import { Types } from "mongoose";

import { TariffModel } from "@/models/tariff.model";
import { PrivilegeModel } from "@/models/privilege.model";

import { validateEmptyFields } from "@/utils/validate-empty-fields";
import { determinePaginationParameters } from "@/utils/determine-pagination-parameters";
import { validateTariff } from "./helpers";

import type { FastifyReply } from "fastify";
import type { Privilege } from "@/types/models/privilege.type";
import type { Tariff } from "@/types/models/tariff.type";
import type { Eloquent } from "@/types/models/eloquent.type";
import type {
  CreateTariffRequest,
  GetTariffRequest,
  ReplaceTariffRequest,
  RemoveTariffRequest,
  GetTariffsResponse,
  GetTariffsRequest,
} from "./types";

export const getTariffs = async (request: GetTariffsRequest): Promise<GetTariffsResponse> => {
  const { page, limit } = determinePaginationParameters(request?.query ?? {});

  const tariffsCount = await TariffModel.countDocuments();

  const totalPages = Math.ceil(tariffsCount / limit);
  const offset = (page - 1) * limit;

  const tariffs = await TariffModel.find({}).sort({ createdAt: "desc" }).skip(offset).limit(limit).lean();

  return { tariffs, totalPages };
};

export const getTariff = async (request: GetTariffRequest, reply: FastifyReply) => {
  const [requestParams, error] = validateEmptyFields(request.params ?? {}, ["id"]);

  if (error) {
    void reply.status(400);
    return error;
  }

  if (!Types.ObjectId.isValid(requestParams.id)) {
    void reply.status(400);
    return new Error("invalid id");
  }

  const tariff = await TariffModel.findById(requestParams.id).lean();

  if (!tariff) {
    void reply.status(404);
    return new Error("tariff not found");
  }

  return tariff;
};

export const createTariff = async (request: CreateTariffRequest, reply: FastifyReply): Promise<Tariff> => {
  const [requestBody, error] = validateTariff(request.body);

  if (error) {
    void reply.status(400);
    throw error;
  }

  for (const privilege of requestBody.privilegies) {
    if (!Types.ObjectId.isValid(privilege.privilegeId)) {
      void reply.status(404);
      throw new Error(`privilege id <${privilege.privilegeId}> invalid`);
    }
  }

  const privilegiesMap = new Map(requestBody.privilegies.map((privilege) => [privilege.privilegeId, privilege]));
  const privilegeIDs = requestBody.privilegies.map(({ privilegeId }) => privilegeId);
  const privilegies = await PrivilegeModel.find({ privilegeId: privilegeIDs }).lean();

  const cleanPrivilegies = privilegies.map<Omit<Privilege, keyof Eloquent>>((privilege) => {
    const currentPrivilege = privilegiesMap.get(privilege.privilegeId);

    return {
      name: privilege.name,
      privilegeId: privilege.privilegeId,
      serviceKey: privilege.serviceKey,
      description: privilege.description,
      amount: currentPrivilege?.amount ?? 0,
      type: privilege.type,
      value: privilege.value,
      price: privilege.price,
    };
  });

  const newTariff = new TariffModel({
    name: requestBody.name,
    price: requestBody.price,
    isCustom: requestBody.isCustom,
    privilegies: cleanPrivilegies,
  });

  await newTariff.save();

  return newTariff;
};

export const replaceTariff = async (request: ReplaceTariffRequest, reply: FastifyReply) => {
  const [requestBody, error] = validateTariff(request.body ?? {});

  if (error) {
    void reply.status(400);
    return error;
  }

  if (!Types.ObjectId.isValid(request.params?.id || "")) {
    void reply.status(400);
    return new Error("invalid id");
  }

  const tariff = await TariffModel.findById(request.params?.id);

  if (!tariff) {
    void reply.status(404);
    return new Error("tariff not found");
  }

  for (const privilege of requestBody.privilegies) {
    if (!Types.ObjectId.isValid(privilege.privilegeId)) {
      void reply.status(404);
      return new Error(`privilege id <${privilege.privilegeId}> invalid`);
    }
  }

  const privilegiesMap = new Map(requestBody.privilegies.map((privilege) => [privilege.privilegeId, privilege]));
  const privilegeIDs = requestBody.privilegies.map(({ privilegeId }) => privilegeId);
  const privilegies = await PrivilegeModel.find({ privilegeId: privilegeIDs }).lean();

  const cleanPrivilegies = privilegies.map<Omit<Privilege, keyof Eloquent>>((privilege) => {
    const currentPrivilege = privilegiesMap.get(privilege.privilegeId);

    return {
      name: privilege.name,
      privilegeId: privilege.privilegeId,
      serviceKey: privilege.serviceKey,
      description: privilege.description,
      amount: currentPrivilege?.amount ?? 0,
      type: privilege.type,
      value: privilege.value,
      price: privilege.price,
    };
  });

  await tariff.replaceOne({
    name: requestBody.name,
    price: requestBody.price,
    isCustom: requestBody.isCustom,
    privilegies: cleanPrivilegies,
  });

  return tariff;
};

export const removeTariff = async (request: RemoveTariffRequest, reply: FastifyReply) => {
  const [{ id }, error] = validateEmptyFields(request.body ?? {}, ["id"]);

  if (error) {
    void reply.status(400);
    return error;
  }

  if (!Types.ObjectId.isValid(id)) {
    void reply.status(400);
    return new Error("invalid id");
  }

  const tariff = await TariffModel.findByIdAndUpdate(id, {
    $set: { isDeleted: true, deletedAt: new Date() },
  }).lean();

  if (!tariff) {
    void reply.status(404);
    return new Error("tariff not found");
  }

  return tariff;
};

export const deleteTariff = async (request: RemoveTariffRequest, reply: FastifyReply) => {
  const [{ id }, error] = validateEmptyFields(request.body ?? {}, ["id"]);

  if (error) {
    void reply.status(400);
    return error;
  }

  if (!Types.ObjectId.isValid(id)) {
    void reply.status(400);
    return new Error("invalid id");
  }

  const tariff = await TariffModel.findByIdAndDelete(id).lean();

  if (!tariff) {
    void reply.status(404);
    return new Error("tariff not found");
  }

  return tariff;
};

export const restoreTariff = async (request: RemoveTariffRequest, reply: FastifyReply) => {
  const [{ id }, error] = validateEmptyFields(request.body ?? {}, ["id"]);

  if (error) {
    void reply.status(400);
    return error;
  }

  if (!Types.ObjectId.isValid(id)) {
    void reply.status(400);
    return new Error("invalid id");
  }

  const tariff = await TariffModel.findByIdAndUpdate(id, { $set: { isDeleted: false } }).lean();

  if (!tariff) {
    void reply.status(404);
    return new Error("tariff not found");
  }

  return tariff;
};