nick-doc/04 - Flows/Dispute Flow.md

title, tags, related_models, related_apis

title	tags	related_models	related_apis
Dispute Flow	flow dispute mediator evidence chat state-machine	Dispute Chat PurchaseRequest Payment	POST /api/disputes POST /api/disputes/:id/assign POST /api/disputes/:id/resolve POST /api/disputes/:id/evidence PATCH /api/disputes/:id/status

Dispute Flow

When something goes wrong (item not delivered, wrong item, fraud), either party can open a dispute. A three-way chat (buyer, seller, admin mediator) is created automatically. After evidence is gathered, the admin resolves the dispute — releasing the escrow to the seller, refunding the buyer, splitting the funds, or rejecting the claim.

Actors

• Buyer — typical initiator.
• Seller — party against whom the dispute is raised (or in rarer cases, initiator).
• Admin / Mediator — assigned to investigate.
• Frontend — buyer/seller "Report issue" buttons in the request detail view; admin dispute dashboard.
• Backend — DisputeService (backend/src/services/dispute/DisputeService.ts), DisputeController (backend/src/controllers/disputeController.ts), routes at backend/src/routes/disputeRoutes.ts.
• MongoDB — disputes, chats, purchaserequests, payments.
• Socket.IO — new-notification, new-message, dispute-updated (planned).

Preconditions

• The related PurchaseRequest exists.
• The initiator is the request's buyer or the related seller.
• Funds are typically held in escrow (Payment.escrowState = 'funded') — disputes on unfunded orders are accepted but have no monetary impact.

Dispute state machine (Dispute.status)

stateDiagram-v2
    [*] --> pending: createDispute()\nresponseDeadline=+48h\ndeadline=+7d
    pending --> in_progress: admin assigned\nassignAdmin()
    in_progress --> resolved: admin resolves\naction ∈ {refund, partial, release, reject}
    in_progress --> closed: admin closes without resolution\n(e.g. duplicate/spam)
    pending --> closed: same
    resolved --> [*]
    closed --> [*]

Resolution actions (from Dispute.resolution.action enum, see Dispute.ts): refund, partial, release, reject (the wording differs slightly in the model — verify with backend/src/models/Dispute.ts).

Step-by-step narrative

Phase 1 — Opening

1. Buyer or seller opens the request detail and clicks "Report problem" (frontend/src/sections/request/components/report-problem-to-admin.tsx).
2. They select a category (delivery, payment, quality, fraud, other), a priority (low | medium | high | urgent), write a description, and optionally upload evidence (images, screenshots, video, document) via POST /api/files/upload.
3. Frontend POSTs POST /api/disputes with { purchaseRequestId, reason, description, priority, category, evidence: [...] }.
4. Backend DisputeService.createDispute (:12-119):
   • Loads the purchase request with populate('selectedOfferId').
   • Resolves the counter-party sellerId by priority: explicit data.sellerId → selectedOffer.sellerId → first of preferredSellerIds. This means once an offer is accepted, the dispute targets the actual seller, not the entire preferred list.
   • Creates the Dispute with status: 'pending', responseDeadline = now + 48h, deadline = now + 7 days, and an empty timeline[].
   • Creates a Chat of type group with the buyer and the resolved seller as participants. The opening message is a system-typed line "اختلاف جدید ایجاد شد: {reason}". The chat's relatedTo = { type: 'PurchaseRequest', id }.
   • Persists dispute.chatId = chat._id.
5. Notifications (currently a TODO in the service — :107-116) should fire new-notification to the seller. Today the chat creation alone provides real-time presence via the new-message socket emit inside Chat.create's lifecycle.

[!warning] Dispute does not auto-pause escrow Today, opening a dispute does not flip Payment.escrowState away from funded. An admin could theoretically still release the escrow before resolving the dispute. Until a disputed flag is added to Payment, admins must check the dispute table before any release/refund action.

Phase 2 — Admin assignment

6. The admin dispute dashboard lists pending disputes (sorted by priority: -1, createdAt: -1).
7. Admin clicks "Pick up" → POST /api/disputes/:id/assign with { adminId } (currently the admin's own id).
8. DisputeService.assignAdmin (:184-223):
   • dispute.adminId = adminId; dispute.status = 'in_progress'.
   • Appends timeline entry { action: 'admin_assigned', performedBy: adminId, ... }.
   • Adds the admin to the dispute chat.participants[] (role admin).
   • Saves.

Phase 3 — Investigation

9. All three parties chat in the dispute chat room (same socket mechanics as Chat Flow). Each party can upload more evidence via POST /api/disputes/:id/evidence — DisputeService.addEvidence (:305-337) appends to dispute.evidence[] and writes a timeline entry evidence_added.
10. The admin may also PATCH /api/disputes/:id/status with intermediate states or notes; this updates dispute.status and writes a timeline entry status_changed.

Phase 4 — Resolution

11. Once the admin has enough information, they call POST /api/disputes/:id/resolve with { action, amount?, currency?, notes? }.
12. DisputeService.resolveDispute (:262-300):
    • dispute.status = 'resolved'
    • dispute.resolution = { action, amount, currency, notes, resolvedBy: adminId, resolvedAt: now }
    • dispute.closedAt = now
    • Appends timeline entry dispute_resolved.
    • Saves.
13. Financial side-effect (manual today): depending on the action, the admin then triggers either the payout (Payout Flow with kind: 'release') or the refund (kind: 'refund', see Escrow Flow). The dispute service does not automatically dispatch the on-chain action.
14. Both parties are notified (TODOs in code — planned: notifyDisputeResolved).

Sequence diagram

sequenceDiagram
    autonumber
    actor B as Buyer
    actor S as Seller
    actor A as Admin
    participant FE as Frontend
    participant BE as Backend
    participant DB as MongoDB
    participant IO as Socket.IO

    B->>FE: "Report problem" on request
    B->>FE: Choose category, priority, evidence
    FE->>BE: POST /api/disputes
    BE->>DB: Dispute.create({status:"pending"})
    BE->>DB: Chat.create({type:"group", participants:[buyer, seller], system message})
    BE->>DB: dispute.chatId = chat._id
    BE-->>FE: { dispute }
    FE-->>B: chat opens (real-time via existing chat join)
    FE-->>S: chat opens (real-time via existing chat join)

    A->>FE: Admin dashboard, click "Pick up"
    FE->>BE: POST /api/disputes/{id}/assign
    BE->>DB: dispute.adminId, status="in_progress", timeline.push
    BE->>DB: chat.participants.push(admin)
    BE-->>FE: { dispute }

    loop investigation
        A->>FE: Chat with B & S
        B-->>BE: POST /api/disputes/{id}/evidence (image)
        BE->>DB: dispute.evidence.push, timeline.push
    end

    A->>FE: Click "Resolve" choose action
    FE->>BE: POST /api/disputes/{id}/resolve { action, amount, notes }
    BE->>DB: dispute.status="resolved", resolution={...}
    alt action="refund"
        A->>BE: trigger refund payout to buyer\n[[Escrow Flow]] / [[Payout Flow]]
    else action="release"
        A->>BE: trigger payout to seller\n[[Payout Flow]]
    else action="partial"
        A->>BE: split — refund X to buyer, release Y to seller
    end
    BE-->>FE: { dispute }
    IO-->>B: 'new-notification' dispute resolved (planned)
    IO-->>S: 'new-notification' dispute resolved (planned)

API calls

Method	Endpoint	Source
POST	/api/disputes	disputeRoutes.ts:12 → DisputeController.createDispute
GET	/api/disputes	disputeRoutes.ts:15 (filters: status, priority, category, adminId, buyer/seller)
GET	/api/disputes/statistics	disputeRoutes.ts:18
GET	/api/disputes/:id	disputeRoutes.ts:21
POST	/api/disputes/:id/assign	disputeRoutes.ts:24
PATCH	/api/disputes/:id/status	disputeRoutes.ts:27
POST	/api/disputes/:id/resolve	disputeRoutes.ts:30
POST	/api/disputes/:id/evidence	disputeRoutes.ts:33

All require authenticateToken (router-level middleware).

Database writes

• disputes — insert on open; updates adminId, status, timeline[], evidence[], resolution, closedAt over the lifecycle.
• chats — new group chat on open; admin appended to participants[] on assignment; messages appended throughout.
• purchaserequests — not directly mutated by the dispute service; the resolution side-effect (release/refund) updates the request via Escrow Flow.
• payments — touched indirectly when the admin performs the financial resolution.
• notifications — TODO markers in code; planned addition.

Socket events emitted

• new-message → chat-{disputeChatId} for each chat line (via the standard ChatService.sendMessage and the system message created in DisputeService.createDispute).
• new-notification (planned) → user-{buyerId} and user-{sellerId} on creation, assignment, evidence-added, resolution.

Side effects

• Three-way chat creation is the most visible side effect — pulls the buyer and seller into a controlled conversation room.
• Timeline append-only log is the audit trail. Surface it in the admin UI for compliance.
• Response deadline = 48h — used by reminders / SLA dashboards (no automated enforcement today). Past-deadline disputes could auto-escalate priority.
• Hard deadline = 7d — same intent: a watchdog could mark long-unresolved disputes for admin attention.

Error / edge cases

• Purchase request missing → 400 Purchase request not found.
• No seller identifiable (orphan request) → dispute still created but with sellerId: undefined; the chat becomes 2-party (buyer + admin only). Recommended: reject creation in this case to avoid mediator-less situations.
• Initiator is neither buyer nor seller → not enforced at service level — should be validated in DisputeController (recommended hardening).
• Same user opens multiple disputes for the same request → no uniqueness constraint today. Consider adding unique on (purchaseRequestId, status:'pending'|'in_progress') to prevent duplicates.
• Evidence URL is hot-linked → frontend uploads through POST /api/files/upload and the URL is served from /uploads. Ensure auth on the upload endpoint to prevent random users from polluting evidence.
• Dispute resolved without financial follow-up → the dispute is "resolved" in record only; the escrow stays in its previous state. Add automation that auto-fires the payout/refund when the admin selects release or refund.
• Admin resigns mid-dispute → no transfer-of-mediator endpoint today. Add POST /api/disputes/:id/reassign.

[!tip] Sort disputes by priority + age The query Dispute.find().sort({ priority: -1, createdAt: -1 }) already used in getDisputes ensures urgent ones bubble to the top. Make sure the admin dashboard uses this default sort.

Linked flows

• Chat Flow — message-level mechanics inside the dispute chat.
• Escrow Flow — the financial state being contested.
• Payout Flow — executed on release resolutions.
• Notification Flow — channels for dispute alerts.
• Delivery Confirmation Flow — disputes often arise from failed delivery.

Source files

• Backend: backend/src/services/dispute/DisputeService.ts
• Backend: backend/src/controllers/disputeController.ts
• Backend: backend/src/routes/disputeRoutes.ts
• Backend: backend/src/models/Dispute.ts
• Frontend: frontend/src/sections/request/components/report-problem-to-admin.tsx
• Frontend: admin dispute dashboard under frontend/src/sections/admin/ (subject to organisation)