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 gear data in the database.
    /// Provides operations to add, retrieve, count, and update gear records per user.
    /// </summary>
    /// <remarks>
    /// This repository interacts with LiteDB to perform CRUD operations on gear items.
    /// Each gear item is associated with a user, allowing for user-specific gear management.
    /// </remarks>
    public class GearRepository : IGearRepository
    {
        #region Public Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="GearRepository"/> 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 gear data operations.
        /// The data provider manages the underlying LiteDatabase connection and provides
        /// typed collection accessors for different entity types.
        /// </remarks>
        public GearRepository(IDataProvider dataProvider)
        {
            _dataProvider = dataProvider;
            _col = _dataProvider.CollOfGear;
        }

        #endregion Public Constructors

        #region Public Methods

        /// <summary>
        /// Adds a new gear item to the database.
        /// </summary>
        /// <param name="newGear">The gear 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 gear item into the database using LiteDB.
        /// The gear item should have all required properties set before insertion.
        /// 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(Gear newGear)
        {
            int result;

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

            return result;
        }

        /// <summary>
        /// Retrieves all gear items from the database.
        /// </summary>
        /// <returns>An enumerable collection containing all gear instances stored 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 gear records from the database, potentially filtered by user.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when the method is called.</exception>
        public IEnumerable<Gear> GetAll()
        {
            throw new NotImplementedException();
        }

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

        /// <summary>
        /// Retrieves a gear item by its unique identifier.
        /// </summary>
        /// <param name="id">The unique identifier of the gear item to retrieve.</param>
        /// <returns>The gear item instance if found, otherwise null.</returns>
        /// <remarks>
        /// Searches the gear collection for a record with the specified ID.
        /// Returns null if no gear item with the matching ID is found in the database.
        /// </remarks>
        public Gear GetById(int id)
        {
            return _col.FindById(new BsonValue(id));
        }

        /// <summary>
        /// Gets the total count of gear items for a specific user.
        /// </summary>
        /// <param name="user">The user whose gear items to count.</param>
        /// <returns>The total number of gear items 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 gear items per user.
        /// </remarks>
        /// <exception cref="NotImplementedException">Thrown when the method is called.</exception>
        public int GetCount()
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// Updates an existing gear item in the database.
        /// </summary>
        /// <param name="updatedGear">The gear item instance containing the updated data.</param>
        /// <returns><see langword="true"/> if the update was successful; otherwise, <see langword="false"/>.</returns>
        /// <remarks>
        /// Updates the gear record in the database with the provided gear item instance.
        /// The gear item must have a valid ID to be updated.
        /// The method returns the result of the underlying LiteDB update operation.
        /// If the gear item does not exist, the update operation will return 0.
        /// </remarks>
        public bool Update(Gear updatedGear)
        {
            return _col.Update(updatedGear);
        }

        #endregion Public Methods

        #region Private Fields

        /// <summary>
        /// The LiteDB collection for gear records.
        /// </summary>
        private readonly ILiteCollection<Gear> _col;

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

        #endregion Private Fields
    }
}