/**
 * Queries de Purchase Intentions usando Prisma
 */

import { prisma } from "../app";
import { Prisma } from "@prisma/client";

export type PurchaseIntentionStatus = "pending" | "accepted" | "rejected" | "expired" | "completed";
export type PaymentMethod = "pix" | "tibia_coins" | "gold_coins" | "trade";

export interface CreatePurchaseIntentionData {
  listing_id: number;
  buyer_id: number;
  payment_method: PaymentMethod;
  buyer_message?: string;
  expires_at?: Date;
  custom_offer_amount?: number | null;
  custom_offer_currency?: PaymentMethod | null;
}

export interface PurchaseIntention {
  intention_id: number;
  listing_id: number;
  buyer_id: number;
  payment_method: string;
  payment_method_change_count: number;
  custom_offer_amount: number | null;
  custom_offer_currency: string | null;
  custom_offer_created_at: Date | null;
  status: PurchaseIntentionStatus;
  buyer_message: string | null;
  seller_response: string | null;
  created_at: Date;
  updated_at: Date;
  expires_at: Date | null;
  accepted_at: Date | null;
  rejected_at: Date | null;
  // Relacionamentos
  listing?: {
    listing_id: number;
    item_name: string;
    seller_id: number;
  };
  buyer?: {
    user_id: number;
    username: string;
    email: string;
  };
}

function serializePurchaseIntention(intention: any): PurchaseIntention {
  if (!intention) return intention;

  return {
    ...intention,
    custom_offer_amount:
      intention.custom_offer_amount !== null && intention.custom_offer_amount !== undefined
        ? Number(intention.custom_offer_amount)
        : null,
    custom_offer_currency: intention.custom_offer_currency ?? null,
    custom_offer_created_at: intention.custom_offer_created_at ?? null,
  };
}

/**
 * Cria uma nova intenção de compra
 */
export async function createPurchaseIntention(
  data: CreatePurchaseIntentionData
): Promise<PurchaseIntention> {
  const result = await prisma.purchaseIntention.create({
    data: {
      listing_id: data.listing_id,
      buyer_id: data.buyer_id,
      payment_method: data.payment_method,
      buyer_message: data.buyer_message || null,
      expires_at: data.expires_at || null,
      status: "pending",
      custom_offer_amount:
        data.custom_offer_amount !== undefined && data.custom_offer_amount !== null
          ? new Prisma.Decimal(data.custom_offer_amount)
          : null,
      custom_offer_currency: data.custom_offer_currency || null,
      custom_offer_created_at:
        data.custom_offer_amount !== undefined && data.custom_offer_amount !== null
          ? new Date()
          : null,
    },
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
  });

  return serializePurchaseIntention(result);
}

/**
 * Busca intenções de um anúncio específico
 */
export async function getPurchaseIntentionsByListing(
  listingId: number,
  filters: { status?: PurchaseIntentionStatus; limit?: number } = {}
): Promise<PurchaseIntention[]> {
  const { status, limit = 50 } = filters;

  const where: any = { listing_id: listingId };
  if (status) {
    where.status = status;
  }

  const intentions = await prisma.purchaseIntention.findMany({
    where,
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
    orderBy: { created_at: "desc" },
    take: limit,
  });

  return intentions.map(serializePurchaseIntention);
}

/**
 * Busca intenções de um comprador
 */
export async function getPurchaseIntentionsByBuyer(
  buyerId: number,
  filters: { status?: PurchaseIntentionStatus; limit?: number } = {}
): Promise<PurchaseIntention[]> {
  const { status, limit = 50 } = filters;

  const where: any = { buyer_id: buyerId };
  if (status) {
    where.status = status;
  }

  const intentions = await prisma.purchaseIntention.findMany({
    where,
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
    orderBy: { created_at: "desc" },
    take: limit,
  });

  return intentions.map(serializePurchaseIntention);
}

/**
 * Busca uma intenção específica por ID
 */
export async function getPurchaseIntentionById(
  intentionId: number
): Promise<PurchaseIntention | null> {
  const intention = await prisma.purchaseIntention.findUnique({
    where: { intention_id: intentionId },
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
  });

  return serializePurchaseIntention(intention);
}

/**
 * Atualiza o status de uma intenção
 */
export async function updatePurchaseIntentionStatus(
  intentionId: number,
  status: PurchaseIntentionStatus,
  sellerResponse?: string
): Promise<PurchaseIntention> {
  const updateData: any = {
    status,
    updated_at: new Date(),
  };

  if (status === "accepted") {
    updateData.accepted_at = new Date();
    updateData.seller_response = sellerResponse || null;
  } else if (status === "rejected") {
    updateData.rejected_at = new Date();
    updateData.seller_response = sellerResponse || null;
  } else if (sellerResponse) {
    updateData.seller_response = sellerResponse;
  }

  const updated = await prisma.purchaseIntention.update({
    where: { intention_id: intentionId },
    data: updateData,
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
  });

  return serializePurchaseIntention(updated);
}

/**
 * Conta intenções pendentes de um anúncio
 */
export async function getPendingIntentionsCount(listingId: number): Promise<number> {
  return await prisma.purchaseIntention.count({
    where: {
      listing_id: listingId,
      status: "pending",
    },
  });
}

/**
 * Verifica se já existe uma intenção pendente para um listing+buyer
 */
export async function hasPendingIntention(
  listingId: number,
  buyerId: number
): Promise<boolean> {
  const count = await prisma.purchaseIntention.count({
    where: {
      listing_id: listingId,
      buyer_id: buyerId,
      status: "pending",
    },
  });

  return count > 0;
}

/**
 * Busca intenção pendente de um comprador para um listing específico
 */
export async function getPendingIntentionByBuyerAndListing(
  listingId: number,
  buyerId: number
): Promise<PurchaseIntention | null> {
  const intention = await prisma.purchaseIntention.findFirst({
    where: {
      listing_id: listingId,
      buyer_id: buyerId,
      status: "pending",
    },
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
    orderBy: {
      created_at: "desc",
    },
  });

  return serializePurchaseIntention(intention);
}

/**
 * Atualiza o método de pagamento de uma intenção
 */
export async function updatePurchaseIntentionPaymentMethod(
  intentionId: number,
  newPaymentMethod: PaymentMethod
): Promise<PurchaseIntention> {
  // Buscar intenção atual
  const intention = await prisma.purchaseIntention.findUnique({
    where: { intention_id: intentionId },
  });

  if (!intention) {
    throw new Error("Intenção não encontrada");
  }

  // Verificar se pode trocar (máximo 1 troca)
  if (intention.payment_method_change_count >= 1) {
    throw new Error("Você já atingiu o limite de trocas de método de pagamento");
  }

  // Verificar se o novo método é diferente
  if (intention.payment_method === newPaymentMethod) {
    throw new Error("O novo método de pagamento deve ser diferente do atual");
  }

  // Atualizar
  const updated = await prisma.purchaseIntention.update({
    where: { intention_id: intentionId },
    data: {
      payment_method: newPaymentMethod,
      payment_method_change_count: intention.payment_method_change_count + 1,
      updated_at: new Date(),
    },
    include: {
      listing: {
        select: {
          listing_id: true,
          item_name: true,
          seller_id: true,
        },
      },
      buyer: {
        select: {
          user_id: true,
          username: true,
          email: true,
        },
      },
    },
  });

  return serializePurchaseIntention(updated);
}

/**
 * Retorna os IDs de anúncios com intenções pendentes para um comprador
 */
export async function getPendingIntentionListingIdsForBuyer(
  buyerId: number,
  listingIds: number[]
): Promise<number[]> {
  if (listingIds.length === 0) {
    return [];
  }

  const intentions = await prisma.purchaseIntention.findMany({
    where: {
      buyer_id: buyerId,
      status: "pending",
      listing_id: {
        in: listingIds,
      },
    },
    select: {
      listing_id: true,
    },
  });

  const uniqueIds = new Set<number>();
  intentions.forEach((intention) => {
    uniqueIds.add(intention.listing_id);
  });

  return Array.from(uniqueIds);
}

export async function getHighestCustomOfferForListing(
  listingId: number
): Promise<{ amount: number; currency: string } | null> {
  const offer = await prisma.purchaseIntention.findFirst({
    where: {
      listing_id: listingId,
      status: { in: ["pending", "accepted"] },
      custom_offer_amount: { not: null },
      custom_offer_currency: { not: null },
    },
    orderBy: { custom_offer_amount: "desc" },
    select: {
      custom_offer_amount: true,
      custom_offer_currency: true,
    },
  });

  if (!offer) {
    return null;
  }

  return {
    amount: Number(offer.custom_offer_amount),
    currency: offer.custom_offer_currency!,
  };
}

export async function getHighestCustomOffersForListings(
  listingIds: number[]
): Promise<Map<number, { amount: number; currency: string }>> {
  if (listingIds.length === 0) {
    return new Map();
  }

  const offers = await prisma.purchaseIntention.findMany({
    where: {
      listing_id: { in: listingIds },
      status: { in: ["pending", "accepted"] },
      custom_offer_amount: { not: null },
      custom_offer_currency: { not: null },
    },
    select: {
      listing_id: true,
      custom_offer_amount: true,
      custom_offer_currency: true,
    },
    orderBy: [
      { listing_id: "asc" },
      { custom_offer_amount: "desc" },
    ],
  });

  const result = new Map<number, { amount: number; currency: string }>();
  for (const offer of offers) {
    if (!result.has(offer.listing_id)) {
      result.set(offer.listing_id, {
        amount: Number(offer.custom_offer_amount),
        currency: offer.custom_offer_currency!,
      });
    }
  }

  return result;
}