import { Prisma, type PrismaClient } from "@capakraken/db";
import {
  CreateCountrySchema,
  CreateMetroCitySchema,
  UpdateCountrySchema,
  UpdateMetroCitySchema,
} from "@capakraken/shared";
import { TRPCError } from "@trpc/server";
import { z } from "zod";

type CountryDb = Pick<PrismaClient, "country">;
type MetroCityDb = Pick<PrismaClient, "metroCity">;

type CountryListInput = {
  isActive?: boolean | undefined;
};

type MetroCityDeleteRecord = {
  _count: {
    resources: number;
  };
};

type CreateCountryInput = z.infer<typeof CreateCountrySchema>;
type UpdateCountryInput = z.infer<typeof UpdateCountrySchema>;
type CreateMetroCityInput = z.infer<typeof CreateMetroCitySchema>;
type UpdateMetroCityInput = z.infer<typeof UpdateMetroCitySchema>;

export function jsonOrNull(val: unknown): Prisma.InputJsonValue | typeof Prisma.JsonNull {
  if (val === null || val === undefined) return Prisma.JsonNull;
  return val as Prisma.InputJsonValue;
}

export function buildCountryListWhere(
  input: CountryListInput,
): Prisma.CountryWhereInput {
  return {
    ...(input.isActive !== undefined ? { isActive: input.isActive } : {}),
  };
}

export async function findCountryByIdentifier<TCountry>(
  db: CountryDb,
  identifier: string,
  extraArgs: Record<string, unknown>,
): Promise<TCountry> {
  const normalizedIdentifier = identifier.trim();
  const upperIdentifier = normalizedIdentifier.toUpperCase();

  let country = await db.country.findUnique({
    where: { id: normalizedIdentifier },
    ...extraArgs,
  }) as TCountry | null;

  if (!country) {
    country = await db.country.findFirst({
      where: { code: { equals: upperIdentifier, mode: "insensitive" } },
      ...extraArgs,
    }) as TCountry | null;
  }

  if (!country) {
    country = await db.country.findFirst({
      where: { name: { equals: normalizedIdentifier, mode: "insensitive" } },
      ...extraArgs,
    }) as TCountry | null;
  }

  if (!country) {
    country = await db.country.findFirst({
      where: { name: { contains: normalizedIdentifier, mode: "insensitive" } },
      ...extraArgs,
    }) as TCountry | null;
  }

  if (!country) {
    throw new TRPCError({
      code: "NOT_FOUND",
      message: `Country not found: ${normalizedIdentifier}`,
    });
  }

  return country;
}

export async function assertCountryCodeAvailable(
  db: CountryDb,
  code: string,
  ignoreId?: string,
): Promise<void> {
  const existing = await db.country.findUnique({ where: { code } });
  if (existing && existing.id !== ignoreId) {
    throw new TRPCError({
      code: "CONFLICT",
      message: `Country code "${code}" already exists`,
    });
  }
}

export function buildCountryCreateData(
  input: CreateCountryInput,
): Prisma.CountryUncheckedCreateInput {
  return {
    code: input.code,
    name: input.name,
    dailyWorkingHours: input.dailyWorkingHours,
    ...(input.scheduleRules !== undefined
      ? { scheduleRules: jsonOrNull(input.scheduleRules) }
      : {}),
  };
}

export function buildCountryUpdateData(
  input: UpdateCountryInput,
): Prisma.CountryUncheckedUpdateInput {
  return {
    ...(input.code !== undefined ? { code: input.code } : {}),
    ...(input.name !== undefined ? { name: input.name } : {}),
    ...(input.dailyWorkingHours !== undefined ? { dailyWorkingHours: input.dailyWorkingHours } : {}),
    ...(input.scheduleRules !== undefined ? { scheduleRules: jsonOrNull(input.scheduleRules) } : {}),
    ...(input.isActive !== undefined ? { isActive: input.isActive } : {}),
  };
}

export function buildMetroCityCreateData(
  input: CreateMetroCityInput,
): Prisma.MetroCityUncheckedCreateInput {
  return {
    name: input.name,
    countryId: input.countryId,
  };
}

export function buildMetroCityUpdateData(
  input: UpdateMetroCityInput,
): Prisma.MetroCityUncheckedUpdateInput {
  return {
    ...(input.name !== undefined ? { name: input.name } : {}),
  };
}

export function assertMetroCityDeletable(
  city: MetroCityDeleteRecord,
): void {
  if (city._count.resources > 0) {
    throw new TRPCError({
      code: "PRECONDITION_FAILED",
      message: `Cannot delete metro city assigned to ${city._count.resources} resource(s)`,
    });
  }
}