#!/bin/bash

if [ -d "$1" ]; then
  NIXHOME=$1
elif [ -d "$(pwd)/nixhome" ]; then
  NIXHOME=$(pwd)/nixhome
else
  echo ""
  echo "::*** Enter [root path] or [leave blank] for default to [[$(pwd)]]"
  read -p "***:: " NIXHOME
  if [ -z "$NIXHOME" ]; then
    NIXHOME=$(pwd)
  fi
fi

if [ ! -e "$NIXHOME/.bashrc" ]; then 
  echo "××× [[$NIXHOME/.bashrc]] not exist! Exit now. ***"
  exit
else
  echo "√√√ NIXHOME = [[$NIXHOME]]"
fi
echo ""

# $2 应当为用户名
if [ "$2" == 'root' ]; then
  HomePath=/root
  TheUser=root
elif [ "$2" ]; then
  HomePath=/home/$2
  TheUser=$2
else
  # 可能是 root 或其他
  HomePath=~
  TheUser=$(whoami)
fi

if [ -d "$HomePath" ]; then

  pushd "$HomePath"
  
  homescriptlist=".emacs .emacs.lisp .bashrc .bash_profile .gitignore.global.txt"
  echo
  echo "::*** Copy or link scripts? [l] to link, [c] to copy, [g] to git import, [anything else] to omit:"
  read -p "***:: " CopyOrLinkScripts
  for homescript in $homescriptlist; do
    if [ -e "$homescript" ] || [ -L "$homescript" ]; then
      mv "$homescript" "$homescript.backup-$(date -u +%Y%m%dT%H%M%Sutc)"
    fi
    if [ "$CopyOrLinkScripts" == 'l' ]; then
      echo "--- Linking [[$NIXHOME/$homescript]] to [[$HomePath/$homescript]] ..."
      ln -s "$NIXHOME/$homescript" ./
    elif [ "$CopyOrLinkScripts" == 'c' ]; then
      echo "--- Copying [[$NIXHOME/$homescript]] to [[$HomePath/$homescript]] ..."
      cp -r "$NIXHOME/$homescript" ./
    elif [ "$CopyOrLinkScripts" == 'g' ]; then
      curl -sSLO "https://git.tic.cc/npm/sysconfig/raw/branch/main/nixhome/$homescript"
    fi
  done  

  echo

  if [ "$(uname)" == "Darwin" ]; then
    echo '--- No need to configure ./ssh/authorized_keys on Mac OS X. Exit now.'
  elif [ "$TheUser" != 'root' ]; then

    mkdir -p "$HomePath/.ssh"
    chmod 700 "$HomePath/.ssh"
    if [ "$2" ]; then
      # 由 root 指定新用户而创建的配置文件的 owner 是 root，而不是新用户，导致新用户无法读取该文件而密钥登录失败，因此要重设 owner。
      chown "$TheUser:$TheUser" "$HomePath/.ssh"
    fi
    if [ -f "$HomePath/.ssh/authorized_keys" ] || [ -L "$HomePath/.ssh/authorized_keys" ]; then
      mv "$HomePath/.ssh/authorized_keys" "$HomePath/.ssh/authorized_keys.backup-$(date -u +%Y%m%dT%H%M%Sutc)"
    fi

    echo "::*** Append or link or omit [[$HomePath/.ssh/authorized_keys]] to config ssh server? [a] for append, [l] for link, [anything else] for omit:"
    read -p "***:: " AuthorizedKeys

    if [ "$AuthorizedKeys" = 'l' ]; then
      echo "--- Linking [[$NIXHOME/authorized_keys]] to [[$HomePath/.ssh/authorized_keys]] ..."
      ln -s "$NIXHOME/.ssh/authorized_keys" "$HomePath/.ssh/authorized_keys"
      sudo chmod 644 "$HomePath/.ssh/authorized_keys" # 确保其他用户能读取 nixhome/.ssh/authorized_keys
    elif [ "$AuthorizedKeys" = 'a' ]; then
      echo "--- Copying [[$NIXHOME/authorized_keys]] to [[$HomePath/.ssh/authorized_keys]] ..."
      cat "$NIXHOME/.ssh/authorized_keys" >> "$HomePath/.ssh/authorized_keys"
      chmod 600 "$HomePath/.ssh/authorized_keys"
    fi
    echo

  fi

  popd
  
else
  echo "!!! Not found [[$HomePath]], please try again."
fi