namespace backend.Install;

public class InstallScriptBuilder
{
    public string Build(string backendUrl)
    {
        return $$"""
#!/usr/bin/env bash
# Smart Assistant installer (idempotent). Re-run to upgrade.
set -euo pipefail

BACKEND_URL="{{backendUrl}}"
ASSISTANT_HOME="$HOME/assistant"
RESET=0
for arg in "$@"; do
    case "$arg" in
        --reset) RESET=1 ;;
    esac
done

echo "Installing system deps (sudo password may be prompted)..."
sudo apt-get update -qq
sudo apt-get install -y --no-install-recommends python3-venv libportaudio2 alsa-utils

mkdir -p "$ASSISTANT_HOME/code" "$ASSISTANT_HOME/state"

if [ ! -d "$ASSISTANT_HOME/.venv" ]; then
    python3 -m venv "$ASSISTANT_HOME/.venv"
fi

echo "Downloading client bundle from $BACKEND_URL ..."
curl -fsSL "$BACKEND_URL/client.tar.gz" | tar -xz -C "$ASSISTANT_HOME/code"

"$ASSISTANT_HOME/.venv/bin/pip" install --quiet -r "$ASSISTANT_HOME/code/requirements.txt"
"$ASSISTANT_HOME/.venv/bin/pip" install --quiet --no-deps -r "$ASSISTANT_HOME/code/requirements-nodeps.txt"

if [ "$RESET" -eq 1 ]; then
    rm -f "$ASSISTANT_HOME/state/config.json"
fi

if [ ! -f "$ASSISTANT_HOME/state/config.json" ]; then
    echo
    read -r -p "Pairing code: " CODE
    "$ASSISTANT_HOME/.venv/bin/python" -m client.pair --backend "$BACKEND_URL" --code "$CODE"
fi

mkdir -p "$HOME/.config/systemd/user"
cat > "$HOME/.config/systemd/user/assistant.service" <<UNIT
[Unit]
Description=Smart Assistant Pi client
After=network-online.target

[Service]
Environment=PA_ALSA_PLUGHW=1
ExecStart=$ASSISTANT_HOME/.venv/bin/python -m client.main
WorkingDirectory=$ASSISTANT_HOME/code
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target
UNIT

loginctl enable-linger "$USER" 2>/dev/null || true
systemctl --user daemon-reload
systemctl --user enable --now assistant
echo "Done. systemctl --user status assistant"
""";
    }
}