина пуста' })

    for (const ci of cartItems) {
      const available = ci.product.quantity
      if (ci.qty > available) {
        return reply.code(409).send({
          error: `Недостаточно товара: "${ci.product.title}". Доступно: ${available} шт.`,
        })
      }
    }

    const itemsPayload = cartItems.map((ci) => ({
      productId: ci.productId,
      qty: ci.qty,
      titleSnapshot: ci.product.title,
      priceCentsSnapshot: ci.product.priceCents,
    }))

    const itemsSubtotalCents = itemsPayload.reduce((sum, i) => sum + i.priceCentsSnapshot * i.qty, 0)
    const deliveryFeeCents = deliveryType === 'delivery' ? 50000 : 0
    const totalCents = itemsSubtotalCents + deliveryFeeCents

    const addressSnapshotJson =
      deliveryType === 'pickup'
        ? JSON.stringify({ deliveryType: 'pickup' })
        : JSON.stringify({
            deliveryType: 'delivery',
            id: address.id,
            label: address.label,
            recipientName: address.recipientName,
            recipientPhone: address.recipientPhone,
            addressLine: address.addressLine,
            comment: address.comment,
            lat: address.lat,
            lng: address.lng,
          })

    let initialStatus = 'PENDING_PAYMENT'
    let deliveryFeeLocked = true
    if (paymentMethod === 'on_pickup') {
      initialStatus = 'IN_PROGRESS'
    } else if (deliveryType === 'delivery') {
      initialStatus = 'PENDING_PAYMENT'
      deliveryFeeLocked = false
    }

    let created
    try {
      created = await prisma.$transaction(async (tx) => {
        for (const ci of cartItems) {
          const res = await tx.product.updateMany({
            where: { id: ci.productId, quantity: { gte: ci.qty } },
            data: { quantity: { decrement: ci.qty } },
          })
          if (res.count !== 1) {
            throw new Error(`Недостаточно товара: "${ci.product.title}"`)
          }
        }

        const order = await tx.order.create({
          data: {
            userId,
            status: initialStatus,
            deliveryFeeLocked,
            deliveryType,
            deliveryCarrier,
            paymentMethod,
            itemsSubtotalCents,
            deliveryFeeCents,
            totalCents,
            currency: 'RUB',
            addressSnapshotJson,
            comment: comment && comment.length ? comment : null,
            items: {
              create: itemsPayload.map((i) => ({
                productId: i.productId,
                qty: i.qty,
                titleSnapshot: i.titleSnapshot,
                priceCentsSnapshot: i.priceCentsSnapshot,
              })),
            },
          },
        })
        await tx.cartItem.deleteMany({ where: { userId } })
        return order
      })
    } catch (e) {
      return reply.code(409).send({
        error: (e instanceof Error && e.message) || 'Недостаточно товара',
      })
    }

    // Emit notification events
    request.server.eventBus.emit(NOTIFICATION_EVENTS.ORDER_CREATED, {
      orderId: created.id,
      userId,
      totalCents: created.totalCents,
      itemsCount: cartItems.length,
      deliveryType: created.deliveryType,
    })

    // Also emit admin notification
    request.server.eventBus.emit('order:created:admin', {
      orderId: created.id,
      userId,
      userEmail: request.user.email || '',
      totalCents: created.totalCents,
      itemsCount: cartItems.length,
      deliveryType: created.deliveryType,
    })

    return reply.code(201).send({ orderId: created.id })
  })

  fastify.get(
    '/api/me/orders',
    { preHandler: [fastify.authenticate] },
    asyncHandler(async (request, reply) => {
      const userId = request.user.sub
      const orders = await prisma.order.findMany({
        where: { userId },
        include: { items: { select: { qty: true } } },
        orderBy: { createdAt: 'desc' },
      })
      return {
        items: orders.map((o) => ({
          id: o.id,
          status: o.status,
          totalCents: o.totalCents,
          currency: o.currency,
          createdAt: o.createdAt,
          updatedAt: o.updatedAt,
          itemsCount: o.items.reduce((s, i) => s + i.qty, 0),
        })),
      }
    }),
  )

  fastify.get(
    '/api/me/orders/:id',
    { preHandler: [fastify.authenticate] },
    asyncHandler(async (request, reply) => {
      const userId = request.user.sub
      const { id } = request.params
      const order = await findUserOrder(prisma, id, userId, {
        items: true,
        messages: { orderBy: { createdAt: 'asc' } },
      })
      return { item: order }
    }),
  )

  fastify.get(
    '/api/me/orders/:id/review-eligibility',
    { preHandler: [fastify.authenticate] },
    asyncHandler(async (request, reply) => {
      const userId = request.user.sub
      const { id } = request.params
      const order = await findUserOrder(prisma, id, userId, { items: true })
      if (order.status !== 'DONE') {
        return { canReview: false, items: [] }
      }

      const uniq = new Map()
      for (const it of order.items) {
        if (!uniq.has(it.productId)) {
          uniq.set(it.productId, {
            productId: it.productId,
            title: it.titleSnapshot,
          })
        }
      }
      const productIds = [...uniq.keys()]
      const existing = await prisma.review.findMany({
        where: { userId, productId: { in: productIds } },
        select: { productId: true },
      })
      const reviewed = new Set(existing.map((r) => r.productId))
      return {
        canReview: true,
        items: [...uniq.values()].map((x) => ({
          ...x,
          hasReview: reviewed.has(x.productId),
        })),
      }
    }),
  )

  fastify.post(
    '/api/me/orders/:id/confirm-received',
    { preHandler: [fastify.authenticate] },
    asyncHandler(async (request, reply) => {
      const userId = request.user.sub
      const { id } = request.params
      const order = await findUserOrder(prisma, id, userId)

      const okDelivery = order.deliveryType === 'delivery' && order.status === 'SHIPPED'
      const okPickup = order.deliveryType === 'pickup' && order.status === 'READY_FOR_PICKUP'
      if (!okDelivery && !okPickup) {
        return reply.code(409).send({ error: 'Сейчас нельзя подтвердить получение заказа' })
      }

      await prisma.order.update({ where: { id }, data: { status: 'DONE' } })
      return { ok: true, status: 'DONE' }
    }),
  )
}