[CLAUDE] App+Api: 7 Details CRUD endpoints + Changelogs query

## DTOs (Application/Contracts/Dtos/ContractDetailDtos.cs) - 7 typed DTOs (ThauPhuDetailDto, GiaoKhoanDetailDto, NhaCungCapDetailDto, DichVuDetailDto, MuaBanDetailDto, NguyenTacNccDetailDto, NguyenTacDvDetailDto) — schema 1-1 với Domain entities - ContractDetailsBundleDto — wrapper trả về theo Type, chỉ 1 list có data (FE đọc field tương ứng, tránh polymorphic deserialize phức tạp) - ContractChangelogDto — full audit entry ## CQRS (Application/Contracts/ContractDetailsFeatures.cs) - GetContractDetailsQuery — load bundle, switch theo Contract.Type chỉ query bảng tương ứng (avoid 7 query waste) - 7 AddXxxDetailCommand handlers — typed payload + EnsureContractType guard (throw ConflictException nếu Contract.Type sai) - DeleteContractDetailCommand generic — dispatch xóa theo Type, log change - Tất cả handler call IChangelogService.LogDetailChangeAsync với summary human-readable (vd "Thêm hạng mục: Đào móng") ## CQRS (Application/Contracts/ContractChangelogFeatures.cs) - ListContractChangelogsQuery (read-only) — desc CreatedAt, default top 200 ## Controller (Api/Controllers/ContractsController.cs) 8 endpoints mới: - GET /api/contracts/{id}/details → bundle theo Type - POST /api/contracts/{id}/details/{thau-phu|giao-khoan|nha-cung-cap| dich-vu|mua-ban|nguyen-tac-ncc|nguyen-tac-dv} → 7 typed POST - DELETE /api/contracts/{id}/details/{detailId} → generic delete - GET /api/contracts/{id}/changelogs → list audit entries Build: dotnet pass (0 error) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-23 10:16:18 +07:00
parent 71c035d31e
commit e6844553a4
4 changed files with 485 additions and 0 deletions
--- a/src/Backend/SolutionErp.Api/Controllers/ContractsController.cs
+++ b/src/Backend/SolutionErp.Api/Controllers/ContractsController.cs
@ -101,6 +101,74 @@ public class ContractsController(IMediator mediator) : ControllerBase
        await mediator.Send(new DeleteContractAttachmentCommand(id, attId), ct);
        return NoContent();
    }
+
+    // ========== Details (per ContractType) ==========
+
+    [HttpGet("{id:guid}/details")]
+    public async Task<ContractDetailsBundleDto> GetDetails(Guid id, CancellationToken ct)
+        => await mediator.Send(new GetContractDetailsQuery(id), ct);
+
+    [HttpPost("{id:guid}/details/thau-phu")]
+    public async Task<IActionResult> AddThauPhuDetail(Guid id, [FromBody] ThauPhuDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddThauPhuDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/giao-khoan")]
+    public async Task<IActionResult> AddGiaoKhoanDetail(Guid id, [FromBody] GiaoKhoanDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddGiaoKhoanDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/nha-cung-cap")]
+    public async Task<IActionResult> AddNhaCungCapDetail(Guid id, [FromBody] NhaCungCapDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddNhaCungCapDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/dich-vu")]
+    public async Task<IActionResult> AddDichVuDetail(Guid id, [FromBody] DichVuDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddDichVuDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/mua-ban")]
+    public async Task<IActionResult> AddMuaBanDetail(Guid id, [FromBody] MuaBanDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddMuaBanDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/nguyen-tac-ncc")]
+    public async Task<IActionResult> AddNguyenTacNccDetail(Guid id, [FromBody] NguyenTacNccDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddNguyenTacNccDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpPost("{id:guid}/details/nguyen-tac-dv")]
+    public async Task<IActionResult> AddNguyenTacDvDetail(Guid id, [FromBody] NguyenTacDvDetailDto body, CancellationToken ct)
+    {
+        var newId = await mediator.Send(new AddNguyenTacDvDetailCommand(id, body), ct);
+        return CreatedAtAction(nameof(GetDetails), new { id }, new { id = newId });
+    }
+
+    [HttpDelete("{id:guid}/details/{detailId:guid}")]
+    public async Task<IActionResult> DeleteDetail(Guid id, Guid detailId, CancellationToken ct)
+    {
+        await mediator.Send(new DeleteContractDetailCommand(id, detailId), ct);
+        return NoContent();
+    }
+
+    // ========== Changelogs (read-only) ==========
+
+    [HttpGet("{id:guid}/changelogs")]
+    public async Task<List<ContractChangelogDto>> GetChangelogs(Guid id, CancellationToken ct)
+        => await mediator.Send(new ListContractChangelogsQuery(id), ct);
 }

 public record TransitionContractBody(ContractPhase TargetPhase, ApprovalDecision Decision, string? Comment);
--- a/src/Backend/SolutionErp.Application/Contracts/ContractChangelogFeatures.cs
+++ b/src/Backend/SolutionErp.Application/Contracts/ContractChangelogFeatures.cs
@ -0,0 +1,26 @@
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Application.Contracts.Dtos;
+
+namespace SolutionErp.Application.Contracts;
+
+// Read-only query — list changelog của 1 HĐ ordered descending CreatedAt
+// (mới nhất trên cùng). Append-only table → không có Update/Delete handler.
+public record ListContractChangelogsQuery(Guid ContractId, int Take = 200) : IRequest<List<ContractChangelogDto>>;
+
+public class ListContractChangelogsQueryHandler(IApplicationDbContext db) : IRequestHandler<ListContractChangelogsQuery, List<ContractChangelogDto>>
+{
+    public async Task<List<ContractChangelogDto>> Handle(ListContractChangelogsQuery request, CancellationToken ct)
+    {
+        return await db.ContractChangelogs.AsNoTracking()
+            .Where(c => c.ContractId == request.ContractId)
+            .OrderByDescending(c => c.CreatedAt)
+            .Take(request.Take)
+            .Select(c => new ContractChangelogDto(
+                c.Id, c.EntityType, c.EntityId, c.Action, c.PhaseAtChange,
+                c.UserId, c.UserName, c.Summary, c.FieldChangesJson, c.ContextNote,
+                c.CreatedAt))
+            .ToListAsync(ct);
+    }
+}
--- a/src/Backend/SolutionErp.Application/Contracts/ContractDetailsFeatures.cs
+++ b/src/Backend/SolutionErp.Application/Contracts/ContractDetailsFeatures.cs
@ -0,0 +1,344 @@
+using FluentValidation;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using SolutionErp.Application.Common.Exceptions;
+using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Application.Contracts.Dtos;
+using SolutionErp.Domain.Contracts;
+using SolutionErp.Domain.Contracts.Details;
+using static SolutionErp.Application.Contracts.ContractDetailsHelpers;
+
+namespace SolutionErp.Application.Contracts;
+
+// 7 ContractType-specific Details CRUD — pattern lặp nhưng schema khác nhau,
+// keep các handler riêng để TS strict mode FE bắt typo + IntelliSense.
+//
+// Endpoint: GET /api/contracts/{id}/details (bundle bộ + auto theo Type)
+//           POST /api/contracts/{id}/details (body có Type discriminator)
+//           PUT /api/contracts/{id}/details/{detailId}
+//           DELETE /api/contracts/{id}/details/{detailId}
+//
+// Helper: handler resolve loại HĐ qua Contract.Type rồi dispatch vào DbSet
+// tương ứng. Validate detail thuộc đúng contract+type.
+
+// ========== GET bundle (Read) ==========
+
+public record GetContractDetailsQuery(Guid ContractId) : IRequest<ContractDetailsBundleDto>;
+
+public class GetContractDetailsQueryHandler(IApplicationDbContext db) : IRequestHandler<GetContractDetailsQuery, ContractDetailsBundleDto>
+{
+    public async Task<ContractDetailsBundleDto> Handle(GetContractDetailsQuery request, CancellationToken ct)
+    {
+        var contract = await db.Contracts.AsNoTracking().FirstOrDefaultAsync(c => c.Id == request.ContractId, ct)
+            ?? throw new NotFoundException("Contract", request.ContractId);
+
+        // Chỉ load list tương ứng với Type — 6 còn lại empty (avoid 7 query waste)
+        var bundle = new ContractDetailsBundleDto(
+            contract.Type,
+            ThauPhu: new(), GiaoKhoan: new(), NhaCungCap: new(), DichVu: new(),
+            MuaBan: new(), NguyenTacNcc: new(), NguyenTacDv: new());
+
+        switch (contract.Type)
+        {
+            case ContractType.HopDongThauPhu:
+                bundle = bundle with
+                {
+                    ThauPhu = await db.ThauPhuDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new ThauPhuDetailDto(d.Id, d.Order, d.HangMuc, d.DonViTinh, d.KhoiLuong, d.DonGia, d.ThanhTien, d.ThoiGianHoanThanh, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongGiaoKhoan:
+                bundle = bundle with
+                {
+                    GiaoKhoan = await db.GiaoKhoanDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new GiaoKhoanDetailDto(d.Id, d.Order, d.MaCongViec, d.TenCongViec, d.DonViTinh, d.KhoiLuong, d.DonGia, d.ThanhTien, d.ThoiGianHoanThanh, d.YeuCauKyThuat, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongNhaCungCap:
+                bundle = bundle with
+                {
+                    NhaCungCap = await db.NhaCungCapDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new NhaCungCapDetailDto(d.Id, d.Order, d.MaSP, d.TenSP, d.ThongSoKyThuat, d.DonViTinh, d.SoLuong, d.DonGia, d.ThanhTien, d.ThoiGianGiao, d.XuatXu, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongDichVu:
+                bundle = bundle with
+                {
+                    DichVu = await db.DichVuDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new DichVuDetailDto(d.Id, d.Order, d.MaDichVu, d.TenDichVu, d.MoTa, d.DonViTinh, d.ThoiGian, d.DonGia, d.ThanhTien, d.TuNgay, d.DenNgay, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongMuaBan:
+                bundle = bundle with
+                {
+                    MuaBan = await db.MuaBanDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new MuaBanDetailDto(d.Id, d.Order, d.MaSP, d.TenSP, d.MoTa, d.DonViTinh, d.SoLuong, d.DonGia, d.ThueVAT, d.ThanhTien, d.XuatXu, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongNguyenTacNCC:
+                bundle = bundle with
+                {
+                    NguyenTacNcc = await db.NguyenTacNccDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new NguyenTacNccDetailDto(d.Id, d.Order, d.NhomSP, d.TenSP, d.DonViTinh, d.DonGiaToiThieu, d.DonGiaToiDa, d.DieuKienGiaoHang, d.DieuKienThanhToan, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+
+            case ContractType.HopDongNguyenTacDichVu:
+                bundle = bundle with
+                {
+                    NguyenTacDv = await db.NguyenTacDvDetails.AsNoTracking()
+                        .Where(d => d.ContractId == request.ContractId)
+                        .OrderBy(d => d.Order)
+                        .Select(d => new NguyenTacDvDetailDto(d.Id, d.Order, d.LoaiDichVu, d.TenDichVu, d.DonViTinh, d.DonGiaToiThieu, d.DonGiaToiDa, d.PhamViDichVu, d.SLA, d.GhiChu))
+                        .ToListAsync(ct),
+                };
+                break;
+        }
+        return bundle;
+    }
+}
+
+// ========== ADD detail (per type) ==========
+
+// Polymorphic input: client gửi Type discriminator + 1 trong 7 typed payload.
+// Strategy: 7 commands riêng — explicit, dễ validate. Controller pick handler
+// theo URL path /thau-phu /giao-khoan /etc, hoặc body Type field (chọn URL —
+// REST hơn).
+
+public record AddThauPhuDetailCommand(Guid ContractId, ThauPhuDetailDto Detail) : IRequest<Guid>;
+public class AddThauPhuDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddThauPhuDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddThauPhuDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongThauPhu, ct);
+        var d = cmd.Detail;
+        var entity = new ThauPhuDetail
+        {
+            ContractId = contract.Id, Order = d.Order, HangMuc = d.HangMuc, DonViTinh = d.DonViTinh,
+            KhoiLuong = d.KhoiLuong, DonGia = d.DonGia, ThanhTien = d.ThanhTien,
+            ThoiGianHoanThanh = d.ThoiGianHoanThanh, GhiChu = d.GhiChu,
+        };
+        db.ThauPhuDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm hạng mục: {d.HangMuc}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddGiaoKhoanDetailCommand(Guid ContractId, GiaoKhoanDetailDto Detail) : IRequest<Guid>;
+public class AddGiaoKhoanDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddGiaoKhoanDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddGiaoKhoanDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongGiaoKhoan, ct);
+        var d = cmd.Detail;
+        var entity = new GiaoKhoanDetail
+        {
+            ContractId = contract.Id, Order = d.Order, MaCongViec = d.MaCongViec, TenCongViec = d.TenCongViec,
+            DonViTinh = d.DonViTinh, KhoiLuong = d.KhoiLuong, DonGia = d.DonGia, ThanhTien = d.ThanhTien,
+            ThoiGianHoanThanh = d.ThoiGianHoanThanh, YeuCauKyThuat = d.YeuCauKyThuat, GhiChu = d.GhiChu,
+        };
+        db.GiaoKhoanDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm công việc: {d.TenCongViec}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddNhaCungCapDetailCommand(Guid ContractId, NhaCungCapDetailDto Detail) : IRequest<Guid>;
+public class AddNhaCungCapDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddNhaCungCapDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddNhaCungCapDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongNhaCungCap, ct);
+        var d = cmd.Detail;
+        var entity = new NhaCungCapDetail
+        {
+            ContractId = contract.Id, Order = d.Order, MaSP = d.MaSP, TenSP = d.TenSP,
+            ThongSoKyThuat = d.ThongSoKyThuat, DonViTinh = d.DonViTinh, SoLuong = d.SoLuong,
+            DonGia = d.DonGia, ThanhTien = d.ThanhTien, ThoiGianGiao = d.ThoiGianGiao,
+            XuatXu = d.XuatXu, GhiChu = d.GhiChu,
+        };
+        db.NhaCungCapDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm sản phẩm: {d.TenSP}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddDichVuDetailCommand(Guid ContractId, DichVuDetailDto Detail) : IRequest<Guid>;
+public class AddDichVuDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddDichVuDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddDichVuDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongDichVu, ct);
+        var d = cmd.Detail;
+        var entity = new DichVuDetail
+        {
+            ContractId = contract.Id, Order = d.Order, MaDichVu = d.MaDichVu, TenDichVu = d.TenDichVu,
+            MoTa = d.MoTa, DonViTinh = d.DonViTinh, ThoiGian = d.ThoiGian, DonGia = d.DonGia,
+            ThanhTien = d.ThanhTien, TuNgay = d.TuNgay, DenNgay = d.DenNgay, GhiChu = d.GhiChu,
+        };
+        db.DichVuDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm dịch vụ: {d.TenDichVu}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddMuaBanDetailCommand(Guid ContractId, MuaBanDetailDto Detail) : IRequest<Guid>;
+public class AddMuaBanDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddMuaBanDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddMuaBanDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongMuaBan, ct);
+        var d = cmd.Detail;
+        var entity = new MuaBanDetail
+        {
+            ContractId = contract.Id, Order = d.Order, MaSP = d.MaSP, TenSP = d.TenSP,
+            MoTa = d.MoTa, DonViTinh = d.DonViTinh, SoLuong = d.SoLuong, DonGia = d.DonGia,
+            ThueVAT = d.ThueVAT, ThanhTien = d.ThanhTien, XuatXu = d.XuatXu, GhiChu = d.GhiChu,
+        };
+        db.MuaBanDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm SP: {d.TenSP}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddNguyenTacNccDetailCommand(Guid ContractId, NguyenTacNccDetailDto Detail) : IRequest<Guid>;
+public class AddNguyenTacNccDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddNguyenTacNccDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddNguyenTacNccDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongNguyenTacNCC, ct);
+        var d = cmd.Detail;
+        var entity = new NguyenTacNccDetail
+        {
+            ContractId = contract.Id, Order = d.Order, NhomSP = d.NhomSP, TenSP = d.TenSP,
+            DonViTinh = d.DonViTinh, DonGiaToiThieu = d.DonGiaToiThieu, DonGiaToiDa = d.DonGiaToiDa,
+            DieuKienGiaoHang = d.DieuKienGiaoHang, DieuKienThanhToan = d.DieuKienThanhToan, GhiChu = d.GhiChu,
+        };
+        db.NguyenTacNccDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm SP nguyên tắc: {d.TenSP}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record AddNguyenTacDvDetailCommand(Guid ContractId, NguyenTacDvDetailDto Detail) : IRequest<Guid>;
+public class AddNguyenTacDvDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<AddNguyenTacDvDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddNguyenTacDvDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await EnsureContractType(db, cmd.ContractId, ContractType.HopDongNguyenTacDichVu, ct);
+        var d = cmd.Detail;
+        var entity = new NguyenTacDvDetail
+        {
+            ContractId = contract.Id, Order = d.Order, LoaiDichVu = d.LoaiDichVu, TenDichVu = d.TenDichVu,
+            DonViTinh = d.DonViTinh, DonGiaToiThieu = d.DonGiaToiThieu, DonGiaToiDa = d.DonGiaToiDa,
+            PhamViDichVu = d.PhamViDichVu, SLA = d.SLA, GhiChu = d.GhiChu,
+        };
+        db.NguyenTacDvDetails.Add(entity);
+        await changelog.LogDetailChangeAsync(contract.Id, entity.Id, ChangelogAction.Insert,
+            summary: $"Thêm DV nguyên tắc: {d.TenDichVu}", phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+// ========== DELETE detail (generic — dispatch theo Type) ==========
+
+public record DeleteContractDetailCommand(Guid ContractId, Guid DetailId) : IRequest;
+
+public class DeleteContractDetailHandler(IApplicationDbContext db, IChangelogService changelog) : IRequestHandler<DeleteContractDetailCommand>
+{
+    public async Task Handle(DeleteContractDetailCommand cmd, CancellationToken ct)
+    {
+        var contract = await db.Contracts.AsNoTracking().FirstOrDefaultAsync(c => c.Id == cmd.ContractId, ct)
+            ?? throw new NotFoundException("Contract", cmd.ContractId);
+
+        // Dispatch xóa theo Type — tránh load tất cả 7 DbSet
+        bool removed = false;
+        string deletedSummary = "Xóa hạng mục";
+        switch (contract.Type)
+        {
+            case ContractType.HopDongThauPhu:
+                var t1 = await db.ThauPhuDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t1 != null) { db.ThauPhuDetails.Remove(t1); removed = true; deletedSummary = $"Xóa hạng mục: {t1.HangMuc}"; }
+                break;
+            case ContractType.HopDongGiaoKhoan:
+                var t2 = await db.GiaoKhoanDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t2 != null) { db.GiaoKhoanDetails.Remove(t2); removed = true; deletedSummary = $"Xóa công việc: {t2.TenCongViec}"; }
+                break;
+            case ContractType.HopDongNhaCungCap:
+                var t3 = await db.NhaCungCapDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t3 != null) { db.NhaCungCapDetails.Remove(t3); removed = true; deletedSummary = $"Xóa SP: {t3.TenSP}"; }
+                break;
+            case ContractType.HopDongDichVu:
+                var t4 = await db.DichVuDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t4 != null) { db.DichVuDetails.Remove(t4); removed = true; deletedSummary = $"Xóa DV: {t4.TenDichVu}"; }
+                break;
+            case ContractType.HopDongMuaBan:
+                var t5 = await db.MuaBanDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t5 != null) { db.MuaBanDetails.Remove(t5); removed = true; deletedSummary = $"Xóa SP: {t5.TenSP}"; }
+                break;
+            case ContractType.HopDongNguyenTacNCC:
+                var t6 = await db.NguyenTacNccDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t6 != null) { db.NguyenTacNccDetails.Remove(t6); removed = true; deletedSummary = $"Xóa SP nguyên tắc: {t6.TenSP}"; }
+                break;
+            case ContractType.HopDongNguyenTacDichVu:
+                var t7 = await db.NguyenTacDvDetails.FirstOrDefaultAsync(d => d.Id == cmd.DetailId && d.ContractId == cmd.ContractId, ct);
+                if (t7 != null) { db.NguyenTacDvDetails.Remove(t7); removed = true; deletedSummary = $"Xóa DV nguyên tắc: {t7.TenDichVu}"; }
+                break;
+        }
+        if (!removed) throw new NotFoundException("ContractDetail", cmd.DetailId);
+
+        await changelog.LogDetailChangeAsync(contract.Id, cmd.DetailId, ChangelogAction.Delete,
+            summary: deletedSummary, phaseAtChange: contract.Phase, ct: ct);
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+// ========== Helpers ==========
+
+internal static class ContractDetailsHelpers
+{
+    public static async Task<Contract> EnsureContractType(IApplicationDbContext db, Guid contractId, ContractType expectedType, CancellationToken ct)
+    {
+        var contract = await db.Contracts.AsNoTracking().FirstOrDefaultAsync(c => c.Id == contractId, ct)
+            ?? throw new NotFoundException("Contract", contractId);
+        if (contract.Type != expectedType)
+            throw new ConflictException($"HĐ này thuộc loại {contract.Type}, không thể thêm chi tiết loại {expectedType}.");
+        return contract;
+    }
+}
--- a/src/Backend/SolutionErp.Application/Contracts/Dtos/ContractDetailDtos.cs
+++ b/src/Backend/SolutionErp.Application/Contracts/Dtos/ContractDetailDtos.cs
@ -0,0 +1,47 @@
+using SolutionErp.Domain.Contracts;
+
+namespace SolutionErp.Application.Contracts.Dtos;
+
+// 7 typed DTOs cho 7 ContractType-specific Details bảng. Map 1-1 với entity
+// trong Domain/Contracts/Details/. Generic ContractDetailItem dùng cho
+// list-mixed view (vd Lịch sử changelog reference).
+
+public record ThauPhuDetailDto(Guid Id, int Order, string HangMuc, string DonViTinh, decimal KhoiLuong, decimal DonGia, decimal ThanhTien, DateTime? ThoiGianHoanThanh, string? GhiChu);
+
+public record GiaoKhoanDetailDto(Guid Id, int Order, string MaCongViec, string TenCongViec, string DonViTinh, decimal KhoiLuong, decimal DonGia, decimal ThanhTien, DateTime? ThoiGianHoanThanh, string? YeuCauKyThuat, string? GhiChu);
+
+public record NhaCungCapDetailDto(Guid Id, int Order, string MaSP, string TenSP, string? ThongSoKyThuat, string DonViTinh, decimal SoLuong, decimal DonGia, decimal ThanhTien, DateTime? ThoiGianGiao, string? XuatXu, string? GhiChu);
+
+public record DichVuDetailDto(Guid Id, int Order, string MaDichVu, string TenDichVu, string? MoTa, string DonViTinh, decimal ThoiGian, decimal DonGia, decimal ThanhTien, DateTime? TuNgay, DateTime? DenNgay, string? GhiChu);
+
+public record MuaBanDetailDto(Guid Id, int Order, string MaSP, string TenSP, string? MoTa, string DonViTinh, decimal SoLuong, decimal DonGia, decimal ThueVAT, decimal ThanhTien, string? XuatXu, string? GhiChu);
+
+public record NguyenTacNccDetailDto(Guid Id, int Order, string NhomSP, string TenSP, string DonViTinh, decimal DonGiaToiThieu, decimal DonGiaToiDa, string? DieuKienGiaoHang, string? DieuKienThanhToan, string? GhiChu);
+
+public record NguyenTacDvDetailDto(Guid Id, int Order, string LoaiDichVu, string TenDichVu, string DonViTinh, decimal DonGiaToiThieu, decimal DonGiaToiDa, string? PhamViDichVu, string? SLA, string? GhiChu);
+
+// Wrapper trả về theo Type — FE đọc field tương ứng (chỉ 1 list có data,
+// 6 list khác empty). Tránh dùng object/dynamic — TS strict mode.
+public record ContractDetailsBundleDto(
+    ContractType Type,
+    List<ThauPhuDetailDto> ThauPhu,
+    List<GiaoKhoanDetailDto> GiaoKhoan,
+    List<NhaCungCapDetailDto> NhaCungCap,
+    List<DichVuDetailDto> DichVu,
+    List<MuaBanDetailDto> MuaBan,
+    List<NguyenTacNccDetailDto> NguyenTacNcc,
+    List<NguyenTacDvDetailDto> NguyenTacDv);
+
+// Changelog DTO cho FE Lịch sử tab
+public record ContractChangelogDto(
+    Guid Id,
+    ChangelogEntityType EntityType,
+    Guid? EntityId,
+    ChangelogAction Action,
+    ContractPhase? PhaseAtChange,
+    Guid? UserId,
+    string? UserName,
+    string? Summary,
+    string? FieldChangesJson,
+    string? ContextNote,
+    DateTime CreatedAt);