#!/bin/bash
# setup-wizard.sh — First-boot configuration wizard for RPi Audio Mixer
#
# Runs on first boot (tty1) before getty starts. Guides the user through:
#   1. Audio interface detection and selection
#   2. WiFi configuration
#   3. Hostname setting
#   4. API key generation
#   5. JACK device configuration
#
# After completion, the wizard disables itself, enables the mixer services,
# and reboots into normal operation.

set -euo pipefail

# ─── Colours ─────────────────────────────────────────────────────────────────

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
BOLD='\033[1m'
NC='\033[0m'

# ─── Configuration paths ────────────────────────────────────────────────────

JACKD_SERVICE="/etc/systemd/system/jackd.service"
MIXER_API_SERVICE="/etc/systemd/system/mixer-api.service"
MIXER_UI_SERVICE="/etc/systemd/system/mixer-ui.service"
CONFIG_TXT="/boot/config.txt"
CMDLINE_TXT="/boot/cmdline.txt"
WPA_CONF="/etc/wpa_supplicant/wpa_supplicant.conf"
HOSTNAME_FILE="/etc/hostname"
HOSTS_FILE="/etc/hosts"

# ─── Helper functions ────────────────────────────────────────────────────────

header() {
    clear
    echo -e "${BLUE}${BOLD}"
    echo "╔══════════════════════════════════════════╗"
    echo "║   RPi Audio Mixer — First-Boot Setup      ║"
    echo "║   $1"
    echo "╚══════════════════════════════════════════╝"
    echo -e "${NC}"
    echo ""
}

prompt() {
    local var_name="$1"
    local default="$2"
    local question="$3"
    local value

    echo -en "${GREEN}${question}${NC} [${default}]: "
    read -r value
    value="${value:-$default}"
    eval "$var_name=\"$value\""
}

prompt_yn() {
    local question="$1"
    local default="${2:-y}"
    local answer

    while true; do
        echo -en "${GREEN}${question}${NC} (y/n) [${default}]: "
        read -r answer
        answer="${answer:-$default}"
        case "$answer" in
            [Yy]*) return 0 ;;
            [Nn]*) return 1 ;;
            *) echo "Please answer y or n" ;;
        esac
    done
}

press_enter() {
    echo ""
    echo -n "Press Enter to continue..."
    read -r
}

# ─── 1. Welcome ──────────────────────────────────────────────────────────────

header "Welcome"

echo "This wizard will configure your Raspberry Pi Audio Mixer."
echo "You'll need:"
echo "  - USB audio interface connected"
echo "  - (Optional) WiFi network name and password"
echo "  - (Optional) Touchscreen connected via HDMI+USB"
echo ""
echo "This only runs once. Settings can be changed later via:"
echo "  /opt/rpi-mixer/config/  — audio/jack/carla configs"
echo "  raspi-config              — system settings"
echo ""
press_enter

# ─── 2. Audio Interface Detection ────────────────────────────────────────────

header "Step 1/5: Audio Interface"

echo "Detecting USB audio interfaces..."
echo ""

# List sound cards
ALSA_CARDS=""
if command -v aplay >/dev/null 2>&1; then
    ALSA_CARDS=$(aplay -l 2>/dev/null | grep -E '^card [0-9]' || true)
fi

if [[ -z "$ALSA_CARDS" ]]; then
    echo -e "${YELLOW}No sound cards detected!${NC}"
    echo ""
    echo "Make sure your USB audio interface is connected."
    echo "You can continue anyway and configure later."
    echo ""

    if prompt_yn "Continue without audio interface?" "y"; then
        echo "Skipping audio interface config."
    else
        echo "Please connect your audio interface and reboot."
        echo "The setup wizard will run again on next boot."
        exit 0
    fi
else
    echo "Found sound cards:"
    echo "$ALSA_CARDS"
    echo ""

    # Detect USB audio card
    USB_CARD=""
    if aplay -l 2>/dev/null | grep -qi "USB"; then
        USB_CARD=$(aplay -l 2>/dev/null | grep -i "USB" | head -1 | awk '{print $2}' | tr -d ':')
        echo -e "${GREEN}USB audio interface detected: card $USB_CARD${NC}"
    else
        echo -e "${YELLOW}No USB audio card found. Using first available card.${NC}"
        USB_CARD=$(echo "$ALSA_CARDS" | head -1 | awk '{print $2}' | tr -d ':')
    fi

    echo ""
    prompt AUDIO_DEV "hw:USB" "ALSA device name for JACK?"

    # Update JACK service with detected device
    sed -i "s/-d hw:USB/-d $AUDIO_DEV/" "$JACKD_SERVICE" 2>/dev/null || true

    # Also update jackdrc
    mkdir -p /etc/jack
    sed -i "s/-d hw:USB/-d $AUDIO_DEV/" /etc/jackdrc 2>/dev/null || true
    echo "/usr/bin/jackd -P 70 -t 2000 -d alsa -d $AUDIO_DEV -r 48000 -p 128 -n 3 -M -X seq" > /etc/jackdrc
fi

press_enter

# ─── 3. WiFi Configuration ───────────────────────────────────────────────────

header "Step 2/5: Network"

# Check if Ethernet is connected
ETH_CONNECTED=false
if ip link show eth0 2>/dev/null | grep -q "state UP"; then
    ETH_CONNECTED=true
    echo -e "${GREEN}Ethernet connected.${NC}"
    echo ""
fi

if prompt_yn "Configure WiFi?" "n"; then
    prompt WIFI_SSID "" "WiFi network name (SSID)"
    echo -n "WiFi password: "
    read -s WIFI_PASS
    echo ""

    # Remove WiFi disable from config.txt
    sed -i 's/^dtoverlay=disable-wifi/#dtoverlay=disable-wifi/' "$CONFIG_TXT" 2>/dev/null || true

    # Write wpa_supplicant config
    cat > "$WPA_CONF" <<WIFIEOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid="$WIFI_SSID"
    psk="$WIFI_PASS"
    key_mgmt=WPA-PSK
}
WIFIEOF
    chmod 600 "$WPA_CONF"
    echo -e "${GREEN}WiFi configured.${NC}"
else
    echo "Skipping WiFi configuration."
fi

echo ""
echo "Network status:"
ip -4 addr show | grep -E "inet " | grep -v "127.0.0.1" | sed 's/^/  /' || echo "  No network interfaces active"

press_enter

# ─── 4. Hostname ─────────────────────────────────────────────────────────────

header "Step 3/5: Hostname"

CURRENT_HOSTNAME=$(hostname 2>/dev/null || cat "$HOSTNAME_FILE" 2>/dev/null || echo "pi-mixer")
prompt NEW_HOSTNAME "$CURRENT_HOSTNAME" "System hostname"

if [[ "$NEW_HOSTNAME" != "$CURRENT_HOSTNAME" ]]; then
    echo "$NEW_HOSTNAME" > "$HOSTNAME_FILE"
    sed -i "s/$CURRENT_HOSTNAME/$NEW_HOSTNAME/g" "$HOSTS_FILE" 2>/dev/null || true
    hostname "$NEW_HOSTNAME" 2>/dev/null || true
    echo -e "${GREEN}Hostname set to: $NEW_HOSTNAME${NC}"
    echo "  Local access: http://${NEW_HOSTNAME}.local:8080"
fi

press_enter

# ─── 5. API Key ──────────────────────────────────────────────────────────────

header "Step 4/5: Security"

CURRENT_API_KEY=$(grep "MIXER_API_KEY" "$MIXER_API_SERVICE" 2>/dev/null | grep -oP 'MIXER_API_KEY=\K[^"]+' | head -1 || echo "")

if [[ -z "$CURRENT_API_KEY" ]] || [[ "$CURRENT_API_KEY" == "MIXER_API_KEY_PLACEHOLDER" ]] || [[ "$CURRENT_API_KEY" == "mixer-local" ]]; then
    NEW_API_KEY=$(head -c 24 /dev/urandom | base64 | tr -dc 'a-zA-Z0-9' | head -c 24)
else
    NEW_API_KEY="$CURRENT_API_KEY"
fi

echo "API key for the mixer web UI and REST API:"
echo -e "  ${BOLD}${NEW_API_KEY}${NC}"
echo ""
echo "You'll need this to access the web interface from another device."
echo "Keep it safe. It can be changed in:"
echo "  $MIXER_API_SERVICE"
echo ""

if prompt_yn "Use a custom API key?" "n"; then
    prompt NEW_API_KEY "$NEW_API_KEY" "API key (no spaces)"
fi

# Update API key in service files
sed -i "s/--api-key [^ ]*/--api-key $NEW_API_KEY/" "$MIXER_API_SERVICE" 2>/dev/null || true
sed -i "s/--api-key [^ ]*/--api-key $NEW_API_KEY/" "$MIXER_UI_SERVICE" 2>/dev/null || true
sed -i "s/MIXER_API_KEY=[^ ]*/MIXER_API_KEY=$NEW_API_KEY/" "$MIXER_UI_SERVICE" 2>/dev/null || true

# Also update the env variable export line
sed -i "/^ExecStart.*mixer-api/,/^$/s/MIXER_API_KEY_PLACEHOLDER/$NEW_API_KEY/" "$MIXER_API_SERVICE" 2>/dev/null || true

echo -e "${GREEN}API key updated.${NC}"

press_enter

# ─── 6. JACK Configuration ───────────────────────────────────────────────────

header "Step 5/5: Audio Settings"

echo "JACK audio server settings:"
echo ""

prompt SAMPLE_RATE "48000" "Sample rate (44100/48000/96000)"
prompt BUFFER_SIZE "128" "Buffer size (64/128/256/512 — lower = less latency)"
prompt PERIODS "3" "Periods per buffer (2 or 3)"

# Update JACK service
sed -i "s/-r [0-9]*/-r $SAMPLE_RATE/" "$JACKD_SERVICE" 2>/dev/null || true
sed -i "s/-p [0-9]*/-p $BUFFER_SIZE/" "$JACKD_SERVICE" 2>/dev/null || true
sed -i "s/-n [0-9]*/-n $PERIODS/" "$JACKD_SERVICE" 2>/dev/null || true

# Calculate approximate latency
LATENCY_MS=$(echo "scale=1; ($BUFFER_SIZE * $PERIODS) / ($SAMPLE_RATE / 1000)" | bc 2>/dev/null || echo "?")
echo ""
echo -e "${GREEN}JACK configured:${NC}"
echo "  Sample rate: $SAMPLE_RATE Hz"
echo "  Buffer size: $BUFFER_SIZE frames"
echo "  Periods:     $PERIODS"
echo "  Latency:     ~${LATENCY_MS}ms round-trip"
echo ""
echo "Lower latency requires more CPU. If you hear xruns (clicks/pops),"
echo "increase buffer size or periods in: $JACKD_SERVICE"

press_enter

# ─── 7. Touchscreen Check ────────────────────────────────────────────────────

header "Touchscreen (optional)"

echo "If a touchscreen is connected via HDMI+USB, the Kivy touch UI"
echo "will start automatically on boot."
echo ""

if prompt_yn "Enable touchscreen UI on boot?" "y"; then
    systemctl enable mixer-ui.service 2>/dev/null || true
    echo -e "${GREEN}Touchscreen UI enabled.${NC}"

    # Check HDMI connection
    if tvservice -s 2>/dev/null | grep -q "HDMI"; then
        echo "  HDMI display detected."
    else
        echo -e "  ${YELLOW}HDMI display not detected. UI may not be visible.${NC}"
    fi
else
    systemctl disable mixer-ui.service 2>/dev/null || true
    echo "Touchscreen UI disabled."
    echo "Start manually: sudo systemctl start mixer-ui"
fi

press_enter

# ─── 8. Finalize ─────────────────────────────────────────────────────────────

header "Setup Complete"

echo "Configuration summary:"
echo "  Hostname:      $(cat $HOSTNAME_FILE 2>/dev/null || echo unknown)"
echo "  Audio device:  ${AUDIO_DEV:-hw:USB}"
echo "  JACK:          ${SAMPLE_RATE:-48000}Hz / ${BUFFER_SIZE:-128}frames / ${PERIODS:-3}periods"
echo "  API key:       ${NEW_API_KEY:-mixer-local}"
echo "  Web UI:        http://$(cat $HOSTNAME_FILE 2>/dev/null || echo pi-mixer).local:8080"
echo "  SSH:           ssh pi@$(cat $HOSTNAME_FILE 2>/dev/null || echo pi-mixer).local"
echo ""

# Enable services
log "Enabling mixer services..."
systemctl enable jackd.service 2>/dev/null || true
systemctl enable mixer-api.service 2>/dev/null || true
systemctl daemon-reload 2>/dev/null || true

# Disable this wizard
log "Disabling first-boot wizard..."
systemctl disable mixer-firstboot.service 2>/dev/null || true

# Write setup-complete marker
date -u +%Y-%m-%dT%H:%M:%SZ > /etc/mixer-setup-complete

echo -e "${GREEN}${BOLD}Rebooting in 5 seconds...${NC}"
echo ""
echo "After reboot, the mixer will start automatically."
echo "  Web UI:  http://$(cat $HOSTNAME_FILE 2>/dev/null || echo pi-mixer).local:8080"
echo "  API Key: ${NEW_API_KEY:-mixer-local}"
echo ""

sleep 5
reboot