using foodmarket.Api.Infrastructure.Authorization;
using foodmarket.Application.Common.Tenancy;
using foodmarket.Application.Money;
using foodmarket.Domain.Money;
using foodmarket.Domain.Purchases;
using foodmarket.Infrastructure.Persistence;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace foodmarket.Api.Controllers.Money;

/// <summary>Отчёты модуля «Деньги»: остатки по счетам, движение за период,
/// долги поставщикам. По образцу МойСклад <c>/report/money/plotseries</c> и
/// <c>/report/counterparty</c> (упрощённо).</summary>
[ApiController]
[Authorize]
[Route("api/money/reports")]
public class MoneyReportsController : ControllerBase
{
    private readonly AppDbContext _db;
    private readonly ITenantContext _tenant;

    public MoneyReportsController(AppDbContext db, ITenantContext tenant)
    {
        _db = db;
        _tenant = tenant;
    }

    public record AccountBalanceRow(Guid AccountId, string Name, MoneyAccountKind Kind,
        string CurrencyCode, decimal OpeningBalance, decimal CurrentBalance, bool IsActive);
    public record BalancesReport(IReadOnlyList<AccountBalanceRow> Accounts, decimal TotalByCurrencySum);

    [HttpGet("balances"), RequiresPermission("MoneyView")]
    public async Task<ActionResult<BalancesReport>> Balances(CancellationToken ct)
    {
        var accounts = await _db.MoneyAccounts.AsNoTracking()
            .OrderBy(a => a.Kind).ThenBy(a => a.Name)
            .ToListAsync(ct);
        var ids = accounts.Select(a => a.Id).ToList();
        var movements = await _db.MoneyTransactions.AsNoTracking()
            .Where(m => ids.Contains(m.AccountId) && m.Status == MoneyTransactionStatus.Posted)
            .GroupBy(m => new { m.AccountId, m.Kind })
            .Select(g => new { g.Key.AccountId, g.Key.Kind, Sum = g.Sum(m => m.Amount) })
            .ToListAsync(ct);
        var currencies = await _db.Currencies.AsNoTracking().Where(c => ids.Any())
            .ToDictionaryAsync(c => c.Id, c => c.Code, ct);

        var rows = accounts.Select(a =>
        {
            var inSum = movements.Where(m => m.AccountId == a.Id &&
                (m.Kind == MoneyTransactionKind.PaymentIn
              || m.Kind == MoneyTransactionKind.CashIn
              || m.Kind == MoneyTransactionKind.TransferIn)).Sum(m => m.Sum);
            var outSum = movements.Where(m => m.AccountId == a.Id &&
                (m.Kind == MoneyTransactionKind.PaymentOut
              || m.Kind == MoneyTransactionKind.CashOut
              || m.Kind == MoneyTransactionKind.TransferOut)).Sum(m => m.Sum);
            return new AccountBalanceRow(a.Id, a.Name, a.Kind,
                currencies.TryGetValue(a.CurrencyId, out var code) ? code : "",
                a.OpeningBalance, MoneyMath.AccountBalance(a.OpeningBalance, inSum, outSum), a.IsActive);
        }).ToList();

        return new BalancesReport(rows, rows.Sum(r => r.CurrentBalance));
    }

    public record MoneyPoint(DateTime Date, decimal Credit, decimal Debit, decimal Balance);
    public record MoneyMovementReport(DateTime From, DateTime To, decimal TotalCredit, decimal TotalDebit, IReadOnlyList<MoneyPoint> Series);

    /// <summary>Движение денежных средств за период (аналог
    /// <c>/report/money/plotseries</c>). Интервал — day/month.</summary>
    [HttpGet("movement"), RequiresPermission("MoneyView")]
    public async Task<ActionResult<MoneyMovementReport>> Movement(
        [FromQuery] DateTime from,
        [FromQuery] DateTime to,
        [FromQuery] string interval = "day",
        [FromQuery] Guid? accountId = null,
        CancellationToken ct = default)
    {
        if (to <= from) return BadRequest(new { code = "bad-range", message = "to должен быть позже from" });
        var fromUtc = DateTime.SpecifyKind(from, DateTimeKind.Utc);
        var toUtc = DateTime.SpecifyKind(to, DateTimeKind.Utc);
        var q = _db.MoneyTransactions.AsNoTracking()
            .Where(m => m.Status == MoneyTransactionStatus.Posted && m.Date >= fromUtc && m.Date < toUtc);
        if (accountId is not null) q = q.Where(m => m.AccountId == accountId);

        var raw = await q.Select(m => new { m.Date, m.Kind, m.Amount }).ToListAsync(ct);

        // Переводы не считаем ни «приходом», ни «расходом» орги — они
        // внутри орги, не меняют совокупных денег. Фильтруем.
        raw = raw.Where(r => r.Kind != MoneyTransactionKind.TransferIn
                          && r.Kind != MoneyTransactionKind.TransferOut).ToList();

        Func<DateTime, DateTime> bucket = interval switch
        {
            "month" => d => new DateTime(d.Year, d.Month, 1, 0, 0, 0, DateTimeKind.Utc),
            _ => d => d.Date,
        };
        var groups = raw.GroupBy(r => bucket(r.Date))
            .Select(g => new
            {
                Date = g.Key,
                Credit = g.Where(x => x.Kind == MoneyTransactionKind.PaymentIn || x.Kind == MoneyTransactionKind.CashIn).Sum(x => x.Amount),
                Debit = g.Where(x => x.Kind == MoneyTransactionKind.PaymentOut || x.Kind == MoneyTransactionKind.CashOut).Sum(x => x.Amount),
            })
            .OrderBy(g => g.Date)
            .ToList();

        var series = groups.Select(g => new MoneyPoint(g.Date, g.Credit, g.Debit, g.Credit - g.Debit)).ToList();
        return new MoneyMovementReport(fromUtc, toUtc, series.Sum(s => s.Credit), series.Sum(s => s.Debit), series);
    }

    public record SupplierDebtRow(
        Guid SupplierId, string SupplierName, string? Bin, string? Phone,
        decimal SuppliesTotal, decimal ReturnsTotal, decimal PaymentsIn, decimal PaymentsOut, decimal AdjustmentDebt,
        decimal Debt,
        DateTime? OldestUnpaidDate, string? OldestUnpaidNumber);
    public record SupplierDebtsReport(IReadOnlyList<SupplierDebtRow> Rows, decimal TotalDebt);

    /// <summary>Долги поставщикам: Σ приёмок − Σ возвратов − Σ оплат + Σ корректировок.
    /// Расчёт в C#, т.к. нужны джойны + aggregate'ы, которые EF транслирует неоптимально.</summary>
    [HttpGet("supplier-debts"), RequiresPermission("MoneyView")]
    public async Task<ActionResult<SupplierDebtsReport>> SupplierDebts(
        [FromQuery] bool withDebtOnly = true,
        CancellationToken ct = default)
    {
        var supplies = await _db.Supplies.AsNoTracking()
            .Where(s => s.Status == SupplyStatus.Posted)
            .GroupBy(s => s.SupplierId)
            .Select(g => new
            {
                SupplierId = g.Key,
                Total = g.Sum(s => s.Total),
                Paid = g.Sum(s => s.PayedSum),
                OldestUnpaid = g.Where(s => s.PayedSum < s.Total).OrderBy(s => s.Date).Select(s => new { s.Date, s.Number }).FirstOrDefault(),
            })
            .ToListAsync(ct);

        var returns = await _db.SupplierReturns.AsNoTracking()
            .Where(r => r.Status == SupplierReturnStatus.Posted)
            .GroupBy(r => r.SupplierId)
            .Select(g => new { SupplierId = g.Key, Total = g.Sum(r => r.Total), Paid = g.Sum(r => r.PayedSum) })
            .ToListAsync(ct);

        var adjustments = await _db.CounterpartyAdjustments.AsNoTracking()
            .Where(a => a.Status == MoneyTransactionStatus.Posted)
            .GroupBy(a => a.CounterpartyId)
            .Select(g => new
            {
                CounterpartyId = g.Key,
                WeOwe = g.Where(a => a.Direction == CounterpartyAdjustmentDirection.WeOwe).Sum(a => a.Amount),
                TheyOwe = g.Where(a => a.Direction == CounterpartyAdjustmentDirection.TheyOwe).Sum(a => a.Amount),
            })
            .ToListAsync(ct);

        var supplierIds = supplies.Select(s => s.SupplierId)
            .Union(returns.Select(r => r.SupplierId))
            .Union(adjustments.Select(a => a.CounterpartyId))
            .Distinct().ToList();

        var suppliers = await _db.Counterparties.AsNoTracking()
            .Where(c => supplierIds.Contains(c.Id))
            .Select(c => new { c.Id, c.Name, c.Bin, c.Phone })
            .ToListAsync(ct);

        var rows = new List<SupplierDebtRow>();
        foreach (var sup in suppliers)
        {
            var s = supplies.FirstOrDefault(x => x.SupplierId == sup.Id);
            var r = returns.FirstOrDefault(x => x.SupplierId == sup.Id);
            var a = adjustments.FirstOrDefault(x => x.CounterpartyId == sup.Id);
            // Долг = (приёмки − оплаченные приёмки) − (возвраты − полученные обратно деньги) + (корр: мы должны − они должны).
            var debt = MoneyMath.SupplierDebt(
                s?.Total ?? 0, s?.Paid ?? 0,
                r?.Total ?? 0, r?.Paid ?? 0,
                a?.WeOwe ?? 0, a?.TheyOwe ?? 0);
            if (withDebtOnly && Math.Abs(debt) < MoneyMath.Eps) continue;
            rows.Add(new SupplierDebtRow(
                sup.Id, sup.Name, sup.Bin, sup.Phone,
                s?.Total ?? 0, r?.Total ?? 0,
                r?.Paid ?? 0, s?.Paid ?? 0,
                (a?.WeOwe ?? 0) - (a?.TheyOwe ?? 0),
                debt,
                s?.OldestUnpaid?.Date, s?.OldestUnpaid?.Number));
        }

        rows = rows.OrderByDescending(x => x.Debt).ToList();
        return new SupplierDebtsReport(rows, rows.Sum(x => x.Debt));
    }
}