using System.Collections.Generic;
using System.Data.Common;
using System.Threading;
using System.Threading.Tasks;
using FrameworkDAL.CustomCode.EntityViewer.DTOs;
using GB5Shared.DTO.Framework.Login;

namespace FrameworkDAL.CustomCode.EntityViewer
{
    // ============================================================
    // IEntityLayoutDAL — Data access for the Entity Viewer layout registry.
    //
    // Activation uses TWO queries (ArchiveActiveVersion + ActivateVersion)
    // that MUST be called inside the same transaction to prevent
    // dual-active-version on crash.
    // ============================================================
    public interface IEntityLayoutDAL
    {
        Task<int> SaveLayout(EntityLayoutDTO dto, LoginDTO loginDTO, CancellationToken ct = default);
        Task<int> UpdateLayout(EntityLayoutDTO dto, LoginDTO loginDTO, CancellationToken ct = default);
        Task<int> DeleteLayout(int entityLayoutId, int modifiedById, LoginDTO loginDTO, CancellationToken ct = default);
        Task<EntityLayoutDTO?> GetLayoutHeaderById(int entityLayoutId, LoginDTO loginDTO, CancellationToken ct = default);

        /// <summary>
        /// Resolves the Active layout for (EntityCode, TenantId): a TenantId-scoped
        /// override wins if it has an Active version, otherwise falls back to the
        /// TenantId IS NULL global default.
        /// </summary>
        Task<EntityLayoutVersionDTO?> GetActiveLayout(string entityCode, int tenantId, LoginDTO loginDTO, CancellationToken ct = default);

        Task<int> SaveLayoutVersion(EntityLayoutVersionDTO dto, LoginDTO loginDTO, CancellationToken ct = default);

        /// <summary>Updates a version's SnapshotJson/VersionLabel in place. Only takes effect
        /// while the version is still Draft (VERSIONSTATUS = 0) — returns 0 rows affected
        /// otherwise, which the BLL turns into an explicit error.</summary>
        Task<int> UpdateLayoutVersion(EntityLayoutVersionDTO dto, LoginDTO loginDTO, CancellationToken ct = default);

        /// <summary>Soft-deletes a version. Only takes effect while still Draft — an
        /// Active/Archived version can never be discarded.</summary>
        Task<int> DeleteLayoutVersion(int entityLayoutVersionId, int modifiedById, LoginDTO loginDTO, CancellationToken ct = default);

        Task<IReadOnlyList<EntityLayoutVersionDTO>> GetLayoutVersionList(int entityLayoutId, LoginDTO loginDTO, CancellationToken ct = default);

        /// <summary>All layout headers with IsComponent = <paramref name="isComponent"/>, joined
        /// to their current Active version summary and (for real entity types) MENTITY's
        /// display name — the Layout Designer's list screen.</summary>
        Task<IReadOnlyList<EntityLayoutListItemDTO>> GetLayoutList(bool isComponent, LoginDTO loginDTO, CancellationToken ct = default);
        Task ArchiveActiveVersion(int entityLayoutId, int modifiedById, LoginDTO loginDTO, DbTransaction tx, CancellationToken ct = default);
        Task ActivateVersion(int entityLayoutVersionId, int modifiedById, LoginDTO loginDTO, DbTransaction tx, CancellationToken ct = default);
    }
}