#!/usr/bin/env bash
# RemoteRig — First-Time Raspberry Pi Zero 2 W Setup
# Target: Debian/Raspberry Pi OS (bookworm)
# Idempotent: safe to run multiple times
#
# Usage:
#   sudo ./setup-pi.sh [--config PATH] [--service-user USER]
#
# Options:
#   --config PATH         Path to config.yaml template to copy to /opt/remoterig/
#   --service-user USER   Systemd service user (default: pi)
#   --static-ip IP        Static IP for wlan0 (default: 192.168.4.10/24)
#   --gateway IP          Gateway for wlan0 (default: 192.168.4.1)
#   --help                Show this help

set -euo pipefail

# ---------------------------------------------------------------------------
# Defaults
# ---------------------------------------------------------------------------
CONFIG_TEMPLATE=""
SERVICE_USER="pi"
STATIC_IP="192.168.4.10/24"
GATEWAY="192.168.4.1"
MOSQUITTO_PKG="mosquitto mosquitto-clients"
DEPLOY_DIR="/opt/remoterig"
SERVICE_NAME="remoterig"
SERVICE_FILE="scripts/remoterig.service"
MOSQUITTO_CONF="/etc/mosquitto/conf.d/remoterig.conf"

# ---------------------------------------------------------------------------
# Help
# ---------------------------------------------------------------------------
usage() {
    sed -n '/^# Usage:/,/^$/p' "$0" | sed 's/^# //'
    exit 0
}

# ---------------------------------------------------------------------------
# Parse args
# ---------------------------------------------------------------------------
while [ $# -gt 0 ]; do
    case "$1" in
        --config)
            CONFIG_TEMPLATE="$2"
            shift 2
            ;;
        --service-user)
            SERVICE_USER="$2"
            shift 2
            ;;
        --static-ip)
            STATIC_IP="$2"
            shift 2
            ;;
        --gateway)
            GATEWAY="$2"
            shift 2
            ;;
        --help|-h)
            usage
            ;;
        *)
            echo "ERROR: unknown option: $1" >&2
            usage
            ;;
    esac
done

# ---------------------------------------------------------------------------
# Pre-flight checks
# ---------------------------------------------------------------------------
if [ "$(id -u)" -ne 0 ]; then
    echo "ERROR: must run as root (sudo ./setup-pi.sh)" >&2
    exit 1
fi

info()  { echo "[INFO]  $*"; }
ok()    { echo "[OK]    $*"; }
skip()  { echo "[SKIP]  $*"; }
warn()  { echo "[WARN]  $*" >&2; }

echo "=============================================="
echo " RemoteRig Pi Zero 2 W Setup"
echo " Target: ${STATIC_IP} via ${GATEWAY}"
echo " Service user: ${SERVICE_USER}"
echo "=============================================="

# ---------------------------------------------------------------------------
# 1. Update package list (always safe)
# ---------------------------------------------------------------------------
info "Updating package list..."
apt-get update -qq

# ---------------------------------------------------------------------------
# 2. Install Mosquitto MQTT broker + clients
# ---------------------------------------------------------------------------
info "Installing Mosquitto..."
if dpkg -l mosquitto mosquitto-clients >/dev/null 2>&1; then
    # Already installed — ensure latest
    apt-get install -y -qq ${MOSQUITTO_PKG} 2>/dev/null && \
        ok "Mosquitto packages up to date" || \
        warn "Mosquitto package update had warnings (non-fatal)"
else
    apt-get install -y -qq ${MOSQUITTO_PKG}
    ok "Mosquitto installed"
fi

# ---------------------------------------------------------------------------
# 3. Configure Mosquitto — anonymous on localhost, listener on 0.0.0.0:1883
# ---------------------------------------------------------------------------
info "Configuring Mosquitto..."
mkdir -p /etc/mosquitto/conf.d

# Write idempotent config
cat > "${MOSQUITTO_CONF}" <<'MQTTEOF'
# RemoteRig Mosquitto configuration
# Closed travel-router LAN — anonymous access is intentional

# Listen on all interfaces (LAN + localhost)
listener 1883 0.0.0.0

# No authentication (closed network, no internet access)
allow_anonymous true
MQTTEOF

ok "Mosquitto config written: ${MOSQUITTO_CONF}"

# ---------------------------------------------------------------------------
# 4. Create /opt/remoterig directory
# ---------------------------------------------------------------------------
info "Creating deploy directory..."
if [ -d "${DEPLOY_DIR}" ]; then
    skip "${DEPLOY_DIR} already exists"
else
    mkdir -p "${DEPLOY_DIR}"
    ok "Created ${DEPLOY_DIR}"
fi

# ---------------------------------------------------------------------------
# 5. Copy config.yaml template (if provided)
# ---------------------------------------------------------------------------
if [ -n "${CONFIG_TEMPLATE}" ] && [ -f "${CONFIG_TEMPLATE}" ]; then
    info "Copying config.yaml template..."
    if [ -f "${DEPLOY_DIR}/config.yaml" ]; then
        skip "${DEPLOY_DIR}/config.yaml already exists (not overwriting)"
    else
        cp "${CONFIG_TEMPLATE}" "${DEPLOY_DIR}/config.yaml"
        ok "Copied config.yaml to ${DEPLOY_DIR}/config.yaml"
    fi
elif [ -n "${CONFIG_TEMPLATE}" ]; then
    warn "Config template '${CONFIG_TEMPLATE}' not found — skipping"
else
    info "No config template provided — skipping"
fi

# Ensure service user owns the deploy directory
chown -R "${SERVICE_USER}:${SERVICE_USER}" "${DEPLOY_DIR}" 2>/dev/null || \
    warn "Could not chown ${DEPLOY_DIR} to ${SERVICE_USER} (user may not exist yet)"

# ---------------------------------------------------------------------------
# 6. Install and enable systemd service
# ---------------------------------------------------------------------------
info "Installing systemd service..."

# Locate the service file relative to this script's directory
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SRC_SERVICE="${SCRIPT_DIR}/remoterig.service"

if [ ! -f "${SRC_SERVICE}" ]; then
    warn "Service file not found at ${SRC_SERVICE} — skipping service install"
    warn "Run this script from the repository root (scripts/setup-pi.sh)"
else
    DST_SERVICE="/etc/systemd/system/${SERVICE_NAME}.service"

    # Copy if different
    if [ -f "${DST_SERVICE}" ]; then
        if cmp -s "${SRC_SERVICE}" "${DST_SERVICE}"; then
            skip "systemd service already installed and up to date"
        else
            cp "${SRC_SERVICE}" "${DST_SERVICE}"
            ok "systemd service updated"
            RELOAD_SYSTEMD=1
        fi
    else
        cp "${SRC_SERVICE}" "${DST_SERVICE}"
        ok "systemd service installed"
        RELOAD_SYSTEMD=1
    fi

    # Substitute the service user
    sed -i "s/^User=.*/User=${SERVICE_USER}/" "${DST_SERVICE}"

    if [ "${RELOAD_SYSTEMD:-0}" -eq 1 ]; then
        systemctl daemon-reload
    fi

    # Enable (idempotent)
    if systemctl is-enabled --quiet "${SERVICE_NAME}" 2>/dev/null; then
        skip "systemd service already enabled"
    else
        systemctl enable "${SERVICE_NAME}"
        ok "systemd service enabled"
    fi
fi

# ---------------------------------------------------------------------------
# 7. Set static IP on wlan0
# ---------------------------------------------------------------------------
info "Configuring static IP on wlan0..."

# Check if wlan0 exists
if ! ip link show wlan0 >/dev/null 2>&1; then
    warn "wlan0 interface not found — skipping static IP configuration"
    warn "Connect Wi-Fi first (raspi-config), then re-run this script"
else
    STATIC_IP_SET=0

    # --- Method A: NetworkManager (default on bookworm) ---
    if command -v nmcli >/dev/null 2>&1; then
        info "Using NetworkManager (nmcli)..."

        # Find the Wi-Fi connection profile
        WIFI_CON=$(nmcli -t -f NAME,TYPE con show 2>/dev/null | grep ':802-11-wireless' | cut -d: -f1 | head -1)

        if [ -n "${WIFI_CON}" ]; then
            CURRENT_IP=$(nmcli -t -f IP4.ADDRESS con show "${WIFI_CON}" 2>/dev/null | cut -d: -f2 | head -1 || true)

            if [ "${CURRENT_IP}" = "${STATIC_IP}" ]; then
                skip "wlan0 already set to ${STATIC_IP} via nmcli"
                STATIC_IP_SET=1
            else
                nmcli con mod "${WIFI_CON}" ipv4.addresses "${STATIC_IP}"
                nmcli con mod "${WIFI_CON}" ipv4.gateway "${GATEWAY}"
                nmcli con mod "${WIFI_CON}" ipv4.dns "${GATEWAY}"
                nmcli con mod "${WIFI_CON}" ipv4.method manual
                nmcli con up "${WIFI_CON}" 2>/dev/null || true
                ok "wlan0 set to ${STATIC_IP} via nmcli (connection: ${WIFI_CON})"
                STATIC_IP_SET=1
            fi
        else
            warn "No Wi-Fi connection profile found in NetworkManager"
        fi
    fi

    # --- Method B: dhcpcd (fallback for older PiOS) ---
    if [ ${STATIC_IP_SET} -eq 0 ] && command -v dhcpcd >/dev/null 2>&1; then
        info "Using dhcpcd..."

        DHCPCD_CONF="/etc/dhcpcd.conf"

        if grep -q "interface wlan0" "${DHCPCD_CONF}" 2>/dev/null; then
            skip "dhcpcd already has wlan0 config"
        else
            cat >> "${DHCPCD_CONF}" <<DHCPCDEOF

# RemoteRig static IP
interface wlan0
static ip_address=${STATIC_IP}
static routers=${GATEWAY}
static domain_name_servers=${GATEWAY}
DHCPCDEOF
            ok "dhcpcd configured for wlan0 static IP"
        fi
        STATIC_IP_SET=1
    fi

    # --- Method C: /etc/network/interfaces (last resort) ---
    if [ ${STATIC_IP_SET} -eq 0 ]; then
        warn "Neither nmcli nor dhcpcd found — attempting /etc/network/interfaces"

        INTERFACES_FILE="/etc/network/interfaces"
        if ! grep -q "iface wlan0 inet static" "${INTERFACES_FILE}" 2>/dev/null; then
            cat >> "${INTERFACES_FILE}" <<NETEOF

# RemoteRig static IP
auto wlan0
iface wlan0 inet static
    address ${STATIC_IP%/*}
    netmask 255.255.255.0
    gateway ${GATEWAY}
NETEOF
            ok "wlan0 static IP configured in ${INTERFACES_FILE}"
        else
            skip "${INTERFACES_FILE} already has static wlan0 config"
        fi
    fi
fi

# ---------------------------------------------------------------------------
# 8. Enable and start Mosquitto
# ---------------------------------------------------------------------------
info "Enabling and starting Mosquitto..."

if systemctl is-active --quiet mosquitto 2>/dev/null; then
    skip "Mosquitto already running"
else
    systemctl enable mosquitto 2>/dev/null || true
    systemctl restart mosquitto
    ok "Mosquitto started"
fi

# Verify Mosquitto is listening
sleep 1
if systemctl is-active --quiet mosquitto 2>/dev/null; then
    ok "Mosquitto is running and listening on :1883"
else
    warn "Mosquitto may not have started — check: sudo systemctl status mosquitto"
fi

# ---------------------------------------------------------------------------
# Summary
# ---------------------------------------------------------------------------
echo ""
echo "=============================================="
echo " Setup complete!"
echo "=============================================="
echo " Mosquitto:  $(systemctl is-active mosquitto 2>/dev/null || echo 'unknown')"
echo " Service:    ${SERVICE_NAME} (systemctl status ${SERVICE_NAME})"
echo " Deploy dir: ${DEPLOY_DIR}"
echo " Static IP:  ${STATIC_IP} on wlan0"
echo ""
echo " Next steps:"
echo "   1. Build the remoterig binary for ARM64:"
echo "      GOOS=linux GOARCH=arm64 go build -o remoterig ./cmd/server"
echo "   2. Copy binary to Pi:"
echo "      scp remoterig pi@192.168.4.10:/opt/remoterig/"
echo "   3. Copy config if needed:"
echo "      scp config.yaml pi@192.168.4.10:/opt/remoterig/"
echo "   4. Start the service:"
echo "      sudo systemctl start remoterig"
echo "   5. Check health:"
echo "      curl http://192.168.4.10:8080/health"
echo ""
echo " To deploy updates, use: scripts/deploy.sh"
echo "=============================================="