import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import { stockAdjustmentLifecycle } from "../db/stockAdjustment.lifecycle.generated";
import type { Selectable, Transaction } from "../generated/kysely-tailordb";
import {
  postInventoryLedgerInternal,
  type PostInventoryMovementLine,
} from "../internal/inventoryPosting";
import { InvalidStatusError, StockAdjustmentNotFoundError } from "../lib/errors.generated";
import type {
  FinancialAccountingCommands,
  FinancialAccountingQueries,
  ItemManagementQueries,
  OrganizationQueries,
} from "../module";

export interface ConfirmStockAdjustmentInput {
  id: string;
}

type AdjustmentEffect = {
  direction: "IN" | "OUT";
  action: "QUANTITY_CHANGE" | "STOCK_TYPE_CHANGE";
  stockType: "AVAILABLE" | "BLOCKED" | "IN_TRANSIT";
};

function getAdjustmentEffects(
  adjustment: Selectable<"StockAdjustment">,
  line: Selectable<"StockAdjustmentLine">,
): AdjustmentEffect[] {
  if (adjustment.adjustmentType === "CORRECTION") {
    return [
      {
        direction: line.adjustmentDirection === "INCREASE" ? "IN" : "OUT",
        action: "QUANTITY_CHANGE",
        stockType: "AVAILABLE",
      },
    ];
  }

  if (adjustment.adjustmentType === "SCRAP") {
    return [
      {
        direction: "OUT",
        action: "QUANTITY_CHANGE",
        stockType: line.fromStockCategory === "BLOCKED" ? "BLOCKED" : "AVAILABLE",
      },
    ];
  }

  if (adjustment.adjustmentType === "BLOCK") {
    return [
      { direction: "OUT", action: "STOCK_TYPE_CHANGE", stockType: "AVAILABLE" },
      { direction: "IN", action: "STOCK_TYPE_CHANGE", stockType: "BLOCKED" },
    ];
  }

  return [
    { direction: "IN", action: "STOCK_TYPE_CHANGE", stockType: "AVAILABLE" },
    { direction: "OUT", action: "STOCK_TYPE_CHANGE", stockType: "BLOCKED" },
  ];
}

/**
 * Function: confirmStockAdjustment
 *
 * Approves and executes a submitted stock adjustment, posting InventoryLedger
 * entries and stock effects through the inventory posting engine.
 * Combines approval and execution into a single step.
 */
export async function run(
  db: Transaction,
  input: ConfirmStockAdjustmentInput,
  ctx: CommandContext,
  itemManagementQueries: Pick<ItemManagementQueries, "getItem">,
  organizationQueries: Pick<OrganizationQueries, "getSite">,
  financialAccountingCommands: Pick<
    FinancialAccountingCommands,
    "createJournalEntry" | "postJournalEntry"
  >,
  financialAccountingQueries: Pick<FinancialAccountingQueries, "getPeriodByDate">,
) {
  const { id } = input;

  const stockAdjustment = await db
    .selectFrom("StockAdjustment")
    .selectAll()
    .where("id", "=", id)
    .forUpdate()
    .executeTakeFirst();

  if (!stockAdjustment) {
    return err(new StockAdjustmentNotFoundError(id));
  }

  const nextAdjustmentStatus = stockAdjustmentLifecycle.tryTransition(
    stockAdjustment.status,
    "confirm",
  );
  if (!nextAdjustmentStatus) {
    return err(new InvalidStatusError(id));
  }

  const lines = await db
    .selectFrom("StockAdjustmentLine")
    .selectAll()
    .where("stockAdjustmentId", "=", id)
    .execute();

  const effectLines = lines.flatMap((line) =>
    getAdjustmentEffects(stockAdjustment, line).map((effect) => ({ line, effect })),
  );

  const movementLines: PostInventoryMovementLine[] = effectLines.map(({ line, effect }) => ({
    direction: effect.direction,
    action: effect.action,
    itemId: line.itemId,
    storageLocationId: line.storageLocationId,
    stockType: effect.stockType,
    quantity: line.quantity,
    unitCost: line.unitCost ?? undefined,
    sourceLineId: line.id,
  }));

  let inventoryLedgerEntries: Selectable<"InventoryLedger">[] = [];
  if (movementLines.length > 0) {
    const postingResult = await postInventoryLedgerInternal(
      db,
      {
        sourceType: "STOCK_ADJUSTMENT",
        sourceId: stockAdjustment.id,
        effectiveDate: stockAdjustment.adjustmentDate,
        lines: movementLines,
      },
      ctx,
      itemManagementQueries,
      organizationQueries,
      financialAccountingCommands,
      financialAccountingQueries,
    );
    if (!postingResult.ok) {
      return postingResult;
    }
    inventoryLedgerEntries = postingResult.value.inventoryLedgerEntries;
  }

  const updatedAdjustment = await db
    .updateTable("StockAdjustment")
    .set({
      status: nextAdjustmentStatus,
    })
    .where("id", "=", id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({
    stockAdjustment: updatedAdjustment,
    inventoryLedgerEntries,
  });
}