using Microsoft.AspNetCore.Mvc;
using Resources;
using Resources.Service;
using System;
using System.Linq;
using System.Linq.Dynamic.Core;
using System.Threading.Tasks;
using Resources.Shared;
using System.Net;
using Newtonsoft.Json;
using System.Collections.Generic;
using System.Reflection;
using Microsoft.AspNetCore.Authorization;

// http://www.restapitutorial.com/httpstatuscodes.html
// https://en.wikipedia.org/wiki/List_of_HTTP_status_codes

namespace Data.WebApi.Controllers
{
  [Route("api/[controller]")]
  //[AllowAnonymous]
  public class EmployeeController : Controller
  {
    private readonly ICustomerResourceService ResourceService;

    public EmployeeController(ICustomerResourceService resourceService)
    {
      ResourceService = resourceService;
    }


    [HttpGet("loginstatus")]
    public IActionResult LoginStatus()
    {
      var isAuthenticated = this.HttpContext.User.Identities.Any(u => u.IsAuthenticated);
      var email = this.User.FindFirst(c => c.Type.ContainsEx("email"))?.Value;

      var result = new
      {
        IsAuthenticated = isAuthenticated,
        Email = email
      };

      return Ok(result);
    }


    [HttpGet("Create")]
    [Authorize(Policy = "HR Only")]
    public IActionResult Create()
    {
      var resource = ResourceService.Create();

      return Json(resource);
    }

    private String RemoveSensitiveFields(EmployeeResource resource)
    {
      // The dynamic Linq Select(params) works only on an IQueryable list
      // thats why 1 one item is added to a list
      var items = new List<EmployeeResource>(new[] { resource }).AsQueryable();

      // Find all property names
      var propertyNames = resource.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance).Select(p => p.Name).ToList();

      // Salary only visible to HR department
      if (!User.HasClaim("Department", "HR"))
        propertyNames.Remove(nameof(EmployeeResource.Salary));

      // Dynamic Linq supports dynamic selector
      var selector = $"new({String.Join(",", propertyNames)})";

      // Create dynamic object with authorized fields 
      var reducedResource = items.Select(selector).First();

      // Create JSON
      var result = JsonConvert.SerializeObject(reducedResource, new JsonSerializerSettings() { Formatting = Formatting.Indented });

      return result;
    }


    [HttpGet("{id:guid}")]
    public async Task<IActionResult> Get(Guid id)
    {
      if (id.IsNullOrEmpty())
        return BadRequest();

      var resource = await ResourceService.FindAsync(id);
            
      return (resource == null) ? NotFound() as IActionResult : new ContentResult() { Content = RemoveSensitiveFields(resource), ContentType = "application/text" };
    }


    [HttpGet("{email}")]
    public IActionResult Email(String email)
    {
      if (email.IsNullOrEmpty())
        return BadRequest();

      var resource = ResourceService.Items().FirstOrDefault(c => c.Email == email);

      return (resource == null) ? NotFound() as IActionResult : new ContentResult() { Content = RemoveSensitiveFields(resource), ContentType = "application/text" };
    }


    [HttpGet]
    public IActionResult Get(String sortBy, String sortDirection, Int32 skip, Int32 take, String search, String searchFields)
    {
      var loadResult = ResourceService.Load(sortBy, sortDirection, skip, take, search, searchFields);

      var fieldNames = loadResult.Items.AsQueryable().ElementType.GetProperties(BindingFlags.Public | BindingFlags.Instance).Select(p => p.Name).ToList();

      // Salary only visible to HR department
      if (!User.HasClaim("Department", "HR"))
        fieldNames.Remove(nameof(EmployeeResource.Salary));

      var selector = $"new({String.Join(",", fieldNames)})";

      var result = new
      {
        CountUnfiltered = loadResult.CountUnfiltered,
        Items = loadResult.Items.AsQueryable().Select(selector)
      };

      return Json(result);
    }


    [HttpPost]
    [Consumes("application/json")]
    [Produces("application/json", Type = typeof(EmployeeResource))]
    [Authorize(Policy = "HR Only")]
    public async Task<IActionResult> Post([FromBody]EmployeeResource resource)
    {
      try
      {
        // Create rescource
        var serviceResult = await ResourceService.InsertAsync(resource);

        // if return error message if needed
        if (serviceResult.Errors.Count > 0)
          return BadRequest(serviceResult);

        // On succes return url with id and newly created resource  
        return CreatedAtAction(nameof(Get), new { id = serviceResult.Resource.Id }, serviceResult.Resource);
      }
      catch (Exception ex)
      {
        var result = new ResourceResult<EmployeeResource>(resource);

        while (ex != null)
          result.Exceptions.Add(ex.Message);

        return BadRequest(result);
      }
    }


    [HttpPut]
    [Authorize(Policy = "HR Only")]
    public async Task<IActionResult> Put([FromBody]EmployeeResource resource)
    {
      try
      {
        var currentResource = await ResourceService.FindAsync(resource.Id);

        if (currentResource == null)
          return NotFound();

        var serviceResult = await ResourceService.UpdateAsync(resource);

        if (serviceResult.Errors.Count > 0)
          return BadRequest(serviceResult);

        return Ok(serviceResult.Resource);
      }
      catch (Exception ex)
      {
        var result = new ResourceResult<EmployeeResource>(resource);

        while (ex != null)
        {
          result.Exceptions.Add(ex.Message);

          if (ex is ConcurrencyException)
            return StatusCode(HttpStatusCode.Conflict.ToInt32(), result);

          ex = ex.InnerException;
        }

        return BadRequest(result);
      }
    }

    [HttpGet("RoleBasedDemo")]
    [Authorize(Roles = "HR-Worker")]
    public IActionResult RoleBasedDemo()
    {
      return Ok("I am role based");
    }


    [HttpDelete("{id}")]
    [Authorize(Policy = "HR-Manager Only")]
    public async Task<IActionResult> Delete(Guid id)
    {
      try
      {
        var serviceResult = await ResourceService.DeleteAsync(id);

        if (serviceResult.Resource == null)
          return NoContent();

        if (serviceResult.Errors.Count > 0)
          return BadRequest(serviceResult);

        return Ok();
      }
      catch (Exception ex)
      {
        var result = new ResourceResult<EmployeeResource>();

        while (ex != null)
          result.Exceptions.Add(ex.Message);

        return BadRequest(result);
      }
    }
  }
}