using BoardApp.Config;

namespace BoardApp.Services;

public sealed class WarehouseCalendarService
{
    public const string WarehouseCalendarDataSrcId = "warehouse_calendar_events";

    private readonly SqlDataSourceService _sql;

    public WarehouseCalendarService(SqlDataSourceService sql)
    {
        _sql = sql;
    }

    private static object? RowVal(Dictionary<string, object?> row, params string[] names)
    {
        foreach (var name in names)
        {
            var kv = row.FirstOrDefault(x => string.Equals(x.Key, name, StringComparison.OrdinalIgnoreCase));
            if (!string.IsNullOrEmpty(kv.Key)) return kv.Value;
        }
        return null;
    }

    public static string FormatDateKey(int y, int m, int d)
        => $"{y}-{m:D2}-{d:D2}";

    private static string? DateKeyFromDatestr(object? v)
    {
        if (v is DateTime dt)
        {
            return FormatDateKey(dt.Year, dt.Month, dt.Day);
        }
        if (v is string s)
        {
            var t = s.Trim();
            if (System.Text.RegularExpressions.Regex.IsMatch(t, @"^\d{4}-\d{2}-\d{2}"))
            {
                return t[..10];
            }
            if (DateTime.TryParse(t, out var dt2))
            {
                return FormatDateKey(dt2.Year, dt2.Month, dt2.Day);
            }
        }
        return null;
    }

    private static string? StrOpt(object? v)
    {
        if (v is null) return null;
        var s = v.ToString()?.Trim();
        return string.IsNullOrEmpty(s) ? null : s;
    }

    private static WarehousePlanEntry RowToPlanEntry(Dictionary<string, object?> row)
    {
        var datestrRaw = RowVal(row, "datestr", "DispatchDate");
        var key = DateKeyFromDatestr(datestrRaw);
        var datestr = key ?? (datestrRaw?.ToString() ?? "");

        return new WarehousePlanEntry
        {
            Datestr = datestr,
            Eventstr = StrOpt(RowVal(row, "eventstr", "ShipmentCode")) ?? "(无单号)",
            Note_a = StrOpt(RowVal(row, "note_a", "C1")),
            Note_b = StrOpt(RowVal(row, "note_b")),
            Event_status = StrOpt(RowVal(row, "event_status")),
            Event_src = StrOpt(RowVal(row, "event_src", "CustomerShortName")),
            Event_to = StrOpt(RowVal(row, "event_to", "ShippingToCountry"))
        };
    }

    public async Task<Dictionary<string, List<WarehousePlanEntry>>> LoadWarehousePlansGroupedByDate(int year, int month)
    {
        var startDate = new DateTime(year, month, 1);
        var endDate = startDate.AddMonths(1);
        var rows = await _sql.ExecuteDataSourceById(WarehouseCalendarDataSrcId, new Dictionary<string, object?>
        {
            ["startDate"] = startDate,
            ["endDate"] = endDate
        });

        var map = new Dictionary<string, List<WarehousePlanEntry>>(StringComparer.Ordinal);
        foreach (var r in rows)
        {
            var key = DateKeyFromDatestr(RowVal(r, "datestr", "DispatchDate"));
            if (key is null) continue;
            if (!map.TryGetValue(key, out var list))
            {
                list = new List<WarehousePlanEntry>();
                map[key] = list;
            }
            var entry = RowToPlanEntry(r);
            entry.Datestr = key;
            list.Add(entry);
        }
        return map;
    }

    public sealed class CalendarCell
    {
        public int? Day { get; set; }
        public string? DateKey { get; set; }
        public bool IsToday { get; set; }
        public List<WarehousePlanEntry> Plans { get; set; } = new();
    }

    public static List<List<CalendarCell>> BuildMonthRows(int year, int month, Dictionary<string, List<WarehousePlanEntry>> plansByDate)
    {
        var firstDay = new DateTime(year, month, 1);
        var daysInMonth = DateTime.DaysInMonth(year, month);
        var startOffset = (((int)firstDay.DayOfWeek) + 6) % 7; // Mon=0..Sun=6

        var today = DateTime.Today;
        var todayKey = FormatDateKey(today.Year, today.Month, today.Day);

        var cells = new List<CalendarCell>();
        for (var i = 0; i < startOffset; i++)
        {
            cells.Add(new CalendarCell { Day = null, DateKey = null, IsToday = false, Plans = new List<WarehousePlanEntry>() });
        }

        for (var d = 1; d <= daysInMonth; d++)
        {
            var key = FormatDateKey(year, month, d);
            cells.Add(new CalendarCell
            {
                Day = d,
                DateKey = key,
                IsToday = string.Equals(key, todayKey, StringComparison.Ordinal),
                Plans = plansByDate.TryGetValue(key, out var ps) ? ps : new List<WarehousePlanEntry>()
            });
        }

        while (cells.Count % 7 != 0)
        {
            cells.Add(new CalendarCell { Day = null, DateKey = null, IsToday = false, Plans = new List<WarehousePlanEntry>() });
        }

        var rows = new List<List<CalendarCell>>();
        for (var i = 0; i < cells.Count; i += 7)
        {
            rows.Add(cells.GetRange(i, 7));
        }
        return rows;
    }
}