using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Newtonsoft.Json;
using StudyLib.API.Data;
using StudyLib.Models;

namespace StudyLib.API.Controllers
{
    [Route("api/[controller]")]
    [Authorize]
    [ApiController]
    public class SubjectsController : ControllerBase
    {
        private readonly StudyLibContext _context;

        public SubjectsController(StudyLibContext context)
        {
            _context = context;
        }

        [HttpGet("list-by-group-id/{groupId}")]
        public async Task<ActionResult<IEnumerable<Subject>>> GetSubjects(long groupId)
        {
            return await _context.Subjects.Where(s => s.Group.ID == groupId).Include(s => s.Comments).Include(s => s.Assignments).Include(s => s.Tests).ToListAsync();
        }

        [HttpGet("get-by-id/{id}")]
        public async Task<ActionResult<Subject>> GetSubject(long id)
        {
            var subject = await _context.Subjects.Where(s => s.ID == id).Include(s => s.Comments).Include(s => s.Assignments).Include(s => s.Tests).SingleOrDefaultAsync();

            if (subject == null)
            {
                return NotFound();
            }

            return subject;
        }

        [HttpPut("update/{id}")]
        public async Task<IActionResult> PutSubject(long id, Subject subject)
        {
            if (id != subject.ID)
            {
                return BadRequest();
            }

            _context.Entry(subject).State = EntityState.Modified;
            foreach (var comment in subject.Comments)
            {
                if (comment.ID >= 1)
                {
                    _context.Entry(comment).State = EntityState.Modified;
                }
                else
                {
                    _context.Comments.Add(comment);
                }
            }

            foreach (var assignment in subject.Assignments)
            {
                if (assignment.ID >= 1)
                {
                    _context.Entry(assignment).State = EntityState.Modified;
                }
                else
                {
                    _context.Assignments.Add(assignment);
                }
            }

            foreach (var test in subject.Tests)
            {
                if (test.ID >= 1)
                {
                    _context.Entry(test).State = EntityState.Modified;
                }
                else
                {
                    _context.Tests.Add(test);
                }
            }

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!SubjectExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return NoContent();
        }

        [HttpPost("add")]
        public async Task<ActionResult<Subject>> PostSubject(Subject subject)
        {
            _context.Subjects.Add(subject);

            await _context.SaveChangesAsync();

            return CreatedAtAction("GetSubject", new { id = subject.ID }, subject);
        }

        // DELETE: api/Subjects/5
        [HttpDelete("delete/{id}")]
        public async Task<ActionResult<Subject>> DeleteSubject(long id)
        {
            var subject = await _context.Subjects.FindAsync(id);
            if (subject == null)
            {
                return NotFound();
            }

            _context.Subjects.Remove(subject);
            await _context.SaveChangesAsync();

            return subject;
        }

        private bool SubjectExists(long id)
        {
            return _context.Subjects.Any(e => e.ID == id);
        }
    }
}