# Plan: One-Time Setup Screen for luci-app-zt-gateway

## Problem

When `luci-app-zt-gateway` is installed on a fresh OpenWrt router, the switch script fails with `Cannot find device "br-zt"` because the prerequisite networking (bridge, routing, hotplug, DHCP) doesn't exist yet. There's no guided setup — the user must manually configure everything via CLI.

## Goal

Add a **Setup** section to the overview UI that:
1. Detects what's already configured vs. what's missing
2. Lets the user run each setup step individually or all at once
3. Shows real-time status after each step
4. For WiFi AP, displays the UCI config to add (user confirms)

## Production Router State (reference)

The router at `root@10.11.12.254` shows the target state:

| Component | UCI/Config | Runtime |
|---|---|---|
| br-zt bridge | `config device type bridge name br-zt` | `ip link show br-zt` |
| brzt interface | `config interface brzt proto static device br-zt ipaddr 10.11.12.254` | `ip addr show br-zt` |
| ZT interface | `config interface zerotier proto none device ztk4jpk77j` | `ip link show ztk4jpk77j` |
| ZT enslavement | hotplug script | `brctl show br-zt` |
| Policy rule | `config rule src 10.11.13.0/24 lookup 100 priority 100` | `ip rule show` |
| Table 100 default | `config route interface brzt target 0.0.0.0 gateway 10.11.12.3 table 100` | `ip route show table 100` |
| Host route | `config route interface brzt target 10.11.12.3` | `ip route show` |
| WIBLAN return | `config route interface brzt target 10.11.13.0 table 100` | — |
| DHCP | `config dhcp brzt interface brzt start 257 limit 254` | — |
| WIBLAN AP | `config wifi-iface wifinet0 device radio0 ssid WIBLAN network brzt` | — |
| IP forwarding | sysctl | `cat /proc/sys/net/ipv4/ip_forward` → 1 |
| Hotplug | `/etc/hotplug.d/net/99-zerotier-bridge` | — |
| rc.local | routes in `/etc/rc.local` | — |

## Architecture

### 1. Setup Script: `root/usr/sbin/zt-gateway-setup`

A new POSIX shell script with subcommands. Idempotent — running any step twice is safe.

```
Usage: zt-gateway-setup <command>

Commands:
  status              Show setup status for all components
  setup-bridge        Create br-zt bridge and detect ZT interface
  setup-routing       Configure ip rules, table 100, ip forwarding
  setup-hotplug       Write /etc/hotplug.d/net/99-zerotier-bridge
  setup-persistence   Write rc.local + UCI network routes
  setup-dhcp          Configure DHCP for WIBLAN subnet
  setup-all           Run all setup steps in order
```

**Environment variables** (same pattern as `zt-gateway-switch`):
- `ZTG_BRIDGE` (default: `br-zt`)
- `ZTG_WIBLAN_CIDR` (default: `10.11.13.0/24`)
- `ZTG_TABLE_MAIN` (default: `100`)
- `ZTG_ZT_NETWORK_ID` (default: auto-detect from `zerotier-cli listnetworks`)

**`status` output** (JSON, for ubus consumption):
```json
{
  "zt_client": true,
  "zt_network_joined": true,
  "zt_interface": "ztk4jpk77j",
  "bridge_exists": true,
  "bridge_has_zt": true,
  "bridge_has_address": true,
  "routing_ready": true,
  "ip_forwarding": true,
  "hotplug_script": true,
  "persistence": true,
  "dhcp_configured": true
}
```

**Key implementation details:**

#### `setup-bridge`
1. Find ZT interface: `zerotier-cli listnetworks` → parse `<dev>` column
2. If no ZT interface found → error "ZeroTier not joined to any network"
3. Create UCI device: `uci set network.zt_bridge=bridge; uci set network.zt_bridge.name=$BRIDGE; uci set network.zt_bridge.bridge_empty=1`
4. Create UCI interface: `uci set network.brzt=interface; uci set network.brzt.proto=static; uci set network.brzt.device=$BRIDGE`
5. Set IP from UCI config (read `global` section for WIBLAN CIDR, derive gateway IP)
6. Create UCI zerotier interface: `uci set network.zerotier=interface; uci set network.zerotier.proto=none; uci set network.zerotier.device=$ZT_IFACE`
7. `uci commit network`
8. Bring up: `ifup brzt; ifup zerotier`
9. Runtime fallback: if `ifup` doesn't enslave, do it manually:
   ```
   ip link add name $BRIDGE type bridge 2>/dev/null || true
   ip link set $BRIDGE up
   ip link set $ZT_IFACE master $BRIDGE
   ```

#### `setup-routing`
1. `echo 1 > /proc/sys/net/ipv4/ip_forward`
2. Persist: add `net.ipv4.ip_forward=1` to `/etc/sysctl.d/99-zt-gateway.conf` + `sysctl -p`
3. `ip rule del from $WIBLAN_CIDR table $TABLE_MAIN 2>/dev/null || true`
4. `ip rule add from $WIBLAN_CIDR table $TABLE_MAIN priority 100`
5. Read `active_gateway` from UCI → get IP from gateway config
6. `ip route replace default via $GW_IP dev $BRIDGE table $TABLE_MAIN`
7. `ip route replace $GW_IP dev $BRIDGE` (host route)
8. `ip route replace $WIBLAN_CIDR dev $BRIDGE table 1` (MWAN return)

#### `setup-hotplug`
Write `/etc/hotplug.d/net/99-zerotier-bridge`:
```sh
#!/bin/sh
# Auto-generated by zt-gateway-setup — do not edit manually.
# Re-enslaves ZT interface to br-zt and restores routes on reconnect.
[ "$INTERFACE" = "$ZT_IFACE" ] && [ "$ACTION" = "add" ] && {
    ip link set $ZT_IFACE master $BRIDGE 2>/dev/null || brctl addif $BRIDGE $ZT_IFACE 2>/dev/null
    ip route del $ZT_SUBNET dev $ZT_IFACE 2>/dev/null
    ip route replace $WIBLAN_CIDR dev $BRIDGE table 1 2>/dev/null
    ip route replace $GW_IP dev $BRIDGE 2>/dev/null
    ip route replace default via $GW_IP dev $BRIDGE table $TABLE_MAIN 2>/dev/null
}
```
The IPs are hardcoded (matching how `persist_all` uses `sed` to update them on switch).

#### `setup-persistence`
Write rc.local entries and UCI network routes (already handled by `persist_all` in the switch script, but `setup-persistence` creates the initial entries).

#### `setup-dhcp`
Write to `/etc/config/dhcp` (NOT `/etc/config/network`):
```sh
uci set dhcp.brzt=dhcp
uci set dhcp.brzt.interface='brzt'
uci set dhcp.brzt.start=257
uci set dhcp.brzt.limit=254
uci set dhcp.brzt.leasetime='12h'
uci add_list dhcp.brzt.dhcp_option='3,$WIBLAN_GW'    # gateway
uci add_list dhcp.brzt.dhcp_option='6,8.8.8.8,1.1.1.1'  # DNS
uci commit dhcp
```
The gateway IP is the router's own IP on br-zt (read from UCI `network.brzt.ipaddr` after bridge setup).

### 2. Backend: `root/usr/share/rpcd/ucode/zt-gateway.uc`

Add a new `setup` ubus method:

```js
setup: {
    args: {
        action: 'string'   // 'status' | 'setup-bridge' | 'setup-routing' | ...
    },
    call: function(req) {
        const action = req.args?.action || 'status';
        const result = system_output(`/usr/sbin/zt-gateway-setup ${shell_quote(action)}`);
        // Parse JSON output, return structured result
    }
}
```

Also update the ACL in `root/usr/share/rpcd/acl.d/luci-app-zt-gateway.json` to allow the `setup` method.

### 3. UI: `htdocs/luci-static/resources/view/zt-gateway/overview.js`

Add a **Setup** section to the overview page. When setup is incomplete, show it prominently at the top. When complete, collapse it or hide it.

#### Setup Panel Layout

```
┌─────────────────────────────────────────────────────────┐
│ Setup                                          [Status] │
├─────────────────────────────────────────────────────────┤
│                                                         │
│  ☑ ZeroTier client installed                           │
│  ☑ Network "whiteblossom" joined (ztk4jpk77j)         │
│                                                         │
│  ☐ Bridge (br-zt)                              [Setup] │
│     Creates br-zt and enslaves ZT interface             │
│                                                         │
│  ☐ Routing (ip rules + table 100)              [Setup] │
│     Configures policy routing for WIBLAN traffic        │
│                                                         │
│  ☐ Hotplug script                                [Setup] │
│     Restores routes when ZT reconnects                  │
│                                                         │
│  ☐ Boot persistence                              [Setup] │
│     Routes survive reboot                               │
│                                                         │
│  ☐ DHCP for WIBLAN                               [Setup] │
│     Assigns IPs to WiFi clients (10.11.13.0/24)        │
│                                                         │
│  ─────────────────────────────────────────────────────  │
│  WiFi AP (WIBLAN)                              [Guide]  │
│     Add to /etc/config/wireless:                        │
│     ┌─────────────────────────────────────────────┐     │
│     │ config wifi-iface 'wifinetN'                │     │
│     │     option device 'radio0'                  │     │
│     │     option mode 'ap'                        │     │
│     │     option ssid 'WIBLAN'                    │     │
│     │     option encryption 'psk2'                │     │
│     │     option key '<your-password>'            │     │
│     │     option network 'brzt'                   │     │
│     └─────────────────────────────────────────────┘     │
│                                                         │
│  [Run All Setup Steps]                                  │
│                                                         │
└─────────────────────────────────────────────────────────┘
```

#### UI Behavior

1. **On page load**: Call `zt-gateway.setup { action: 'status' }` to get current state
2. **Render checklist**: Each step shows ✓ (green) or ✗ (gray) with a [Setup] button
3. **[Setup] button**: Calls `zt-gateway.setup { action: 'setup-bridge' }` (etc.), then refreshes status
4. **[Run All]**: Calls `zt-gateway.setup { action: 'setup-all' }`, then refreshes status
5. **WiFi Guide**: Shows the UCI config snippet to add (read-only, with copy button)
6. **After all steps complete**: Collapse the setup section, show normal overview

#### Status Detection Logic (in `zt-gateway-setup status`)

| Check | How |
|---|---|
| ZT client installed | `command -v zerotier-cli` |
| ZT network joined | `zerotier-cli listnetworks 2>/dev/null \| grep -q OK` |
| ZT interface name | Parse `zerotier-cli listnetworks` → `<dev>` column |
| Bridge exists | `ip link show $BRIDGE 2>/dev/null` |
| Bridge has ZT | `brctl show $BRIDGE 2>/dev/null \| grep -q $ZT_IFACE` |
| Bridge has address | `ip -o -4 addr show dev $BRIDGE 2>/dev/null` |
| IP forwarding | `cat /proc/sys/net/ipv4/ip_forward` |
| Policy rule | `ip rule show \| grep "from $WIBLAN_CIDR.*lookup $TABLE_MAIN"` |
| Table 100 default | `ip route show table $TABLE_MAIN \| grep -q "default via"` |
| Hotplug script | `[ -x /etc/hotplug.d/net/99-zerotier-bridge ]` |
| Persistence | Check rc.local has routes |
| DHCP | `uci get dhcp.brzt.interface 2>/dev/null` |
### 4. Files to Create/Modify

| File | Action | Purpose |
|---|---|---|
| `root/usr/sbin/zt-gateway-setup` | **Create** | Setup script with subcommands |
| `root/usr/share/rpcd/ucode/zt-gateway.uc` | **Modify** | Add `setup` ubus method |
| `root/usr/share/rpcd/acl.d/luci-app-zt-gateway.json` | **Modify** | Add `setup` to ubus read/write ACL |
| `htdocs/luci-static/resources/view/zt-gateway/overview.js` | **Modify** | Add setup panel section |
| `root/etc/config/zt-gateway` | **Modify** | Add `wiblan_subnet` and `zt_network_id` options to global |
| `docs/INSTALL.md` | **Modify** | Document setup screen in installation guide |

### 5. UCI Config Additions

Add to `config global` in `root/etc/config/zt-gateway`:
```
option wiblan_subnet '10.11.13.0/24'
option wiblan_gateway '10.11.12.254'
option wiblan_dhcp_start '257'
option wiblan_dhcp_limit '254'
option zt_network_id ''
```

These allow the setup script and UI to derive all IP addresses from config rather than hardcoding.

### 6. Verification

1. **Deploy to router**: `HOST=root@10.11.12.254 mise run deploy:install`
2. **Open UI**: Navigate to Services > ZeroTier Gateway
3. **Setup panel**: Should show checklist with current state (most items ✓ since router is pre-configured)
4. **Fresh test**: Deploy to a clean OpenWrt container (`docker compose up openwrt-luci`), verify setup panel shows all ✗
5. **Run setup**: Click [Run All], verify all items turn ✓
6. **Switch test**: After setup, select a gateway and switch — should succeed
7. **Reboot test**: After setup, reboot — verify routes survive

### 7. Implementation Order

1. Create `zt-gateway-setup` script with `status` command only
2. Add `setup` ubus method to backend
3. Add ACL for `setup` method
4. Add setup panel to UI (read-only status display)
5. Implement `setup-bridge` in script
6. Implement `setup-routing` in script
7. Implement `setup-hotplug` in script
8. Implement `setup-persistence` in script
9. Implement `setup-dhcp` in script
10. Implement `setup-all` in script
11. Wire [Setup] buttons in UI to call backend
12. Add WiFi AP guide section
13. Update UCI config with new options
14. Update deploy task and docs
15. Test end-to-end