import { Injectable } from '@nestjs/common';
import { CreateExpenseDto } from './dto/create-expense.dto';
import { UpdateExpenseDto } from './dto/update-expense.dto';
import { ExpenseDataService } from './expense-data.service';
import { GetExpenseDto } from './dto/get-expense.dto';
import { Temporal } from '@js-temporal/polyfill';

@Injectable()
export class ExpensesService {
  public constructor(private expenseDataService: ExpenseDataService) { }

  public async findAll(): Promise<GetExpenseDto[]> {
    const expenses = await this.expenseDataService.getAll();

    return expenses.map(exp => {
      return { ...exp, date: Temporal.PlainDate.from(exp.date) };
    })
  }

  public async findById(id: string): Promise<GetExpenseDto> {
    const expense = await this.expenseDataService.getById(id);
    if (!expense) {
      throw new Error('No expense found');
    }

    return { ...expense, date: Temporal.PlainDate.from(expense.date) };
  }

  public async create(createExpense: CreateExpenseDto): Promise<GetExpenseDto> {
    const date = createExpense.date.toString();
    const category = { id: createExpense.categoryId };
    const merchant = createExpense.merchantId ? { id: createExpense.merchantId } : undefined;
    const tags = createExpense.tagIds?.map(id => {
      return { id };
    })

    const expense = await this.expenseDataService.create({
      date,
      cents: createExpense.cents,
      note: createExpense.note,
      category,
      merchant,
      tags
    });

    return { ...expense, date: Temporal.PlainDate.from(expense.date) };
  }

  public async update(updateExpense: UpdateExpenseDto): Promise<GetExpenseDto> {
    const date = updateExpense.date.toString();
    const category = { id: updateExpense.categoryId };
    const merchant = updateExpense.merchantId ? { id: updateExpense.merchantId } : undefined;
    const tags = updateExpense.tagIds?.map(id => {
      return { id };
    })
    const expense = await this.expenseDataService.update({
      id: updateExpense.id,
      date,
      cents: updateExpense.cents,
      note: updateExpense.note,
      category,
      merchant,
      tags
    });

    return { ...expense, date: Temporal.PlainDate.from(expense.date) };
  }

  public async remove(id: string): Promise<void> {
    await this.expenseDataService.delete(id);
  }
}