#!/usr/bin/env miaou-bash

# 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)
readonly BACKUP='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"
      echo "read: $user_bashrc"
      [[ ! -f "$user_bashrc" ]] && continue
      cmp -s /etc/skel/.bashrc "$user_bashrc" && continue

      local first_change
      if first_change=$(diff /etc/skel/.bashrc "$user_bashrc" | head -n1); then
        :
      else
        if [[ $first_change =~ $appended_regex ]]; then
          if new_lines=$(diff /etc/skel/.bashrc "$user_bashrc" | grep '^> ' | sed 's/^> //'); then
            :
          else
            # echo -e "$new_lines"

            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 <$user> merged succesfully"
          fi
        else
          local backup="$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: $backup"
        fi
      fi
    done
    sudo mv /etc/skel/.bashrc /etc/skel/.bashrc.ORIGINAL
    echo 'fixing users .bashrc...DONE'
  fi
  sudo ln -sf "$MIAOU_BASH_DIR"/etc/skel/.bashrc /etc/skel/.bashrc
}

function link_etc {
  local filename="$1" subfolder="${2:-}"
  local link_name="$filename"
  [[ -v LINK_NAME ]] && link_name="$LINK_NAME"

  local source="$MIAOU_BASH_DIR/etc"
  local destination="/etc"
  [[ -n "$subfolder" ]] && source+="/${subfolder}" && destination+="/${subfolder}"
  if [[ -L "$destination/$link_name" ]]; then
    if [[ "$(readlink "$destination/$link_name")" != "$source/$filename" ]]; then
      ln -sf "$source/$filename" "$destination/$link_name"
      echo "link $source/$link_name updated"
    fi
  else
    if [[ -f "$destination/$link_name" ]]; then
      mv "$destination/$link_name" "$destination/$link_name.$BACKUP"
      echo "$destination/$link_name.$BACKUP saved!"
    fi
    ln -s "$source/$filename" "$destination/$link_name"
    echo "link $source/$link_name 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 vimrc.core vim
  link_etc vimrc.miaou vim
  link_etc vimrc.rookie vim

  if in_azerty_zone 2>/dev/null; then
    link_etc vimrc.azerty vim
    LINK_NAME=vimrc.local link_etc vimrc.local.azerty vim
  else
    link_etc vimrc.local vim
  fi
  link_etc 20-miaou-bash.sh profile.d
  link_etc bash.bashrc
  link_etc inputrc # last command required to detect successful installation
}

function force_reload {
  bind -f /etc/inputrc 2>/dev/null # arch: dismiss harmless warning
  source /etc/profile
}

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!

  sudo mkdir -p /etc/ghostty
  link_etc config ghostty

  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[$user]}"
    local user_ghostty_config="$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
}

# MAIN

source "$MIAOU_BASH_DIR/lib/functions.bash"
assert_root

DISTRO_LIKE=$(fetch_distro_like)
install_required_packages
fix_users_bashrc
fix_terminfo_ghostty
ghostty_global_config
link_config_files
force_reload