using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Runtime.InteropServices.ComTypes;
using Flurl.Util;
using IOL.Fagprove.Data;
using IOL.Fagprove.Data.DTOs;
using IOL.Fagprove.Data.Enums;
using IOL.Fagprove.Data.Models;
using IOL.Fagprove.Services.Interfaces;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Graph;
using IOL.Fagprove.Services;

namespace IOL.Fagprove.Controllers
{
    public class ReservationsController : BaseController
    {
        private readonly AppDbContext _context;
        private readonly IAppReservationService _reservationService;

        public ReservationsController(AppDbContext context, IAppReservationService reservationService)
        {
            _context = context;
            _reservationService = reservationService;
        }
        // /api/reservations
        [HttpGet]
        public ActionResult<List<Reservation>> GetReservationsForUser()
        {
            return _context.Reservations.Where(r => r.UserId == LoggedInUser.Id).ToList();
        }

        [HttpGet("all")]
        [Authorize("Administrator")]
        public ActionResult<List<ReservationDto>> GetAllReservations()
        {
            return _context.Reservations.Select(r => new ReservationDto
            {
                Id = r.Id,
                Cabin = _context.Cabins.SingleOrDefault(c => c.Id == r.ReservationObjectId).Name ?? "",
                From = r.From.ToString("dd-MM-yyyy"),
                To = r.To.ToString("dd-MM-yyyy"),
                Status = r.Status,
                Name = _context.Users.SingleOrDefault(u => u.Id == r.UserId).Name ?? "Ukjent bruker"
            }).ToList();
        }

        [HttpGet("occupancy")]
        public ActionResult<List<DateTime>> GetOccupany(Guid cabinId)
        {
            var today = DateTime.Today;
            var reservationsForThisCabin = _context.Reservations.Where(r => r.ReservationObjectId == cabinId 
                                                                               && r.From > today && r.Status == ReservationStatus.Granted).ToList();
            if (reservationsForThisCabin.Count == 0) return default;
            var occupiedDates = new List<DateTime>();
            foreach (var reservation in reservationsForThisCabin)
            {
                for (var dt = reservation.From; dt <= reservation.To; dt = dt.AddDays(1))
                {
                    occupiedDates.Add(dt.Date);
                }
            }

            return occupiedDates;
        }

        [HttpPost("create")]
        public ActionResult CreateReservation(Reservation data)
        {
            var reservationIsPossible = _reservationService.ReservationIsPossible(data);
            if (!reservationIsPossible) return BadRequest(new {error = "Reservasjonen er ikke mulig lenger."});
            data.UserId = LoggedInUser.Id;
            data.CreatedBy = LoggedInUser.Id;
            data.CreatedUtc = DateTime.UtcNow;
            data.Status = ReservationStatus.Pending;
            _context.Reservations.Add(data);
            _context.SaveChanges();
            return Ok();
        }

        [HttpGet("grant")]
        [Authorize("Administrator")]
        public ActionResult GrantReservation(Guid id)
        {
            if (id == Guid.Empty) return BadRequest();
            var reservation = _context.Reservations.SingleOrDefault(r => r.Id == id);
            if (reservation == default) return BadRequest(new {error = "Fant ikke reservasjonen"});
            if (reservation.Status == ReservationStatus.Granted || reservation.Status == ReservationStatus.Expired) return BadRequest(new {error = "Denne reservasjonen er allerede godkjent"});
            reservation.Status = ReservationStatus.Granted;
            reservation.ModifiedBy = LoggedInUser.Id;
            reservation.ModifiedUtc = DateTime.UtcNow;
            _context.Reservations.Update(reservation);
            _context.Entry(reservation).Property(x => x.CreatedBy).IsModified = false;
            _context.Entry(reservation).Property(x => x.CreatedUtc).IsModified = false;
            _context.Entry(reservation).Property(x => x.Id).IsModified = false;
            _context.SaveChanges();
            // TODO: Inform user if mail fails
            var emailSent = _reservationService.SendReservationStatusMail(reservation);
            return Ok();
        }

        [HttpGet("deny")]
        [Authorize("Administrator")]
        public ActionResult DenyReservation(Guid id)
        {
            if (id == Guid.Empty) return BadRequest();
            var reservation = _context.Reservations.SingleOrDefault(r => r.Id == id);
            if (reservation == default) return BadRequest(new {error = "Fant ikke reservasjonen"});
            if (reservation.Status == ReservationStatus.Rejected || reservation.Status == ReservationStatus.Expired) return BadRequest(new {error = "Denne reservasjonen er allerede avvist"});
            reservation.Status = ReservationStatus.Rejected;
            reservation.ModifiedBy = LoggedInUser.Id;
            reservation.ModifiedUtc = DateTime.UtcNow;
            _context.Reservations.Update(reservation);
            _context.Entry(reservation).Property(x => x.CreatedBy).IsModified = false;
            _context.Entry(reservation).Property(x => x.CreatedUtc).IsModified = false;
            _context.Entry(reservation).Property(x => x.Id).IsModified = false;
            _context.SaveChanges();
            // TODO: Inform user if mail fails
            var emailSent = _reservationService.SendReservationStatusMail(reservation);
            return Ok();
        }

        [HttpDelete("delete")]
        public ActionResult DeleteReservation(Guid reservationId)
        {
            var reservation = _context.Reservations.SingleOrDefault(r => r.Id == reservationId);
            if (reservation == default) return BadRequest(new {error = "Fant ikke reservasjonen"});
            if (reservation.UserId != LoggedInUser.Id) return Unauthorized(new {error = "Du har ikke lov til å slette denne reservasjonen"});
            _context.Reservations.Remove(reservation);
            _context.SaveChanges();
            return Ok();
        }
    }
}