using System.Collections.Generic;
using System.Data.Common;
using System.Threading;
using System.Threading.Tasks;
using GB5Shared.DTO.Draft;
using GB5Shared.DTO.Framework.Login;

namespace GB5Shared.Draft
{
    public interface IDraftRowBLL
    {
        /// <summary>
        /// Auto-saves the draft header (every 30s timer or significant action).
        /// Allocates a DraftId via AutoNumber on first call.
        /// Returns the DraftId for the FE to store and reuse.
        /// </summary>
        Task<string> UpsertHeaderAsync(
            DraftSessionDTO dto,
            LoginDTO login,
            CancellationToken ct);

        /// <summary>
        /// Upserts one dirty row. Rejects RowState=Unchanged silently (log warning only).
        /// High-frequency endpoint — intentionally lightweight.
        /// </summary>
        Task<string> UpsertRowAsync(
            DraftRowDTO dto, LoginDTO login, CancellationToken ct);

        /// <summary>Returns the draft header for the given session, or null if not found.</summary>
        Task<DraftHeaderDTO?> GetDraftHeaderAsync(string sessionGuid, LoginDTO login, CancellationToken ct);

        /// <summary>Returns all dirty rows for crash recovery, ordered for tree reconstruction.</summary>
        Task<string> GetDraftRowsAsync(string sessionGuid, LoginDTO login, CancellationToken ct);

        /// <summary>
        /// Typed dirty-row fetch for entity-BLL promotion at final Save (distinct from the
        /// JSON-returning GetDraftRowsAsync used by the FE-facing GetDraftRows endpoint).
        /// Entity BLLs partition the result via DraftRowBLL.DeserializeRows/GetServerIds.
        /// </summary>
        Task<IEnumerable<DraftRowDTO>> GetDraftRowsForPromotionAsync(string sessionGuid, LoginDTO login, CancellationToken ct);

        /// <summary>Returns draft pool items for the sharing/resume screen.</summary>
        Task<string> GetDraftPoolAsync(int menuId, LoginDTO login, CancellationToken ct);

        /// <summary>Discards the draft. ActionType=8=Discarded.</summary>
        Task<string> DiscardDraftAsync(string sessionGuid, LoginDTO login, CancellationToken ct);

        /// <summary>
        /// Shares the draft to targetUserId.
        /// Application-layer ownership check precedes the SP call (defence in depth).
        /// </summary>
        Task<string> ShareDraftAsync(DraftShareDTO dto, LoginDTO login, CancellationToken ct);

        /// <summary>
        /// Deletes TDRAFT_ROWS + TDRAFT for the session after a successful final save.
        /// MUST be called inside the entity's save transaction (tx).
        /// ActionType=7=Submitted.
        /// </summary>
        Task CleanupAfterSaveAsync(string sessionGuid, LoginDTO login, DbTransaction tx, CancellationToken ct);

    }
}