using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace ScrumTaskboard.Controllers
{
    [Route("[controller]")]
    [ApiController]
    public class UserstoriesController : ControllerBase
    {
        private readonly TaskContext _context;

        public UserstoriesController(TaskContext context)
        {
            _context = context;
        }

        // GET: api/userstories
        [HttpGet]
        public async Task<ActionResult<IEnumerable<ScrumUserstory>>> GetUserstory([FromQuery]string? title, [FromQuery]int? statusid, [FromQuery]int? categoryid, [FromQuery]int? createdbyid, [FromQuery]int? projectid, [FromQuery]int? sprintid, [FromQuery]ScrumPrio? priority)
        {
            var filtered = _context.Userstories.AsQueryable();

            if (title != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.title.Contains(title));
            }
            if (statusid != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.statusid == statusid);
            }
            if (categoryid != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.categoryid == categoryid);
            }
            if (createdbyid != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.createdbyid == createdbyid);
            }
            if (projectid != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.projectid == projectid);
            }
            if (sprintid != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.sprintid == sprintid);
            }
            if (priority != null)
            {
                filtered = filtered.Where<ScrumUserstory>(t => t.priority == priority);
            }


            return await filtered.ToListAsync();
        }

        // GET: api/userstories/1
        [HttpGet("{id}")]
        public async Task<ActionResult<ScrumUserstory>> GetUserstory(int id)
        {
            var userstory = await _context.Userstories.FindAsync(id);

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

            return userstory;
        }

        // PUT: api/userstories/1
        [HttpPut("{id}")]
        public async Task<IActionResult> PutUserstory(int id, ScrumUserstory userstory)
        {
            // Die ID der Userstory darf nicht geändert werden
            if (id != userstory.id)
            {
                return BadRequest();
            }

            // Speichere die geänderten Userstory im Context
            _context.Entry(userstory).State = EntityState.Modified;

            try
            {
                // Übernehme die Änderungen in die Datenbank
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                // Wenn die Userstory nicht existiert, gib Statuscode 404 zurück
                if (!UserstoryExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return NoContent();
        }

        // POST: api/userstories
        [HttpPost]
        public async Task<ActionResult<ScrumUserstory>> PostTask(ScrumUserstory userstory)
        {
            _context.Userstories.Add(userstory);
            await _context.SaveChangesAsync();

            // Die neue Userstory wurde erstellt und kann über die GetUserstory Methode abgerufen werden.
            return CreatedAtAction("GetUserstory", new { id = userstory.id }, userstory);
        }

        // DELETE: api/userstories/1
        [HttpDelete("{id}")]
        public async Task<ActionResult<ScrumUserstory>> DeleteUserstory(int id)
        {
            var userstory = await _context.Userstories.FindAsync(id);
            if (userstory == null)
            {
                return NotFound();
            }

            // Entferne die Userstory aus dem Context
            _context.Userstories.Remove(userstory);
            // Speichere die Änderungen in der Datenbank
            await _context.SaveChangesAsync();

            return userstory;
        }

        /// <summary>
        /// Prüft, ob eine Userstory mit der angegebenen ID bereits existiert.
        /// </summary>
        private bool UserstoryExists(int id)
        {
            return _context.Userstories.Any(e => e.id == id);
        }
    }
}