#!/usr/bin/env bash
# Preflight: catch problems before we install anything.
# Fail fast and loud, with remediation hints.

preflight_all() {
  preflight_session
  preflight_remote_session
  preflight_gpu
  preflight_kms_modeset
  preflight_audio
  preflight_headless
}

preflight_session() {
  if [[ "${SESSION_TYPE:-}" != "wayland" ]]; then
    warn "Session type '$SESSION_TYPE' — KMS capture works at the DRM level so it can still succeed,"
    warn "but this installer's defaults assume Hyprland on Wayland."
  else
    ok "Wayland session detected"
  fi
}

preflight_remote_session() {
  # Sunshine's user service needs the local Wayland session to be reachable.
  # If we're over pure SSH (no forwarded DBUS / WAYLAND_DISPLAY), the service start
  # at the end of the install will fail. Warn now so the user knows.
  if [[ -n "${SSH_CONNECTION:-}" && -z "${WAYLAND_DISPLAY:-}" && -z "${DISPLAY:-}" ]]; then
    warn "Running over SSH without a graphical session. Packages will install,"
    warn "but the systemd --user service will only come up cleanly once you log in"
    warn "to Hyprland on the console. That's fine — just log in afterwards."
  fi
}

preflight_gpu() {
  case "$GPU_VENDOR" in
    nvidia)
      if ! command -v nvidia-smi >/dev/null 2>&1; then
        case "$DISTRO" in
          arch)
            warn "nvidia-smi not found yet — nvidia-utils will be installed shortly."
            ;;
          debian)
            # On Ubuntu the NVIDIA driver install isn't our job; we don't pull
            # in nvidia-driver-* because the right version depends on the
            # kernel / Secure Boot / cloud-vendor combo. Tell the user.
            err "nvidia-smi not found and no NVIDIA kernel module loaded."
            err "Install the driver before re-running this installer. Common paths on Ubuntu:"
            err "    sudo ubuntu-drivers install   # picks the recommended branch"
            err "    sudo apt install nvidia-driver-550-server   # explicit pin"
            err "Then reboot (or modprobe nvidia) so 'nvidia-smi -L' returns the GPU."
            exit 1
            ;;
        esac
        return 0
      fi
      if ! nvidia-smi -L >/dev/null 2>&1; then
        err "nvidia-smi exists but can't talk to the driver. Driver not loaded?"
        err "Check: 'lsmod | grep nvidia' and 'dmesg | grep -i nvidia'"
        exit 1
      fi
      ok "NVIDIA driver responsive ($(nvidia-smi -L | head -n1))"
      ;;
    amd)
      if ! lsmod | grep -q '^amdgpu'; then
        warn "amdgpu kernel module not loaded. Hardware encode (VAAPI) will likely fail until it is."
      else
        ok "amdgpu kernel module loaded"
      fi
      ;;
    intel)
      ok "Intel GPU — encoder packages will be installed in the packages step."
      ;;
  esac
}

preflight_kms_modeset() {
  # KMS capture needs nvidia-drm.modeset=1 on NVIDIA. Driver 560+ defaults to 1,
  # but if the user is on something older or has explicitly set 0, capture will fail.
  [[ "$GPU_VENDOR" == "nvidia" ]] || return 0

  # Cmdline check is read-only and reliable when explicitly set.
  if grep -q 'nvidia-drm.modeset=1' /proc/cmdline; then
    ok "nvidia-drm.modeset=1 set on kernel cmdline"
    return 0
  fi
  if grep -q 'nvidia-drm.modeset=0' /proc/cmdline; then
    err "nvidia-drm.modeset=0 is set on the kernel cmdline. KMS capture WILL fail."
    err "Remove it (e.g., from /boot/loader/entries/*.conf or /etc/kernel/cmdline + reinstall-kernels)"
    err "and reboot before running this installer."
    exit 1
  fi

  # Not on cmdline — check the runtime parameter. On 560+ this defaults to Y.
  # /sys file is root-readable; modinfo gives the default without sudo.
  local default=""
  if command -v modinfo >/dev/null 2>&1; then
    default="$(modinfo -F parm nvidia_drm 2>/dev/null | awk -F: '/^modeset:/ {print $2}' | head -n1 || true)"
  fi
  if [[ -n "$default" ]]; then
    info "nvidia_drm modeset default per modinfo: ${default## }"
  fi
  warn "nvidia-drm.modeset=1 not explicitly set on cmdline."
  warn "Modern drivers (≥560) default to enabled, so this is usually fine — but if KMS"
  warn "capture fails after install, add 'nvidia-drm.modeset=1' to your kernel cmdline."
}

preflight_audio() {
  # Sunshine captures audio via the PulseAudio API; on Omarchy that's pipewire-pulse.
  if pkg_installed pipewire-pulse; then
    ok "pipewire-pulse present (audio capture path OK)"
  else
    warn "pipewire-pulse is not installed. Audio capture may not work until it is."
  fi
}

preflight_headless() {
  # Only relevant in headless mode. Checks are non-fatal: install can proceed
  # even if the compositor isn't reachable right now (hooks just won't
  # function until it is).
  [[ "${STREAM_MODE:-}" == "headless" ]] || return 0

  case "${COMPOSITOR:-none}" in
    hyprland)
      ok "hyprctl on PATH"
      if [[ -n "${HYPRLAND_INSTANCE_SIGNATURE:-}" ]]; then
        ok "Hyprland instance signature present in environment"
      else
        local rt="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"
        if compgen -G "$rt/hypr/*/" >/dev/null 2>&1; then
          ok "Hyprland runtime directory found under $rt/hypr/"
        else
          warn "Hyprland not currently running. Install will proceed; hooks engage on next Hyprland login."
        fi
      fi
      ;;
    sway)
      ok "swaymsg/sway on PATH"
      local rt="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"
      if compgen -G "$rt/sway-ipc.*.sock" >/dev/null 2>&1; then
        ok "Sway IPC socket present under $rt"
      else
        info "Sway not running yet — install will start sway-headless.service before sunshine."
      fi
      ;;
    none|*)
      warn "No wlroots compositor detected. Install will attempt to install one (Sway on Debian/Ubuntu)."
      ;;
  esac

  if pkg_installed jq; then
    ok "jq installed (prep-cmd hooks have their parser)"
  else
    info "jq not installed yet — will be installed in the packages step."
  fi
}