import { err, ok } from "@tailor-platform/erp-kit/core";
import { Decimal } from "decimal.js";
import type { Transaction } from "../../../generated/kysely-tailordb";
import { StandardCostNotFoundError } from "../../../lib/errors.generated";
import { pushNonZero, type CostingFact, type CostingRole } from "../journalEntry";

export async function priceStandardReceipt(
  db: Transaction,
  args: {
    itemId: string;
    quantity: Decimal;
    unitCost?: Decimal;
    counterpartRole: CostingRole;
  },
) {
  const { itemId, quantity, unitCost, counterpartRole } = args;

  const standard = await db
    .selectFrom("StandardCost")
    .selectAll()
    .where("itemId", "=", itemId)
    .orderBy("version", "desc")
    .limit(1)
    .executeTakeFirst();
  if (!standard) {
    return err(new StandardCostNotFoundError(itemId));
  }

  const std = new Decimal(standard.unitCost);
  const actual = unitCost ?? std;
  const standardValue = std.mul(quantity);
  const actualValue = actual.mul(quantity);
  const variance = actualValue.minus(standardValue);

  const facts: CostingFact[] = [];
  pushNonZero(facts, {
    role: "INVENTORY",
    dcIndicator: "DR",
    amount: standardValue.toString(),
  });
  pushNonZero(facts, {
    role: counterpartRole,
    dcIndicator: "CR",
    amount: actualValue.toString(),
  });
  pushNonZero(facts, {
    role: "PPV",
    dcIndicator: variance.gt(0) ? "DR" : "CR",
    amount: variance.abs().toString(),
  });

  return ok(facts);
}

export async function priceStandardIssue(
  db: Transaction,
  args: {
    itemId: string;
    quantity: Decimal;
    counterpartRole: CostingRole;
  },
) {
  const { itemId, quantity, counterpartRole } = args;

  const standard = await db
    .selectFrom("StandardCost")
    .selectAll()
    .where("itemId", "=", itemId)
    .orderBy("version", "desc")
    .limit(1)
    .executeTakeFirst();
  if (!standard) {
    return err(new StandardCostNotFoundError(itemId));
  }

  const issueValue = new Decimal(standard.unitCost).mul(quantity);

  const facts: CostingFact[] = [];
  pushNonZero(facts, {
    role: counterpartRole,
    dcIndicator: "DR",
    amount: issueValue.toString(),
  });
  pushNonZero(facts, {
    role: "INVENTORY",
    dcIndicator: "CR",
    amount: issueValue.toString(),
  });

  return ok(facts);
}