"use client";

import React from "react";
import { api } from "@/trpc/react";
import type { Session } from "next-auth";
import type { PublicUser } from "next-auth";
import { calculateSplits, type Payment } from "@/lib/utils/expense";

export enum SplitTypeEnum {
  Fixed = "fixed",
  Percentage = "percentage",
  Equal = "equal",
}
export type SplitType = keyof typeof SplitTypeEnum;
export const splitTypeKeys = Object.keys(SplitTypeEnum);

export const useExpenseSplit = (amount: number, session: Session) => {
  const [friends] = api.friend.getAll.useSuspenseQuery();
  const [friendTarget, setFriendTarget] = React.useState<string>();
  const [participants, setParticipants] = React.useState<Array<PublicUser>>([
    session.user,
  ]);
  const [activeSplitType, setActiveSplitType] =
    React.useState<SplitType>("Equal");
  const [payments, setPayments] = React.useState<Array<Payment>>([
    { amount: amount, userId: session.user.id },
  ]);

  const [splits, setSplits] = React.useState<
    Record<string /* user.id */, string /* amount */>
  >({});

  React.useEffect(() => {
    // const generateSplitsAmount = () => {
    //   var newSplits: Record<string, SplitType> = {};
    //   participants.forEach((user) => {
    //     newSplits[user.id!] = splits[user.id!] ?? {};
    //   });
    //   console.log(newSplits);
    //   return newSplits;
    // };

    setSplits(
      calculateSplits(
        {
          amount,
          users: participants.map((user) => user.id!),
          splitType: activeSplitType,
        }
        // generateSplitsAmount()
      )
    );
  }, [participants, activeSplitType, amount]);

  const addParticipant = (newUser: PublicUser) => {
    setParticipants((prev) =>
      prev.find((user) => user.id === newUser.id) ? prev : [...prev, newUser]
    );
  };
  const removeParticipant = (userId: string) => {
    setParticipants((prev) => prev.filter((user) => user.id !== userId));
  };

  return {
    friends,
    amount,
    participants,
    addParticipant,
    removeParticipant,
    friendTarget,
    setFriendTarget,
    splitType: activeSplitType,
    setSplitType: setActiveSplitType,
    payments,
    setPayments,
    //
    splits,
  };
};

export type ExpenseSplitHook = ReturnType<typeof useExpenseSplit>;