# Design Document: PostgreSQL Migration

## Overview

Migrate the CVE Dashboard backend from SQLite (`cve_database.db`, 13MB) to PostgreSQL 16 running in a dedicated Docker container (`steam-postgres`) on port 5433. The primary architectural change is decomposing the monolithic `ivanti_findings_cache.findings_json` blob (2.6MB TEXT column) into individual rows in an `ivanti_findings` table. This eliminates JSON parsing on every request, enables indexed per-BU filtering, provides per-BU closed finding counts, and removes SQLite's single-writer lock that blocks reads during sync.

The Postgres instance is fully isolated from the existing Postgres on port 5432 (belonging to another project). The frontend requires zero changes — the API contract remains identical.

## Architecture

```mermaid
graph TB
    subgraph "Frontend (port 3000)"
        FE[React SPA]
    end

    subgraph "Backend (port 3001 prod / 3003 dev)"
        SERVER[Express Server]
        POOL[pg Pool - max 10 connections]
        ROUTES[Route Handlers - async/await]
        SYNC[Ivanti Sync Logic]
    end

    subgraph "Docker: steam-postgres (port 5433)"
        PG[(PostgreSQL 16 Alpine)]
        DB[cve_dashboard database]
        VOL[steam-pgdata volume]
    end

    subgraph "Existing Infrastructure (DO NOT TOUCH)"
        OTHER_PG[(Other Postgres - port 5432)]
        SQLITE[(SQLite backup - cve_database.db)]
    end

    FE -->|Same API contract| SERVER
    SERVER --> ROUTES
    ROUTES --> POOL
    SYNC --> POOL
    POOL -->|DATABASE_URL| PG
    PG --> DB
    DB --> VOL
```

### Key Architecture Decisions

| Decision | Rationale |
|----------|-----------|
| Dedicated Docker container on port 5433 | Isolation from existing Postgres on 5432; independent lifecycle |
| `pg` package with connection pool (max 10) | Concurrent reads during writes; no single-writer lock |
| Individual finding rows instead of JSON blob | Indexed queries, per-BU filtering in SQL, no JSON.parse |
| Closed findings stored with `bu_ownership` | Enables per-BU closed counts (currently only global count) |
| Batch upsert via `INSERT ... ON CONFLICT` | Idempotent sync; no data loss on re-runs |
| Blue-green cutover on same port | <30s downtime; instant rollback by reverting .env |

## Components and Interfaces

### 1. Connection Pool Module (`backend/db.js`)

New module that creates and exports a `pg` Pool instance. All route files import this instead of receiving a `db` (sqlite3) parameter.

```js
// backend/db.js
const { Pool } = require('pg');

const pool = new Pool({
    connectionString: process.env.DATABASE_URL,
    // postgresql://steam:<password>@localhost:5433/cve_dashboard
    max: 10,
    idleTimeoutMillis: 30000,
    connectionTimeoutMillis: 5000,
});

// Log pool errors (connection drops, etc.)
pool.on('error', (err) => {
    console.error('[DB Pool] Unexpected error on idle client:', err.message);
});

// Warn when approaching pool exhaustion
let activeCount = 0;
pool.on('acquire', () => {
    activeCount++;
    if (activeCount >= 8) {
        console.warn(`[DB Pool] WARNING: ${activeCount}/10 connections active — approaching exhaustion`);
    }
});
pool.on('release', () => { activeCount--; });

module.exports = pool;
```

### 2. Route Migration Pattern

Every route file changes from callback-based SQLite to async/await Postgres:

**Before (SQLite):**
```js
function createUsersRouter(db, requireAuth, requireGroup, logAudit) {
    router.get('/', async (req, res) => {
        try {
            const users = await new Promise((resolve, reject) => {
                db.all(
                    'SELECT id, username, email, user_group AS "group" FROM users ORDER BY created_at DESC',
                    (err, rows) => {
                        if (err) reject(err);
                        else resolve(rows);
                    }
                );
            });
            res.json(users);
        } catch (err) {
            res.status(500).json({ error: 'Failed to fetch users' });
        }
    });
}
```

**After (Postgres):**
```js
const pool = require('../db');

function createUsersRouter(requireAuth, requireGroup, logAudit) {
    router.get('/', async (req, res) => {
        try {
            const { rows: users } = await pool.query(
                'SELECT id, username, email, user_group AS "group" FROM users ORDER BY created_at DESC'
            );
            res.json(users);
        } catch (err) {
            console.error('Get users error:', err);
            res.status(500).json({ error: 'Failed to fetch users' });
        }
    });
}
```

### 3. Query Pattern Translation

| SQLite Pattern | Postgres Equivalent |
|----------------|-------------------|
| `db.get(sql, [params], callback)` | `const { rows } = await pool.query(sql, [params]); const row = rows[0];` |
| `db.all(sql, [params], callback)` | `const { rows } = await pool.query(sql, [params]);` |
| `db.run(sql, [params], callback)` | `await pool.query(sql, [params]);` or with `RETURNING` |
| `?` placeholders | `$1, $2, $3...` numbered params |
| `INSERT OR IGNORE` | `INSERT ... ON CONFLICT DO NOTHING` |
| `datetime('now')` | `NOW()` |
| `LIKE` (case-sensitive) | `ILIKE` (case-insensitive) |

### 4. Ivanti Sync Component (Rewritten)

The sync logic changes from "serialize all findings to JSON blob" to "upsert individual rows":

```js
// backend/routes/ivantiFindings.js — sync logic (simplified)
async function syncFindings(pool) {
    const allFindings = await fetchAllFromIvanti(); // paginated API calls

    // Batch upsert in chunks of 100
    for (let i = 0; i < allFindings.length; i += 100) {
        const batch = allFindings.slice(i, i + 100);
        const values = [];
        const placeholders = batch.map((f, idx) => {
            const offset = idx * 14;
            values.push(f.id, f.hostId, f.title, f.severity, f.vrrGroup,
                        f.hostName, f.ipAddress, f.dns, f.status, f.slaStatus,
                        f.dueDate, f.lastFoundOn, f.buOwnership, f.cves || []);
            return `($${offset+1},$${offset+2},$${offset+3},$${offset+4},$${offset+5},
                    $${offset+6},$${offset+7},$${offset+8},$${offset+9},$${offset+10},
                    $${offset+11},$${offset+12},$${offset+13},$${offset+14},'open')`;
        });

        await pool.query(`
            INSERT INTO ivanti_findings (id, host_id, title, severity, vrr_group,
                host_name, ip_address, dns, status, sla_status,
                due_date, last_found_on, bu_ownership, cves, state)
            VALUES ${placeholders.join(',')}
            ON CONFLICT (id) DO UPDATE SET
                title = EXCLUDED.title,
                severity = EXCLUDED.severity,
                host_name = EXCLUDED.host_name,
                ip_address = EXCLUDED.ip_address,
                dns = EXCLUDED.dns,
                status = EXCLUDED.status,
                sla_status = EXCLUDED.sla_status,
                due_date = EXCLUDED.due_date,
                last_found_on = EXCLUDED.last_found_on,
                bu_ownership = EXCLUDED.bu_ownership,
                cves = EXCLUDED.cves,
                state = EXCLUDED.state,
                synced_at = NOW()
        `, values);
    }

    // Update sync metadata
    await pool.query(`
        UPDATE ivanti_sync_state SET
            total = (SELECT COUNT(*) FROM ivanti_findings WHERE state = 'open'),
            synced_at = NOW(),
            sync_status = 'success',
            error_message = NULL
        WHERE id = 1
    `);
}
```

### 5. Auth Middleware Migration

```js
// backend/middleware/auth.js — After
const pool = require('../db');

function requireAuth() {
    return async (req, res, next) => {
        const sessionId = req.cookies?.session_id;
        if (!sessionId) return res.status(401).json({ error: 'Authentication required' });

        try {
            const { rows } = await pool.query(
                `SELECT s.*, u.id as user_id, u.username, u.email, u.role,
                        u.user_group, u.bu_teams, u.is_active
                 FROM sessions s
                 JOIN users u ON s.user_id = u.id
                 WHERE s.session_id = $1 AND s.expires_at > NOW()`,
                [sessionId]
            );
            const session = rows[0];
            if (!session) return res.status(401).json({ error: 'Session expired or invalid' });
            if (!session.is_active) return res.status(401).json({ error: 'Account is disabled' });

            req.user = {
                id: session.user_id,
                username: session.username,
                email: session.email,
                role: session.role,
                group: session.user_group,
                teams: session.bu_teams ? session.bu_teams.split(',').filter(Boolean) : []
            };
            next();
        } catch (err) {
            console.error('Auth middleware error:', err);
            return res.status(500).json({ error: 'Authentication error' });
        }
    };
}
```

## Data Models

### Complete DDL for `ivanti_findings` Table

```sql
CREATE TABLE IF NOT EXISTS ivanti_findings (
    id TEXT PRIMARY KEY,                    -- Ivanti finding ID (e.g. "HF-12345")
    host_id INTEGER,
    title TEXT NOT NULL DEFAULT '',
    severity NUMERIC(4,2) NOT NULL DEFAULT 0,
    vrr_group TEXT NOT NULL DEFAULT '',
    host_name TEXT NOT NULL DEFAULT '',
    ip_address TEXT NOT NULL DEFAULT '',
    dns TEXT NOT NULL DEFAULT '',
    status TEXT NOT NULL DEFAULT '',
    sla_status TEXT NOT NULL DEFAULT '',
    due_date DATE,
    last_found_on DATE,
    bu_ownership TEXT NOT NULL DEFAULT '',
    cves TEXT[] DEFAULT '{}',               -- Postgres array type
    workflow_id TEXT,
    workflow_state TEXT,
    workflow_type TEXT,
    state TEXT NOT NULL DEFAULT 'open' CHECK (state IN ('open', 'closed')),
    note TEXT NOT NULL DEFAULT '',           -- Merged from ivanti_finding_notes
    override_host_name TEXT,                -- Merged from ivanti_finding_overrides
    override_dns TEXT,                      -- Merged from ivanti_finding_overrides
    synced_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Performance indexes
CREATE INDEX IF NOT EXISTS idx_findings_state ON ivanti_findings(state);
CREATE INDEX IF NOT EXISTS idx_findings_bu ON ivanti_findings(bu_ownership);
CREATE INDEX IF NOT EXISTS idx_findings_severity ON ivanti_findings(severity);
CREATE INDEX IF NOT EXISTS idx_findings_state_bu ON ivanti_findings(state, bu_ownership);
```

### Core Tables (Postgres DDL)

```sql
-- Users
CREATE TABLE IF NOT EXISTS users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(50) UNIQUE NOT NULL,
    email VARCHAR(255) UNIQUE NOT NULL,
    password_hash VARCHAR(255) NOT NULL,
    role VARCHAR(20) NOT NULL DEFAULT 'viewer' CHECK (role IN ('admin', 'editor', 'viewer')),
    is_active BOOLEAN DEFAULT TRUE,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    last_login TIMESTAMPTZ,
    user_group VARCHAR(20) NOT NULL DEFAULT 'Read_Only',
    bu_teams TEXT NOT NULL DEFAULT ''
);

-- Sessions
CREATE TABLE IF NOT EXISTS sessions (
    id SERIAL PRIMARY KEY,
    session_id VARCHAR(255) UNIQUE NOT NULL,
    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    expires_at TIMESTAMPTZ NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_sessions_session_id ON sessions(session_id);
CREATE INDEX IF NOT EXISTS idx_sessions_user_id ON sessions(user_id);
CREATE INDEX IF NOT EXISTS idx_sessions_expires ON sessions(expires_at);

-- Audit Logs
CREATE TABLE IF NOT EXISTS audit_logs (
    id SERIAL PRIMARY KEY,
    user_id INTEGER,
    username VARCHAR(50) NOT NULL,
    action VARCHAR(50) NOT NULL,
    entity_type VARCHAR(50) NOT NULL,
    entity_id VARCHAR(100),
    details TEXT,
    ip_address VARCHAR(45),
    created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_audit_created_at ON audit_logs(created_at);

-- CVEs
CREATE TABLE IF NOT EXISTS cves (
    id SERIAL PRIMARY KEY,
    cve_id VARCHAR(20) NOT NULL,
    vendor VARCHAR(100) NOT NULL,
    severity VARCHAR(20) NOT NULL,
    description TEXT,
    published_date DATE,
    status VARCHAR(50) DEFAULT 'Open',
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    created_by INTEGER,
    UNIQUE(cve_id, vendor)
);

-- Jira Tickets
CREATE TABLE IF NOT EXISTS jira_tickets (
    id SERIAL PRIMARY KEY,
    cve_id TEXT NOT NULL,
    vendor TEXT NOT NULL,
    ticket_key TEXT NOT NULL,
    url TEXT,
    summary TEXT,
    status TEXT DEFAULT 'Open' CHECK(status IN ('Open', 'In Progress', 'Closed')),
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti Sync State (replaces ivanti_findings_cache metadata)
CREATE TABLE IF NOT EXISTS ivanti_sync_state (
    id INTEGER PRIMARY KEY DEFAULT 1 CHECK (id = 1),
    total INTEGER DEFAULT 0,
    workflows_json TEXT DEFAULT '[]',
    synced_at TIMESTAMPTZ,
    sync_status TEXT DEFAULT 'never',
    error_message TEXT
);

-- Ivanti Counts Cache (for FP workflow counts)
CREATE TABLE IF NOT EXISTS ivanti_counts_cache (
    id INTEGER PRIMARY KEY DEFAULT 1 CHECK (id = 1),
    open_count INTEGER DEFAULT 0,
    closed_count INTEGER DEFAULT 0,
    synced_at TIMESTAMPTZ,
    fp_workflow_counts_json TEXT DEFAULT '{}',
    fp_id_counts_json TEXT DEFAULT '{}'
);

-- Ivanti Counts History
CREATE TABLE IF NOT EXISTS ivanti_counts_history (
    id SERIAL PRIMARY KEY,
    open_count INTEGER NOT NULL,
    closed_count INTEGER NOT NULL,
    recorded_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti Finding Archives
CREATE TABLE IF NOT EXISTS ivanti_finding_archives (
    id SERIAL PRIMARY KEY,
    finding_id TEXT NOT NULL UNIQUE,
    finding_title TEXT NOT NULL DEFAULT '',
    host_name TEXT NOT NULL DEFAULT '',
    ip_address TEXT NOT NULL DEFAULT '',
    current_state TEXT NOT NULL CHECK(current_state IN ('ARCHIVED','RETURNED','CLOSED','CLOSED_GONE')),
    last_severity NUMERIC(4,2) NOT NULL DEFAULT 0,
    first_archived_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    last_transition_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti Archive Transitions
CREATE TABLE IF NOT EXISTS ivanti_archive_transitions (
    id SERIAL PRIMARY KEY,
    archive_id INTEGER NOT NULL REFERENCES ivanti_finding_archives(id),
    from_state TEXT NOT NULL,
    to_state TEXT NOT NULL,
    severity_at_transition NUMERIC(4,2) NOT NULL DEFAULT 0,
    reason TEXT NOT NULL DEFAULT '',
    transitioned_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Ivanti Sync Anomaly Log
CREATE TABLE IF NOT EXISTS ivanti_sync_anomaly_log (
    id SERIAL PRIMARY KEY,
    sync_timestamp TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    open_count_delta INTEGER NOT NULL DEFAULT 0,
    closed_count_delta INTEGER NOT NULL DEFAULT 0,
    newly_archived_count INTEGER NOT NULL DEFAULT 0,
    returned_count INTEGER NOT NULL DEFAULT 0,
    classification_json TEXT NOT NULL DEFAULT '{}',
    return_classification_json TEXT NOT NULL DEFAULT '{}',
    is_significant BOOLEAN NOT NULL DEFAULT FALSE,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti Finding BU History
CREATE TABLE IF NOT EXISTS ivanti_finding_bu_history (
    id SERIAL PRIMARY KEY,
    finding_id TEXT NOT NULL,
    finding_title TEXT NOT NULL DEFAULT '',
    host_name TEXT NOT NULL DEFAULT '',
    previous_bu TEXT NOT NULL,
    new_bu TEXT NOT NULL,
    detected_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti FP Submissions
CREATE TABLE IF NOT EXISTS ivanti_fp_submissions (
    id SERIAL PRIMARY KEY,
    user_id INTEGER NOT NULL,
    username TEXT NOT NULL,
    ivanti_workflow_batch_id INTEGER,
    ivanti_generated_id TEXT,
    ivanti_workflow_batch_uuid TEXT,
    workflow_name TEXT NOT NULL,
    reason TEXT NOT NULL,
    description TEXT,
    expiration_date TEXT NOT NULL,
    scope_override TEXT NOT NULL DEFAULT 'Authorized',
    finding_ids_json TEXT NOT NULL,
    queue_item_ids_json TEXT NOT NULL,
    attachment_count INTEGER DEFAULT 0,
    attachment_results_json TEXT,
    status TEXT NOT NULL DEFAULT 'success' CHECK(status IN ('success', 'partial', 'failed')),
    lifecycle_status TEXT NOT NULL DEFAULT 'submitted' CHECK(lifecycle_status IN ('submitted', 'approved', 'rejected', 'rework', 'resubmitted')),
    error_message TEXT,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NULL
);

-- Ivanti FP Submission History
CREATE TABLE IF NOT EXISTS ivanti_fp_submission_history (
    id SERIAL PRIMARY KEY,
    submission_id INTEGER NOT NULL REFERENCES ivanti_fp_submissions(id) ON DELETE CASCADE,
    user_id INTEGER NOT NULL,
    username TEXT NOT NULL,
    change_type TEXT NOT NULL CHECK(change_type IN ('created', 'fields_updated', 'findings_added', 'attachments_added', 'status_changed')),
    change_details_json TEXT,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Ivanti Todo Queue
CREATE TABLE IF NOT EXISTS ivanti_todo_queue (
    id SERIAL PRIMARY KEY,
    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    finding_id TEXT NOT NULL,
    finding_title TEXT,
    cves_json TEXT,
    ip_address TEXT,
    hostname TEXT,
    vendor TEXT NOT NULL,
    workflow_type TEXT NOT NULL CHECK(workflow_type IN ('FP', 'Archer', 'CARD', 'GRANITE')),
    status TEXT NOT NULL DEFAULT 'pending' CHECK(status IN ('pending', 'complete')),
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_todo_queue_user ON ivanti_todo_queue(user_id, status);

-- Atlas Action Plans Cache
CREATE TABLE IF NOT EXISTS atlas_action_plans_cache (
    id SERIAL PRIMARY KEY,
    host_id INTEGER NOT NULL UNIQUE,
    has_action_plan BOOLEAN NOT NULL DEFAULT FALSE,
    plan_count INTEGER NOT NULL DEFAULT 0,
    plans_json TEXT NOT NULL DEFAULT '[]',
    synced_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Compliance Tables
CREATE TABLE IF NOT EXISTS compliance_uploads (
    id SERIAL PRIMARY KEY,
    filename TEXT NOT NULL,
    report_date TEXT,
    uploaded_by INTEGER REFERENCES users(id) ON DELETE SET NULL,
    uploaded_at TIMESTAMPTZ DEFAULT NOW(),
    new_count INTEGER DEFAULT 0,
    resolved_count INTEGER DEFAULT 0,
    recurring_count INTEGER DEFAULT 0,
    summary_json TEXT
);

CREATE TABLE IF NOT EXISTS compliance_items (
    id SERIAL PRIMARY KEY,
    upload_id INTEGER NOT NULL REFERENCES compliance_uploads(id) ON DELETE CASCADE,
    hostname TEXT NOT NULL,
    ip_address TEXT,
    device_type TEXT,
    team TEXT,
    metric_id TEXT NOT NULL,
    metric_desc TEXT,
    category TEXT,
    extra_json TEXT,
    status TEXT NOT NULL DEFAULT 'active' CHECK(status IN ('active', 'resolved')),
    first_seen_upload_id INTEGER REFERENCES compliance_uploads(id) ON DELETE SET NULL,
    resolved_upload_id INTEGER REFERENCES compliance_uploads(id) ON DELETE SET NULL,
    seen_count INTEGER DEFAULT 1,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE TABLE IF NOT EXISTS compliance_notes (
    id SERIAL PRIMARY KEY,
    hostname TEXT NOT NULL,
    metric_id TEXT NOT NULL,
    note TEXT NOT NULL,
    group_id TEXT,
    created_by INTEGER REFERENCES users(id) ON DELETE SET NULL,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Knowledge Base
CREATE TABLE IF NOT EXISTS knowledge_base (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    slug VARCHAR(255) UNIQUE NOT NULL,
    description TEXT,
    category VARCHAR(100),
    file_path VARCHAR(500),
    file_name VARCHAR(255),
    file_type VARCHAR(50),
    file_size INTEGER,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    created_by INTEGER REFERENCES users(id)
);

-- Archer Tickets
CREATE TABLE IF NOT EXISTS archer_tickets (
    id SERIAL PRIMARY KEY,
    exc_number TEXT NOT NULL UNIQUE,
    archer_url TEXT,
    status TEXT DEFAULT 'Draft' CHECK(status IN ('Draft', 'Open', 'Under Review', 'Accepted')),
    cve_id TEXT NOT NULL,
    vendor TEXT NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW()
);

-- Documents
CREATE TABLE IF NOT EXISTS documents (
    id SERIAL PRIMARY KEY,
    cve_id VARCHAR(20) NOT NULL,
    vendor VARCHAR(100) NOT NULL,
    name VARCHAR(255) NOT NULL,
    type VARCHAR(50) NOT NULL,
    file_path VARCHAR(500) NOT NULL,
    file_size VARCHAR(20),
    mime_type VARCHAR(100),
    uploaded_at TIMESTAMPTZ DEFAULT NOW(),
    notes TEXT
);

-- Required Documents (seed data)
CREATE TABLE IF NOT EXISTS required_documents (
    id SERIAL PRIMARY KEY,
    vendor VARCHAR(100) NOT NULL,
    document_type VARCHAR(50) NOT NULL,
    is_mandatory BOOLEAN DEFAULT TRUE,
    description TEXT
);
```

### Per-BU Count Queries

```sql
-- Open count for specific BUs (used by counts endpoint with teams filter)
SELECT COUNT(*) FROM ivanti_findings
WHERE state = 'open' AND bu_ownership ILIKE ANY(ARRAY['%STEAM%', '%ACCESS-ENG%']);

-- Closed count for specific BUs
SELECT COUNT(*) FROM ivanti_findings
WHERE state = 'closed' AND bu_ownership ILIKE ANY(ARRAY['%STEAM%', '%ACCESS-ENG%']);

-- Aggregated counts grouped by BU and state (single query)
SELECT bu_ownership, state, COUNT(*) as count
FROM ivanti_findings
GROUP BY bu_ownership, state;

-- Global totals (no filter — backward compatible)
SELECT state, COUNT(*) as count
FROM ivanti_findings
GROUP BY state;
```

### Data Migration Script Design (`backend/scripts/migrate-to-postgres.js`)

```mermaid
flowchart TD
    A[Open SQLite read-only] --> B[Connect to Postgres pool]
    B --> C[Create all tables IF NOT EXISTS]
    C --> D[Copy simple tables]
    D --> E[Parse findings_json blob]
    E --> F[Insert individual finding rows state=open]
    F --> G[Merge ivanti_finding_notes → findings.note]
    G --> H[Merge ivanti_finding_overrides → findings.override_*]
    H --> I[Verify row counts]
    I --> J[Print summary report]
```

The migration script:
1. Opens SQLite with `OPEN_READONLY` flag
2. Connects to Postgres via `DATABASE_URL`
3. Creates schema idempotently (`IF NOT EXISTS`)
4. Copies each table using batch inserts with `ON CONFLICT` for idempotency
5. Special handling for findings: parses `findings_json`, creates one row per finding
6. Merges notes and overrides into the corresponding finding rows
7. Verifies source vs destination row counts
8. Never modifies the SQLite file

## Correctness Properties

*A property is a characteristic or behavior that should hold true across all valid executions of a system — essentially, a formal statement about what the system should do. Properties serve as the bridge between human-readable specifications and machine-verifiable correctness guarantees.*

### Property 1: Upsert Idempotence

*For any* finding synced N times (N ≥ 1) with the same finding ID, the `ivanti_findings` table SHALL contain exactly one row for that finding ID, with the data from the most recent sync.

**Validates: Requirements 3.5, 6.6**

### Property 2: Finding Storage Preserves State and BU Ownership

*For any* finding (open or closed) stored in `ivanti_findings`, querying it back by ID SHALL return the same `state` and `bu_ownership` values it was stored with.

**Validates: Requirements 3.4, 4.1**

### Property 3: Count Query Accuracy

*For any* set of findings in `ivanti_findings` and any BU filter (including empty/no filter), the count query result SHALL equal the actual number of rows matching that filter and state combination.

**Validates: Requirements 4.2, 4.3, 4.5**

### Property 4: Migration Data Preservation (Findings)

*For any* finding in the source `findings_json` blob with associated notes (from `ivanti_finding_notes`) and overrides (from `ivanti_finding_overrides`), the migrated `ivanti_findings` row SHALL contain the finding data with `state = 'open'`, the correct `note` value, and the correct `override_host_name`/`override_dns` values.

**Validates: Requirements 7.4, 7.5, 7.6**

### Property 5: Migration Table Copy Preservation

*For any* table copied from SQLite to Postgres, the row count in Postgres SHALL equal the row count in SQLite, and each row's data SHALL be equivalent (accounting for type conversions: 0/1 → boolean, DATETIME → TIMESTAMPTZ).

**Validates: Requirements 7.7, 7.8**

### Property 6: Migration Idempotence

*For any* initial state of the SQLite and Postgres databases, running the migration script N times (N ≥ 1) SHALL produce the same final state in Postgres as running it exactly once (no duplicate rows, no errors).

**Validates: Requirements 7.3, 7.9**

### Property 7: Migration Source Safety

*For any* execution of the migration script, the SQLite database file SHALL remain byte-for-byte identical before and after (checksum unchanged).

**Validates: Requirements 7.10**

### Property 8: Schema Creation Idempotence

*For any* number of times the schema creation DDL is executed against the same database, the resulting schema SHALL be identical (no errors, same tables, same indexes, same constraints).

**Validates: Requirements 2.5**

### Property 9: API Response Shape Preservation

*For any* valid API request to any endpoint, the response JSON structure (top-level keys and value types) after migration SHALL be identical to the pre-migration response structure.

**Validates: Requirements 10.1**

## Error Handling

| Error Scenario | Handling Strategy |
|----------------|-------------------|
| Pool connection failure | `pool.on('error')` logs error; automatic reconnection on next query attempt |
| Pool exhaustion (all 10 busy) | Queries queue internally; warning logged at 8 active connections |
| Query timeout | `connectionTimeoutMillis: 5000` — rejects after 5s with error |
| Sync failure mid-batch | Transaction rollback; `sync_status = 'error'` with message; previous data preserved |
| Migration script failure | Idempotent design — safe to re-run; prints error and exits with code 1 |
| Docker container crash | `--restart unless-stopped` auto-recovers; pool reconnects on next query |
| Invalid finding data | `NOT NULL DEFAULT ''` columns prevent null constraint violations; CHECK constraints reject invalid state values |
| Rollback needed | Stop Postgres backend → revert `.env` → restart SQLite backend; SQLite file always preserved |

### Error Response Format (Unchanged)

All error responses maintain the existing format:
```json
{ "error": "Human-readable error message" }
```

With appropriate HTTP status codes: 400 (validation), 401 (auth), 403 (permission), 404 (not found), 500 (server error).

## Testing Strategy

### Unit Tests (Example-Based)

- Verify each route returns correct response shape with known test data
- Verify auth middleware rejects expired sessions
- Verify parameter placeholder conversion (`?` → `$1`) in all queries
- Verify schema DDL executes without errors
- Verify migration script handles empty tables gracefully

### Property-Based Tests

Property-based testing is appropriate for this feature because the core operations (upsert, count queries, data migration) have clear input/output behavior with universal properties that hold across a wide input space.

**Library**: [fast-check](https://github.com/dubzzz/fast-check) (JavaScript PBT library)

**Configuration**: Minimum 100 iterations per property test.

**Tag format**: `Feature: postgres-migration, Property {number}: {property_text}`

Each correctness property (1-9) maps to a single property-based test:
- Property 1: Generate random findings, upsert each N times, verify exactly one row per ID
- Property 2: Generate findings with random state/bu_ownership, store and retrieve, verify equality
- Property 3: Generate random finding sets, insert, run count queries with random filters, verify accuracy
- Property 4: Generate random findings JSON with notes/overrides, run migration logic, verify merged output
- Property 5: Generate random table rows, copy via migration, verify count and data equivalence
- Property 6: Run migration logic N times on same input, verify final state equals single-run state
- Property 7: Checksum SQLite before/after migration, verify unchanged
- Property 8: Run schema DDL N times, verify no errors and same schema
- Property 9: Compare response shapes between SQLite and Postgres backends for same requests

### Integration Tests

- Docker container health check (port 5433 accessible)
- Full sync cycle: trigger sync → verify rows created → verify counts endpoint
- Concurrent read during write: start sync, simultaneously query findings, verify no blocking
- Performance: GET /findings < 500ms, GET /counts < 100ms with 6000+ rows
- Cutover simulation: stop/start backend, verify API responds correctly

### Development Isolation

- Test backend runs on port 3003 with `DATABASE_URL` pointing to Postgres
- Production backend continues on port 3001 with SQLite (no `DATABASE_URL` set)
- Switching is controlled by presence of `DATABASE_URL` environment variable
- All work on `feature/multi-tenancy` branch