using Microsoft.EntityFrameworkCore;
using Strata.SqlTools.Breakdowns.SqlServer;
using Strata.SqlTools.EFCore.Abstractions;
using Strata.SqlTools.EFCore.Models;

namespace Strata.SqlTools.EFCore.Services;

/// <summary>
/// Interface for a generic repository pattern for QueryBreakdown entities.
/// Provides a simplified API for common database operations.
/// </summary>
public interface IQueryBreakdownRepository
{
    /// <summary>
    /// Adds a new QueryBreakdown to the repository and saves changes.
    /// </summary>
    /// <param name="queryBreakdown">The QueryBreakdown to add.</param>
    /// <returns>The ID of the added entity.</returns>
    Task<int> AddAsync(QueryBreakdown queryBreakdown);

    /// <summary>
    /// Retrieves a QueryBreakdown by ID and converts it from the entity.
    /// </summary>
    /// <param name="id">The ID of the QueryBreakdown entity.</param>
    /// <returns>The QueryBreakdown, or null if not found.</returns>
    Task<QueryBreakdown?> GetByIdAsync(int id);

    /// <summary>
    /// Retrieves a QueryBreakdownEntity by ID.
    /// </summary>
    /// <param name="id">The ID of the entity.</param>
    /// <returns>The QueryBreakdownEntity, or null if not found.</returns>
    Task<QueryBreakdownEntity?> GetEntityByIdAsync(int id);

    /// <summary>
    /// Gets all QueryBreakdowns.
    /// </summary>
    /// <returns>A list of all QueryBreakdowns.</returns>
    Task<List<QueryBreakdown>> GetAllAsync();

    /// <summary>
    /// Gets all QueryBreakdownEntities.
    /// </summary>
    /// <returns>A list of all QueryBreakdownEntities.</returns>
    Task<List<QueryBreakdownEntity>> GetAllEntitiesAsync();

    /// <summary>
    /// Updates an existing QueryBreakdown and saves changes.
    /// </summary>
    /// <param name="id">The ID of the entity to update.</param>
    /// <param name="queryBreakdown">The updated QueryBreakdown.</param>
    Task UpdateAsync(int id, QueryBreakdown queryBreakdown);

    /// <summary>
    /// Deletes a QueryBreakdown by ID and saves changes.
    /// </summary>
    /// <param name="id">The ID of the entity to delete.</param>
    /// <returns>True if the entity was deleted; false if not found.</returns>
    Task<bool> DeleteAsync(int id);

    /// <summary>
    /// Gets the count of all QueryBreakdown entities.
    /// </summary>
    /// <returns>The count of entities.</returns>
    Task<int> GetCountAsync();
}

/// <summary>
/// Implementation of IQueryBreakdownRepository for managing QueryBreakdown entities in Entity Framework Core.
/// </summary>
public class QueryBreakdownRepository : IQueryBreakdownRepository
{
    private readonly DbContext _context;
    private readonly IQueryBreakdownMapper _mapper;

    /// <summary>
    /// Initializes a new instance of the QueryBreakdownRepository.
    /// </summary>
    /// <param name="context">The EF Core DbContext.</param>
    /// <param name="mapper">The mapper for converting between QueryBreakdown and QueryBreakdownEntity.</param>
    public QueryBreakdownRepository(DbContext context, IQueryBreakdownMapper mapper)
    {
        ArgumentNullException.ThrowIfNull(context);
        ArgumentNullException.ThrowIfNull(mapper);

        _context = context;
        _mapper = mapper;
    }

    /// <summary>
    /// Adds a new QueryBreakdown to the repository and saves changes.
    /// </summary>
    public async Task<int> AddAsync(QueryBreakdown queryBreakdown)
    {
        ArgumentNullException.ThrowIfNull(queryBreakdown);

        var (entity, parameters, withClauses) = _mapper.MapToEntityWithRelations(queryBreakdown);

        // Add the main entity
        _context.Set<QueryBreakdownEntity>().Add(entity);
        await _context.SaveChangesAsync();

        // Add related entities with foreign key set
        foreach (var param in parameters)
        {
            param.QueryBreakdownEntityId = entity.Id;
            _context.Set<QueryParameterEntity>().Add(param);
        }

        foreach (var withClause in withClauses)
        {
            withClause.QueryBreakdownEntityId = entity.Id;
            _context.Set<WithClauseEntity>().Add(withClause);
        }

        await _context.SaveChangesAsync();
        return entity.Id;
    }

    /// <summary>
    /// Retrieves a QueryBreakdown by ID and converts it from the entity.
    /// </summary>
    public async Task<QueryBreakdown?> GetByIdAsync(int id)
    {
        var entity = await _context.Set<QueryBreakdownEntity>()
            .Include(e => e.Parameters)
            .Include(e => e.WithClauses)
            .FirstOrDefaultAsync(e => e.Id == id);

        return entity != null ? _mapper.MapToDomainModelWithRelations(entity) : null;
    }

    /// <summary>
    /// Retrieves a QueryBreakdownEntity by ID.
    /// </summary>
    public async Task<QueryBreakdownEntity?> GetEntityByIdAsync(int id)
    {
        return await _context.Set<QueryBreakdownEntity>()
            .FirstOrDefaultAsync(e => e.Id == id);
    }

    /// <summary>
    /// Gets all QueryBreakdowns.
    /// </summary>
    public async Task<List<QueryBreakdown>> GetAllAsync()
    {
        var entities = await _context.Set<QueryBreakdownEntity>().ToListAsync();
        return entities.ConvertAll(e => _mapper.MapToDomainModel(e));
    }

    /// <summary>
    /// Gets all QueryBreakdownEntities.
    /// </summary>
    public async Task<List<QueryBreakdownEntity>> GetAllEntitiesAsync()
    {
        return await _context.Set<QueryBreakdownEntity>().ToListAsync();
    }

    /// <summary>
    /// Updates an existing QueryBreakdown and saves changes.
    /// </summary>
    public async Task UpdateAsync(int id, QueryBreakdown queryBreakdown)
    {
        ArgumentNullException.ThrowIfNull(queryBreakdown);

        var entity = await _context.Set<QueryBreakdownEntity>().FirstOrDefaultAsync(e => e.Id == id);
        if (entity == null)
        {
            throw new InvalidOperationException($"QueryBreakdown with ID {id} not found.");
        }

        var updatedEntity = _mapper.MapToEntity(queryBreakdown);

        // Update the main entity
        entity.SelectClause = updatedEntity.SelectClause;
        entity.SelectClauseComment = updatedEntity.SelectClauseComment;
        entity.FromClause = updatedEntity.FromClause;
        entity.FromClauseComment = updatedEntity.FromClauseComment;
        entity.WhereClause = updatedEntity.WhereClause;
        entity.WhereClauseComment = updatedEntity.WhereClauseComment;
        entity.GroupByClause = updatedEntity.GroupByClause;
        entity.GroupByClauseComment = updatedEntity.GroupByClauseComment;
        entity.HavingClause = updatedEntity.HavingClause;
        entity.HavingClauseComment = updatedEntity.HavingClauseComment;
        entity.OrderByClause = updatedEntity.OrderByClause;
        entity.OrderByClauseComment = updatedEntity.OrderByClauseComment;
        entity.WithClause = updatedEntity.WithClause;
        entity.RawSql = updatedEntity.RawSql;
        entity.SetupClausesJson = updatedEntity.SetupClausesJson;
        entity.FinishClausesJson = updatedEntity.FinishClausesJson;
        entity.ParametersJson = updatedEntity.ParametersJson;
        entity.UpdatedAt = DateTime.UtcNow;

        // Delete and recreate related entities
        var existingParameters = _context.Set<QueryParameterEntity>().Where(p => p.QueryBreakdownEntityId == id);
        _context.Set<QueryParameterEntity>().RemoveRange(existingParameters);

        var existingWithClauses = _context.Set<WithClauseEntity>().Where(w => w.QueryBreakdownEntityId == id);
        _context.Set<WithClauseEntity>().RemoveRange(existingWithClauses);

        var (_, parameters, withClauses) = _mapper.MapToEntityWithRelations(queryBreakdown);

        foreach (var param in parameters)
        {
            param.QueryBreakdownEntityId = id;
            _context.Set<QueryParameterEntity>().Add(param);
        }

        foreach (var withClause in withClauses)
        {
            withClause.QueryBreakdownEntityId = id;
            _context.Set<WithClauseEntity>().Add(withClause);
        }

        await _context.SaveChangesAsync();
    }

    /// <summary>
    /// Deletes a QueryBreakdown by ID and saves changes.
    /// </summary>
    public async Task<bool> DeleteAsync(int id)
    {
        var entity = await _context.Set<QueryBreakdownEntity>().FirstOrDefaultAsync(e => e.Id == id);
        if (entity == null)
        {
            return false;
        }

        _context.Set<QueryBreakdownEntity>().Remove(entity);
        await _context.SaveChangesAsync();
        return true;
    }

    /// <summary>
    /// Gets the count of all QueryBreakdown entities.
    /// </summary>
    public async Task<int> GetCountAsync()
    {
        return await _context.Set<QueryBreakdownEntity>().CountAsync();
    }
}