#!/bin/bash

# blob:summary=Move off the Omarchy package repository and remove it from pacman.conf
# blob:args=[--apply]
# blob:requires-sudo=true

set -e

pacman_conf=/etc/pacman.conf
apply=false
[[ ${1-} == --apply ]] && apply=true

drop_packages=(
  omarchy
  omarchy-keyring
  omarchy-settings
  omarchy-nvim
  omacalc
  omacut
  omawrite
  tensaku
  tobi-try
  cliamp
  herdr
  ttfx
  linux-omarchy
  linux-omarchy-headers
  asdcontrol
)

substitutions=(
  "ttf-jetbrains-mono-nerd-basic:ttf-jetbrains-mono-nerd"
  "hyprland-preview-share-picker:hyprland-preview-share-picker-git"
)

aur_managed=(
  aether
  limine-mkinitcpio-hook
  limine-snapper-sync
  localsend
  minecraft-launcher
  mise-bin
  spotify
  ttf-ia-writer
  tzupdate
  ufw-docker
  visual-studio-code-bin
  xdg-terminal-exec
  yaru-icon-theme
  yay
)

installed() {
  pacman -Q "$1" &>/dev/null
}

heading() {
  printf '\n%s\n' "$1"
}

if ! grep -q '^\[omarchy\]' "$pacman_conf"; then
  echo "The [omarchy] repository is already absent from $pacman_conf."
  exit 0
fi

echo "Migrating off the Omarchy package repository."
echo
echo "Booted kernel: $(uname -r)"

if ! installed linux; then
  echo
  echo "REFUSING: the stock 'linux' package is not installed, and this would" >&2
  echo "remove linux-omarchy. Install 'linux' first." >&2
  exit 1
fi

heading "Remove (Omarchy's own software, and hardware support this machine does not use):"
for package in "${drop_packages[@]}"; do
  installed "$package" && echo "  $package"
done

heading "Replace with an equivalent:"
for pair in "${substitutions[@]}"; do
  from=${pair%%:*}
  to=${pair##*:}
  installed "$from" && echo "  $from -> $to"
done

heading "Keep, rebuilt from the AUR on the next update:"
for package in "${aur_managed[@]}"; do
  installed "$package" && echo "  $package"
done

heading "Then: comment out [omarchy] in $pacman_conf and resync."

if [[ $apply == false ]]; then
  echo
  echo "This was a dry run. Re-run with --apply to carry it out."
  exit 0
fi

echo
read -rp "Apply all of the above? [y/N] " answer
[[ $answer == [yY] ]] || exit 0

blob-sudo-keepalive

for pair in "${substitutions[@]}"; do
  from=${pair%%:*}
  to=${pair##*:}
  installed "$from" || continue
  echo "Installing $to..."
  if pacman -Sl core extra multilib 2>/dev/null | awk -v n="$to" '$2==n {found=1} END {exit !found}'; then
    sudo pacman -S --needed --noconfirm "$to"
  else
    yay -S --needed --noconfirm "$to"
  fi
  sudo pacman -Rdd --noconfirm "$from" || true
done

to_remove=()
for package in "${drop_packages[@]}"; do
  installed "$package" && to_remove+=("$package")
done
if (( ${#to_remove[@]} )); then
  echo "Removing ${#to_remove[@]} package(s)..."
  sudo pacman -Rns --noconfirm "${to_remove[@]}"
fi

backup="$pacman_conf.bak.$(date +%s)"
echo "Backing up $pacman_conf to $backup"
sudo cp "$pacman_conf" "$backup"

sudo awk '
  /^\[omarchy\]/ { in_block = 1; print "# [omarchy] removed by blob-repo-migrate"; next }
  in_block && /^\[/ { in_block = 0 }
  in_block && /^Server[[:space:]]*=/ { print "# " $0; next }
  in_block && /^[[:space:]]*$/ { in_block = 0 }
  { print }
' "$pacman_conf" > /tmp/pacman.conf.blob && sudo install -m644 /tmp/pacman.conf.blob "$pacman_conf"
rm -f /tmp/pacman.conf.blob

echo "Resyncing package databases..."
sudo pacman -Syy

heading "Done. Remaining foreign packages (now AUR-managed):"
pacman -Qmq | sed 's/^/  /'

heading "Next steps:"
echo "  blob update              rebuilds the AUR packages above from source"
echo "  pacman -Qtdq             check for orphans the removals left behind"
echo "  $backup   restore point if anything is wrong"