// Copyright (c) ServiceStack, Inc. All Rights Reserved.
// License: https://raw.github.com/ServiceStack/ServiceStack/master/license.txt

using System;
using System.Collections.Generic;
using System.Linq;
using ServiceStack.Auth;
using ServiceStack.DataAnnotations;

namespace ServiceStack.Aws.DynamoDb;

public class DynamoDbAuthRepository(IPocoDynamo db, bool initSchema = false)
    : DynamoDbAuthRepository<UserAuth, UserAuthDetails>(db, initSchema);

public partial class DynamoDbAuthRepository<TUserAuth, TUserAuthDetails> : IUserAuthRepository, IManageRoles, IClearable, IRequiresSchema, IManageApiKeys, IQueryUserAuth
    where TUserAuth : class, IUserAuth
    where TUserAuthDetails : class, IUserAuthDetails
{
    public IPocoDynamo Db { get; private set; }

    public bool LowerCaseUsernames { get; set; }

    public class UserIdUserAuthDetailsIndex : IGlobalIndex<TUserAuthDetails>
    {
        [HashKey]
        public string UserId { get; set; }

        [RangeKey]
        public string Provider { get; set; }

        public int UserAuthId { get; set; }

        public int Id { get; set; }
    }

    public class UsernameUserAuthIndex : IGlobalIndex<TUserAuth>
    {
        [HashKey]
        public string UserName { get; set; }

        [RangeKey]
        public int Id { get; set; }
    }

    [ProjectionType(DynamoProjectionType.All)]
    public class ApiKeyIdIndex : IGlobalIndex<ApiKey>
    {
        [HashKey]
        public string Id { get; set; }

        [RangeKey]
        public string UserAuthId { get; set; }

        public string Environment { get; set; }
        public string KeyType { get; set; }

        public DateTime CreatedDate { get; set; }
        public DateTime? ExpiryDate { get; set; }
        public DateTime? CancelledDate { get; set; }
        public string Notes { get; set; }

        //Custom Reference Data
        public int? RefId { get; set; }
        public string RefIdStr { get; set; }
        public Dictionary<string, string> Meta { get; set; }
    }

    public DynamoDbAuthRepository(IPocoDynamo db, bool initSchema=false)
    {
        this.Db = db;

        if (initSchema)
            InitSchema();
    }

    private void ValidateNewUser(IUserAuth newUser, string password)
    {
        newUser.ThrowIfNull("newUser");
        password.ThrowIfNullOrEmpty("password");

        if (newUser.UserName.IsNullOrEmpty() && newUser.Email.IsNullOrEmpty())
            throw new ArgumentNullException("UserName or Email is required");

        if (!newUser.UserName.IsNullOrEmpty())
        {
            if (!HostContext.GetPlugin<AuthFeature>().IsValidUsername(newUser.UserName))
                throw new ArgumentException("UserName contains invalid characters", "UserName");
        }
    }

    private void AssertNoExistingUser(IUserAuth newUser, IUserAuth exceptForExistingUser = null)
    {
        if (newUser.UserName != null)
        {
            var existingUser = GetUserAuthByUserName(newUser.UserName);
            if (existingUser != null
                && (exceptForExistingUser == null || existingUser.Id != exceptForExistingUser.Id))
                throw new ArgumentException($"User {newUser.UserName} already exists");
        }
        if (newUser.Email != null)
        {
            var existingUser = GetUserAuthByUserName(newUser.Email);
            if (existingUser != null
                && (exceptForExistingUser == null || existingUser.Id != exceptForExistingUser.Id))
                throw new ArgumentException($"Email {newUser.Email} already exists");
        }
    }

    public IUserAuth CreateUserAuth(IUserAuth newUser, string password)
    {
        newUser.ValidateNewUser(password);

        AssertNoExistingUser(newUser);

        Sanitize(newUser);

        newUser.PopulatePasswordHashes(password);
        newUser.CreatedDate = DateTime.UtcNow;
        newUser.ModifiedDate = newUser.CreatedDate;

        Db.PutItem((TUserAuth)newUser);

        newUser = DeSanitize(Db.GetItem<TUserAuth>(newUser.Id));
        return newUser;
    }

    public IUserAuth UpdateUserAuth(IUserAuth existingUser, IUserAuth newUser)
    {
        newUser.ValidateNewUser();

        AssertNoExistingUser(newUser);

        newUser.PasswordHash = existingUser.PasswordHash;
        newUser.Salt = existingUser.Salt;
        newUser.DigestHa1Hash = existingUser.DigestHa1Hash;
        newUser.CreatedDate = existingUser.CreatedDate;
        newUser.ModifiedDate = DateTime.UtcNow;

        Db.PutItem(Sanitize((TUserAuth)newUser));

        newUser = DeSanitize(Db.GetItem<TUserAuth>(newUser.Id));
        return newUser;
    }

    //DynamoDb does not allow null hash keys on Global Indexes
    //Workaround by populating UserName with Email when null
    private T Sanitize<T>(T userAuth) where T : IUserAuth
    {
        if (userAuth.UserName == null)
            userAuth.UserName = userAuth.Email;

        if (this.LowerCaseUsernames)
            userAuth.UserName = userAuth.UserName.ToLower();
            
        return userAuth;
    }

    private IUserAuth DeSanitize(TUserAuth userAuth)
    {
        if (userAuth == null)
            return null;
            
        if (userAuth.UserName != null && userAuth.UserName.Contains("@"))
        {
            if (userAuth.Email == null)
                userAuth.Email = userAuth.UserName;

            userAuth.UserName = null;
        }

        return userAuth;
    }

    public virtual void LoadUserAuth(IAuthSession session, IAuthTokens tokens)
    {
        session.ThrowIfNull("session");

        var userAuth = GetUserAuth(session, tokens);
        LoadUserAuth(session, userAuth);
    }

    private void LoadUserAuth(IAuthSession session, IUserAuth userAuth)
    {
        session.PopulateSession(userAuth, this);
    }

    public virtual IUserAuth GetUserAuth(string userAuthId)
    {
        return DeSanitize(Db.GetItem<TUserAuth>(int.Parse(userAuthId)));
    }

    public void SaveUserAuth(IAuthSession authSession)
    {
        if (authSession == null)
            throw new ArgumentNullException(nameof(authSession));

        var userAuth = !authSession.UserAuthId.IsNullOrEmpty()
            ? Db.GetItem<TUserAuth>(int.Parse(authSession.UserAuthId))
            : authSession.ConvertTo<TUserAuth>();

        if (userAuth.Id == default(int) && !authSession.UserAuthId.IsNullOrEmpty())
            userAuth.Id = int.Parse(authSession.UserAuthId);

        userAuth.ModifiedDate = DateTime.UtcNow;
        if (userAuth.CreatedDate == default(DateTime))
            userAuth.CreatedDate = userAuth.ModifiedDate;

        Db.PutItem(Sanitize(userAuth));
    }

    public void SaveUserAuth(IUserAuth userAuth)
    {
        if (userAuth == null)
            throw new ArgumentNullException(nameof(userAuth));

        userAuth.ModifiedDate = DateTime.UtcNow;
        if (userAuth.CreatedDate == default(DateTime))
            userAuth.CreatedDate = userAuth.ModifiedDate;

        Db.PutItem(Sanitize((TUserAuth)userAuth));
    }

    public List<IUserAuthDetails> GetUserAuthDetails(string userAuthId)
    {
        var id = int.Parse(userAuthId);
        return Db.Query(Db.FromQuery<TUserAuthDetails>(q => q.UserAuthId == id))
            .Cast<IUserAuthDetails>().ToList();
    }

    public IUserAuthDetails CreateOrMergeAuthSession(IAuthSession authSession, IAuthTokens tokens)
    {
        TUserAuth userAuth = (TUserAuth)GetUserAuth(authSession, tokens)
                             ?? typeof(TUserAuth).CreateInstance<TUserAuth>();

        TUserAuthDetails authDetails = null;
        var index = GetUserAuthByProviderUserId(tokens.Provider, tokens.UserId);
        if (index != null)
            authDetails = Db.GetItem<TUserAuthDetails>(index.UserAuthId, index.Id);

        if (authDetails == null)
        {
            authDetails = typeof(TUserAuthDetails).CreateInstance<TUserAuthDetails>();
            authDetails.Provider = tokens.Provider;
            authDetails.UserId = tokens.UserId;
        }

        authDetails.PopulateMissing(tokens, overwriteReserved: true);
        userAuth.PopulateMissingExtended(authDetails);

        userAuth.ModifiedDate = DateTime.UtcNow;
        if (userAuth.CreatedDate == default(DateTime))
            userAuth.CreatedDate = userAuth.ModifiedDate;

        Sanitize(userAuth);

        Db.PutItem(userAuth);

        authDetails.UserAuthId = userAuth.Id;

        authDetails.ModifiedDate = userAuth.ModifiedDate;
        if (authDetails.CreatedDate == default(DateTime))
            authDetails.CreatedDate = userAuth.ModifiedDate;

        Db.PutItem(authDetails);

        return authDetails;
    }

    public IUserAuth GetUserAuth(IAuthSession authSession, IAuthTokens tokens)
    {
        if (!authSession.UserAuthId.IsNullOrEmpty())
        {
            var userAuth = GetUserAuth(authSession.UserAuthId);
            if (userAuth != null)
                return userAuth;
        }
        if (!authSession.UserAuthName.IsNullOrEmpty())
        {
            var userAuth = GetUserAuthByUserName(authSession.UserAuthName);
            if (userAuth != null)
                return userAuth;
        }

        if (tokens == null || tokens.Provider.IsNullOrEmpty() || tokens.UserId.IsNullOrEmpty())
            return null;

        var authProviderIndex = GetUserAuthByProviderUserId(tokens.Provider, tokens.UserId);
        if (authProviderIndex != null)
        {
            var userAuth = DeSanitize(Db.GetItem<TUserAuth>(authProviderIndex.UserAuthId));
            return userAuth;
        }
        return null;
    }

    private UserIdUserAuthDetailsIndex GetUserAuthByProviderUserId(string provider, string userId)
    {
        var oAuthProvider = Db.FromQueryIndex<UserIdUserAuthDetailsIndex>(
                q => q.UserId == userId && q.Provider == provider)
            .Exec()
            .FirstOrDefault();

        return oAuthProvider;
    }

    public IUserAuth GetUserAuthByUserName(string userNameOrEmail)
    {
        if (userNameOrEmail == null)
            return null;

        if (LowerCaseUsernames)
            userNameOrEmail = userNameOrEmail.ToLower();

        var index = Db.FromQueryIndex<UsernameUserAuthIndex>(q => q.UserName == userNameOrEmail)
            .Exec().FirstOrDefault();
        if (index == null)
            return null;

        var userAuthId = index.Id;

        return DeSanitize(Db.GetItem<TUserAuth>(userAuthId));
    }

    public virtual bool TryAuthenticate(string userName, string password, out IUserAuth userAuth)
    {
        userAuth = GetUserAuthByUserName(userName);
        if (userAuth == null)
            return false;

        if (userAuth.VerifyPassword(password, out var needsRehash))
        {
            this.RecordSuccessfulLogin(userAuth, needsRehash, password);
            return true;
        }

        this.RecordInvalidLoginAttempt(userAuth);

        userAuth = null;
        return false;
    }

    public virtual bool TryAuthenticate(Dictionary<string, string> digestHeaders, string privateKey, int nonceTimeOut, string sequence, out IUserAuth userAuth)
    {
        userAuth = GetUserAuthByUserName(digestHeaders["username"]);
        if (userAuth == null)
            return false;

        if (userAuth.VerifyDigestAuth(digestHeaders, privateKey, nonceTimeOut, sequence))
        {
            this.RecordSuccessfulLogin(userAuth);
            return true;
        }

        this.RecordInvalidLoginAttempt(userAuth);

        userAuth = null;
        return false;
    }

    public IUserAuth UpdateUserAuth(IUserAuth existingUser, IUserAuth newUser, string password)
    {
        ValidateNewUser(newUser, password);

        AssertNoExistingUser(newUser, existingUser);

        //DynamoDb does not allow null hash keys on Global Indexes
        //Workaround by populating UserName with Email when null
        if (newUser.UserName == null)
            newUser.UserName = newUser.Email;

        if (this.LowerCaseUsernames)
            newUser.UserName = newUser.UserName.ToLower();

        var hash = existingUser.PasswordHash;
        var salt = existingUser.Salt;
        if (password != null)
            HostContext.Resolve<IHashProvider>().GetHashAndSaltString(password, out hash, out salt);

        var digestHash = existingUser.DigestHa1Hash;
        if (password != null || existingUser.UserName != newUser.UserName)
            digestHash = new DigestAuthFunctions().CreateHa1(newUser.UserName, DigestAuthProvider.Realm, password);

        newUser.Id = existingUser.Id;
        newUser.PasswordHash = hash;
        newUser.Salt = salt;
        newUser.DigestHa1Hash = digestHash;
        newUser.CreatedDate = existingUser.CreatedDate;
        newUser.ModifiedDate = DateTime.UtcNow;

        Db.PutItem(Sanitize((TUserAuth)newUser));

        return newUser;
    }

    public void DeleteUserAuth(string userAuthId)
    {
        var userId = int.Parse(userAuthId);

        Db.DeleteItem<TUserAuth>(userAuthId);

        var userAuthDetails = Db.FromQuery<TUserAuthDetails>(x => x.UserAuthId == userId)
            .Select(x => new { x.UserAuthId, x.Id })
            .Exec();
        var userAuthDetailsKeys = userAuthDetails.Map(x => new DynamoId(x.UserAuthId, x.Id));
        Db.DeleteItems<TUserAuthDetails>(userAuthDetailsKeys);

        var userAuthRoles = Db.FromQuery<UserAuthRole>(x => x.UserAuthId == userId)
            .Select(x => x.Id)
            .Exec();
        var userAuthRolesKeys = userAuthRoles.Map(x => new DynamoId(x.UserAuthId, x.Id));
        Db.DeleteItems<UserAuthRole>(userAuthRolesKeys);
    }

    public void Clear()
    {
        Db.DeleteItems<TUserAuth>(Db.FromScan<TUserAuth>().ExecColumn(x => x.Id));

        var qDetails = Db.FromScan<TUserAuthDetails>().Select(x => new { x.UserAuthId, x.Id });
        Db.DeleteItems<TUserAuthDetails>(qDetails.Exec().Map(x => new DynamoId(x.UserAuthId, x.Id)));

        var qRoles = Db.FromScan<UserAuthRole>().Select(x => new { x.UserAuthId, x.Id });
        Db.DeleteItems<UserAuthRole>(qRoles.Exec().Map(x => new DynamoId(x.UserAuthId, x.Id)));
    }

    public virtual ICollection<string> GetRoles(string userAuthId)
    {
        var authId = int.Parse(userAuthId);
        return Db.FromQuery<UserAuthRole>(x => x.UserAuthId == authId)
            .Filter(x => x.Role != null)
            .Exec()
            .Map(x => x.Role);
    }

    public virtual ICollection<string> GetPermissions(string userAuthId)
    {
        var authId = int.Parse(userAuthId);
        return Db.FromQuery<UserAuthRole>(x => x.UserAuthId == authId)
            .Filter(x => x.Permission != null)
            .Exec()
            .Map(x => x.Permission);
    }

    public virtual void GetRolesAndPermissions(string userAuthId, out ICollection<string> roles, out ICollection<string> permissions)
    {
        var authId = int.Parse(userAuthId);
        var results = Db.FromQuery<UserAuthRole>(x => x.UserAuthId == authId)
            .Exec();

        roles = new List<string>();
        permissions = new List<string>();
        foreach (var result in results)
        {
            if (result.Role != null)
                roles.Add(result.Role);
            if (result.Permission != null)
                permissions.Add(result.Permission);
        }
    }

    public virtual bool HasRole(string userAuthId, string role)
    {
        if (role == null)
            throw new ArgumentNullException(nameof(role));

        if (userAuthId == null)
            return false;

        var authId = int.Parse(userAuthId);

        return Db.FromQuery<UserAuthRole>(x => x.UserAuthId == authId)
            .Filter(x => x.Role == role)
            .Exec()
            .Any();
    }

    public virtual bool HasPermission(string userAuthId, string permission)
    {
        if (permission == null)
            throw new ArgumentNullException(nameof(permission));

        if (userAuthId == null)
            return false;

        var authId = int.Parse(userAuthId);

        return Db.FromQuery<UserAuthRole>(x => x.UserAuthId == authId)
            .Filter(x => x.Permission == permission)
            .Exec()
            .Any();
    }

    public virtual void AssignRoles(string userAuthId, ICollection<string> roles = null, ICollection<string> permissions = null)
    {
        var userAuth = GetUserAuth(userAuthId);
        var now = DateTime.UtcNow;

        var userRoles = Db.FromQuery<UserAuthRole>(q => q.UserAuthId == userAuth.Id)
            .Exec().ToList();

        if (!roles.IsEmpty())
        {
            var roleSet = userRoles.Where(x => x.Role != null).Select(x => x.Role).ToSet();
            foreach (var role in roles)
            {
                if (!roleSet.Contains(role))
                {
                    Db.PutRelatedItem(userAuth.Id, new UserAuthRole
                    {
                        Role = role,
                        CreatedDate = now,
                        ModifiedDate = now,
                    });
                }
            }
        }

        if (!permissions.IsEmpty())
        {
            var permissionSet = userRoles.Where(x => x.Permission != null).Select(x => x.Permission).ToSet();
            foreach (var permission in permissions)
            {
                if (!permissionSet.Contains(permission))
                {
                    Db.PutRelatedItem(userAuth.Id, new UserAuthRole
                    {
                        Permission = permission,
                        CreatedDate = now,
                        ModifiedDate = now,
                    });
                }
            }
        }
    }

    public virtual void UnAssignRoles(string userAuthId, ICollection<string> roles = null, ICollection<string> permissions = null)
    {
        var userAuth = GetUserAuth(userAuthId);

        if (!roles.IsEmpty())
        {
            var authRoleIds = Db.FromQuery<UserAuthRole>(x => x.UserAuthId == userAuth.Id)
                .Filter(x => roles.Contains(x.Role))
                .Select(x => new { x.UserAuthId, x.Id })
                .Exec()
                .Map(x => new DynamoId(x.UserAuthId, x.Id));

            Db.DeleteItems<UserAuthRole>(authRoleIds);
        }

        if (!permissions.IsEmpty())
        {
            var authRoleIds = Db.FromQuery<UserAuthRole>(x => x.UserAuthId == userAuth.Id)
                .Filter(x => permissions.Contains(x.Permission))
                .Select(x => new { x.UserAuthId, x.Id })
                .Exec()
                .Map(x => new DynamoId(x.UserAuthId, x.Id));

            Db.DeleteItems<UserAuthRole>(authRoleIds);
        }
    }

    public void InitApiKeySchema() { }

    public bool ApiKeyExists(string apiKey)
    {
        return Db.FromQueryIndex<ApiKeyIdIndex>(x => x.Id == apiKey).Exec(1).Count > 0;
    }

    public ApiKey GetApiKey(string apiKey)
    {
        return Db.FromQueryIndex<ApiKeyIdIndex>(x => x.Id == apiKey)
            .ExecInto<ApiKey>()
            .FirstOrDefault();
    }

    public List<ApiKey> GetUserApiKeys(string userId)
    {
        return Db.FromQuery<ApiKey>(x => x.UserAuthId == userId)
            .Filter(x => x.CancelledDate == null
                         && (x.ExpiryDate == null || x.ExpiryDate >= DateTime.UtcNow))
            .Exec()
            .OrderByDescending(x => x.CreatedDate)
            .ToList();
    }

    public void StoreAll(IEnumerable<ApiKey> apiKeys)
    {
        Db.PutItems(apiKeys);
    }

    private bool hasInitSchema = false;

    public void InitSchema()
    {
        if (hasInitSchema)
            return;

        hasInitSchema = true;

        var alreadyAddedAttributes = typeof(TUserAuth).HasAttribute<ReferencesAttribute>();
        if (!alreadyAddedAttributes)
        {
            typeof(TUserAuth).AddAttributes(
                new ReferencesAttribute(typeof(UsernameUserAuthIndex)));
        }

        Db.RegisterTable<TUserAuth>();
        var metadata = Db.GetTableMetadata<TUserAuth>();
        metadata.LocalIndexes.Clear();

        if (!alreadyAddedAttributes)
        {
            typeof(TUserAuthDetails).AddAttributes(
                new ReferencesAttribute(typeof(UserIdUserAuthDetailsIndex)),
                new CompositeKeyAttribute("UserAuthId", "Id"));
        }

        Db.RegisterTable<TUserAuthDetails>();

        if (!alreadyAddedAttributes)
        {
            typeof(UserAuthRole).AddAttributes(
                new CompositeKeyAttribute("UserAuthId", "Id"));
        }

        Db.RegisterTable<UserAuthRole>();

        if (!alreadyAddedAttributes)
        {
            typeof(ApiKey).AddAttributes(
                new ReferencesAttribute(typeof(ApiKeyIdIndex)),
                new CompositeKeyAttribute("UserAuthId", "Id"));
        }

        Db.RegisterTable<ApiKey>();

        Db.InitSchema();
    }

    public List<IUserAuth> GetUserAuths(string orderBy = null, int? skip = null, int? take = null)
    {
        return Db.FromScan<TUserAuth>().Exec().SortAndPage(orderBy, skip, take).Map(DeSanitize).ToList();
    }

    public List<IUserAuth> SearchUserAuths(string query, string orderBy = null, int? skip = null, int? take = null)
    {
        return Db.FromScan<TUserAuth>().Filter(x => 
                x.UserName.Contains(query) || x.DisplayName.Contains(query) || x.Company.Contains(query))
            .Exec().SortAndPage(orderBy, skip, take).Map(DeSanitize).ToList();
    }
}