# CONSTANTS

readonly AZERTY_ZONES=(
  'Europe/Paris'
  'Indian/Reunion'
  'Indian/Mayotte'
  'America/Cayenne'
  'America/Guadeloupe'
  'America/Martinique'
  'Pacific/Noumea'
  'Pacific/Tahiti'
)
readonly REQUIRED_PKGS=(file jq vim git bash-completion)
readonly BACKUP_SUFFIX='.ORIGINAL'

# FUNCTIONS

function usr_bin_miaou_bash {
  ln -sf "$MIAOU_BASH_DIR/bin/miaou-bash" /usr/bin/miaou-bash
}

function install_required_packages {
  . "$MIAOU_BASH_DIR"/tools/pkg_add "${REQUIRED_PKGS[@]}"
}

function fix_users_bashrc {
  if [[ -f /etc/skel/.bashrc ]] && ! cmp -s /etc/skel/.bashrc "$MIAOU_BASH_DIR"/etc/skel/.bashrc; then
    echo 'fixing users .bashrc...'
    local skel_count_lines
    skel_count_lines=$(wc -l /etc/skel/.bashrc | cut -d' ' -f1)

    local appended_regex="^${skel_count_lines}a"

    # for pre-existant users
    build_associative_user_homes
    for user in "${!USER_HOMES[@]}"; do
      local user_bashrc="${USER_HOMES[$user]}/.bashrc"
      local first_change
      echo "read: $user_bashrc"
      [[ ! -f "$user_bashrc" ]] && continue
      if cmp -s /etc/skel/.bashrc "$user_bashrc"; then
        echo 'no change: replaced by skel'
        sudo -u "$user" -- cp "$MIAOU_BASH_DIR"/etc/skel/.bashrc "$user_bashrc"
      elif first_change=$(diff /etc/skel/.bashrc "$user_bashrc" | head -n1); then
        echo 'no change: should not occur'
      elif [[ $first_change =~ $appended_regex ]]; then
        if new_lines=$(diff /etc/skel/.bashrc "$user_bashrc" | grep '^> ' | sed 's/^> //'); then
          echo 'no new lines: should not occur'
        else
          sudo -u "$user" -- cp "$MIAOU_BASH_DIR"/etc/skel/.bashrc "$user_bashrc"
          echo -e "$new_lines" | sudo -u "$user" -- tee -a "$user_bashrc"
          echo "INFO: .bashrc for user <$user> merged succesfully"
        fi
      elif ! cmp -s "$MIAOU_BASH_DIR"/etc/skel/.bashrc "$user_bashrc"; then
        local backup="$user_bashrc".ORIGINAL
        sudo -u "$user" -- mv "$user_bashrc" "$backup"
        sudo -u "$user" -- cp "$MIAOU_BASH_DIR"/etc/skel/.bashrc "$user_bashrc"
        >&2 echo "WARN: .bashrc for user <$user> has forked from skeleton, please resolve conflict manually from backup: $backup"
      fi
    done
    sudo mv /etc/skel/.bashrc /etc/skel/.bashrc.ORIGINAL
    echo 'fixing users .bashrc...DONE'
  fi
  sudo ln -sf "$MIAOU_BASH_DIR"/etc/skel/.bashrc /etc/skel/.bashrc
}

function link_etc {
  local source="$MIAOU_BASH_DIR/etc/$1"
  local target="/etc/${2:-$1}"

  if [[ -L "$target" ]]; then
    if [[ "$(readlink "$target")" != "$source" ]]; then
      sudo ln -sf "$source" "$target"
      echo "link $target updated"
    fi
  else
    if [[ -f "$target" ]]; then
      sudo mv "$target" "$target$BACKUP_SUFFIX"
      echo "$target$BACKUP_SUFFIX saved!"
    fi
    sudo mkdir -p "$(dirname "$target")"
    sudo ln -s "$source" "$target"
    echo "link $target created"
  fi
}

function arch_profile {
  if ! cmp -s /etc/profile "$MIAOU_BASH_DIR"/etc/profile.arch; then
    sudo cp "$MIAOU_BASH_DIR"/etc/profile.arch /etc/profile
    echo 'arch /etc/profile fixed!'
  fi
}

function arch_vimrc {
  mkdir -p /etc/vim
  if ! grep -q '/etc/vim/vimrc.local' /etc/vimrc; then
    cat >>/etc/vimrc <<EOF
" Source a global configuration file if available
if filereadable("/etc/vim/vimrc.local")
  source /etc/vim/vimrc.local
endif
EOF
    echo "vimrc source /etc/vim/vimrc.local if any"
  fi
}

function is_arch_like {
  [[ "$DISTRO_LIKE" == 'arch' ]]
}

function is_debian_like {
  [[ "$DISTRO_LIKE" == 'debian' ]]
}

function link_config_files {
  is_arch_like && arch_vimrc && arch_profile

  link_etc vim/vimrc.core
  link_etc vim/vimrc.miaou
  link_etc vim/vimrc.rookie

  if in_azerty_zone 2>/dev/null; then
    link_etc vim/vimrc.azerty
    link_etc vim/vimrc.local.azerty vim/vimrc.local
  else
    link_etc vim/vimrc.local
  fi
  link_etc profile.d/zz-miaou-bash.sh
  link_etc bash.bashrc
  link_etc bash_completion.d/miaou-bash.complete
  link_etc inputrc # last command required to detect successful installation
}

function in_azerty_zone {
  [[ -L /etc/localtime ]] || return 4

  local zone
  zone=$(readlink /etc/localtime)
  zone="${zone#/usr/share/zoneinfo/}" # remove prefix
  for i in "${AZERTY_ZONES[@]}"; do [[ "$zone" == "$i" ]] && return; done
  return 5
}

function fix_terminfo_ghostty {
  if ! infocmp xterm-ghostty >/dev/null 2>&1; then
    tic -x "$MIAOU_BASH_DIR"/assets/terminfo/ghostty 2>/dev/null
    echo 'terminfo ghostty succesfully compiled'
  fi
}

function build_associative_user_homes {
  if [[ ! -v USER_HOMES ]]; then
    declare -gA USER_HOMES
    while IFS=: read -r user _ uid _ _ home _; do
      if [[ $uid -ge 1000 && $user != 'nobody' ]]; then
        USER_HOMES[$user]="$home"
      fi
    done </etc/passwd
  fi
}

function ghostty_global_config {
  ! command -v ghostty >/dev/null && return # ghostty not yet installed!

  link_etc ghostty/config

  if [[ ! -f /etc/skell/.config/ghostty/config ]]; then
    # ghostty config skeleton for new users
    mkdir -p /etc/skel/.config/ghostty
    echo 'config-file = /etc/ghostty/config' >/etc/skel/.config/ghostty/config
  fi

  # change ghostty configuration for any normal user
  build_associative_user_homes
  for user in "${!USER_HOMES[@]}"; do
    local user_home="${USER_HOMES[$user]}"
    if [[ ! -d "$user_home" ]]; then
      >&2 echo "WARNING: home directory: $user_home missing for user: $user! bypassing..."
      continue
    fi
    local user_ghostty_config="$user_home"/.config/ghostty/config.ghostty
    if [[ ! -f "$user_ghostty_config" ]]; then
      sudo -u "$user" -- mkdir -p "$user_home"/.config/ghostty
      echo -e "# global config\nconfig-file = /etc/ghostty/config\n" |
        sudo -u "$user" -- tee "$user_ghostty_config" >/dev/null
      echo "new predefined ghostty config file for user: $user"
    elif ! grep -q 'config-file = /etc/ghostty/config' "$user_ghostty_config"; then
      # prepend on top
      echo -e "# global config\nconfig-file = /etc/ghostty/config\n" |
        sudo -u "$user" -- tee "$user_ghostty_config".tmp >/dev/null
      cat "$user_ghostty_config" |
        sudo -u "$user" -- tee -a "$user_ghostty_config".tmp >/dev/null
      rm "$user_ghostty_config"
      sudo -u "$user" mv "$user_ghostty_config".tmp "$user_ghostty_config"
      echo "modify pre-existant ghostty config file for user: $user"
    fi
  done
}

function link_miaou_bash {
  sudo ln -sf "$MIAOU_BASH_DIR"/bin/miaou-bash /usr/bin/
}

function create_sudoers {
  if [[ ! -f /etc/sudoers.d/miaou-bash ]]; then
    echo 'Defaults:%sudo env_keep += "MIAOU_BASH_DIR"' | sudo tee /etc/sudoers.d/miaou-bash >/dev/null
    sudo chmod 440 /etc/sudoers.d/miaou-bash
  fi
}

function launch_hooks {
  find "$MIAOU_BASH_DIR"/hooks.d -maxdepth 1 -name "after-upgrade*" -type f -executable |
    sort |
    while read -r hook; do
      echo "Processing: $hook"

      # shellcheck disable=SC1090
      if ! miaou-bash "$hook" 3>/dev/null 2>&1; then
        echo 'WARNING: hook failure, bypassed'
      fi
      echo ----------------------
    done
}

function apply_mode {
  if [[ "$MIAOU_BASH_MODE" == hosted ]]; then
    sudo mkdir /var/lib/miaou-bash -p
    sudo cp "$MIAOU_BASH_DIR"/.semver_git_tag /var/lib/miaou-bash/semver_current
  fi
}

# MAIN

source "$MIAOU_BASH_DIR"/lib/functions.bash

assert_root
fetch_distro_like
install_required_packages
fix_users_bashrc
fix_terminfo_ghostty
ghostty_global_config
link_config_files
link_miaou_bash
create_sudoers
fetch_mode
apply_mode
launch_hooks