Kol

chaincode/src/contracts/fabric-student-storage.js

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+
+'use strict';
+
+const { Contract } = require('fabric-contract-api');
+const { ClientIdentity } = require('fabric-shim');
+
+class FabricStudentStorage extends Contract {
+    constructor() {
+        super('org.fabric.keyvaluestorage');
+    }
+
+    async createStudentRec(data, studentEmail, fullName) {
+        const id = new ClientIdentity(data.stub);
+        if (id.cert.subject.orgUnitName !== 'admin') {
+            throw new Error("Access error");
+        }
+        const recordAsBytes = await data.stub.getState(studentEmail);
+
+        if (recordAsBytes && recordAsBytes.toString().length !== 0) {
+            throw new Error("User already exists");
+        }
+
+        const record = {
+            fullName: fullName,
+            semesters: []
+        }
+        const newRecordInBytes = Buffer.from(JSON.stringify(record));
+        await data.stub.putState(studentEmail, newRecordInBytes);
+        return JSON.stringify(record, null, 4);
+    }
+
+    async getRecords(data, email) {
+        const identity = new ClientIdentity(data.stub);
+        if (identity.cert.subject.orgUnitName !== 'admin') {
+            throw new Error("Access error");
+        }
+        const record = await data.stub.getState(email);
+        if (!record || record.toString().length === 0) {
+            throw new Error("No user with this email");
+        }
+        return JSON.parse(record.toString());
+    }
+
+    async updateRecords(data, email, record) {
+        const recordBytes = Buffer.from(JSON.stringify(record));
+        await data.stub.putState(email, recordBytes);
+    }
+
+    async addSubject(data, studentEmail, semester, subject) {
+        const record = await getStudentRecord(data, studentEmail);
+        const teacherEmail = identity.cert.subject.commonName;
+        if (!record.semesters[semester]) {
+            record.semesters[semester] = {};
+        }
+        record.semesters[semester][subject] = {
+            lector: teacherEmail,
+            themes: []
+        }
+        await updateStudentRecord(data, studentEmail, record);
+        return JSON.stringify(record, null, 4);
+    }
+
+    async createGrade(data, studentEmail, semester, subject, theme, grade) {
+        const record = await getStudentRecord(data, studentEmail);
+        if (!record.semesters[semester]?.[subject]) {
+            throw new Error("This subject is absent in the specified semester");
+        }
+        record.semesters[semester][subject].themes.push([
+            {
+                title: theme,
+                rating: grade,
+                date: Date.now()
+            }
+        ]);
+        await updateStudentRecord(data, studentEmail, record);
+        return JSON.stringify(record, null, 4);
+    }
+
+    async getAllGrades(data, studentEmail) {
+        const record = await getStudentRecord(data, studentEmail);
+        return JSON.stringify(record.semesters, null, 4);
+    }
+
+    async getStudentGradesBySemester(data, studentEmail, semester) {
+        const record = await getStudentRecord(data, studentEmail);
+        return JSON.stringify(record.semesters[semester] || [], null, 4);
+    }
+}
+
+module.exports = FabricStudentStorage;