using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;
using System.IO;
using System.Collections.Generic;
using PSTW_CentralSystem.Areas.OTcalculate.Models;
using System;
using System.Linq;

namespace PSTW_CentralSystem.Areas.OTcalculate.Services
{
    public class OvertimePdfService
    {
        public MemoryStream GenerateOvertimeTablePdf(
            List<OtRegisterModel> records,
            int departmentId,
            string userFullName,
            string departmentName,
            int userStateId,
            int weekendId,
            List<CalendarModel> publicHolidays,
            bool isAdminUser = false,
            byte[]? logoImage = null)
        {
            records = records.OrderBy(r => r.OtDate).ToList();

            var stream = new MemoryStream();

            Document.Create(container =>
            {
                container.Page(page =>
                {
                    page.Size(PageSizes.A4.Landscape());
                    page.Margin(30);

                    page.Content().Column(column =>
                    {
                        // Header
                        column.Item().Row(row =>
                        {
                            row.RelativeItem(2).Column(col =>
                            {
                                if (logoImage != null)
                                {
                                    col.Item().Container().Height(36).Image(logoImage, ImageScaling.FitArea);
                                    col.Spacing(10);
                                }

                                col.Item().Text($"Name: {userFullName}").FontSize(9).SemiBold();
                                col.Item().Text($"Department: {departmentName}").FontSize(9).Italic();
                                col.Item().Text($"Overtime Record: {GetMonthYearString(records)}").FontSize(9).Italic();
                            });

                            row.RelativeItem(1).AlignRight().Text($"Generated: {DateTime.Now:dd MMM yyyy HH:mm}")
                                .FontSize(9).FontColor(Colors.Grey.Medium);
                        });

                        column.Item().PaddingVertical(10).LineHorizontal(0.5f).LineColor(Colors.Grey.Lighten2);

                        // Table
                        column.Item().Table(table =>
                        {
                            // Columns
                            table.ColumnsDefinition(columns =>
                            {
                                columns.RelativeColumn(0.7f); // Day
                                columns.RelativeColumn(1.1f); // Date
                                columns.RelativeColumn(0.8f); // Office From
                                columns.RelativeColumn(0.8f); // Office To
                                columns.RelativeColumn(0.8f); // Office Break
                                columns.RelativeColumn(0.9f); // After From
                                columns.RelativeColumn(0.9f); // After To
                                columns.RelativeColumn(0.9f); // After Break
                                columns.RelativeColumn();     // Total OT
                                columns.RelativeColumn();     // Break Hours
                                columns.RelativeColumn();     // Net OT
                                if (departmentId == 2 || isAdminUser)
                                    columns.RelativeColumn(); // Station
                                columns.RelativeColumn(2.7f); // Description
                            });

                            // Header
                            table.Header(header =>
                            {
                                header.Cell().RowSpan(2).Background("#e0f7da").Border(0.25f).Padding(5).Text("Days").FontSize(9).Bold().AlignCenter();
                                header.Cell().RowSpan(2).Background("#d0ead2").Border(0.25f).Padding(5).Text("Date").FontSize(9).Bold().AlignCenter();

                                header.Cell().ColumnSpan(3).Background("#dceefb").Border(0.25f).Padding(5).Text("Office Hours\n(8:30 - 17:30)").FontSize(9).Bold().AlignCenter();
                                header.Cell().ColumnSpan(3).Background("#edf2f7").Border(0.25f).Padding(5).Text("After Office Hours\n(17:30 - 8:30)").FontSize(9).Bold().AlignCenter();

                                header.Cell().RowSpan(2).Background("#fdebd0").Border(0.25f).Padding(5).Text("Total OT\nHours").FontSize(9).Bold().AlignCenter();
                                header.Cell().RowSpan(2).Background("#fdebd0").Border(0.25f).Padding(5).Text("Break Hours\n(min)").FontSize(9).Bold().AlignCenter();
                                header.Cell().RowSpan(2).Background("#fdebd0").Border(0.25f).Padding(5).Text("Net OT\nHours").FontSize(9).Bold().AlignCenter();

                                if (departmentId == 2 || isAdminUser)
                                    header.Cell().RowSpan(2).Background("#d0f0ef").Border(0.25f).Padding(5).Text("Station").FontSize(9).Bold().AlignCenter();

                                header.Cell().RowSpan(2).Background("#e3f2fd").Border(0.25f).Padding(5).Text("Description").FontSize(9).Bold().AlignCenter();

                                // Subheaders for Office/After
                                header.Cell().Background("#dceefb").Border(0.25f).Padding(5).Text("From").FontSize(9).Bold().AlignCenter();
                                header.Cell().Background("#dceefb").Border(0.25f).Padding(5).Text("To").FontSize(9).Bold().AlignCenter();
                                header.Cell().Background("#dceefb").Border(0.25f).Padding(5).Text("Break (min)").FontSize(9).Bold().AlignCenter();

                                header.Cell().Background("#edf2f7").Border(0.25f).Padding(5).Text("From").FontSize(9).Bold().AlignCenter();
                                header.Cell().Background("#edf2f7").Border(0.25f).Padding(5).Text("To").FontSize(9).Bold().AlignCenter();
                                header.Cell().Background("#edf2f7").Border(0.25f).Padding(5).Text("Break (min)").FontSize(9).Bold().AlignCenter();
                            });

                            // Data
                            double totalOTSum = 0;
                            int totalBreakSum = 0;
                            TimeSpan totalNetOt = TimeSpan.Zero;
                            bool alternate = false;

                            if (!records.Any())
                            {
                                uint colspan = (uint)(departmentId == 2 ? 13 : 12);
                                table.Cell().ColumnSpan(colspan).Border(0.5f).Padding(10).AlignCenter()
                                    .Text("No records found for selected month and year.")
                                    .FontSize(10).FontColor(Colors.Grey.Darken2).Italic();
                            }
                            else
                            {
                                foreach (var r in records)
                                {
                                    var totalOT = CalculateTotalOT(r);
                                    var totalBreak = (r.OfficeBreak ?? 0) + (r.AfterBreak ?? 0);
                                    var netOT = totalOT - TimeSpan.FromMinutes(totalBreak);

                                    totalOTSum += totalOT.TotalHours;
                                    totalBreakSum += totalBreak;
                                    totalNetOt += netOT;

                                    string rowBg = alternate ? "#f9f9f9" : "#ffffff";
                                    alternate = !alternate;

                                    string backgroundColor = GetDayCellBackgroundColor(r.OtDate, userStateId, publicHolidays, weekendId);

                                    void AddCell(string value, bool center = true, string? bg = null)
                                    {
                                        var text = table.Cell().Background(bg ?? rowBg).Border(0.25f).Padding(5).Text(value).FontSize(9);
                                        if (center)
                                            text.AlignCenter();
                                        else
                                            text.AlignLeft();
                                    }

                                    AddCell(r.OtDate.ToString("ddd"), true, backgroundColor);
                                    AddCell(r.OtDate.ToString("dd/MM/yyyy"));

                                    AddCell(FormatTime(r.OfficeFrom));
                                    AddCell(FormatTime(r.OfficeTo));
                                    AddCell(r.OfficeBreak > 0 ? $"{r.OfficeBreak}" : "");

                                    AddCell(FormatTime(r.AfterFrom));
                                    AddCell(FormatTime(r.AfterTo));
                                    AddCell(r.AfterBreak > 0 ? $"{r.AfterBreak}" : "");

                                    AddCell(totalOT > TimeSpan.Zero ? $"{totalOT:hh\\:mm}" : "");
                                    AddCell(totalBreak > 0 ? $"{totalBreak}" : "");
                                    AddCell(netOT > TimeSpan.Zero ? $"{netOT:hh\\:mm}" : "");

                                    if (departmentId == 2 || isAdminUser)
                                        AddCell(r.Stations?.StationName ?? "");

                                    table.Cell().Background(rowBg).Border(0.25f).Padding(5)
                                        .Text(r.OtDescription ?? "-").FontSize(9).WrapAnywhere().LineHeight(1.2f);
                                }

                                // Totals row
                                int totalCols = departmentId == 2 ? 13 : 12;
                                int spanCols = departmentId == 2 ? 9 : 8;

                                for (int i = 0; i < spanCols; i++)
                                    table.Cell().Background("#d8d1f5").Border(0.80f).Padding(5)
                                        .Text(i == 0 ? "TOTAL" : "").Bold().FontSize(9).AlignCenter();

                                table.Cell().Background("#d8d1f5").Border(0.80f).Padding(5)
                                    .Text($"{TimeSpan.FromHours(totalOTSum):hh\\:mm}").Bold().FontSize(9).AlignCenter();
                                table.Cell().Background("#d8d1f5").Border(0.80f).Padding(5)
                                    .Text($"{TimeSpan.FromMinutes(totalBreakSum):hh\\:mm}").Bold().FontSize(9).AlignCenter();
                                table.Cell().Background("#d8d1f5").Border(0.80f).Padding(5)
                                    .Text($"{totalNetOt:hh\\:mm}").Bold().FontSize(9).AlignCenter();

                                if (departmentId == 2 || isAdminUser)
                                    table.Cell().Background("#d8d1f5").Border(0.80f);
                                table.Cell().Background("#d8d1f5").Border(0.80f);
                            }
                        });
                    });
                });
            }).GeneratePdf(stream);

            stream.Position = 0;
            return stream;
        }

        private TimeSpan CalculateTotalOT(OtRegisterModel r)
        {
            TimeSpan office = (r.OfficeTo ?? TimeSpan.Zero) - (r.OfficeFrom ?? TimeSpan.Zero);
            TimeSpan after = (r.AfterTo ?? TimeSpan.Zero) - (r.AfterFrom ?? TimeSpan.Zero);
            if (after < TimeSpan.Zero)
                after += TimeSpan.FromHours(24);
            return office + after;
        }

        private string FormatTime(TimeSpan? time)
        {
            if (time == null || time == TimeSpan.Zero)
                return "";
            return time.Value.ToString(@"hh\:mm");
        }

        private string GetMonthYearString(List<OtRegisterModel> records)
        {
            if (records == null || !records.Any())
                return "No Data";
            var firstDate = records.First().OtDate;
            return $"{firstDate:MMMM yyyy}";
        }

        private string GetDayCellBackgroundColor(DateTime date, int userStateId, List<CalendarModel> publicHolidays, int weekendId)
        {
            if (publicHolidays.Any(h => h.HolidayDate.Date == date.Date))
                return "#ffc0cb"; // Pink

            var dayOfWeek = date.DayOfWeek;
            if ((weekendId == 1 && (dayOfWeek == DayOfWeek.Friday || dayOfWeek == DayOfWeek.Saturday)) ||
                (weekendId == 2 && (dayOfWeek == DayOfWeek.Saturday || dayOfWeek == DayOfWeek.Sunday)))
                return "#add8e6"; // Blue

            return "#ffffff"; // Default
        }

    }
}