import { defaultGqlPermission, defaultPermission } from "@tailor-platform/erp-kit/core";
import { db, type TailorAnyDBType } from "@tailor-platform/sdk";

export const AVERAGE_COST_EVENT_TYPES = ["RECEIPT", "ISSUE", "COST_ADJUSTMENT"] as const;

const builtins = (params: { itemType?: TailorAnyDBType; companyType?: TailorAnyDBType }) => {
  const itemId = db.uuid().description("Foreign key to Item");
  const companyId = db.uuid().description("Foreign key to Company");
  return {
    itemId: params.itemType
      ? itemId.relation({
          type: "n-1",
          toward: { type: params.itemType, as: "item" },
          backward: "averageCosts",
        })
      : itemId,
    companyId: params.companyType
      ? companyId.relation({
          type: "n-1",
          toward: { type: params.companyType, as: "company" },
          backward: "averageCosts",
        })
      : companyId,
    sequence: db.int().description("1-based event position within the item and company"),
    eventType: db.enum(AVERAGE_COST_EVENT_TYPES).description("Costed event that produced this row"),
    quantityBefore: db.decimal().description("On-hand quantity before this event"),
    unitCostBefore: db.decimal().description("Moving average unit cost before this event"),
    quantity: db
      .decimal()
      .description("Signed quantity the event moved; positive for receipts, negative for issues"),
    unitCost: db
      .decimal({ optional: true })
      .description("Unit cost the event was valued at; null for COST_ADJUSTMENT events"),
    quantityAfter: db.decimal().description("On-hand quantity after this event"),
    unitCostAfter: db.decimal().description("Moving average unit cost after this event"),
  };
};

export function createAverageCostType(params: {
  itemType?: TailorAnyDBType;
  companyType?: TailorAnyDBType;
}) {
  return db
    .table("AverageCost", {
      ...builtins(params),
      createdAt: db.fields.timestamps().createdAt,
    })
    .indexes({
      fields: ["itemId", "companyId", "sequence"],
      unique: true,
      name: "average_cost_item_company_sequence_unique_idx",
    })
    .permission(defaultPermission)
    .gqlPermission(defaultGqlPermission);
}

export const averageCost = createAverageCostType({});