# REXO Task: quiXzoom + LandveX Transaction System

## Overview
Build automated transaction monitoring and customer self-service for quiXzoom (DE) and LandveX (SE/TX).

## Part 1: quiXzoom Event Streaming

### Requirements
- Log EVERY transaction event to Kafka topic `quixzoom.events`
- Events: user lifecycle, job lifecycle, payments, payouts, QZ tokens
- Full searchability via Elasticsearch
- Real-time alerting for anomalies

### Database Schema (PostgreSQL)
```sql
-- Events table (immutable)
CREATE TABLE qz_events (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    event_type TEXT NOT NULL, -- user.registered, job.matched, payment.received, etc
    payload JSONB NOT NULL,
    user_id UUID,
    job_id UUID,
    company_id UUID,
    amount DECIMAL(15,2),
    currency TEXT,
    status TEXT, -- success, failed, pending
    ip_address INET,
    user_agent TEXT,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_qz_events_type ON qz_events(event_type, created_at DESC);
CREATE INDEX idx_qz_events_user ON qz_events(user_id, created_at DESC);
CREATE INDEX idx_qz_events_job ON qz_events(job_id);
```

### API Endpoints
- `POST /api/v1/events` — ingest event
- `GET /api/v1/events/search` — search events (Elasticsearch)
- `GET /api/v1/events/:user_id` — user transaction history
- `GET /api/v1/events/summary` — aggregated stats

### Kafka Topics
- `quixzoom.events` — all events
- `quixzoom.payments` — payment events for ledger
- `quixzoom.payouts` — payout events for ledger
- `quixzoom.alerts` — anomaly alerts

## Part 2: LandveX Customer Portal

### Requirements
- Self-service: view contract, invoices, usage
- Automatic recurring billing (Stripe)
- No manual invoicing — everything is automated

### Database Schema
```sql
-- Contracts (auto-generated)
CREATE TABLE lv_contracts (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    company_id UUID NOT NULL,
    plan_type TEXT NOT NULL, -- basic, pro, enterprise
    start_date DATE NOT NULL,
    end_date DATE,
    auto_renew BOOLEAN DEFAULT TRUE,
    monthly_fee DECIMAL(15,2) NOT NULL,
    currency TEXT DEFAULT 'SEK',
    status TEXT DEFAULT 'active',
    stripe_subscription_id TEXT,
    metadata JSONB DEFAULT '{}',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Invoices (auto-generated)
CREATE TABLE lv_invoices (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    contract_id UUID REFERENCES lv_contracts(id),
    invoice_number TEXT NOT NULL,
    period_start DATE NOT NULL,
    period_end DATE NOT NULL,
    amount DECIMAL(15,2) NOT NULL,
    vat_amount DECIMAL(15,2) NOT NULL,
    total_amount DECIMAL(15,2) NOT NULL,
    currency TEXT DEFAULT 'SEK',
    status TEXT DEFAULT 'draft', -- draft, sent, paid, overdue
    stripe_invoice_id TEXT,
    paid_at TIMESTAMPTZ,
    metadata JSONB DEFAULT '{}',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Usage tracking
CREATE TABLE lv_usage (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    contract_id UUID REFERENCES lv_contracts(id),
    resource_type TEXT NOT NULL, -- api_calls, storage, users
    quantity DECIMAL(15,2) NOT NULL,
    unit TEXT NOT NULL,
    period DATE NOT NULL,
    metadata JSONB DEFAULT '{}',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
```

### API Endpoints
- `GET /api/v1/contract` — view current contract
- `GET /api/v1/invoices` — list invoices
- `GET /api/v1/invoices/:id/download` — download PDF
- `GET /api/v1/usage` — view usage report
- `POST /api/v1/upgrade` — upgrade/downgrade plan
- `POST /api/v1/cancel` — request cancellation

### Frontend
- Customer dashboard (React/Vue)
- Invoice viewer with PDF download
- Usage charts (Chart.js)
- Stripe payment integration

## Part 3: Automated Accounting

### Requirements
- Every payment → auto-booked to ledger
- Every payout → auto-booked to ledger
- VAT calculated per transaction
- Employer contributions calculated per payroll

### Integration Points
- quiXzoom payments → BOC ledger (SEK/USD)
- LandveX invoices → BOC ledger (SEK)
- Payroll → BOC ledger (SEK)
- Intercompany → BOC ledger (USD/SEK conversion)

## Deliverables
1. Go backend with Chi router
2. PostgreSQL migrations
3. Kafka producers/consumers
4. Elasticsearch indexing
5. React frontend for customer portal
6. Stripe integration
7. Automated accounting hooks

## Notes
- Use RS256 auth (same as BOC)
- Multi-tenant (3 companies)
- Currency: SEK for LandveX AB, USD for quiXzoom Inc + Landvex Inc
- All code must be production-ready with tests