using General_Ledger_Service.Infra;
using General_Ledger_Service.Interfaces.Repositories;
using General_Ledger_Service.Models;
using Microsoft.EntityFrameworkCore;

namespace General_Ledger_Service.Repositories
{
    public class TaxRepository(AppDBContext context) : ITaxRepository
    {
        private readonly AppDBContext _context = context;

        public async Task<TaxType?> GetTaxTypeByCodeAsync(string code) =>
            await _context.TaxTypes.FirstOrDefaultAsync(t => t.Code == code);

        public async Task<List<TaxType>> GetAllTaxTypesAsync() =>
            await _context.TaxTypes.OrderBy(t => t.Code).ToListAsync();

        public async Task<TaxCode?> GetEffectiveTaxCodeByCodeAsync(string code, DateOnly txnDate) =>
            await _context.TaxCodes.FirstOrDefaultAsync(tc =>
                tc.Code == code &&
                tc.EffectiveFrom <= txnDate &&
                (tc.EffectiveTo == null || tc.EffectiveTo >= txnDate));

        public async Task<TaxCode?> GetByCodeAsync(string code) =>
            await _context.TaxCodes.FirstOrDefaultAsync(tc => tc.Code == code);

        public Task<TaxCode> AddTaxCodeAsync(TaxCode taxCode) =>
            RepositoryHelpers.AddAsync(_context.TaxCodes, taxCode);

        public async Task<List<TaxCode>> GetAllTaxCodesAsync() =>
            await _context.TaxCodes.OrderBy(tc => tc.Code).ToListAsync();

        // Accounting_System_Design_LKAS.md Section 11.7 - Non-Deductible Expenses. Expense is
        // debit-normal, so base_credit - base_debit is negative for a normal balance; ABS() here
        // (rather than in the Service layer) since this figure is always presented as a positive
        // "Add:" line, same convention ReportService applies for the P&L's Expense-side sections.
        public async Task<decimal> GetNonDeductibleExpensesAsync(DateOnly periodStart, DateOnly periodEnd)
        {
            var net = await _context.JournalEntryLines
                .Where(l => l.Journal.IsPosted
                            && l.Journal.EntryDate >= periodStart
                            && l.Journal.EntryDate <= periodEnd
                            && l.Account.AccountTypeId == 5
                            && !l.Account.IsTaxDeductible)
                .SumAsync(l => (decimal?)(l.BaseCredit - l.BaseDebit)) ?? 0m;

            return Math.Abs(net);
        }

        // Reused for APIT/WHT/quarterly-tax-payment credit accounts (Section 11.7, steps 8-10) -
        // each is a plain credit-normal balance sum against one configured accounts.account_id.
        public async Task<decimal> GetAccountCreditActivityAsync(long accountId, DateOnly periodStart, DateOnly periodEnd)
        {
            return await _context.JournalEntryLines
                .Where(l => l.Journal.IsPosted
                            && l.Journal.EntryDate >= periodStart
                            && l.Journal.EntryDate <= periodEnd
                            && l.AccountId == accountId)
                .SumAsync(l => (decimal?)(l.BaseCredit - l.BaseDebit)) ?? 0m;
        }
    }
}