Distribution/Features/Scheme/ISchemeRepository.cs

@@ -0,0 +1,19 @@
+namespace Distribution.Features.Scheme;
+
+public interface ISchemeRepository
+{
+    Task<Models.Scheme?> GetByIdAsync(Guid id);
+    Task<List<Models.Scheme>> GetAllAsync(Guid? regionId = null);
+    Task AddAsync(Models.Scheme entity);
+    void Update(Models.Scheme entity);
+    void Remove(Models.Scheme entity);
+
+    Task<List<Models.SchemeRedemption>> GetRedemptionsAsync(Guid schemeId);
+    Task AddRedemptionAsync(Models.SchemeRedemption entity);
+    Task<bool> HasRedemptionAsync(Guid schemeId, Guid orderId);
+
+    Task<Models.SchemeBundleComponent?> GetBundleComponentAsync(Guid schemeId, Guid itemId);
+    Task AddBundleComponentAsync(Models.SchemeBundleComponent entity);
+    void UpdateBundleComponent(Models.SchemeBundleComponent entity);
+    void RemoveBundleComponent(Models.SchemeBundleComponent entity);
+}

Distribution/Features/Scheme/SchemeController.cs

@@ -0,0 +1,139 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Distribution.Features.Scheme;
+
+[ApiController]
+[Route("api/schemes")]
+[Authorize]
+public class SchemeController(SchemeService service) : ControllerBase
+{
+    [HttpGet]
+    public async Task<IActionResult> GetAll([FromQuery] Guid? regionId) =>
+        Ok(await service.GetAllAsync(regionId));
+
+    [HttpGet("{id:guid}")]
+    public async Task<IActionResult> GetById(Guid id)
+    {
+        var result = await service.GetByIdAsync(id);
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> Create(CreateSchemeRequest request, CancellationToken ct)
+    {
+        try
+        {
+            var result = await service.CreateAsync(request, ct);
+            return CreatedAtAction(nameof(GetById), new { id = result.Id }, result);
+        }
+        catch (InvalidOperationException ex)
+        {
+            return BadRequest(new { error = ex.Message });
+        }
+    }
+
+    [HttpPut("{id:guid}")]
+    public async Task<IActionResult> Update(Guid id, UpdateSchemeRequest request, CancellationToken ct)
+    {
+        try
+        {
+            var result = await service.UpdateAsync(id, request, ct);
+            return result is null ? NotFound() : Ok(result);
+        }
+        catch (InvalidOperationException ex)
+        {
+            return BadRequest(new { error = ex.Message });
+        }
+    }
+
+    [HttpDelete("{id:guid}")]
+    public async Task<IActionResult> Delete(Guid id, CancellationToken ct)
+    {
+        var deleted = await service.DeleteAsync(id, ct);
+        return deleted ? NoContent() : NotFound();
+    }
+
+    [HttpPut("{id:guid}/free-goods-rule")]
+    public async Task<IActionResult> SetFreeGoodsRule(Guid id, SetFreeGoodsRuleRequest request, CancellationToken ct)
+    {
+        try
+        {
+            var result = await service.SetFreeGoodsRuleAsync(id, request, ct);
+            return result is null ? NotFound() : Ok(result);
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Conflict(new { error = ex.Message });
+        }
+    }
+
+    [HttpDelete("{id:guid}/free-goods-rule")]
+    public async Task<IActionResult> ClearFreeGoodsRule(Guid id, CancellationToken ct)
+    {
+        var result = await service.ClearFreeGoodsRuleAsync(id, ct);
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpPut("{id:guid}/bundle-components/{itemId:guid}")]
+    public async Task<IActionResult> UpsertBundleComponent(Guid id, Guid itemId, UpsertBundleComponentRequest request, CancellationToken ct)
+    {
+        try
+        {
+            var result = await service.UpsertBundleComponentAsync(id, itemId, request, ct);
+            return result is null ? NotFound() : Ok(result);
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Conflict(new { error = ex.Message });
+        }
+    }
+
+    [HttpDelete("{id:guid}/bundle-components/{itemId:guid}")]
+    public async Task<IActionResult> RemoveBundleComponent(Guid id, Guid itemId, CancellationToken ct)
+    {
+        var result = await service.RemoveBundleComponentAsync(id, itemId, ct);
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpGet("eligible")]
+    public async Task<IActionResult> GetEligible([FromQuery] Guid storeId, [FromQuery] Guid orderId)
+    {
+        var result = await service.EvaluateEligibilityAsync(storeId, orderId);
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpGet("{id:guid}/spend")]
+    public async Task<IActionResult> GetSpend(Guid id)
+    {
+        var result = await service.GetSpendAsync(id);
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpGet("{id:guid}/roi")]
+    public async Task<IActionResult> GetROI(Guid id)
+    {
+        var result = await service.GetROIAsync(id);
+        return result is null ? NotFound() : Ok(result);
+    }
+}
+
+[ApiController]
+[Route("api/orders")]
+[Authorize]
+public class SchemeOrderController(SchemeService service) : ControllerBase
+{
+    [HttpPost("{id:guid}/apply-scheme")]
+    public async Task<IActionResult> ApplyScheme(Guid id, ApplySchemeRequest request, CancellationToken ct)
+    {
+        try
+        {
+            var result = await service.ApplySchemeAsync(id, request.SchemeId, ct);
+            return result is null ? NotFound() : Ok(result);
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Conflict(new { error = ex.Message });
+        }
+    }
+}

Distribution/Features/Scheme/SchemeDTOs.cs

@@ -0,0 +1,111 @@
+using Distribution.Models;
+
+namespace Distribution.Features.Scheme;
+
+// ── Rule config payloads for percentage-based rules (serialized into Scheme.RuleConfig) ──
+
+public record SlabDiscountConfig(List<SlabTier> Tiers);
+
+public record SlabTier(decimal MinOrderAmount, decimal DiscountPercent);
+
+public record FlatPercentConfig(decimal DiscountPercent);
+
+// ── Requests ────────────────────────────────────────────────────────────
+
+public record BundleComponentRequest(Guid ItemId, int Qty);
+
+/// <summary>
+/// TriggerItemId/TriggerQty/FreeItemId/FreeQty/BundleComponents are optional so plain discount
+/// schemes (SlabDiscount/FlatPercent) can omit them entirely. When RuleType is BuyXGetY, supplying
+/// TriggerItemId+TriggerQty+FreeItemId+FreeQty here creates the scheme fully populated in one call
+/// instead of a separate PUT .../free-goods-rule. When RuleType is FreeBundle, supplying
+/// FreeItemId+FreeQty+BundleComponents does the same. These can still be added/edited later via
+/// PUT .../free-goods-rule and PUT .../bundle-components/{itemId}.
+/// </summary>
+public record CreateSchemeRequest(
+    string Name,
+    SchemeRuleType RuleType,
+    string? RuleConfig,
+    Guid? RegionId,
+    string? EligibleSegment,
+    DateTime DateRangeFrom,
+    DateTime DateRangeTo,
+    bool AgentLimitExempt,
+    decimal? BaselineExpectedSales,
+    Guid? TriggerItemId = null,
+    int? TriggerQty = null,
+    Guid? FreeItemId = null,
+    decimal? FreeQty = null,
+    List<BundleComponentRequest>? BundleComponents = null);
+
+public record UpdateSchemeRequest(
+    string Name,
+    string? RuleConfig,
+    Guid? RegionId,
+    string? EligibleSegment,
+    DateTime DateRangeFrom,
+    DateTime DateRangeTo,
+    bool AgentLimitExempt,
+    decimal? BaselineExpectedSales);
+
+public record ApplySchemeRequest(Guid SchemeId);
+
+/// <summary>
+/// Sets the free-goods payout for a scheme. For BuyXGetY, TriggerItemId/TriggerQty are required
+/// (what the store must buy); for FreeBundle they are ignored — the required items instead come
+/// from the scheme's bundle-components CRUD. FreeItemId/FreeQty is the payout in both cases.
+/// </summary>
+public record SetFreeGoodsRuleRequest(Guid? TriggerItemId, int? TriggerQty, Guid FreeItemId, decimal FreeQty);
+
+public record UpsertBundleComponentRequest(int Qty);
+
+// ── Responses ───────────────────────────────────────────────────────────
+
+public record BundleComponentResponse(Guid ItemId, string Sku, string ItemName, int Qty);
+
+public record SchemeResponse(
+    Guid Id,
+    string Name,
+    SchemeRuleType RuleType,
+    string? RuleConfig,
+    Guid? TriggerItemId,
+    string? TriggerItemName,
+    int? TriggerQty,
+    Guid? FreeItemId,
+    string? FreeItemName,
+    decimal? FreeQty,
+    List<BundleComponentResponse> BundleComponents,
+    Guid? RegionId,
+    string? RegionName,
+    string? EligibleSegment,
+    DateTime DateRangeFrom,
+    DateTime DateRangeTo,
+    bool AgentLimitExempt,
+    decimal? BaselineExpectedSales,
+    bool IsActive,
+    DateTime CreatedAt);
+
+public record SchemeEligibilityResponse(
+    Guid SchemeId,
+    string SchemeName,
+    SchemeRuleType RuleType,
+    bool Eligible,
+    string? Reason,
+    decimal? DiscountAmount,
+    Guid? FreeItemId,
+    decimal? FreeQty);
+
+public record SchemeRedemptionResponse(
+    Guid Id,
+    Guid SchemeId,
+    Guid? OrderId,
+    decimal? DiscountAmount,
+    Guid? FreeItemId,
+    string? FreeItemName,
+    decimal? FreeQty,
+    decimal? FreeItemCostValue,
+    DateTime RedeemedAt);
+
+public record SchemeSpendResponse(Guid SchemeId, decimal TotalDiscountSpend, decimal TotalFreeGoodsCostSpend, decimal TotalSpend, int RedemptionCount);
+
+public record SchemeROIResponse(Guid SchemeId, decimal BaselineExpectedSales, decimal ActualSales, decimal IncrementalSales, decimal TotalSpend, decimal? ROI);

Distribution/Features/Scheme/SchemeRepository.cs

@@ -0,0 +1,67 @@
+using Distribution.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace Distribution.Features.Scheme;
+
+public class SchemeRepository(AppDBContext context) : ISchemeRepository
+{
+    public async Task<Models.Scheme?> GetByIdAsync(Guid id) =>
+        await context.Schemes
+            .Include(s => s.Region)
+            .Include(s => s.TriggerItem)
+            .Include(s => s.FreeItem)
+            .Include(s => s.BundleComponents).ThenInclude(c => c.Item)
+            .FirstOrDefaultAsync(s => s.Id == id);
+
+    public async Task<List<Models.Scheme>> GetAllAsync(Guid? regionId = null)
+    {
+        var query = context.Schemes
+            .Include(s => s.Region)
+            .Include(s => s.TriggerItem)
+            .Include(s => s.FreeItem)
+            .Include(s => s.BundleComponents).ThenInclude(c => c.Item)
+            .Where(s => s.IsActive);
+
+        if (regionId.HasValue) query = query.Where(s => s.FK_RegionId == regionId);
+
+        return await query.ToListAsync();
+    }
+
+    public async Task AddAsync(Models.Scheme entity) =>
+        await context.Schemes.AddAsync(entity);
+
+    public void Update(Models.Scheme entity) =>
+        context.Schemes.Update(entity);
+
+    public void Remove(Models.Scheme entity)
+    {
+        entity.IsActive = false;
+        context.Schemes.Update(entity);
+    }
+
+    public async Task<List<Models.SchemeRedemption>> GetRedemptionsAsync(Guid schemeId) =>
+        await context.SchemeRedemptions
+            .Include(r => r.FreeItem)
+            .Include(r => r.Order)
+            .Where(r => r.FK_SchemeId == schemeId)
+            .ToListAsync();
+
+    public async Task AddRedemptionAsync(Models.SchemeRedemption entity) =>
+        await context.SchemeRedemptions.AddAsync(entity);
+
+    public async Task<bool> HasRedemptionAsync(Guid schemeId, Guid orderId) =>
+        await context.SchemeRedemptions.AnyAsync(r => r.FK_SchemeId == schemeId && r.FK_OrderId == orderId);
+
+    public async Task<Models.SchemeBundleComponent?> GetBundleComponentAsync(Guid schemeId, Guid itemId) =>
+        await context.SchemeBundleComponents
+            .FirstOrDefaultAsync(c => c.FK_SchemeId == schemeId && c.FK_ItemId == itemId);
+
+    public async Task AddBundleComponentAsync(Models.SchemeBundleComponent entity) =>
+        await context.SchemeBundleComponents.AddAsync(entity);
+
+    public void UpdateBundleComponent(Models.SchemeBundleComponent entity) =>
+        context.SchemeBundleComponents.Update(entity);
+
+    public void RemoveBundleComponent(Models.SchemeBundleComponent entity) =>
+        context.SchemeBundleComponents.Remove(entity);
+}

Distribution/Features/Scheme/SchemeService.cs

@@ -0,0 +1,515 @@
+using System.Text.Json;
+using Distribution.Features.Item;
+using Distribution.Features.Order;
+using Distribution.Features.Stock;
+using Distribution.Features.Store;
+using Distribution.Infra.UoW;
+using Distribution.Models;
+
+namespace Distribution.Features.Scheme;
+
+public class SchemeService(
+    ISchemeRepository repo,
+    IOrderRepository orderRepo,
+    IItemRepository itemRepo,
+    IStoreRepository storeRepo,
+    IStockRepository stockRepo,
+    IUnitOfWork uow)
+{
+    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);
+
+    private static SchemeResponse ToResponse(Models.Scheme s) =>
+        new(s.Id, s.Name, s.RuleType, s.RuleConfig,
+            s.FK_TriggerItemId, s.TriggerItem?.Name, s.TriggerQty,
+            s.FK_FreeItemId, s.FreeItem?.Name, s.FreeQty,
+            s.BundleComponents.Select(c => new BundleComponentResponse(c.FK_ItemId, c.Item.Sku, c.Item.Name, c.Qty)).ToList(),
+            s.FK_RegionId, s.Region?.Name, s.EligibleSegment,
+            s.DateRangeFrom, s.DateRangeTo, s.AgentLimitExempt, s.BaselineExpectedSales, s.IsActive, s.CreatedAt);
+
+    private static SchemeRedemptionResponse ToRedemptionResponse(SchemeRedemption r) =>
+        new(r.Id, r.FK_SchemeId, r.FK_OrderId, r.DiscountAmount, r.FK_FreeItemId, r.FreeItem?.Name,
+            r.FreeQty, r.FreeItemCostValue, r.RedeemedAt);
+
+    // ── CRUD ───────────────────────────────────────────────────────────────
+
+    public async Task<List<SchemeResponse>> GetAllAsync(Guid? regionId = null)
+    {
+        var schemes = await repo.GetAllAsync(regionId);
+        return schemes.Select(ToResponse).ToList();
+    }
+
+    public async Task<SchemeResponse?> GetByIdAsync(Guid id)
+    {
+        var scheme = await repo.GetByIdAsync(id);
+        return scheme is null || !scheme.IsActive ? null : ToResponse(scheme);
+    }
+
+    /// <summary>
+    /// createScheme(schemeRules, eligibility, dateRange). RuleConfig is only meaningful for
+    /// SlabDiscount/FlatPercent. For BuyXGetY/FreeBundle, the free-goods payout (and bundle
+    /// components) can be supplied inline here to create a fully-populated scheme in one call, or
+    /// added afterwards via SetFreeGoodsRuleAsync / UpsertBundleComponentAsync.
+    /// </summary>
+    public async Task<SchemeResponse> CreateAsync(CreateSchemeRequest request, CancellationToken ct = default)
+    {
+        ValidatePercentRuleConfig(request.RuleType, request.RuleConfig);
+        if (request.DateRangeFrom > request.DateRangeTo)
+            throw new InvalidOperationException("DateRangeFrom must not be after DateRangeTo.");
+
+        var hasFreeGoodsRule = request.FreeItemId.HasValue || request.FreeQty.HasValue ||
+            request.TriggerItemId.HasValue || request.TriggerQty.HasValue;
+        if (hasFreeGoodsRule)
+            await ValidateFreeGoodsRuleAsync(request.RuleType, request.TriggerItemId, request.TriggerQty, request.FreeItemId, request.FreeQty);
+
+        if (request.BundleComponents is { Count: > 0 })
+        {
+            if (request.RuleType != SchemeRuleType.FreeBundle)
+                throw new InvalidOperationException("BundleComponents only applies to FreeBundle schemes.");
+            foreach (var c in request.BundleComponents)
+            {
+                if (c.Qty <= 0)
+                    throw new InvalidOperationException("Bundle component Qty must be positive.");
+                if (await itemRepo.GetByIdAsync(c.ItemId) is null)
+                    throw new InvalidOperationException($"Bundle component item '{c.ItemId}' not found.");
+            }
+        }
+
+        var scheme = new Models.Scheme
+        {
+            Name = request.Name,
+            RuleType = request.RuleType,
+            RuleConfig = request.RuleConfig,
+            FK_RegionId = request.RegionId,
+            EligibleSegment = request.EligibleSegment,
+            DateRangeFrom = request.DateRangeFrom,
+            DateRangeTo = request.DateRangeTo,
+            AgentLimitExempt = request.AgentLimitExempt,
+            BaselineExpectedSales = request.BaselineExpectedSales
+        };
+
+        if (hasFreeGoodsRule)
+        {
+            scheme.FK_TriggerItemId = request.RuleType == SchemeRuleType.BuyXGetY ? request.TriggerItemId : null;
+            scheme.TriggerQty = request.RuleType == SchemeRuleType.BuyXGetY ? request.TriggerQty : null;
+            scheme.FK_FreeItemId = request.FreeItemId;
+            scheme.FreeQty = request.FreeQty;
+        }
+
+        await uow.BeginAsync(ct);
+        try
+        {
+            await repo.AddAsync(scheme);
+            if (request.BundleComponents is { Count: > 0 })
+            {
+                foreach (var c in request.BundleComponents)
+                    await repo.AddBundleComponentAsync(new SchemeBundleComponent { FK_SchemeId = scheme.Id, FK_ItemId = c.ItemId, Qty = c.Qty });
+            }
+            await uow.CommitAsync(ct);
+        }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return (await GetByIdAsync(scheme.Id))!;
+    }
+
+    public async Task<SchemeResponse?> UpdateAsync(Guid id, UpdateSchemeRequest request, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(id);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        ValidatePercentRuleConfig(scheme.RuleType, request.RuleConfig);
+        if (request.DateRangeFrom > request.DateRangeTo)
+            throw new InvalidOperationException("DateRangeFrom must not be after DateRangeTo.");
+
+        scheme.Name = request.Name;
+        scheme.RuleConfig = request.RuleConfig;
+        scheme.FK_RegionId = request.RegionId;
+        scheme.EligibleSegment = request.EligibleSegment;
+        scheme.DateRangeFrom = request.DateRangeFrom;
+        scheme.DateRangeTo = request.DateRangeTo;
+        scheme.AgentLimitExempt = request.AgentLimitExempt;
+        scheme.BaselineExpectedSales = request.BaselineExpectedSales;
+
+        await uow.BeginAsync(ct);
+        try { repo.Update(scheme); await uow.CommitAsync(ct); }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return ToResponse(scheme);
+    }
+
+    public async Task<bool> DeleteAsync(Guid id, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(id);
+        if (scheme is null || !scheme.IsActive) return false;
+
+        await uow.BeginAsync(ct);
+        try { repo.Remove(scheme); await uow.CommitAsync(ct); }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return true;
+    }
+
+    // ── Free-goods rule CRUD (BuyXGetY trigger + shared payout) ──────────────
+
+    public async Task<SchemeResponse?> SetFreeGoodsRuleAsync(Guid schemeId, SetFreeGoodsRuleRequest request, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        await ValidateFreeGoodsRuleAsync(scheme.RuleType, request.TriggerItemId, request.TriggerQty, request.FreeItemId, request.FreeQty);
+
+        scheme.FK_TriggerItemId = scheme.RuleType == SchemeRuleType.BuyXGetY ? request.TriggerItemId : null;
+        scheme.TriggerQty = scheme.RuleType == SchemeRuleType.BuyXGetY ? request.TriggerQty : null;
+        scheme.FK_FreeItemId = request.FreeItemId;
+        scheme.FreeQty = request.FreeQty;
+
+        await uow.BeginAsync(ct);
+        try { repo.Update(scheme); await uow.CommitAsync(ct); }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return (await GetByIdAsync(schemeId))!;
+    }
+
+    public async Task<SchemeResponse?> ClearFreeGoodsRuleAsync(Guid schemeId, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        scheme.FK_TriggerItemId = null;
+        scheme.TriggerQty = null;
+        scheme.FK_FreeItemId = null;
+        scheme.FreeQty = null;
+
+        await uow.BeginAsync(ct);
+        try { repo.Update(scheme); await uow.CommitAsync(ct); }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return (await GetByIdAsync(schemeId))!;
+    }
+
+    // ── Bundle component CRUD (FreeBundle required items) ────────────────────
+
+    public async Task<SchemeResponse?> UpsertBundleComponentAsync(Guid schemeId, Guid itemId, UpsertBundleComponentRequest request, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        if (scheme.RuleType != SchemeRuleType.FreeBundle)
+            throw new InvalidOperationException("Bundle components only apply to FreeBundle schemes.");
+        if (request.Qty <= 0)
+            throw new InvalidOperationException("Qty must be positive.");
+
+        var item = await itemRepo.GetByIdAsync(itemId)
+            ?? throw new InvalidOperationException("Item not found.");
+
+        var existing = await repo.GetBundleComponentAsync(schemeId, itemId);
+
+        await uow.BeginAsync(ct);
+        try
+        {
+            if (existing is null)
+            {
+                await repo.AddBundleComponentAsync(new SchemeBundleComponent
+                {
+                    FK_SchemeId = schemeId,
+                    FK_ItemId = item.Id,
+                    Qty = request.Qty
+                });
+            }
+            else
+            {
+                existing.Qty = request.Qty;
+                repo.UpdateBundleComponent(existing);
+            }
+            await uow.CommitAsync(ct);
+        }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return (await GetByIdAsync(schemeId))!;
+    }
+
+    public async Task<SchemeResponse?> RemoveBundleComponentAsync(Guid schemeId, Guid itemId, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        var existing = await repo.GetBundleComponentAsync(schemeId, itemId);
+        if (existing is null) return null;
+
+        await uow.BeginAsync(ct);
+        try { repo.RemoveBundleComponent(existing); await uow.CommitAsync(ct); }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        return (await GetByIdAsync(schemeId))!;
+    }
+
+    // ── evaluateSchemeEligibility(storeId, orderId) ──────────────────────────
+
+    public async Task<List<SchemeEligibilityResponse>?> EvaluateEligibilityAsync(Guid storeId, Guid orderId)
+    {
+        var store = await storeRepo.GetByIdWithRegionAsync(storeId);
+        if (store is null || !store.IsActive) return null;
+
+        var order = await orderRepo.GetByIdAsync(orderId);
+        if (order is null || !order.IsActive) return null;
+
+        var orderItems = await orderRepo.GetItemsByOrderIdAsync(orderId);
+        var regionId = store.Route?.FK_RegionId;
+
+        var candidates = await repo.GetAllAsync();
+        var result = new List<SchemeEligibilityResponse>();
+
+        foreach (var scheme in candidates)
+        {
+            if (scheme.FK_RegionId.HasValue && scheme.FK_RegionId != regionId)
+                continue;
+            if (!string.IsNullOrEmpty(scheme.EligibleSegment) &&
+                !string.Equals(scheme.EligibleSegment, store.Segment, StringComparison.OrdinalIgnoreCase))
+                continue;
+            if (order.OrderDate < scheme.DateRangeFrom || order.OrderDate > scheme.DateRangeTo)
+                continue;
+
+            result.Add(EvaluateRule(scheme, orderItems));
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Scope-only check (region, segment, date range as of today) with no order to evaluate line
+    /// items against — used by Store Management's `checkStoreSchemeEligibility(storeId, schemeId)`
+    /// (12_store_management.md), which has no order context. Returns null if the store or scheme
+    /// doesn't exist; otherwise (Eligible, Reason) — Eligible here means "in scope for this store",
+    /// not "this order's items satisfy the rule" (use EvaluateEligibilityAsync for that).
+    /// </summary>
+    public async Task<(bool Eligible, string? Reason)?> CheckStoreScopeEligibilityAsync(Guid storeId, Guid schemeId)
+    {
+        var store = await storeRepo.GetByIdWithRegionAsync(storeId);
+        if (store is null || !store.IsActive) return null;
+
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        var regionId = store.Route?.FK_RegionId;
+        if (scheme.FK_RegionId.HasValue && scheme.FK_RegionId != regionId)
+            return (false, "Scheme is not available in the store's region.");
+
+        if (!string.IsNullOrEmpty(scheme.EligibleSegment) &&
+            !string.Equals(scheme.EligibleSegment, store.Segment, StringComparison.OrdinalIgnoreCase))
+            return (false, $"Scheme is only available to the '{scheme.EligibleSegment}' segment.");
+
+        var today = DateTime.Now;
+        if (today < scheme.DateRangeFrom || today > scheme.DateRangeTo)
+            return (false, "Scheme is not currently active (outside its date range).");
+
+        return (true, null);
+    }
+
+    private static SchemeEligibilityResponse EvaluateRule(Models.Scheme scheme, List<OrderItem> orderItems)
+    {
+        switch (scheme.RuleType)
+        {
+            case SchemeRuleType.BuyXGetY:
+            {
+                if (scheme.FK_TriggerItemId is null || scheme.TriggerQty is null or <= 0 ||
+                    scheme.FK_FreeItemId is null || scheme.FreeQty is null or <= 0)
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false,
+                        "Scheme has no free-goods rule configured.", null, null, null);
+
+                var boughtQty = orderItems.Where(i => i.FK_ItemId == scheme.FK_TriggerItemId).Sum(i => i.Quantity);
+                if (boughtQty < scheme.TriggerQty)
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false,
+                        $"Requires {scheme.TriggerQty} of the trigger item; order has {boughtQty}.", null, null, null);
+
+                var multiplier = boughtQty / scheme.TriggerQty.Value;
+                return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, true, null,
+                    null, scheme.FK_FreeItemId, scheme.FreeQty * multiplier);
+            }
+            case SchemeRuleType.FreeBundle:
+            {
+                if (scheme.BundleComponents.Count == 0 || scheme.FK_FreeItemId is null || scheme.FreeQty is null or <= 0)
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false,
+                        "Scheme has no bundle components or free-goods payout configured.", null, null, null);
+
+                var missing = scheme.BundleComponents
+                    .Where(c => orderItems.Where(i => i.FK_ItemId == c.FK_ItemId).Sum(i => i.Quantity) < c.Qty)
+                    .ToList();
+                if (missing.Count > 0)
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false,
+                        "Order is missing required bundle components.", null, null, null);
+
+                return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, true, null,
+                    null, scheme.FK_FreeItemId, scheme.FreeQty);
+            }
+            case SchemeRuleType.FlatPercent:
+            {
+                if (string.IsNullOrEmpty(scheme.RuleConfig))
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false, "Scheme has no RuleConfig.", null, null, null);
+                var cfg = JsonSerializer.Deserialize<FlatPercentConfig>(scheme.RuleConfig, JsonOptions)!;
+                var orderTotal = orderItems.Sum(i => i.Quantity * i.UnitPrice);
+                return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, true, null,
+                    Math.Round(orderTotal * cfg.DiscountPercent / 100m, 2), null, null);
+            }
+            case SchemeRuleType.SlabDiscount:
+            {
+                if (string.IsNullOrEmpty(scheme.RuleConfig))
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false, "Scheme has no RuleConfig.", null, null, null);
+                var cfg = JsonSerializer.Deserialize<SlabDiscountConfig>(scheme.RuleConfig, JsonOptions)!;
+                var orderTotal = orderItems.Sum(i => i.Quantity * i.UnitPrice);
+                var tier = cfg.Tiers.Where(t => orderTotal >= t.MinOrderAmount)
+                    .OrderByDescending(t => t.MinOrderAmount).FirstOrDefault();
+                if (tier is null)
+                    return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false,
+                        "Order total does not meet any slab threshold.", null, null, null);
+
+                return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, true, null,
+                    Math.Round(orderTotal * tier.DiscountPercent / 100m, 2), null, null);
+            }
+            default:
+                return new SchemeEligibilityResponse(scheme.Id, scheme.Name, scheme.RuleType, false, "Unknown rule type.", null, null, null);
+        }
+    }
+
+    // ── applySchemeDiscount(orderId, schemeId) ───────────────────────────────
+
+    public async Task<SchemeRedemptionResponse?> ApplySchemeAsync(Guid orderId, Guid schemeId, CancellationToken ct = default)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null || !scheme.IsActive) return null;
+
+        var order = await orderRepo.GetByIdAsync(orderId);
+        if (order is null || !order.IsActive) return null;
+
+        if (await repo.HasRedemptionAsync(schemeId, orderId))
+            throw new InvalidOperationException("This scheme has already been redeemed against this order.");
+
+        var orderItems = await orderRepo.GetItemsByOrderIdAsync(orderId);
+        var eligibility = EvaluateRule(scheme, orderItems);
+        if (!eligibility.Eligible)
+            throw new InvalidOperationException(eligibility.Reason ?? "Order is not eligible for this scheme.");
+
+        var redemption = new SchemeRedemption
+        {
+            FK_SchemeId = schemeId,
+            FK_OrderId = orderId,
+            DiscountAmount = eligibility.DiscountAmount
+        };
+
+        var newOrderItems = new List<OrderItem>();
+
+        if (eligibility.FreeItemId.HasValue && eligibility.FreeQty is > 0)
+        {
+            var freeItem = await itemRepo.GetByIdAsync(eligibility.FreeItemId.Value)
+                ?? throw new InvalidOperationException("Free item not found.");
+
+            var availableQty = (await stockRepo.GetBalancesByItemAsync(freeItem.Id)).Sum(b => b.Quantity);
+            if (availableQty < eligibility.FreeQty.Value)
+                throw new InvalidOperationException($"Insufficient stock of '{freeItem.Sku}' to fulfil the free-goods scheme.");
+
+            newOrderItems.Add(new OrderItem
+            {
+                FK_OrderId = orderId,
+                FK_ItemId = freeItem.Id,
+                Quantity = (int)eligibility.FreeQty.Value,
+                UnitPrice = 0m
+            });
+
+            redemption.FK_FreeItemId = freeItem.Id;
+            redemption.FreeQty = eligibility.FreeQty;
+            redemption.FreeItemCostValue = freeItem.CostPrice ?? 0m;
+        }
+
+        await uow.BeginAsync(ct);
+        try
+        {
+            if (newOrderItems.Count > 0) await orderRepo.AddItemsAsync(newOrderItems);
+            await repo.AddRedemptionAsync(redemption);
+            await uow.CommitAsync(ct);
+        }
+        catch { await uow.RollbackAsync(ct); throw; }
+
+        var reloaded = (await repo.GetRedemptionsAsync(schemeId)).First(r => r.Id == redemption.Id);
+        return ToRedemptionResponse(reloaded);
+    }
+
+    // ── trackSchemeSpend(schemeId) ───────────────────────────────────────────
+
+    public async Task<SchemeSpendResponse?> GetSpendAsync(Guid schemeId)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null) return null;
+
+        var redemptions = await repo.GetRedemptionsAsync(schemeId);
+        var discountSpend = redemptions.Sum(r => r.DiscountAmount ?? 0m);
+        var freeGoodsSpend = redemptions.Sum(r => (r.FreeItemCostValue ?? 0m) * (r.FreeQty ?? 0m));
+
+        return new SchemeSpendResponse(schemeId, discountSpend, freeGoodsSpend, discountSpend + freeGoodsSpend, redemptions.Count);
+    }
+
+    // ── getSchemeROI(schemeId) ───────────────────────────────────────────────
+
+    public async Task<SchemeROIResponse?> GetROIAsync(Guid schemeId)
+    {
+        var scheme = await repo.GetByIdAsync(schemeId);
+        if (scheme is null) return null;
+
+        var redemptions = await repo.GetRedemptionsAsync(schemeId);
+        var spend = await GetSpendAsync(schemeId);
+
+        var actualSales = redemptions
+            .Where(r => r.Order is not null)
+            .Select(r => r.Order!)
+            .Distinct()
+            .Sum(o => o.TotalAmount);
+
+        var baseline = scheme.BaselineExpectedSales ?? 0m;
+        var incremental = actualSales - baseline;
+        decimal? roi = spend!.TotalSpend > 0 ? incremental / spend.TotalSpend : null;
+
+        return new SchemeROIResponse(schemeId, baseline, actualSales, incremental, spend.TotalSpend, roi);
+    }
+
+    private async Task ValidateFreeGoodsRuleAsync(SchemeRuleType ruleType, Guid? triggerItemId, int? triggerQty, Guid? freeItemId, decimal? freeQty)
+    {
+        if (ruleType is not (SchemeRuleType.BuyXGetY or SchemeRuleType.FreeBundle))
+            throw new InvalidOperationException($"Free-goods rule only applies to BuyXGetY or FreeBundle schemes, not '{ruleType}'.");
+
+        if (ruleType == SchemeRuleType.BuyXGetY)
+        {
+            if (triggerItemId is null || triggerQty is null or <= 0)
+                throw new InvalidOperationException("BuyXGetY requires TriggerItemId and a positive TriggerQty.");
+            if (await itemRepo.GetByIdAsync(triggerItemId.Value) is null)
+                throw new InvalidOperationException("Trigger item not found.");
+        }
+
+        if (freeItemId is null || freeQty is null or <= 0)
+            throw new InvalidOperationException("FreeItemId and a positive FreeQty are required.");
+        if (await itemRepo.GetByIdAsync(freeItemId.Value) is null)
+            throw new InvalidOperationException("Free item not found.");
+    }
+
+    private static void ValidatePercentRuleConfig(SchemeRuleType ruleType, string? ruleConfig)
+    {
+        if (ruleType is not (SchemeRuleType.SlabDiscount or SchemeRuleType.FlatPercent)) return;
+
+        if (string.IsNullOrWhiteSpace(ruleConfig))
+            throw new InvalidOperationException($"RuleConfig is required for RuleType '{ruleType}'.");
+
+        try
+        {
+            if (ruleType == SchemeRuleType.SlabDiscount)
+            {
+                var slab = JsonSerializer.Deserialize<SlabDiscountConfig>(ruleConfig, JsonOptions) ?? throw new JsonException();
+                if (slab.Tiers.Count == 0)
+                    throw new InvalidOperationException("SlabDiscount scheme requires at least one tier.");
+            }
+            else
+            {
+                _ = JsonSerializer.Deserialize<FlatPercentConfig>(ruleConfig, JsonOptions) ?? throw new JsonException();
+            }
+        }
+        catch (JsonException)
+        {
+            throw new InvalidOperationException($"RuleConfig is not valid JSON for RuleType '{ruleType}'.");
+        }
+    }
+}

Distribution/Program.cs

@@ -12,6 +12,7 @@ using Distribution.Features.Region;
 using Distribution.Features.Ride;
 using Distribution.Features.Role;
 using Distribution.Features.Route;
+using Distribution.Features.Scheme;
 using Distribution.Features.Store;
 using Distribution.Features.Store.Kyc;
 using Distribution.Features.Supplier;
@@ -59,6 +60,7 @@ builder.Services.AddScoped<IRideCancelRequestRepository, RideCancelRequestReposi
 builder.Services.AddScoped<IStoreKycDocumentRepository, StoreKycDocumentRepository>();
 builder.Services.AddScoped<IPriceListRepository, PriceListRepository>();
 builder.Services.AddScoped<ISupplierRepository, SupplierRepository>();
+builder.Services.AddScoped<ISchemeRepository, SchemeRepository>();
 
 builder.Services.AddScoped<RegionService>();
 builder.Services.AddScoped<RouteService>();
@@ -81,6 +83,7 @@ builder.Services.AddScoped<SupplierService>();
 builder.Services.AddScoped<DriverProfileService>();
 builder.Services.AddScoped<DriverComplianceConfigService>();
 builder.Services.AddScoped<RideService>();
+builder.Services.AddScoped<SchemeService>();
 
 builder.Services.AddHttpContextAccessor();
 builder.Services.AddScoped<ICurrentUserService, CurrentUserService>();