-- Phase 3b — bulk_book_transactions RPC.
--
-- The second of the two multi-tx ↔ multi-voucher flows. Where
-- match_batch_allocate takes 1 tx and spreads it across N invoices, this
-- RPC takes N bank transactions on the SAME day and rolls them up into
-- ONE combined verifikat (samlingsverifikation per BFL 5 kap 6§ st 3).
--
-- The kiosk masshantering case: 10 daily card/Swish receipts → one
-- voucher with either (a) one debit/credit pair per tx (one_line_per_tx
-- mode, full audit detail) or (b) one summed debit + one summed credit
-- per account (sum_per_account mode, compact verifikat).
--
-- Two branches:
--
--   1. Link to existing posted verifikat (p_existing_journal_entry_id set):
--      No new JE. Inserts N transaction_voucher_links rows. Validates that
--      the JE's 19xx net equals sum(tx.amount). Use case: SIE-imported
--      day-summary voucher; user retroactively links the bank lines.
--
--   2. Create new combined verifikat (p_new_entry set):
--      The route's applyTemplate() has already done ratio/VAT expansion
--      per the chosen mode. The RPC validates the lines are balanced and
--      the 1930 net matches sum(tx.amount), then inserts the verifikat
--      atomically (commit_journal_entry assigns the voucher number).
--
-- Same security pattern as match_batch_allocate: caller membership check,
-- SELECT … FOR UPDATE on each tx in id order (deadlock-stable).

CREATE OR REPLACE FUNCTION public.bulk_book_transactions(
  p_tx_ids uuid[],
  p_existing_journal_entry_id uuid,
  p_new_entry jsonb,
  p_user_id uuid,
  p_company_id uuid
)
RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path TO 'public'
AS $$
DECLARE
  v_tx RECORD;
  v_tx_id uuid;
  v_tx_date date;
  v_total_amount numeric := 0;
  v_total_amount_abs numeric;
  v_direction text;  -- 'income' (positive) or 'expense' (negative)
  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_now timestamptz := now();
BEGIN
  -- Caller membership check (matches match_batch_allocate hardening).
  IF NOT EXISTS (
    SELECT 1 FROM public.company_members
    WHERE user_id = auth.uid() 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;

  -- Validate each tx + accumulate amount/date. Lock in id order for
  -- deadlock stability. Reject early if any tx isn't eligible.
  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;
    -- Also reject txs that are already linked via the junction (from a
    -- prior bulk-book that hasn't been undone).
    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;

    -- All txs must share the same date (BFL gemensam-verifikation requires
    -- same dag) and the same direction (an income tx and expense tx in
    -- one batch would need offset booking, out of scope for v1).
    IF v_tx_date IS NULL THEN
      v_tx_date := v_tx.date;
      v_direction := CASE WHEN v_tx.amount > 0 THEN 'income' ELSE 'expense' END;
    ELSE
      IF v_tx.date <> v_tx_date THEN
        RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_DATE_MISMATCH',
          'details', jsonb_build_object('expected', v_tx_date, 'got', v_tx.date, 'tx_id', v_tx.id));
      END IF;
      IF (v_tx.amount > 0 AND v_direction = 'expense')
         OR (v_tx.amount < 0 AND v_direction = 'income') THEN
        RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_DIRECTION_MISMATCH',
          'details', jsonb_build_object('tx_id', v_tx.id));
      END IF;
    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 <> array_length(p_tx_ids, 1) 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);

  -- ── Branch A: link to existing verifikat ──────────────────────────
  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_VOUCHER_NOT_FOUND');
    END IF;

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

    -- Sum the 19xx net (debits − credits) on the existing voucher.
    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 account_number >= '1900' AND account_number <= '1999';

    IF v_voucher_bank_net = 0 THEN
      RETURN jsonb_build_object('ok', false, 'code', 'BULK_BOOK_NO_BANK_LINE');
    END IF;

    -- The 19xx net must equal sum(tx.amount) — income txs are positive
    -- (debit 1930), expense txs are negative (credit 1930). v_total_amount
    -- carries the sign; v_voucher_bank_net (debit − credit) does too.
    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;

    -- Insert the junction rows. allocated_amount carries the tx's signed
    -- amount; readers reconstruct per-tx contribution from this field.
    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
        (p_user_id, p_company_id, v_tx.id, p_existing_journal_entry_id, v_tx.amount, 'bank_line');
    END LOOP;

    -- For N=1: also set transactions.journal_entry_id so the existing 1:1
    -- reader path (inbox card, reconciliation status) keeps working.
    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;

    RETURN jsonb_build_object(
      'ok', true,
      'mode', 'link_existing',
      'journal_entry_id', p_existing_journal_entry_id,
      'voucher_series', v_voucher.voucher_series,
      'voucher_number', v_voucher.voucher_number,
      'linked_tx_count', v_tx_count,
      'tx_sum', v_total_amount
    );
  END IF;

  -- ── Branch B: create new combined verifikat ───────────────────────
  -- p_new_entry shape: { description, lines: [{ account_number, debit_amount,
  --                                              credit_amount, currency,
  --                                              line_description?, sort_order? }] }

  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;

  -- Sum debits/credits + 19xx net, verify balance + bank-leg match.
  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;
    IF v_line_account >= '1900' AND v_line_account <= '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;

  -- Resolve fiscal period for the (shared) tx date — ORDER BY DESC for
  -- deterministic overlap resolution (same as match_batch_allocate).
  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, p_user_id, p_company_id, v_fiscal_period_id, 0, v_voucher_series,
     v_tx_date, v_entry_description, 'manual', 'draft');

  -- Re-iterate lines in JSON order, preserving caller-supplied sort_order
  -- when present, otherwise falling back to insertion order.
  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;

  -- Commit (assigns voucher_number, flips to 'posted', enforces period lock
  -- + balance triggers).
  SELECT voucher_number INTO v_voucher_number
  FROM public.commit_journal_entry(p_company_id, v_journal_entry_id);

  -- Insert junction rows for each tx.
  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
      (p_user_id, 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;

  RETURN jsonb_build_object(
    'ok', true,
    'mode', 'create_new',
    'journal_entry_id', v_journal_entry_id,
    'voucher_series', v_voucher_series,
    'voucher_number', v_voucher_number,
    'linked_tx_count', v_tx_count,
    'tx_sum', v_total_amount
  );
END;
$$;

COMMENT ON FUNCTION public.bulk_book_transactions(uuid[], uuid, jsonb, uuid, uuid) IS
  'Bulk-book N bank transactions sharing the same date into a single combined verifikat (samlingsverifikation per BFL 5 kap 6§). Two branches: link to an existing posted verifikat, or create a new one from pre-computed lines (route does template expansion). Returns { ok, journal_entry_id, voucher_number, linked_tx_count, tx_sum } on success or { ok: false, code, details } on guard failure.';

NOTIFY pgrst, 'reload schema';