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

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

  if (!unitCost) {
    return err(new UnitCostRequiredError(itemId));
  }

  await db
    .insertInto("FifoCost")
    .values({
      costLayerId: layerId,
      version: 1,
      unitCost: unitCost.toString(),
    })
    .execute();

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

  return ok(facts);
}

export async function priceFifoIssue(
  db: Transaction,
  args: { slices: ConsumedSlice[]; counterpartRole: CostingRole },
) {
  const { slices, counterpartRole } = args;

  let issueValue = new Decimal(0);
  for (const slice of slices) {
    const price = await db
      .selectFrom("FifoCost")
      .selectAll()
      .where("costLayerId", "=", slice.layerId)
      .orderBy("version", "desc")
      .limit(1)
      .executeTakeFirst();
    if (!price) {
      return err(new FifoCostNotFoundError(slice.layerId));
    }
    issueValue = issueValue.plus(slice.quantity.mul(price.unitCost));
  }

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

  return ok(facts);
}