namespace Admin.NET.Plugin.AiDOP.MaterialWarehouse.InventoryPosting.Inventory;

/// <summary>
/// C5 库存事务服务（服务化 pr_SFM_InventoryTransactionProcessing2）。
/// 职责边界：仅库存事务合法性(9 守卫) + 量变(calculator) + 流水；不含 C1/C2/C3/C4/C6/C7/Outbox/Domain 解析/Controller。
/// 流程：LoadContext → 9 守卫(失败=ValidationFailure,0 写) → BuildWriteSet → store.WriteAtomic(单事务,异常全回滚=Error)。
/// </summary>
public sealed class InventoryTransactionService
{
    private readonly IInventoryUnitOfWorkFactory _uowFactory;

    public InventoryTransactionService(IInventoryUnitOfWorkFactory uowFactory)
    {
        _uowFactory = uowFactory ?? throw new ArgumentNullException(nameof(uowFactory));
    }

    public async Task<InventoryPostingResult> PostAsync(IReadOnlyList<InventoryTransactionCommand> cmds)
    {
        if (cmds == null) throw new ArgumentNullException(nameof(cmds));
        if (cmds.Count == 0)
            return new InventoryPostingResult { Outcome = InventoryPostingOutcome.Success, WrittenRows = 0, LegacyReturnMsg = "保存成功" };

        // 独立入口：自建 UoW（锁边界）→ ExecuteWithinAsync（C5 内部规则）→ Commit。
        await using var uow = _uowFactory.Create();
        try
        {
            var ctx = await uow.LockAndLoadAsync(cmds);
            var result = await ExecuteWithinAsync(ctx, cmds, ws => uow.WriteAsync(ws));
            if (result.Outcome == InventoryPostingOutcome.Success)
                await uow.CommitAsync();
            else
                await uow.RollbackAsync();   // 守卫失败 → 结束事务、0 写
            return result;
        }
        catch (Exception ex)
        {
            try { await uow.RollbackAsync(); } catch { /* 回滚失败不掩盖原异常 */ }
            return new InventoryPostingResult
            {
                Outcome = InventoryPostingOutcome.Error,
                WrittenRows = 0,
                ErrorCode = "INV_POST_FAILED",
                ErrorMessage = ex.Message,
                LegacyReturnMsg = "保存失败，" + (ex.Message ?? string.Empty),
            };
        }
    }

    /// <summary>
    /// 组合事务入口：在**调用方已开事务/已锁定加载**的前提下执行 C5 内部规则——
    /// **G1-G9 守卫（本服务拥有）+ Calculator + BuildWriteSet + 经 writeInventory 落写**；**不 Commit**。
    /// 供 IqcReceiptOrchestrator 在外层事务内调用，避免 Orchestrator 直接构造写集绕过守卫。
    /// LIVE 顺序：调用方先 CheckInv→C6，再调本方法（内部才跑 9 守卫），与 LIVE 一致。
    /// </summary>
    public static async Task<InventoryPostingResult> ExecuteWithinAsync(
        InventoryContext lockedCtx, IReadOnlyList<InventoryTransactionCommand> cmds, Func<InventoryWriteSet, Task> writeInventory)
    {
        if (lockedCtx == null) throw new ArgumentNullException(nameof(lockedCtx));
        if (cmds == null) throw new ArgumentNullException(nameof(cmds));
        if (writeInventory == null) throw new ArgumentNullException(nameof(writeInventory));
        if (cmds.Count == 0)
            return new InventoryPostingResult { Outcome = InventoryPostingOutcome.Success, WrittenRows = 0, LegacyReturnMsg = "保存成功" };

        var errors = InventoryGuardValidator.Validate(cmds, lockedCtx);   // ← G1-G9 归属 C5
        if (errors.Count > 0)
            return new InventoryPostingResult
            {
                Outcome = InventoryPostingOutcome.ValidationFailure,
                GuardErrors = errors,
                WrittenRows = 0,
                ErrorCode = "INV_GUARD_" + (int)errors[0].Code,
                ErrorMessage = errors[0].Message,
                LegacyReturnMsg = errors[0].Message,
            };

        var writeSet = BuildWriteSet(cmds, lockedCtx);
        await writeInventory(writeSet);
        return new InventoryPostingResult
        {
            Outcome = InventoryPostingOutcome.Success,
            WrittenRows = writeSet.TotalWrites,
            LegacyReturnMsg = "保存成功",
        };
    }

    /// <summary>据命令 + 上下文计算 W1-W6 写集（纯，无副作用；可单测路由/量变）。</summary>
    public static InventoryWriteSet BuildWriteSet(IReadOnlyList<InventoryTransactionCommand> cmds, InventoryContext ctx)
    {
        if (cmds == null) throw new ArgumentNullException(nameof(cmds));
        if (ctx == null) throw new ArgumentNullException(nameof(ctx));

        var ws = new InventoryWriteSet();

        // W1/W2 InvMaster：按 item+loc 聚合
        foreach (var g in cmds.GroupBy(c => (c.ItemNum, c.Location)))
        {
            var delta = SumDeltas(g);
            var before = ctx.GetInvMaster(g.Key.ItemNum, g.Key.Location) ?? new InventoryBalance();
            var hasInbound = g.Any(c => c.ChangeQty > 0m);
            ws.InvMasterWrites.Add(new InvMasterWrite
            {
                TenantId = g.First().TenantId,
                DomainCode = g.First().DomainCode,
                ItemNum = g.Key.ItemNum,
                Location = g.Key.Location,
                Delta = delta,
                After = InventoryBalanceCalculator.Apply(before, delta),
                InsertIfMissing = !ctx.HasInvMaster(g.Key.ItemNum, g.Key.Location) && hasInbound,
                User = g.First().User,
            });
        }

        // W3 ItemMaster.Location → ado_item_location_state：仅当当前默认库位为空、且有非空 Location 的命令（取首个）
        foreach (var g in cmds.GroupBy(c => c.ItemNum))
        {
            if (!string.IsNullOrEmpty(ctx.GetItemDefaultLocation(g.Key))) continue;
            var loc = g.Select(c => c.Location).FirstOrDefault(l => !string.IsNullOrEmpty(l));
            if (string.IsNullOrEmpty(loc)) continue;
            ws.ItemLocationWrites.Add(new ItemLocationWrite
            {
                TenantId = g.First().TenantId,
                DomainCode = g.First().DomainCode,
                ItemNum = g.Key,
                DefaultLocation = loc,
                User = g.First().User,
            });
        }

        // W4/W5 LocationDetail：按 item+loc+lot+refs 聚合（写入维度始终含批次，与 LIVE 一致）
        foreach (var g in cmds.GroupBy(c => (c.ItemNum, c.Location, Lot: c.LotSerial ?? "", Refs: c.Refs ?? "")))
        {
            var delta = SumDeltas(g);
            var before = ctx.GetLocationDetail(g.Key.ItemNum, g.Key.Location, g.Key.Lot, g.Key.Refs) ?? new InventoryBalance();
            var hasInbound = g.Any(c => c.ChangeQty > 0m);
            ws.LocationDetailWrites.Add(new LocationDetailWrite
            {
                TenantId = g.First().TenantId,
                DomainCode = g.First().DomainCode,
                ItemNum = g.Key.ItemNum,
                Location = g.Key.Location,
                LotSerial = g.Key.Lot,   // 空批空串（Phase 2 契约）
                Refs = g.Key.Refs,
                Delta = delta,
                After = InventoryBalanceCalculator.Apply(before, delta),
                InsertIfMissing = ctx.GetLocationDetail(g.Key.ItemNum, g.Key.Location, g.Key.Lot, g.Key.Refs) == null && hasInbound,
                Cost = g.Max(c => c.Price),
                Curr = g.Select(c => c.Curr).FirstOrDefault(x => !string.IsNullOrEmpty(x)),
                User = g.First().User,
            });
        }

        // W6 流水：每命令一行（按 Seq 稳定顺序），BeginBalance = 变动前 LocationDetail 在手
        foreach (var c in cmds.OrderBy(c => c.Seq))
        {
            var d = InventoryBalanceCalculator.ComputeRowDeltas(c);
            var beforeQoh = ctx.GetLocationDetail(c.ItemNum, c.Location, c.LotSerial ?? "", c.Refs ?? "")?.QtyOnHand ?? 0m;
            var hist = InventoryBalanceCalculator.BuildTransHist(c, d, beforeQoh);
            ws.TransactionRows.Add(new InventoryTransactionRow
            {
                TenantId = c.TenantId,
                DomainCode = c.DomainCode,
                PostingId = c.PostingId,
                TransactionGroupId = c.TransactionGroupId,
                Seq = c.Seq,
                ItemNum = c.ItemNum,
                Location = c.Location,
                LotSerial = c.LotSerial ?? "",
                TransType = hist.TransType,
                QtyChange = hist.QtyChange,
                BeginBalance = hist.BeginBalance,
                FreezeQty = hist.FreezeQty,
                Assay = hist.Assay,
                Amt = hist.Amt,
                WorkOrd = c.WorkOrd,
                ShipperNum = c.ShipperNum,
                Remark = c.Remark,
                Fbillno = c.Fbillno,
                Receiver = c.Receiver,
                RctQcNbr = c.RctQcNbr,
                User = c.User,
            });
        }

        return ws;
    }

    private static InventoryDeltas SumDeltas(IEnumerable<InventoryTransactionCommand> group)
    {
        var acc = new InventoryDeltas();
        foreach (var c in group)
        {
            var d = InventoryBalanceCalculator.ComputeRowDeltas(c);
            acc.Conv += d.Conv;
            acc.DeltaQtyOnHand += d.DeltaQtyOnHand;
            acc.DeltaAvailStatusQty += d.DeltaAvailStatusQty;
            acc.DeltaAssay += d.DeltaAssay;
            acc.DeltaFreezeQty += d.DeltaFreezeQty;
            acc.DeltaQtyOnOrd += d.DeltaQtyOnOrd;
        }
        return acc;
    }
}