using System;
using System.Collections.Generic;
using LiteDB;
using skydiveLogs_api.Domain;
using skydiveLogs_api.DomainService.Repositories;
using skydiveLogs_api.Infrastructure.Interfaces;

namespace skydiveLogs_api.Infrastructure
{
    /// <summary>
    /// Repository class for managing favorite drop zone data in the database.
    /// Provides operations to add, delete, retrieve, and manage favorite drop zones per user.
    /// </summary>
    /// <remarks>
    /// This repository interacts with LiteDB to perform operations on favorite drop zones,
    /// where each favorite drop zone is associated with both a user and a drop zone.
    /// </remarks>
    public class FavoriteDropZoneRepository : IFavoriteDropZoneRepository
    {
        #region Public Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="FavoriteDropZoneRepository"/> class.
        /// </summary>
        /// <param name="dataProvider">The data provider used for database access operations.</param>
        /// <remarks>
        /// This constructor initializes the repository with a reference to the data provider
        /// and sets up the collection for favorite drop zone data operations.
        /// The data provider manages the underlying LiteDatabase connection and provides
        /// typed collection accessors for different entity types.
        /// </remarks>
        public FavoriteDropZoneRepository(IDataProvider dataProvider)
        {
            _dataProvider = dataProvider;
            _col = _dataProvider.CollOfFavoriteDropZone;
        }

        #endregion Public Constructors

        #region Public Methods

        /// <summary>
        /// Adds a new favorite drop zone to the database.
        /// </summary>
        /// <param name="favoriteToAdd">The favorite drop zone instance to insert into the database.</param>
        /// <returns>The number of rows affected. Returns 0 if the insert operation failed.</returns>
        /// <remarks>
        /// Attempts to insert the new favorite drop zone into the database using LiteDB.
        /// If an exception occurs during insertion, the method returns 0.
        /// The returned value indicates the number of records affected by the insert operation.
        /// </remarks>
        public int Add(FavoriteDropZone favoriteToAdd)
        {
            int result;

            try
            {
                var tmp = _col.Insert(favoriteToAdd);
                result = tmp.AsInt32;
            }
            catch
            {
                result = 0;
            }

            return result;
        }

        /// <summary>
        /// Deletes favorite drop zone entries by drop zone ID and user ID.
        /// </summary>
        /// <param name="dropZoneId">The unique identifier of the drop zone to delete favorites for.</param>
        /// <param name="userId">The unique identifier of the user whose favorites to delete.</param>
        /// <returns>The number of rows affected. Returns 0 if the delete operation failed or no records matched.</returns>
        /// <remarks>
        /// Deletes all favorite drop zone records where both the drop zone ID and user ID match the provided values.
        /// This operation is commonly used to remove a specific user's favorites for a particular drop zone.
        /// </remarks>
        public int Delete(int dropZoneId, int userId)
        {
            return _col.DeleteMany(d => d.DropZone.Id == dropZoneId && d.User.Id == userId);
        }

        /// <summary>
        /// Retrieves all favorite drop zones for a specific user.
        /// </summary>
        /// <param name="user">The user whose favorite drop zones to retrieve.</param>
        /// <returns>An enumerable collection containing all favorite drop zone instances belonging to the specified user.</returns>
        /// <remarks>
        /// Queries the favorite drop zone collection and retrieves all records where the user ID matches the provided user.
        /// Each returned record includes navigation properties to the associated user and drop zone entities.
        /// Returns an empty collection if the user has no favorite drop zones.
        /// </remarks>
        public IEnumerable<FavoriteDropZone> GetAll(User user)
        {
            return _col.Query()
                       .Where(j => j.User.Id == user.Id)
                       .ToList();
        }

        /// <summary>
        /// Retrieves all favorite drop zones from the database.
        /// </summary>
        /// <returns>An enumerable collection containing all favorite drop zone instances in the database.</returns>
        /// <remarks>
        /// This method is not currently implemented and throws a <see cref="NotImplementedException"/> when called.
        /// Implement this method to retrieve all favorite drop zones across all users in the system.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when the method is called.</exception>
        public IEnumerable<FavoriteDropZone> GetAll()
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// Retrieves a favorite drop zone by its unique identifier.
        /// </summary>
        /// <param name="id">The unique identifier of the favorite drop zone to retrieve.</param>
        /// <returns>The favorite drop zone instance if found, otherwise null.</returns>
        /// <remarks>
        /// Searches the favorite drop zone collection for a record with the specified ID.
        /// This method currently returns null as it's not implemented with proper filtering by ID.
        /// Implement this method to retrieve a specific favorite drop zone by its database ID.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when attempting to retrieve by ID.</exception>
        public FavoriteDropZone GetById(int id)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// Gets the total count of favorite drop zones for a specific user.
        /// </summary>
        /// <param name="user">The user whose favorite drop zones to count.</param>
        /// <returns>The total number of favorite drop zones for the specified user.</returns>
        /// <remarks>
        /// This method is not currently implemented and throws a <see cref="NotImplementedException"/> when called.
        /// Implement this method to retrieve the count of favorite drop zones per user.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when the method is called.</exception>
        public int GetCount()
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// Updates an existing favorite drop zone in the database.
        /// </summary>
        /// <param name="updated">The favorite drop zone instance containing the updated data.</param>
        /// <returns><see langword="true"/> if the update was successful; otherwise, <see langword="false"/>.</returns>
        /// <remarks>
        /// This method is not currently implemented and throws a <see cref="NotImplementedException"/> when called.
        /// Implement this method to update existing favorite drop zone records in the database.
        /// Note: Favorite drop zones may not typically be updated; consider using Add for new favorites.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when attempting to update.</exception>
        public bool Update(FavoriteDropZone updated)
        {
            throw new NotImplementedException();
        }

        #endregion Public Methods

        #region Private Fields

        /// <summary>
        /// The LiteDB collection for favorite drop zone records.
        /// </summary>
        private readonly ILiteCollection<FavoriteDropZone> _col;

        /// <summary>
        /// The data provider used for database access operations.
        /// </summary>
        private readonly IDataProvider _dataProvider;

        #endregion Private Fields
    }
}