#!/bin/bash

# Function to check if a package is installed
is_installed() {
  pacman -Qi "$1" &> /dev/null
}

# Function to check if a package is installed
is_group_installed() {
  pacman -Qg "$1" &> /dev/null
}

# Packages and Flatpaks you don't want, one name per line (# starts a comment).
# install_packages and install-flatpaks.sh leave them out, so update doesn't
# put back what you've removed.
SKIP_PACKAGES="$HOME/.config/coredesktop/skip-packages"

# Print each argument that isn't in SKIP_PACKAGES, one per line
without_skipped() {
  local -A skip=()
  local name
  if [ -f "$SKIP_PACKAGES" ]; then
    while read -r name _; do
      [[ -n "$name" && "$name" != \#* ]] && skip["$name"]=1
    done < "$SKIP_PACKAGES"
  fi
  for name in "$@"; do
    [ -n "${skip[$name]}" ] || echo "$name"
  done
}

# Function to install packages if not already installed
install_packages() {
  local packages=()
  local to_install=()

  local as_deps=()

  mapfile -t packages < <(without_skipped "$@")
  # pacman -Qdq with no names would list every dependency on the system
  [ ${#packages[@]} -ne 0 ] || return 0

  for pkg in "${packages[@]}"; do
    if ! is_installed "$pkg" && ! is_group_installed "$pkg"; then
      to_install+=("$pkg")
    fi
  done

  # A package first installed as another one's dependency becomes an orphan
  # when that one is removed, and updates.d/95-cleanup.sh removes orphans
  mapfile -t as_deps < <(pacman -Qdq "${packages[@]}" 2> /dev/null)
  if [ ${#as_deps[@]} -ne 0 ]; then
    sudo pacman -D --asexplicit "${as_deps[@]}" > /dev/null
  fi

  if [ ${#to_install[@]} -ne 0 ]; then
    echo "Installing: ${to_install[*]}"
    yay -S --noconfirm --answerdiff=None --answeredit=None --answerclean=None "${to_install[@]}"
  fi
}

FEDERATED_REPO_URL="https://gitea.federated.computer/api/packages/Federated_Computer/arch"
FEDERATED_REPO_KEY="6AB7C080D87C74BEE3925A026329376994F18B4E"

# Add Federated Computer's pacman repo, which Gitea serves and signs, and trust
# its key. Does nothing if both are already set up.
ensure_federated_repo() {
  if ! sudo pacman-key --list-keys "$FEDERATED_REPO_KEY" &> /dev/null; then
    curl -fsSL "$FEDERATED_REPO_URL/repository.key" | sudo pacman-key --add - || return 1
    sudo pacman-key --lsign-key "$FEDERATED_REPO_KEY" > /dev/null || return 1
  fi

  if ! grep -q '^\[federated\]' /etc/pacman.conf; then
    printf '\n[federated]\nSigLevel = Required DatabaseRequired\nServer = %s/$repo/$arch\n' \
      "$FEDERATED_REPO_URL" | sudo tee -a /etc/pacman.conf > /dev/null || return 1
  fi
}

# Function to install pipx applications if not already installed
install_pipx_apps() {
  local installed app status=0
  installed="$(pipx list --short 2> /dev/null | cut -d' ' -f1)"

  for app in "$@"; do
    if ! grep -qx "$app" <<< "$installed"; then
      echo "Installing $app with pipx..."
      pipx install "$app" || status=1
    fi
  done
  return $status
}

# Reinstall gext if missing or broken. Its pipx venv goes stale when Arch
# upgrades Python, and migrations run before updates.d/60-pipx.sh rebuilds it.
ensure_gext() {
  ~/.local/bin/gext --version &> /dev/null && return 0
  echo "gext missing or broken, reinstalling..."
  pipx uninstall gnome-extensions-cli &> /dev/null || true
  pipx install --python "$(which python3)" gnome-extensions-cli --system-site-packages
}

# Function to remove pacman/AUR packages if installed
remove_packages() {
  local packages=("$@")
  local to_remove=()

  # Match the exact name: pacman -Q also finds a package that provides it, such
  # as herdr-bin for herdr, which pacman -R won't remove by that name
  # An AUR package built with makepkg's debug option comes with pkg-debug,
  # which nothing depends on, so -Rns leaves it behind, and its files conflict
  # with the replacement's (voxtype-debug with voxtype-bin-debug)
  for pkg in "${packages[@]}"; do
    if [ "$(pacman -Qq "$pkg" 2> /dev/null)" = "$pkg" ]; then
      to_remove+=("$pkg")
    fi
    if [ "$(pacman -Qq "$pkg-debug" 2> /dev/null)" = "$pkg-debug" ]; then
      to_remove+=("$pkg-debug")
    fi
  done

  if [ ${#to_remove[@]} -ne 0 ]; then
    echo "Removing: ${to_remove[*]}"
    sudo pacman -Rns --noconfirm "${to_remove[@]}"
  fi
}

# Function to remove flatpak applications if installed
remove_flatpaks() {
  local flatpaks=("$@")
  local to_remove=()

  for pak in "${flatpaks[@]}"; do
    if flatpak info --system "$pak" &> /dev/null; then
      to_remove+=("$pak")
    fi
  done

  if [ ${#to_remove[@]} -ne 0 ]; then
    echo "Removing flatpaks: ${to_remove[*]}"
    sudo flatpak uninstall --system --noninteractive "${to_remove[@]}"
  fi
}

# Function to enable systemd services if not already enabled
# With --now, also start the services enabled here, after making systemd read
# the unit files that packages just installed
enable_services() {
  local now=()
  if [ "$1" = "--now" ]; then
    now=(--now)
    shift
    sudo systemctl daemon-reload
  fi
  for service in "$@"; do
    # audit records the services you turn off; leave those off
    if grep -qsx "system $service" "$HOME/.config/coredesktop/services-off"; then
      echo "$service is turned off (see audit)."
    elif ! systemctl is-enabled "$service" &> /dev/null; then
      echo "Enabling $service..."
      sudo systemctl enable "${now[@]}" "$service"
    else
      echo "$service is already enabled."
    fi
  done
}

# Run each script in migrations/ that hasn't run on this machine yet, oldest
# first. A migration is recorded as done only when it succeeds, and the first
# failure stops the run so a later migration never runs ahead of an earlier one.
run_migrations() {
  local dir="${COREDESKTOP:-$HOME/.local/share/coredesktop}/migrations"
  local state="$HOME/.local/state/coredesktop/migrations"
  local file name

  mkdir -p "$state"
  for file in "$dir"/*.sh; do
    [ -f "$file" ] || continue
    name="$(basename "$file")"
    [ -f "$state/$name" ] && continue

    echo "Running migration $name..."
    if ! bash "$file"; then
      echo "Migration $name failed; it will run again on the next update."
      return 1
    fi
    touch "$state/$name"
  done
}

# Output of the last update's pacman -Su, written by updates.d/10-pacman.sh
PACMAN_UPDATE_LOG="$HOME/.local/state/coredesktop/pacman-update.log"

# True if the last update rebuilt the initramfs and mkinitcpio reported a
# failure. Rebooting then can leave the machine unbootable.
initramfs_build_failed() {
  [ -f "$PACMAN_UPDATE_LOG" ] || return 1
  grep -q "Updating linux initcpios" "$PACMAN_UPDATE_LOG" || return 1
  grep -q "==> ERROR" "$PACMAN_UPDATE_LOG" && return 0

  # Every image built must report success. Older mkinitcpio says "==> Image
  # generation successful", newer says "==> Initcpio image generation successful".
  local built succeeded
  built="$(grep -c "==> Building image from preset" "$PACMAN_UPDATE_LOG")"
  succeeded="$(grep -cE "==> (Initcpio i|I)mage generation successful" "$PACMAN_UPDATE_LOG")"
  (( succeeded == 0 || succeeded < built ))
}

# pacman downloads from the first mirror in this list (system/mirrors.sh keeps
# it fresh). Overridable for the tests.
MIRRORLIST="${MIRRORLIST:-/etc/pacman.d/mirrorlist}"
# A mirror further behind Arch than this is stale; most sync every few hours.
# Used by version and updates.d/10-pacman.sh.
# shellcheck disable=SC2034
MIRROR_STALE_HOURS=24

# The first mirror in MIRRORLIST, without its /$repo/os/$arch
first_mirror() {
  sed -nE 's/^[[:space:]]*Server[[:space:]]*=[[:space:]]*//p' "$MIRRORLIST" 2> /dev/null \
    | head -n 1 | sed -E 's#/\$repo.*##'
}

# Print how many hours ago the first mirror last synced with Arch, from the
# timestamp mirrors publish in lastsync. Fails if it couldn't tell.
mirror_age_hours() {
  local mirror lastsync
  mirror="$(first_mirror)"
  [ -n "$mirror" ] || return 1
  lastsync="$(curl -sf --max-time 10 "$mirror/lastsync" 2> /dev/null)" || return 1
  [[ "$lastsync" =~ ^[0-9]+$ ]] || return 1
  echo $(( ($(date +%s) - lastsync) / 3600 ))
}

# Install a script atomically (copy to a temp file, then rename over the target)
# so a copy of it that is running right now keeps reading the old file
install_script() {
  local tmp
  tmp="$(mktemp "$2.XXXXXX")" && cp "$1" "$tmp" && chmod 755 "$tmp" && mv -f "$tmp" "$2"
}