Smart Contact Access Control

[Aditya8369]

Completed: Verify fixes with error check (7/7)

No errors. Here's a summary of all four fixes applied to CropChain.sol:

---

Fix 1 — transferOwnership: revoke/grant DEFAULT_ADMIN_ROLE atomically

Before: Transferred the owner variable but left DEFAULT_ADMIN_ROLE held by the previous owner forever, giving them permanent backdoor access to grantStakeholderRole, transferOwnership, etc.
After: _revokeRole(DEFAULT_ADMIN_ROLE, previousOwner) + _grantRole(DEFAULT_ADMIN_ROLE, newOwner) are called atomically. The previous owner's legacy roles[] entry is also cleared to None.

---

Fix 2 — setRole: keep OZ AccessControl in sync with the legacy roles[] map

Before: Setting roles[user] = ActorRole.Farmer had no effect on FARMER_ROLE in OZ AccessControl, so the user would fail createBatch (onlyRole(FARMER_ROLE)) and all _canUpdateStage checks.
After: Old OZ role is revoked and the new one is granted atomically. Also guards against assigning ActorRole.Admin through this function (must go through transferOwnership), and protects the owner's own role.

---

Fix 3 — cancelListing: replace stale owner reference with hasRole(DEFAULT_ADMIN_ROLE, ...)

Before: msg.sender == owner — after ownership transfer the old privileged account (who kept DEFAULT_ADMIN_ROLE) could no longer cancel listings; the new owner could.
After: hasRole(DEFAULT_ADMIN_ROLE, msg.sender) — consistent with the rest of the admin-guard pattern and always reflects who is actually privileged.

---

Fix 4 — grantStakeholderRole: sync legacy roles[] mapping when granting OZ roles

Before: A user granted MANDI_ROLE via this function would pass onlyRole(MANDI_ROLE) and _canUpdateStage, but would fail onlyAuthorized (legacy map check) and the createListing Mandi check.
After: The legacy roles[] entry is set alongside _grantRole, and RoleUpdated is emitted for full observability.

closes #180

[netlify]

❌ Deploy Preview for roaring-ganache-c7465f failed. Why did it fail? →

Name	Link
🔨 Latest commit	a82bf56
🔍 Latest deploy log	https://app.netlify.com/projects/roaring-ganache-c7465f/deploys/69ad66d3ae675a0008d37358

[Copilot]

Pull request overview

This PR combines (a) smart-contract access control hardening in CropChain.sol (role/owner synchronization) with (b) an end-to-end “Smart Planting” crop recommendation feature spanning a new Python ML microservice, a new backend API route, and a new frontend page + navigation.

Changes:

• Harden CropChain.sol ownership/role transitions by syncing legacy roles[] with OZ AccessControl and updating admin checks.
• Add a Python Flask ML microservice (training + /predict + Dockerization) and wire it into the Node backend via /api/recommend.
• Add a new React page + service for crop recommendations and link it into the app route/header.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 15 comments.

Show a summary per file

File	Description
contracts/CropChain.sol	Sync legacy roles[] mapping with OZ AccessControl in setRole / transferOwnership; admin check update in cancelListing; legacy sync in grantStakeholderRole.
backend/server.js	Adds POST /api/recommend endpoint (validated + rate-limited) that calls the ML microservice.
backend/services/cropRecommendationService.js	Adds an axios client for calling the ML microservice (/predict, /health).
backend/validations/cropRecommendationSchema.js	Adds Joi validation for recommendation inputs.
ml-service/app.py	New Flask API exposing /health and /predict and loading/training the model.
ml-service/train.py	New training script to generate synthetic data and persist model.joblib.
ml-service/requirements.txt	Python dependencies for the microservice.
ml-service/Dockerfile	Containerizes the ML service and pre-trains the model at build time.
docker-compose.yml	Adds the ml-service container and wires backend env/dependencies.
src/services/cropRecommendationService.ts	Frontend fetch wrapper for POST /api/recommend.
src/pages/CropRecommendation.tsx	New UI page for input sliders and displaying recommendation results.
src/components/Header.tsx	Adds nav link to the new crop recommendation page.
src/App.tsx	Adds route for /crop-recommendation.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Aditya8369]

@vedhapprakashni solved the suggestions arised

[Nitya-003]

@Aditya8369 Resolve the conflicts please.

[Aditya8369]

@Nitya-003 resolved