import { createContext, DomainError } from "@tailor-platform/erp-kit/app";
import { createResolver, t } from "@tailor-platform/sdk";
import { getDB } from "@/generated/kysely-tailordb";
import { finModulesExport } from "@/modules";

/**
 * createJournalEntry — raise a DRAFT journal entry (仕訳) in the general ledger.
 *
 * Thin wrapper over the native financial-accounting `createJournalEntry`. The
 * caller picks the accounting period; the company is derived from it so the UI
 * only needs one scope selector. Each line carries exactly one of a debit or a
 * credit amount (decimal strings); the native command enforces the double-entry
 * rules (≥2 lines, debit XOR credit, positive amounts). Balance (Σdebit=Σcredit)
 * is enforced later at post time.
 */
export default createResolver({
  name: "createJournalEntry",
  operation: "mutation",
  input: {
    accountingPeriodId: t.string().description("Accounting period the entry posts to"),
    entryDate: t
      .string({ optional: true })
      .description("Entry date (YYYY-MM-DD); defaults to today"),
    description: t.string({ optional: true }).description("Journal entry description"),
    lines: t
      .object(
        {
          accountId: t.string().description("GL account (coa-management) ID"),
          debit: t.string({ optional: true }).description("Debit amount (decimal string)"),
          credit: t.string({ optional: true }).description("Credit amount (decimal string)"),
          description: t.string({ optional: true }).description("Line description"),
        },
        { array: true },
      )
      .description("Journal lines (at least two; each carries a debit or a credit)"),
  },
  body: async (context) => {
    const ctx = createContext(context);
    const db = getDB("main-db");
    return db
      .transaction()
      .execute(async (trx) => {
        if (context.input.lines.length < 2) {
          throw new DomainError("A journal entry requires at least two lines.");
        }

        const period = await trx
          .selectFrom("AccountingPeriod")
          .select(["companyId"])
          .where("id", "=", context.input.accountingPeriodId)
          .executeTakeFirst();
        if (!period) {
          throw new DomainError(`Accounting period not found: ${context.input.accountingPeriodId}`);
        }

        const result = await finModulesExport.commands.createJournalEntry(
          trx,
          {
            header: {
              companyId: period.companyId,
              accountingPeriodId: context.input.accountingPeriodId,
              entryDate: context.input.entryDate ? new Date(context.input.entryDate) : new Date(),
              description: context.input.description ?? undefined,
            },
            lines: context.input.lines.map((line) => ({
              accountId: line.accountId,
              debitAmount: line.debit?.trim() ? line.debit.trim() : null,
              creditAmount: line.credit?.trim() ? line.credit.trim() : null,
              description: line.description?.trim() ? line.description.trim() : null,
            })),
          },
          ctx,
        );

        if (!result.ok) {
          switch (result.error.code) {
            case "FINANCIAL_ACCOUNTING_COMPANY_NOT_FOUND":
              throw new DomainError("The company for this accounting period no longer exists.");
            case "FINANCIAL_ACCOUNTING_ACCOUNTING_PERIOD_NOT_FOUND":
              throw new DomainError(
                `Accounting period not found: ${context.input.accountingPeriodId}`,
              );
            case "FINANCIAL_ACCOUNTING_ACCOUNTING_PERIOD_COMPANY_MISMATCH":
              throw new DomainError("The accounting period belongs to a different company.");
            case "FINANCIAL_ACCOUNTING_INVALID_ENTRY_DATE":
              throw new DomainError(
                "The entry date is invalid for the selected accounting period.",
              );
            case "FINANCIAL_ACCOUNTING_MINIMUM_LINES_NOT_MET":
              throw new DomainError("A journal entry requires at least two lines.");
            case "FINANCIAL_ACCOUNTING_ACCOUNT_NOT_FOUND":
              throw new DomainError(
                `A referenced GL account does not exist: ${result.error.message}`,
              );
            case "FINANCIAL_ACCOUNTING_ACCOUNT_INACTIVE":
              throw new DomainError(`A referenced GL account is inactive: ${result.error.message}`);
            case "FINANCIAL_ACCOUNTING_INVALID_DEBIT_CREDIT":
              throw new DomainError(
                "Each line must carry exactly one positive debit or credit amount.",
              );
            case "UNAUTHENTICATED":
              throw new DomainError("Authentication is required");
            case "INSUFFICIENT_PERMISSION":
              throw new DomainError("You do not have permission to perform this action");
            default:
              throw result.error satisfies never;
          }
        }

        return {
          id: result.value.journalEntry.id,
          status: result.value.journalEntry.status,
        };
      })
      .catch((err: unknown) => {
        if (err instanceof DomainError) throw err;
        throw new Error("Failed to create the journal entry", { cause: err });
      });
  },
  output: t
    .object({
      id: t.string().description("Journal entry ID"),
      status: t.string().description("Document status (DRAFT)"),
    })
    .description("CreateJournalEntry response"),
});