using Microsoft.AspNetCore.Mvc;
using System.ComponentModel.DataAnnotations;
using System.Globalization;

namespace BankSampahApp.Controllers.Main;

[Route("Main/[controller]/[action]")]
public class LaporanKeuanganController : Controller
{
    private static readonly List<MonthlyTransactionSnapshot> _monthlyTransactions =
    [
        new(2025, 1, 12_500_000m, 18_200_000m),
        new(2025, 2, 10_350_000m, 16_750_000m),
        new(2025, 3, 9_800_000m, 17_150_000m),
        new(2025, 4, 11_200_000m, 15_600_000m),
        new(2025, 5, 12_200_000m, 18_900_000m),
        new(2025, 6, 10_450_000m, 14_800_000m),
        new(2025, 7, 9_900_000m, 19_750_000m),
        new(2025, 8, 11_650_000m, 17_500_000m),
        new(2025, 9, 12_400_000m, 18_350_000m),
        new(2024, 10, 10_050_000m, 15_500_000m),
        new(2024, 11, 11_250_000m, 16_200_000m),
        new(2024, 12, 12_800_000m, 18_600_000m)
    ];

    private static readonly List<ManualExpense> _manualExpenses =
    [
        new() { Id = 1, ExpenseDate = new DateTime(2025, 1, 12), Title = "Transport & Operasional", Amount = 1_200_000m, Notes = "Pengiriman sampah ke offtaker" },
        new() { Id = 2, ExpenseDate = new DateTime(2025, 3, 8), Title = "Perawatan Timbangan", Amount = 800_000m, Notes = "Kalibrasi timbangan BSU" },
        new() { Id = 3, ExpenseDate = new DateTime(2025, 5, 20), Title = "Konsumsi Sosialisasi", Amount = 450_000m, Notes = "Kegiatan edukasi warga" },
        new() { Id = 4, ExpenseDate = new DateTime(2024, 11, 14), Title = "Biaya Listrik Gudang", Amount = 600_000m, Notes = "Tagihan bulan berjalan" }
    ];

    public IActionResult Index()
    {
        var years = _monthlyTransactions
            .Select(t => t.Year)
            .Concat(_manualExpenses.Select(e => e.ExpenseDate.Year))
            .Distinct()
            .OrderByDescending(y => y)
            .ToList();

        if (!years.Any())
        {
            years.Add(DateTime.UtcNow.Year);
        }

        ViewBag.AvailableYears = years;
        ViewBag.DefaultYear = years.First();
        return View("~/Views/Main/LaporanKeuangan/Index.cshtml");
    }

    [HttpGet]
    public IActionResult Table(int? year)
    {
        var selectedYear = year ?? GetLatestYear();
        var rows = BuildRows(selectedYear);
        var totalSaldo = rows.LastOrDefault()?.SaldoAkumulatif ?? 0m;

        var data = rows.Select((row, index) => new
        {
            no = index + 1,
            bulan = row.Bulan,
            pembelian = row.Pembelian,
            penjualan = row.Penjualan,
            pengeluaran = row.PengeluaranLain,
            labaRugi = row.LabaRugiBulanan,
            saldo = row.SaldoAkumulatif,
            isProfit = row.LabaRugiBulanan >= 0
        });

        return Json(new { data, totalSaldo });
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public IActionResult TambahPengeluaran([FromForm] PengeluaranInput input)
    {
        if (!ModelState.IsValid || input.Nominal <= 0)
        {
            return BadRequest(new { message = "Data pengeluaran tidak valid" });
        }

        var newExpense = new ManualExpense
        {
            Id = _manualExpenses.Any() ? _manualExpenses.Max(x => x.Id) + 1 : 1,
            ExpenseDate = input.Tanggal,
            Title = input.NamaPengeluaran,
            Amount = input.Nominal,
            Notes = input.Keterangan ?? string.Empty
        };

        _manualExpenses.Add(newExpense);
        return Json(new { success = true });
    }

    private static List<FinancialRow> BuildRows(int year)
    {
        var rows = new List<FinancialRow>();
        var culture = new CultureInfo("id-ID");
        decimal saldoAkumulatif = 0m;

        for (int month = 1; month <= 12; month++)
        {
            var baseData = _monthlyTransactions.FirstOrDefault(t => t.Year == year && t.Month == month);
            var pembelian = baseData?.Pembelian ?? 0m;
            var penjualan = baseData?.Penjualan ?? 0m;
            var pengeluaranLain = _manualExpenses
                .Where(e => e.ExpenseDate.Year == year && e.ExpenseDate.Month == month)
                .Sum(e => e.Amount);

            var labaRugi = penjualan - (pembelian + pengeluaranLain);
            saldoAkumulatif += labaRugi;

            rows.Add(new FinancialRow
            {
                Bulan = culture.DateTimeFormat.GetMonthName(month) + " " + year,
                Pembelian = pembelian,
                Penjualan = penjualan,
                PengeluaranLain = pengeluaranLain,
                LabaRugiBulanan = labaRugi,
                SaldoAkumulatif = saldoAkumulatif
            });
        }

        return rows;
    }

    private static int GetLatestYear()
    {
        return _monthlyTransactions.Select(t => t.Year)
            .Concat(_manualExpenses.Select(e => e.ExpenseDate.Year))
            .DefaultIfEmpty(DateTime.UtcNow.Year)
            .Max();
    }

    private record MonthlyTransactionSnapshot(int Year, int Month, decimal Pembelian, decimal Penjualan);

    private class ManualExpense
    {
        public int Id { get; set; }
        public DateTime ExpenseDate { get; set; }
        public string Title { get; set; } = string.Empty;
        public decimal Amount { get; set; }
        public string Notes { get; set; } = string.Empty;
    }

    public class PengeluaranInput
    {
        [Required]
        public DateTime Tanggal { get; set; }

        [Required]
        [StringLength(150)]
        public string NamaPengeluaran { get; set; } = string.Empty;

        [Range(typeof(decimal), "0.01", "79228162514264337593543950335")]
        public decimal Nominal { get; set; }

        [StringLength(200)]
        public string? Keterangan { get; set; }
    }

    private class FinancialRow
    {
        public string Bulan { get; set; } = string.Empty;
        public decimal Pembelian { get; set; }
        public decimal Penjualan { get; set; }
        public decimal PengeluaranLain { get; set; }
        public decimal LabaRugiBulanan { get; set; }
        public decimal SaldoAkumulatif { get; set; }
    }
}