#!/usr/bin/env bash
# Distro detection + small dispatch layer so the rest of the installer can
# stay distro-agnostic. Two backends supported today: Arch (Omarchy) and
# Debian/Ubuntu.
#
# Sourced once at the top of install.sh / uninstall.sh. detect_distro must
# run before any of the dispatch helpers; require_supported_distro calls it
# for you.

# Populated by detect_distro:
#   DISTRO          - "arch" | "debian" (ubuntu folds into debian)
#   DISTRO_ID       - raw ID from /etc/os-release (e.g. "ubuntu", "arch")
#   DISTRO_VERSION  - VERSION_ID from /etc/os-release (e.g. "24.04"), empty on Arch
detect_distro() {
  if [[ -n "${DISTRO:-}" ]]; then
    return 0
  fi

  local id="" id_like="" version_id=""
  if [[ -r /etc/os-release ]]; then
    # shellcheck disable=SC1091
    . /etc/os-release
    id="${ID:-}"
    id_like="${ID_LIKE:-}"
    version_id="${VERSION_ID:-}"
  fi

  DISTRO_ID="$id"
  DISTRO_VERSION="$version_id"

  case "$id" in
    arch|manjaro|endeavouros|omarchy)
      DISTRO="arch"
      ;;
    ubuntu|debian|pop|linuxmint)
      DISTRO="debian"
      ;;
    *)
      # Fall back to ID_LIKE.
      if [[ " $id_like " == *" arch "* ]]; then
        DISTRO="arch"
      elif [[ " $id_like " == *" debian "* || " $id_like " == *" ubuntu "* ]]; then
        DISTRO="debian"
      elif [[ -f /etc/arch-release ]]; then
        DISTRO="arch"
      elif command -v apt-get >/dev/null 2>&1; then
        DISTRO="debian"
      elif command -v pacman >/dev/null 2>&1; then
        DISTRO="arch"
      else
        DISTRO="unknown"
      fi
      ;;
  esac
  export DISTRO DISTRO_ID DISTRO_VERSION
}

require_supported_distro() {
  detect_distro
  case "$DISTRO" in
    arch)
      if ! command -v yay >/dev/null 2>&1; then
        err "yay is required to install AUR packages on Arch. Install yay first."
        exit 1
      fi
      ;;
    debian)
      if ! command -v apt-get >/dev/null 2>&1; then
        err "apt-get not found — Debian/Ubuntu install path requires it."
        exit 1
      fi
      ;;
    *)
      err "Unsupported distro (ID='${DISTRO_ID:-unknown}'). Supported: Arch family, Debian/Ubuntu family."
      exit 1
      ;;
  esac
}

# ---------------------------------------------------------------------------
# Package query / install dispatch.

# True if package is installed.
pkg_installed() {
  case "$DISTRO" in
    arch)   pacman -Qi "$1" >/dev/null 2>&1 ;;
    debian) dpkg-query -W -f='${Status}' "$1" 2>/dev/null | grep -q '^install ok installed$' ;;
    *)      return 1 ;;
  esac
}

# Install one or more packages. Idempotent: only installs missing ones.
# On Arch, uses yay; on Debian/Ubuntu, uses apt-get. The Arch-only yay_install
# function below is kept as an alias for code that explicitly wants AUR.
pkg_install() {
  local missing=()
  local p
  for p in "$@"; do
    pkg_installed "$p" || missing+=("$p")
  done
  if [[ ${#missing[@]} -eq 0 ]]; then
    ok "Already installed: $*"
    return 0
  fi
  info "Installing: ${missing[*]}"
  case "$DISTRO" in
    arch)
      yay -S --needed --noconfirm "${missing[@]}"
      ;;
    debian)
      _apt_ensure_updated
      as_root env DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends "${missing[@]}"
      ;;
    *)
      err "Don't know how to install packages on distro '$DISTRO'"
      return 1
      ;;
  esac
}

# Cache `apt-get update` for this script run; running it on every pkg_install
# call would be slow and noisy.
_APT_UPDATED=0
_apt_ensure_updated() {
  [[ "$_APT_UPDATED" -eq 1 ]] && return 0
  info "Refreshing apt package lists"
  as_root env DEBIAN_FRONTEND=noninteractive apt-get update -y >/dev/null
  _APT_UPDATED=1
}

# Install a local .deb file. Resolves its dependencies via apt.
deb_install_local() {
  local deb_path="$1"
  [[ -f "$deb_path" ]] || { err "deb not found: $deb_path"; return 1; }
  _apt_ensure_updated
  info "Installing $(basename "$deb_path") via apt-get"
  as_root env DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends "$deb_path"
}

# Remove a package if installed. Quiet no-op if absent.
pkg_remove() {
  local p
  for p in "$@"; do
    pkg_installed "$p" || continue
    case "$DISTRO" in
      arch)   as_root pacman -Rns --noconfirm "$p" ;;
      debian) as_root env DEBIAN_FRONTEND=noninteractive apt-get purge -y "$p" ;;
    esac
  done
}

# ---------------------------------------------------------------------------
# CA trust-store dispatch.
#
# Arch:     /etc/ca-certificates/trust-source/anchors/<name>.pem  + update-ca-trust
# Debian:   /usr/local/share/ca-certificates/<name>.crt           + update-ca-certificates

# Path where we'll drop our CA anchor for this distro. Stable across runs.
ca_anchor_path() {
  case "$DISTRO" in
    arch)   echo "/etc/ca-certificates/trust-source/anchors/omarchy-stream-ca.pem" ;;
    debian) echo "/usr/local/share/ca-certificates/omarchy-stream-ca.crt" ;;
    *)      echo "" ;;
  esac
}

# Refresh the system trust store after writing a new anchor.
ca_update_trust() {
  case "$DISTRO" in
    arch)   as_root update-ca-trust extract >/dev/null ;;
    debian) as_root update-ca-certificates >/dev/null ;;
    *)      warn "Unknown distro — CA trust update skipped"; return 1 ;;
  esac
}