using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using Kreta.BusinessLogic.Security;
using Kreta.Framework.Security;
using Newtonsoft.Json;

namespace Kreta.Web.Security
{
    /// <summary>
    /// Extension methods for ClaimsIdentity
    /// </summary>
    public static class ClaimsIdentityExtensions
    {
        /// <summary>
        /// Checks whether a given claim exists
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="predicate">The search predicate.</param>
        /// <returns>true/false</returns>
        public static bool ClaimExists(this ClaimsIdentity identity, Predicate<Claim> predicate)
        {

            Claim claim = identity.FindClaims(predicate).FirstOrDefault();
            return claim != null;
        }

        /// <summary>
        /// Checks whether a given claim exists
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <returns>true/false</returns>
        public static bool ClaimExists(this ClaimsIdentity identity, string claimType)
        {
            return identity.ClaimExists(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Checks whether a given claim exists
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        /// <returns>true/false</returns>
        public static bool ClaimExists(this ClaimsIdentity identity, string claimType, string value)
        {
            return identity.ClaimExists(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                c.Value.Equals(value, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Checks whether a given claim exists
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        /// <param name="issuer">The issuer.</param>
        /// <returns>true/false</returns>
        public static bool ClaimExists(this ClaimsIdentity identity, string claimType, string value, string issuer)
        {

            return identity.ClaimExists(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                c.Value.Equals(value, StringComparison.OrdinalIgnoreCase) &&
                c.Issuer.Equals(issuer, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Demands a specific claim.
        /// </summary>
        /// <param name="identity">The principal.</param>
        /// <param name="predicate">The search predicate.</param>
        public static void DemandClaim(this ClaimsIdentity identity, Predicate<Claim> predicate)
        {
            if (!identity.ClaimExists(predicate))
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Demands a specific claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        public static void DemandClaim(this ClaimsIdentity identity, string claimType)
        {
            try
            {
                identity.DemandClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Demands a specific claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        public static void DemandClaim(this ClaimsIdentity identity, string claimType, string value)
        {

            try
            {
                identity.DemandClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                    claim.Value.Equals(value, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Demands a specific claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        /// <param name="issuer">The issuer.</param>
        public static void DemandClaim(this ClaimsIdentity identity, string claimType, string value, string issuer)
        {
            try
            {
                identity.DemandClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                    claim.Value.Equals(value, StringComparison.OrdinalIgnoreCase) &&
                    claim.Issuer.Equals(issuer, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Denies a specific claim.
        /// </summary>
        /// <param name="principal">The identity.</param>
        /// <param name="predicate">The search predicate.</param>
        public static void DenyClaim(this ClaimsIdentity identity, Predicate<Claim> predicate)
        {
            foreach (Claim claim in identity.FindClaims(predicate))
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Denies a specific claim.
        /// </summary>
        /// <param name="principal">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        public static void DenyClaim(this ClaimsIdentity identity, string claimType)
        {
            try
            {
                identity.DenyClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Denies a specific claim.
        /// </summary>
        /// <param name="principal">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        public static void DenyClaim(this ClaimsIdentity identity, string claimType, string value)
        {
            try
            {
                identity.DenyClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                    claim.Value.Equals(value, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Denies a specific claim.
        /// </summary>
        /// <param name="principal">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="value">The value.</param>
        /// <param name="issuer">The issuer.</param>
        public static void DenyClaim(this ClaimsIdentity identity, string claimType, string value, string issuer)
        {
            try
            {
                identity.DenyClaim(claim =>
                    claim.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                    claim.Value.Equals(value, StringComparison.OrdinalIgnoreCase) &&
                    claim.Issuer.Equals(issuer, StringComparison.OrdinalIgnoreCase));
            }
            catch (SecurityException)
            {
                throw new SecurityException();
            }
        }

        /// <summary>
        /// Finds all instances of the specified claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="predicate">The search predicate.</param>
        /// <returns>List of claims that match the search criteria</returns>
        public static IEnumerable<Claim> FindClaims(this ClaimsIdentity identity, Predicate<Claim> predicate)
        {
            return from claim in identity.Claims
                   where predicate(claim)
                   select claim;
        }

        /// <summary>
        /// Finds all instances of the specified claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <returns>List of claims that match the search criteria</returns>
        public static IEnumerable<Claim> FindClaims(this ClaimsIdentity identity, string claimType)
        {
            return identity.FindClaims(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Finds all instances of the specified claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="issuer">The issuer.</param>
        /// <returns>List of claims that match the search criteria</returns>
        public static IEnumerable<Claim> FindClaims(this ClaimsIdentity identity, string claimType, string issuer)
        {
            return identity.FindClaims(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                c.Issuer.Equals(issuer, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Finds all instances of the specified claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="issuer">The issuer.</param>
        /// <param name="value">The value.</param>
        /// <returns>List of claims that match the search criteria</returns>
        public static IEnumerable<Claim> FindClaims(this ClaimsIdentity identity, string claimType, string issuer, string value)
        {
            return identity.FindClaims(c =>
                c.Type.Equals(claimType, StringComparison.OrdinalIgnoreCase) &&
                c.Value.Equals(value, StringComparison.OrdinalIgnoreCase) &&
                c.Issuer.Equals(issuer, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Finds all instances of the specified claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claim">Search claim.</param>
        /// <returns>List of claims that match the search criteria</returns>
        public static IEnumerable<Claim> FindClaims(this ClaimsIdentity identity, Claim claim)
        {
            return identity.FindClaims(c =>
                c.Type.Equals(claim.Type, StringComparison.OrdinalIgnoreCase) &&
                c.Value.Equals(claim.Value, StringComparison.OrdinalIgnoreCase) &&
                c.Issuer.Equals(claim.Issuer, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Retrieves the value of a claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <returns>The value</returns>
        public static string GetClaimValue(this ClaimsIdentity identity, string claimType)
        {
            string value = null;
            if (identity.TryGetClaimValue(claimType, out value))
            {
                return value;
            }

            throw new Exception("Claim not found exception");// ClaimNotFoundException(string.Format(CultureInfo.CurrentCulture, Messages.ClaimNotFound, claimType));
        }

        /// <summary>
        /// Retrieves the value of a claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="issuer">The issuer.</param>
        /// <returns>The value</returns>
        public static string GetClaimValue(this ClaimsIdentity identity, string claimType, string issuer)
        {
            string value = null;
            if (identity.TryGetClaimValue(claimType, issuer, out value))
            {
                return value;
            }

            throw new Exception("Claim not found exception"); //throw new ClaimNotFoundException(string.Format(CultureInfo.CurrentCulture, Messages.ClaimNotFound, claimType));
        }

        /// <summary>
        /// Tries to retrieve the value of a claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="claimValue">The claim value.</param>
        /// <returns>The value</returns>
        public static bool TryGetClaimValue(this ClaimsIdentity identity, string claimType, out string claimValue)
        {

            claimValue = null;
            Claim claim = identity.FindClaims(claimType).FirstOrDefault();

            if (claim != null)
            {
                claimValue = claim.Value;
                return true;
            }

            return false;
        }

        /// <summary>
        /// Tries to retrieve the value of a claim.
        /// </summary>
        /// <param name="identity">The identity.</param>
        /// <param name="claimType">Type of the claim.</param>
        /// <param name="issuer">The issuer.</param>
        /// <param name="claimValue">The claim value.</param>
        /// <returns>The value</returns>
        public static bool TryGetClaimValue(this ClaimsIdentity identity, string claimType, string issuer, out string claimValue)
        {
            claimValue = null;
            Claim claim = identity.FindClaims(claimType, issuer).FirstOrDefault();

            if (claim != null)
            {
                claimValue = claim.Value;
                return true;
            }

            return false;
        }

        public static bool HasResource(this ClaimsIdentity identity, string resourceName)
        {
            var resourcesJSON = identity.GetClaimValue(KretaClaimTypes.Resource);
            var resources = JsonConvert.DeserializeObject<List<string>>(resourcesJSON);

            return resources.Contains(resourceName);
        }
    }
}