Semi-Offline Synchronization Protocol (ANBK Standard)

1. Assessment Data Sync Sequence

The sync protocol coordinates periodic data transfer between local lab servers and the central portal: pulling encrypted question packages (Pull Data) and pushing student examination responses (Push Results).

mermaid

sequenceDiagram
    autonumber
    participant LabServer as School Lab CBT Server
    participant Portal as Intelektika Central Hub
    participant DB as MongoDB Database

    LabServer->>Portal: POST /api/v1/sync/verify-server { serverCode, npsn, token }
    Portal->>DB: Validate license status & server authorization
    Portal-->>LabServer: HTTP 200 OK (Handshake Successful)

    LabServer->>Portal: GET /api/v1/sync/pull-questions?serverCode=SRV-20201234-01
    Portal-->>LabServer: Encrypted Exam Package + SHA-256 Checksum

    Note over LabServer: Exam Administered Offline in School Lab

    LabServer->>Portal: POST /api/v1/sync/push-answers { serverCode, checksum, payload }
    Portal->>Portal: Verify Checksum SHA-256 of Response Payload
    Portal->>DB: Save Student Answers & Write SyncLog Audit Entry
    Portal-->>LabServer: HTTP 200 OK (Sync Receipt Issued)

2. Sync Action Domain Matrix (`SyncAction`)

Action Code	Enum (`SyncAction`)	Primary Purpose	Flow Direction
Verify Server	`verify_server`	Initial handshake validating lab server authenticity	Client $
ightarrow$ Server
Pull Data	`pull_data`	Retrieval of student rosters, schedules & exam packages	Server $
ightarrow$ Client
Push Results	`push_results`	Transmission of encrypted student examination answers	Client $
ightarrow$ Server
Heartbeat	`heartbeat`	Real-time status ping reporting connected student counts	Client $
ightarrow$ Server

3. Server Monitoring Model (`ServerMonitor`)

Heartbeat requests update live server status records in the server_monitors MongoDB collection:

go

type ServerMonitor struct {
    ID                bson.ObjectID `bson:"_id,omitempty" json:"id"`
    ServerCode        string        `bson:"server_code" json:"server_code"`
    NPSN              string        `bson:"npsn" json:"npsn"`
    SchoolName        string        `bson:"school_name" json:"school_name"`
    HardwareID        string        `bson:"hardware_id,omitempty" json:"hardware_id,omitempty"`
    Status            string        `bson:"status" json:"status"` // online, offline, syncing
    ActiveExamsCount  int           `bson:"active_exams_count" json:"active_exams_count"`
    ConnectedStudents int           `bson:"connected_students" json:"connected_students"`
    ClientIP          string        `bson:"client_ip" json:"client_ip"`
    ClientVersion     string        `bson:"client_version" json:"client_version"`
    LastPingAt        time.Time     `bson:"last_ping_at" json:"last_ping_at"`
    UpdatedAt         time.Time     `bson:"updated_at" json:"updated_at"`
}