using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using AutoMapper;
using AutoMapper.QueryableExtensions;
using IdentityServer4.Extensions;
using InternshipSystem.Api.Result;
using InternshipSystem.Api.Security;
using InternshipSystem.Repository;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace InternshipSystem.Api.Controllers
{
    [Route("editions")]
    public class EditionController : ControllerBase
    {
        private InternshipDbContext Context { get; }
        private IMapper Mapper { get; }

        public EditionController(InternshipDbContext context, IMapper mapper)
        {
            Context = context;
            Mapper = mapper;
        }

        /// <summary>
        /// Get accessible editions
        /// </summary>
        /// <response code="200">Editions accessible by the current user</response>
        /// <response code="401">This action is only available for authorized student</response>
        /// <returns></returns>
        [HttpGet]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [Authorize]
        public async Task<ActionResult<IEnumerable<EditionResult>>> GetAvailableEditions([FromServices] User user, CancellationToken token)
        {
            var editions = 
                await Context.Editions
                    .Where(edition =>
                        edition.Internships
                            .Any(internship => internship.Student.Id == user.PersonNumber))
                    .ProjectTo<EditionResult>(Mapper.ConfigurationProvider)
                    .ToListAsync(token);
            
            if (editions.IsNullOrEmpty()) 
            {
                return NotFound();
            }
            
            return Ok(editions);
        }
        
        /// <summary>
        /// Get accessible editions
        /// </summary>
        /// <response code="200">Editions accessible by the current user</response>
        /// <response code="401">This action is only available for authorized student</response>
        /// <response code="404"/>
        /// <returns></returns>
        [HttpGet("{id}")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status401Unauthorized)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<ActionResult<EditionResult>> GetEditionInfo(Guid id, CancellationToken token)
        {
            var edition = 
                await Context.Editions
                    .Where(e => e.Id == id)
                    .ProjectTo<EditionResult>(Mapper.ConfigurationProvider)
                    .FirstOrDefaultAsync(token);
            
            if (edition == null) 
            {
                return NotFound();
            }
            
            return Ok(edition);
        }
        
        /// <summary>
        /// Get current edition's configuration
        /// </summary>
        /// <response code="200">Parameters of edition registered for by student</response>
        /// <response code="401">This action is only available for authorized student registered for this edition edition</response>
        /// <response code="404">Specified edition doesn't exist</response>
        /// <returns></returns>
        [HttpGet("current")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [Authorize(Policy = Policies.RegisteredOnly)]
        public async Task<ActionResult<EditionConfigurationResult>> GetEditionsConfiguration([FromServices] User user, CancellationToken token)
        {
            var edition = 
                await Context.Editions
                    .Include(e => e.AvailableSubjects)
                    .Include(e => e.Course)
                    .Where(e => e.Id == user.EditionId)
                    .ProjectTo<EditionConfigurationResult>(Mapper.ConfigurationProvider)
                    .FirstOrDefaultAsync(token);

            if (edition == null)
            {
                return NotFound();
            }
            
            return Ok(edition);
        }
    }
}