using AccountsDAL.DTO.AccountsReports;
using AccountsDAL.Query.AccountReports;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.QueryExecutor;

namespace AccountsDAL.CustomCode.AccountReports.AccountProfitLoss
{
    public class AccountProfitLossReportDAL : IAccountProfitLossReportDAL
    {
        private readonly IQueryExecutor _queryExecutor;

        public AccountProfitLossReportDAL(IQueryExecutor queryExecutor)
        {
            _queryExecutor = queryExecutor;
        }

        public async Task<ProfitLossResultDTO> GetProfitLossReport(
            int firstNumber, int maxResult, AccountReportCriteria criteria,
            List<AccountReportSortOptionDTO> sortBy, LoginDTO loginDTO)
        {
            var (filter, parameters) = AccountReportFilterBuilder.Build(criteria, loginDTO);

            parameters.Add("CurrencyBasis", criteria.CurrencyBasis);
            parameters.Add("Offset", Math.Max(0, firstNumber - 1));
            parameters.Add("PageSize", maxResult);

            var orderBy = AccountReportSortBuilder.BuildTrialBalanceOrderBy(sortBy, ProfitLossReportQB.DETAIL_DEFAULT_ORDER_BY);
            var finalSql = ProfitLossReportQB.GET_PROFIT_LOSS_DETAIL.Replace("{DynamicFilter}", filter).Replace("{OrderBy}", orderBy);

            var paged = await _queryExecutor
                .QueryPagedAsync<ProfitLossReportDTO>(loginDTO, finalSql, parameters)
                .ConfigureAwait(false);
            var items = (paged.Items ?? Enumerable.Empty<ProfitLossReportDTO>()).ToList();

            var totalsSql = ProfitLossReportQB.GET_PROFIT_LOSS_TOTALS.Replace("{DynamicFilter}", filter);
            var totals = await _queryExecutor
                .QuerySingleAsync<ProfitLossTotalsDTO>(loginDTO, totalsSql, parameters)
                .ConfigureAwait(false);

            var tradingDebit = totals?.TradingDebit ?? 0;
            var tradingCredit = totals?.TradingCredit ?? 0;
            var pandLDebit = totals?.PandLDebit ?? 0;
            var pandLCredit = totals?.PandLCredit ?? 0;

            var grossProfit = tradingCredit - tradingDebit;
            var netProfit = grossProfit + (pandLCredit - pandLDebit);

            InsertSummaryRows(items, grossProfit, netProfit);

            return new ProfitLossResultDTO
            {
                Items = items,
                TotalCount = paged.TotalCount,
                TradingDebit = tradingDebit,
                TradingCredit = tradingCredit,
                PandLDebit = pandLDebit,
                PandLCredit = pandLCredit,
                NetProfit = netProfit
            };
        }

        // Gross Profit and Net Profit are differences between two subtotals, not sums the generic
        // grouping/subtotal engine (GB5Shared.Export.GroupTreeBuilder) can derive on its own — same
        // justification Trial Balance uses for its Retained-Earnings plug row (see
        // TrialBalanceReportQB.cs class header). Everything else (Total Income/Total Expense per
        // section, Schedule/Group/Account subtotals) comes free from that engine once the
        // ISGROUPCOLUMN chain is seeded correctly, so only these two rows need C#-side insertion.
        // Gross Profit is positioned right after the last Trading-section row (skipped if the period
        // has no Trading activity at all); Net Profit always closes the whole result set.
        private static void InsertSummaryRows(List<ProfitLossReportDTO> items, decimal grossProfit, decimal netProfit)
        {
            var lastTradingIndex = items.FindLastIndex(r => r.Section == "Trading");
            if (lastTradingIndex >= 0)
            {
                items.Insert(lastTradingIndex + 1, BuildSummaryRow("Trading", "Gross Profit", "GrossProfit", grossProfit));
            }

            items.Add(BuildSummaryRow("P&L", "Net Profit", "NetProfit", netProfit));
        }

        // `net` here is already in "profit-positive" polarity (Credit total - Debit total — see
        // caller). Every other row in this report uses the opposite, NET_EXPR-native polarity
        // (Debit-heavy = positive => Debit column; Credit-heavy = negative => Credit column, shown
        // positive) — same rule every Income row already renders under, since income postings are
        // credit-heavy. Flip the sign here so a real profit lands in the Credit column alongside the
        // Income rows it's summarizing, and a loss lands in Debit alongside Expense rows.
        private static ProfitLossReportDTO BuildSummaryRow(string section, string label, string rowType, decimal net) => new()
        {
            Section = section,
            NatureType = label,
            RowType = rowType,
            EffectiveAccountName = label,
            AccountName = label,
            Debit = net < 0 ? -net : 0,
            Credit = net > 0 ? net : 0,
        };

        private class ProfitLossTotalsDTO
        {
            public decimal TradingDebit { get; set; }
            public decimal TradingCredit { get; set; }
            public decimal PandLDebit { get; set; }
            public decimal PandLCredit { get; set; }
        }
    }
}