using Microsoft.EntityFrameworkCore;
using System.Linq.Expressions;

namespace Core.Blueprint.DAL.SQLServer
{
    /// <summary>
    /// Defines the contract for a generic repository to manage entities in a SQL Server database.
    /// </summary>
    /// <typeparam name="TEntity">The type of the entity managed by the repository. Must be a class.</typeparam>
    /// <typeparam name="TContext">The type of the database context used by the repository. Must inherit from <see cref="DbContext"/>.</typeparam>
    public interface IEntityRepository<TEntity, TContext>
        where TEntity : class
        where TContext : DbContext
    {
        /// <summary>
        /// Retrieves all entities of type <typeparamref name="T"/> from the database.
        /// </summary>
        /// <returns>A task representing the asynchronous operation, with a collection of entities as the result.</returns>
        Task<IEnumerable<TEntity>> GetAllAsync();

        /// <summary>
        /// Retrieves all entities of type <typeparamref name="T"/> from the database that match a specified condition.
        /// </summary>
        /// <param name="predicate">An expression to filter the entities.</param>
        /// <returns>A task representing the asynchronous operation, with a collection of matching entities as the result.</returns>
        Task<IEnumerable<TEntity>> GetByConditionAsync(Expression<Func<TEntity, bool>> predicate);

        /// <summary>
        /// Retrieves a single entity of type <typeparamref name="T"/> by its identifier.
        /// </summary>
        /// <param name="id">The identifier of the entity to retrieve.</param>
        /// <returns>A task representing the asynchronous operation, with the entity as the result, or null if not found.</returns>
        Task<TEntity?> GetByIdAsync(int id);

        /// <summary>
        /// Retrieves the first entity of type <typeparamref name="T"/> that matches a specified condition, or null if no match is found.
        /// </summary>
        /// <param name="predicate">An expression to filter the entities.</param>
        /// <returns>A task representing the asynchronous operation, with the matching entity as the result, or null if none match.</returns>
        Task<TEntity?> FirstOrDefaultAsync(Expression<Func<TEntity, bool>> predicate);

        /// <summary>
        /// Adds a new entity of type <typeparamref name="T"/> to the database.
        /// </summary>
        /// <param name="entity">The entity to add.</param>
        /// <returns>A task representing the asynchronous operation.</returns>
        Task AddAsync(TEntity entity);

        /// <summary>
        /// Adds multiple entities of type <typeparamref name="T"/> to the database.
        /// </summary>
        /// <param name="entities">The collection of entities to add.</param>
        /// <returns>A task representing the asynchronous operation.</returns>
        Task AddRangeAsync(IEnumerable<TEntity> entities);

        /// <summary>
        /// Updates an existing entity of type <typeparamref name="T"/> in the database.
        /// </summary>
        /// <param name="entity">The entity to update.</param>
        /// <returns>The updated entity.</returns>
        TEntity Update(TEntity entity);

        /// <summary>
        /// Updates multiple entities of type <typeparamref name="T"/> in the database.
        /// </summary>
        /// <param name="entities">The collection of entities to update.</param>
        void UpdateRange(IEnumerable<TEntity> entities);

        /// <summary>
        /// Deletes an entity of type <typeparamref name="T"/> from the database.
        /// </summary>
        /// <param name="entity">The entity to delete.</param>
        void Delete(TEntity entity);

        /// <summary>
        /// Deletes multiple entities of type <typeparamref name="T"/> from the database.
        /// </summary>
        /// <param name="entities">The collection of entities to delete.</param>
        void DeleteRange(IEnumerable<TEntity> entities);

        /// <summary>
        /// Determines whether any entities of type <typeparamref name="T"/> exist in the database that match a specified condition.
        /// </summary>
        /// <param name="predicate">An expression to filter the entities.</param>
        /// <returns>A task representing the asynchronous operation, with a boolean result indicating whether any match exists.</returns>
        Task<bool> AnyAsync(Expression<Func<TEntity, bool>> predicate);

        /// <summary>
        /// Executes a raw SQL query and maps the result to entities of type <typeparamref name="T"/>.
        /// </summary>
        /// <param name="sql">The raw SQL query to execute.</param>
        /// <param name="parameters">Optional parameters for the SQL query.</param>
        /// <returns>A task representing the asynchronous operation, with a collection of entities as the result.</returns>
        Task<IEnumerable<TEntity>> ExecuteRawSqlAsync(string sql, params object[] parameters);

        /// <summary>
        /// Counts the total number of entities of type <typeparamref name="T"/> in the database.
        /// </summary>
        /// <returns>A task representing the asynchronous operation, with the count as the result.</returns>
        Task<int> CountAsync();

        /// <summary>
        /// Saves all pending changes to the database.
        /// </summary>
        /// <returns>A task representing the asynchronous operation.</returns>
        Task SaveAsync();
    }
}