using System;
using System.Linq;
using System.Linq.Expressions;
using BlueWest.Data;
using BlueWest.WebApi.EF;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace BlueWest.WebApi.Controllers
{
    /// <summary>
    /// The controller responsible to fetch currency data
    /// </summary>
    [ApiController]
    [Route("[controller]")]
    public partial class CurrencyController : ControllerBase
    {
        private readonly CountryDbContext _dbContext;

        /// <summary>
        /// Api Controller for Currency data
        /// </summary>
        /// <param name="dbContext"></param>
        public CurrencyController(CountryDbContext dbContext)
        {
            _dbContext = dbContext;
        }

        /// <summary>
        /// Gets the currency data from currency table
        /// </summary>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [HttpGet]
        public ActionResult GetCurrencies()
        {
            var currencies = _dbContext.Currencies
                .Select(currency => new CurrencyUnique(currency))
                .ToArray();

            return Ok(currencies);
        }


        /// <summary>
        ///  Gets a currency by the currency number (id)
        /// </summary>
        /// <param name="currencyId">The id of the currency to get</param>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [HttpGet("{currencyId}", Name = nameof(GetCurrencyById))]
        public ActionResult GetCurrencyById(int currencyId)
        {
            var queryResult =
                from aCurrency in _dbContext.Currencies
                where aCurrency.Id == currencyId
                select new CurrencyUnique(aCurrency);

            var currency = queryResult.SingleOrDefault();

            if (currency != null)
            {
                return Ok(currency);
            }

            return new NotFoundResult();
        }

        /// <summary>
        /// Add Currency to the table of currencies
        /// </summary>
        /// <param name="currencyToCreate">Currency data to create</param>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status201Created)]
        [HttpPost]
        public ActionResult AddCurrency(CurrencyCreate currencyToCreate)
        {
            var (success, newCurrency) = _dbContext.AddCurrency(currencyToCreate);

            if (!success)
            {
                return new NotFoundResult();
            }

            return CreatedAtRoute(nameof(GetCurrencyById), new {CurrencyId = newCurrency.Code}, newCurrency);

        }

        /// <summary>
        /// Update a currency data from the Currency table in the database
        /// </summary>
        /// <param name="currencyNumber">The currency number we want to update</param>
        /// <param name="currencyToUpdate">Currency Data to update</param>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [HttpPut("{currencyNumber}")]
        public ActionResult UpdateCurrency(int currencyNumber, CurrencyUpdate currencyToUpdate)
        {
            var (success, currency) = _dbContext.UpdateCurrency(currencyToUpdate, currencyNumber);

            if (success)
            {
                return Ok(currency);
            }

            return new NotFoundResult();
        }

        /// <summary>
        ///  Gets a specific country id in a country
        /// </summary>
        /// <param name="currencyId">The id of the currency</param>
        /// <param name="countryId">The id of the country</param>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [HttpGet("{currencyId}/countries/{countryId}", Name = nameof(GetCurrencyById))]
        public ActionResult GetCountry(int currencyId, int countryId)
        {
            var countryQuery =
                from aCurrency in _dbContext.Currencies
                where aCurrency.Id == currencyId
                let countries = aCurrency.Countries
                from country in countries
                where country.Id == countryId
                select new CountryUnique(country);

            var queryResult = countryQuery.SingleOrDefault();
            
            if (queryResult == null)
            {
                return new NotFoundResult();
            }
            
            return Ok(queryResult);

        }

        /// <summary>
        /// Add Currency to the table of currencies
        /// </summary>
        /// <param name="currencyId"></param>
        /// <param name="countryToCreate"></param>
        /// <returns></returns>
        [ProducesResponseType(StatusCodes.Status201Created)]
        [HttpPost("{currencyId}/countries")]
        public ActionResult AddCountry(int currencyId, CountryCreate countryToCreate)
        {
            /*var (success, message, country) = _dbContext.AddCountry(currencyId, countryToCreate,
                new Expression<Func<Country, bool>>[]
                {
                    x => x.Code == countryToCreate.Code,
                    y => y.StateName == countryToCreate.StateName,
                    z => z.Alpha2Code == countryToCreate.Alpha2Code
                });

            if (!success)
            {
                return new ConflictObjectResult(message);
            }

            return Ok(country);*/
            return null;
        }
        
    }
}