using System.Linq;
using System.Threading.Tasks;
using InternshipSystem.Api.Queries;
using InternshipSystem.Core;
using InternshipSystem.Repository;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace InternshipSystem.Api.Controllers
{
    [ApiController]
    [Route("document")]
    public class DocumentsController : ControllerBase
    {
        private InternshipDbContext Context { get; }

        public DocumentsController(InternshipDbContext context)
        {
            Context = context;
        }

        /// <summary>
        /// Fill out required document, 
        /// </summary>
        /// <param name="document">Documents Scan and description, and Id of filled document</param>
        /// <returns></returns>
        /// <response code="200">If change was successfully registered</response>
        /// <response code="400">If the provided query was malformed</response>
        /// <response code="404">Id doesn't match any required document</response>
        /// <response code="401">This action is only available for authorized student registered for current edition</response>
        [HttpPost]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [ProducesResponseType(StatusCodes.Status401Unauthorized)]
        public async Task<ActionResult> AddDocumentToInternship([FromBody] DocumentPublishRequest document)
        {
            // TODO:
            // if not authorised then
            // return Unauthorized();
            
            // TODO:
            // is request is valid??
            // if not then
            // return BadRequest();
            
            var studentInternship = await GetCurrentStudentInternship();
            if (document.Id != null)
            {
                var doc = studentInternship.Documentation
                    .Find(d => d.Id == document.Id);
                if (doc == null)
                    return NotFound();
                doc.Description = document.Description;
                doc.Scan = document.Scan;
                doc.Type = document.Type;
                doc.State = DocumentState.Submitted;
            }
            else
            {
                studentInternship.Documentation.Add(
                    new Document()
                    {
                        Description = document.Description,
                        Scan = document.Scan,
                        Type = document.Type,
                        State = DocumentState.Submitted
                    });
            }

            await Context.SaveChangesAsync();
            return Ok();
        }

        //TODO: rewrite when authentication will be implemented
        private async Task<Internship> GetCurrentStudentInternship()
        {
            return Context.Editions
                .FirstAsync().Result
                .Internships
                .First();
        }
    }
}