-- PR #610 round-2 fixes for bulk_book_transactions.
--
-- Genuine findings from compliance-swarm + swedish-compliance on the
-- round-1 (PR #608) migration:
--
--   1. Chart-of-accounts validation missing inside the RPC. Route's
--      manual branch validates account_numbers; the template branch
--      does not, and a direct DB caller (psql, future MCP) can bypass
--      both. Defense-in-depth: validate inside the RPC's Branch B
--      line-build loop so every line, regardless of how it got there,
--      is checked against the company's active chart_of_accounts.
--      (OWASP V8.2.1, SOC 2 CC6.3, swedish-compliance)
--
--   2. Document inheritance CTE missing tenant isolation on the doc
--      side. UPDATE joined on t.document_id = d.id without filtering
--      d.company_id = p_company_id. If a tx's document_id somehow
--      pointed at a cross-company doc (multi-tenant bug scenario),
--      the update would link a foreign tenant's document to the
--      target verifikat. Adding the explicit predicate closes the
--      door at the data layer.
--      (OWASP V1.2.5, ISO A.8.2, SOC 2 CC6.6, swedish-compliance —
--       four bots converge on the same finding)
--
--   3. Bank-leg range check was a bare lexicographic comparison on a
--      text column. With the schema-level 4-digit format guard it
--      works today, but a 5-digit number or one with a stray space
--      would silently pass/fail. Add an explicit length(4) guard
--      alongside the range so the check is robust to schema drift.
--      (swedish-compliance)
--
--   4. SECURITY DEFINER without explicit role grants. Add
--      REVOKE ALL FROM PUBLIC + GRANT EXECUTE TO authenticated on
--      both bulk_book_transactions and match_batch_allocate for
--      least-privilege.
--      (SOC 2 CC6.1)
--
-- Function body otherwise byte-identical to round 1.

DROP FUNCTION IF EXISTS public.bulk_book_transactions(uuid[], uuid, jsonb, uuid);

CREATE OR REPLACE FUNCTION public.bulk_book_transactions(
  p_tx_ids uuid[],
  p_existing_journal_entry_id uuid,
  p_new_entry jsonb,
  p_company_id uuid
)
RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path TO 'public'
AS $$
DECLARE
  v_tx RECORD;
  v_tx_date date;
  v_total_amount numeric := 0;
  v_total_amount_abs numeric;
  v_direction text;
  v_tx_count int := 0;

  v_voucher RECORD;
  v_voucher_bank_net numeric := 0;

  v_fiscal_period_id uuid;
  v_period_is_closed boolean;
  v_period_locked_at timestamptz;

  v_journal_entry_id uuid;
  v_voucher_series text := 'A';
  v_voucher_number int;
  v_entry_description text;

  v_line jsonb;
  v_line_account text;
  v_line_debit numeric;
  v_line_credit numeric;
  v_line_currency text;
  v_lines_total_debit numeric := 0;
  v_lines_total_credit numeric := 0;
  v_lines_bank_net numeric := 0;
  v_sort_order int := 0;

  v_docs_linked int := 0;
  v_target_je uuid;

  v_invalid_accounts text[];

  v_now timestamptz := now();
  v_caller uuid := auth.uid();
BEGIN
  IF v_caller IS NULL THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_UNAUTHORIZED');
  END IF;
  IF NOT EXISTS (
    SELECT 1 FROM public.company_members
    WHERE user_id = v_caller AND company_id = p_company_id
  ) THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_UNAUTHORIZED');
  END IF;

  IF p_tx_ids IS NULL OR array_length(p_tx_ids, 1) IS NULL THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_NO_TXS');
  END IF;

  IF (p_existing_journal_entry_id IS NULL AND p_new_entry IS NULL)
     OR (p_existing_journal_entry_id IS NOT NULL AND p_new_entry IS NOT NULL) THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_INVALID_PAYLOAD');
  END IF;

  FOR v_tx IN
    SELECT * FROM public.transactions
    WHERE id = ANY(p_tx_ids) AND company_id = p_company_id
    ORDER BY id
    FOR UPDATE
  LOOP
    v_tx_count := v_tx_count + 1;
    IF v_tx.journal_entry_id IS NOT NULL THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_TX_ALREADY_BOOKED',
        'details', jsonb_build_object('tx_id', v_tx.id));
    END IF;
    IF EXISTS (
      SELECT 1 FROM public.transaction_voucher_links tvl
      WHERE tvl.transaction_id = v_tx.id
    ) THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_TX_ALREADY_BOOKED',
        'details', jsonb_build_object('tx_id', v_tx.id, 'via', 'transaction_voucher_links'));
    END IF;
    IF v_tx.amount = 0 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_TX_ZERO_AMOUNT',
        'details', jsonb_build_object('tx_id', v_tx.id));
    END IF;

    IF v_tx_date IS NULL THEN
      v_tx_date := v_tx.date;
    ELSIF v_tx_date <> v_tx.date THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_DATE_MISMATCH',
        'details', jsonb_build_object('first_date', v_tx_date, 'other_date', v_tx.date));
    END IF;

    IF v_direction IS NULL THEN
      v_direction := CASE WHEN v_tx.amount > 0 THEN 'income' ELSE 'expense' END;
    ELSIF (v_direction = 'income' AND v_tx.amount < 0)
       OR (v_direction = 'expense' AND v_tx.amount > 0) THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_DIRECTION_MISMATCH',
        'details', jsonb_build_object('expected', v_direction, 'tx_id', v_tx.id));
    END IF;

    v_total_amount := v_total_amount + v_tx.amount;
  END LOOP;

  IF v_tx_count = 0 THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_TXS_NOT_FOUND');
  END IF;

  IF v_tx_count <> COALESCE(array_length(p_tx_ids, 1), 0) THEN
    RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_TXS_NOT_FOUND',
      'details', jsonb_build_object('expected', array_length(p_tx_ids, 1), 'found', v_tx_count));
  END IF;

  v_total_amount_abs := ABS(v_total_amount);

  IF p_existing_journal_entry_id IS NOT NULL THEN
    SELECT * INTO v_voucher FROM public.journal_entries
    WHERE id = p_existing_journal_entry_id AND company_id = p_company_id
    FOR UPDATE;

    IF NOT FOUND THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_JE_NOT_FOUND',
        'details', jsonb_build_object('journal_entry_id', p_existing_journal_entry_id));
    END IF;

    IF v_voucher.status <> 'posted' THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_JE_NOT_POSTED',
        'details', jsonb_build_object('status', v_voucher.status));
    END IF;

    -- Round-2 fix: explicit 4-digit length guard alongside the BETWEEN
    -- range. The lexicographic comparison is safe on 4-digit strings;
    -- the length guard is defense-in-depth against schema drift.
    SELECT COALESCE(SUM(debit_amount - credit_amount), 0) INTO v_voucher_bank_net
    FROM public.journal_entry_lines
    WHERE journal_entry_id = p_existing_journal_entry_id
      AND length(account_number) = 4
      AND account_number BETWEEN '1900' AND '1999';

    IF ABS(v_voucher_bank_net - v_total_amount) > 0.005 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_AMOUNT_MISMATCH',
        'details', jsonb_build_object(
          'tx_sum', v_total_amount, 'voucher_bank_net', v_voucher_bank_net));
    END IF;

    FOR v_tx IN
      SELECT * FROM public.transactions
      WHERE id = ANY(p_tx_ids) AND company_id = p_company_id
      ORDER BY id
    LOOP
      INSERT INTO public.transaction_voucher_links
        (user_id, company_id, transaction_id, journal_entry_id, allocated_amount, role)
      VALUES
        (v_caller, p_company_id, v_tx.id, p_existing_journal_entry_id, v_tx.amount, 'bank_line');
    END LOOP;

    IF v_tx_count = 1 THEN
      UPDATE public.transactions
      SET journal_entry_id = p_existing_journal_entry_id,
          reconciliation_method = 'manual',
          is_business = TRUE,
          updated_at = v_now
      WHERE id = p_tx_ids[1];
    ELSE
      UPDATE public.transactions
      SET is_business = TRUE, updated_at = v_now
      WHERE id = ANY(p_tx_ids);
    END IF;

    v_target_je := p_existing_journal_entry_id;
    v_voucher_series := v_voucher.voucher_series;
    v_voucher_number := v_voucher.voucher_number;

  ELSE
    v_entry_description := p_new_entry->>'description';
    IF v_entry_description IS NULL OR LENGTH(TRIM(v_entry_description)) = 0 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_MISSING_DESCRIPTION');
    END IF;

    IF jsonb_typeof(p_new_entry->'lines') IS DISTINCT FROM 'array'
       OR jsonb_array_length(p_new_entry->'lines') < 2 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_NO_LINES');
    END IF;

    -- Round-2 fix: chart-of-accounts allowlist check inside the RPC.
    -- The route's manual branch validates account_numbers, but the
    -- template branch and any direct DB caller bypass that check.
    -- Doing it here ensures every line, regardless of path, is verified
    -- against the company's active BAS chart.
    WITH submitted AS (
      SELECT DISTINCT value->>'account_number' AS acct
      FROM jsonb_array_elements(p_new_entry->'lines')
    )
    SELECT array_agg(s.acct ORDER BY s.acct) INTO v_invalid_accounts
    FROM submitted s
    WHERE NOT EXISTS (
      SELECT 1 FROM public.chart_of_accounts coa
      WHERE coa.account_number = s.acct
        AND coa.company_id = p_company_id
        AND coa.is_active = true
    );
    IF v_invalid_accounts IS NOT NULL AND array_length(v_invalid_accounts, 1) > 0 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_INVALID_ACCOUNT',
        'details', jsonb_build_object('invalid_accounts', v_invalid_accounts));
    END IF;

    FOR v_line IN SELECT * FROM jsonb_array_elements(p_new_entry->'lines')
    LOOP
      v_line_account := v_line->>'account_number';
      v_line_debit := COALESCE((v_line->>'debit_amount')::numeric, 0);
      v_line_credit := COALESCE((v_line->>'credit_amount')::numeric, 0);
      IF v_line_debit < 0 OR v_line_credit < 0 THEN
        RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_NEGATIVE_LINE',
          'details', jsonb_build_object('account', v_line_account));
      END IF;
      IF v_line_debit > 0 AND v_line_credit > 0 THEN
        RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_BOTH_SIDES_NONZERO',
          'details', jsonb_build_object('account', v_line_account));
      END IF;
      v_lines_total_debit := v_lines_total_debit + v_line_debit;
      v_lines_total_credit := v_lines_total_credit + v_line_credit;
      -- Round-2 fix: length(4) guard alongside the BETWEEN range.
      IF length(v_line_account) = 4 AND v_line_account BETWEEN '1900' AND '1999' THEN
        v_lines_bank_net := v_lines_bank_net + v_line_debit - v_line_credit;
      END IF;
    END LOOP;

    IF ABS(v_lines_total_debit - v_lines_total_credit) > 0.005 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_UNBALANCED',
        'details', jsonb_build_object(
          'debit_sum', v_lines_total_debit, 'credit_sum', v_lines_total_credit));
    END IF;

    IF ABS(v_lines_bank_net - v_total_amount) > 0.005 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_AMOUNT_MISMATCH',
        'details', jsonb_build_object(
          'tx_sum', v_total_amount,
          'lines_bank_net', v_lines_bank_net));
    END IF;

    SELECT id, is_closed, locked_at INTO v_fiscal_period_id, v_period_is_closed, v_period_locked_at
    FROM public.fiscal_periods
    WHERE company_id = p_company_id AND v_tx_date BETWEEN period_start AND period_end
    ORDER BY period_start DESC LIMIT 1;

    IF v_fiscal_period_id IS NULL THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_NO_FISCAL_PERIOD',
        'details', jsonb_build_object('tx_date', v_tx_date));
    END IF;

    IF v_period_is_closed OR v_period_locked_at IS NOT NULL THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_PERIOD_LOCKED',
        'details', jsonb_build_object('fiscal_period_id', v_fiscal_period_id));
    END IF;

    v_journal_entry_id := gen_random_uuid();

    INSERT INTO public.journal_entries
      (id, user_id, company_id, fiscal_period_id, voucher_number, voucher_series,
       entry_date, description, source_type, status)
    VALUES
      (v_journal_entry_id, v_caller, p_company_id, v_fiscal_period_id, 0, v_voucher_series,
       v_tx_date, v_entry_description, 'manual', 'draft');

    v_sort_order := 0;
    FOR v_line IN SELECT * FROM jsonb_array_elements(p_new_entry->'lines')
    LOOP
      v_line_account := v_line->>'account_number';
      v_line_debit := COALESCE((v_line->>'debit_amount')::numeric, 0);
      v_line_credit := COALESCE((v_line->>'credit_amount')::numeric, 0);
      v_line_currency := COALESCE(v_line->>'currency', 'SEK');

      INSERT INTO public.journal_entry_lines
        (journal_entry_id, account_number, debit_amount, credit_amount, currency,
         sort_order, line_description)
      VALUES
        (v_journal_entry_id, v_line_account, v_line_debit, v_line_credit, v_line_currency,
         COALESCE((v_line->>'sort_order')::int, v_sort_order),
         v_line->>'line_description');

      v_sort_order := v_sort_order + 1;
    END LOOP;

    SELECT voucher_number INTO v_voucher_number
    FROM public.commit_journal_entry(p_company_id, v_journal_entry_id);

    FOR v_tx IN
      SELECT * FROM public.transactions
      WHERE id = ANY(p_tx_ids) AND company_id = p_company_id
      ORDER BY id
    LOOP
      INSERT INTO public.transaction_voucher_links
        (user_id, company_id, transaction_id, journal_entry_id, allocated_amount, role)
      VALUES
        (v_caller, p_company_id, v_tx.id, v_journal_entry_id, v_tx.amount, 'bank_line');
    END LOOP;

    IF v_tx_count = 1 THEN
      UPDATE public.transactions
      SET journal_entry_id = v_journal_entry_id,
          is_business = TRUE,
          updated_at = v_now
      WHERE id = p_tx_ids[1];
    ELSE
      UPDATE public.transactions
      SET is_business = TRUE, updated_at = v_now
      WHERE id = ANY(p_tx_ids);
    END IF;

    v_target_je := v_journal_entry_id;
  END IF;

  -- Round-2 fix: explicit tenant isolation on the document side.
  -- Without d.company_id = p_company_id, a cross-tenant document_id
  -- on a transactions row (multi-tenant bug scenario) could link a
  -- foreign tenant's doc onto this verifikat.
  WITH linked AS (
    UPDATE public.document_attachments AS d
    SET journal_entry_id = v_target_je,
        updated_at = v_now
    FROM public.transactions AS t
    WHERE t.id = ANY(p_tx_ids)
      AND t.company_id = p_company_id
      AND t.document_id = d.id
      AND d.company_id = p_company_id
      AND d.journal_entry_id IS NULL
    RETURNING d.id
  )
  SELECT COUNT(*)::int INTO v_docs_linked FROM linked;

  RETURN jsonb_build_object(
    'ok', true,
    'mode', CASE WHEN p_existing_journal_entry_id IS NOT NULL THEN 'link_existing' ELSE 'create_new' END,
    'journal_entry_id', v_target_je,
    'voucher_series', v_voucher_series,
    'voucher_number', v_voucher_number,
    'linked_tx_count', v_tx_count,
    'tx_sum', v_total_amount,
    'docs_linked', v_docs_linked
  );
END;
$$;

COMMENT ON FUNCTION public.bulk_book_transactions(uuid[], uuid, jsonb, uuid) IS
  'Bulk-book N bank transactions sharing the same date into a single combined verifikat (samlingsverifikation per BFL 5 kap 6§). PR #610 round 2: chart_of_accounts allowlist enforced inside the RPC (defense-in-depth against direct callers + template path); doc inheritance CTE tenant-scoped on both transaction and document sides; bank-leg range guarded by length(4) + BETWEEN.';

-- Round-2 fix: explicit role grants (SOC 2 CC6.1) on both new RPCs.
REVOKE ALL ON FUNCTION public.bulk_book_transactions(uuid[], uuid, jsonb, uuid) FROM PUBLIC;
GRANT EXECUTE ON FUNCTION public.bulk_book_transactions(uuid[], uuid, jsonb, uuid) TO authenticated;

REVOKE ALL ON FUNCTION public.match_batch_allocate(uuid, jsonb, uuid) FROM PUBLIC;
GRANT EXECUTE ON FUNCTION public.match_batch_allocate(uuid, jsonb, uuid) TO authenticated;

NOTIFY pgrst, 'reload schema';