#!/bin/bash

export COPY_MODULE_PATH="$(dirname $(realpath "${BASH_SOURCE:-$0}"))"
module_load debug
module_load confirm

copy () {

  if ! which rsync &> /dev/null; then echo rsync must be installed to use this function; return 6; fi    

  local SHOST; local DHOST; local sshargs; local args
  local SRC; local DEST; local mirror; local quiet 
  local SPATH; local DPATH; local exec; local list; local verbose
  local usesudo;local cmd;local noconfirm;local merge

  args=()

  help() {

  cat <<EOF  

usage:
rsync <script options> source destination <rsync options> --- <ssh options>

Available Script Options
-r, run the command by this script uses --dry-run.  When ready pass this flag.  
-s, run command as sudo
-l, list the rsync command that will be run instead of running it.  removes --dry-run. 
    great for generating a rsync command to be used elsewhere 
-p, make path at destination if need be.  careful  will creating missing subdirectories    
-e, rsync --exclude , as many of these as desired
-m, merge source inside destination instead of making folder at destination, good for changing destination folder name
-M, copy as "mirror"  uses options.   -a --numeric-ids --delete --delete-excluded --force
-f, rsync --exclude-from <path>, can have multiple 
-F, copy a filesystem, uses -M mirror plus  -xHAXS, and uses sudo (i.e. -s script option)
-n, no confirm, will always confirm command unless this is set
-q, quiet, suppress progress
-v, verbose, same as -v for rsync option, unset if -q is set
-a, archive, same as -a for rsync option, basic identical copy with recursion
-c, clean tranfer meaning will not transfer folder with trash, cache, log, nodemodules
-C, show excludes for clean transfer
-h, this help text  

source or destination may include a <host>: prefix but not both

use 'fcopy <src> <dest>' for fast copy  uses  -r -q -m -n -a
EOF

  }
  
  # parse sshcp options
  local OPTION
  local OPTARG
  local OPTIND
  while getopts 'avMqpf:le:rcCmd:shnF' OPTION; do
    # echo OPTION $OPTION ARG $OPTARG INDX $OPTIND
    case "$OPTION" in
      s)
        usesudo=sudo
        ;;
      c) 
      # clean out unneeded folders like cache, trash, log
           args+=("--exclude-from=$COPY_MODULE_PATH/cache-trash-log.exc")
        ;;
      C) 
        echo "## clean transfer exclusions found in $COPY_MODULE_PATH/cache-trash-log.exc ##"
        cat "$COPY_MODULE_PATH/cache-trash-log.exc"
        echo -e "\n##############################################"
        return 0
        ;;
      q)
       quiet=true 
      ;; 
      n)
        noconfirm=true
        ;;
      e)
        args+=("--exclude=$OPTARG")
        ;;
      f)
        args+=("--exclude-from=$OPTARG")
        ;;  
      F)
        args+=("-xHAXS")
        mirror=true
        usesudo=sudo
        args+=("--exclude-from=$COPY_MODULE_PATH/cache-trash-log.exc")
        ;;            
      p)
        args+=("--mkpath")
        ;;          
      m)
        merge=true
        ;;
      M)
        mirror=true
        ;;
      l)
        list=true
        ;;
      v)
        verbose="-v"
        ;;  
      r)
        exec=true
        ;;        
      a)
        args+=("-a")
        ;;  
      h) 
        help
        return 0  
      ;;  
      *)
        >&2 echo fatal: unknown remote script option $OPTION, aborting 
        help
        return 1
        ;;
      esac
  done

  shift $((OPTIND - 1))

  [ $# -lt 2 ] && echo both a source and destination need to be passed && return 2

 # source parse
  SRC=$1; shift
  if [[ $SRC =~ ":" ]]; then
   echo source is remote
   SHOST=${SHOST:-$(sed 's/\(.*\):.*/\1/' <<< "$SRC")}
   SPATH=$(sed 's/.*:\(.*\)/\1/' <<< "$SRC") 
   else
  #  echo source is local
   SPATH=$SRC
   fi
  # destination parse
  DEST=$1;shift
   if [[ $DEST =~ ":" ]]; then
  #  echo destination is remote
   DHOST=${DHOST:-$(sed 's/\(.*\):.*/\1/' <<< "$DEST")} 
   DPATH=$(sed 's/.*:\(.*\)/\1/' <<< "$DEST") 
   else
  #  echo destination is local
   DPATH=$DEST
   fi
   [[ $DHOST && $SHOST ]] && echo this script can not process remote host to remote host transfer && return 5
  # is source or destination is remote, create -e ssh sync option
  if [[ $DHOST || $SHOST ]]; then
    if ! module_load ssh &>/dev/null; then 
      echo unable to load ssh module
      echo likely the uci network repo has not been installed
      echo to do a remote copy this repo which contains the ssh module
      echo "must be installed.  Try \"module_load uci-shell-install; install_shell_network\""
      return 6
    fi  
    if [[ ! $(get_user_host ${DHOST:-$SHOST}) ]]; then
      >&2 echo fatal: the host ${DHOST:-$SHOST} is not valid, aborting remote copy
      return 1
    fi 
    # parse ssh arguments from the rest
    debug $( ( IFS=$','; echo all arguments: "$*" ) )
    for ((d=1; d<$#; ++d)); do
    [[ ${!d} == "---" ]] && break
    done
    if [[ $d -lt $# ]]; then  # if there are extra ssh arguments
      debug found --- at $d
      sshargs=("${@:$d+1:$#}") 
      debug $( ( IFS=$','; echo "ssh arguments: ${sshargs[*]}" ) )
      args+=("${@:1:$d-1}")
      debug $( ( IFS=$','; echo remaining arguments to parse: "$*" ) )
      else
        args+=("${@:1}")
    fi
    args+=( "$(remove_end_spaces "-e '$(ssh -l "${sshargs[*]}")'")") 
  fi    

  # assemble options
  [[ ! $exec ]] && args+=(--dry-run -v)
  [[ ! $quiet ]] && args+=(--info=progress2 $verbose)
  [[ $mirror ]] && args+=(-a --numeric-ids --delete --delete-excluded --force)

  [[ ! -v PS1 ]] && noconfirm=true
  if [[ ! $noconfirm && ! $list ]]; then
    if [[ $merge ]]; then
     # todo mirror option
     confirm The contents within $SPATH will be $([[ $mirror ]] && echo mirrored || echo placed ) inside $DPATH || return 0
     else
     confirm the directory $(basename $SPATH) of $SPATH will be $([[ $mirror ]] && echo mirrored || echo put ) at destination $DPATH/$(basename $SPATH)? || return 0
    fi
  fi  
  cmd="$usesudo $(which rsync) ${args[*]} $SRC$([[ $merge ]] && echo "/") $DEST" 
  [[ $list ]] && echo "$cmd" && return 0  
  if [[ ! $quiet ]]; then  [[ $exec ]] && echo executing the copy command || echo dry run of command, use -r to execute; fi
  if eval $cmd; then
      [[ ! $quiet ]] && echo copy success! 
      debug $cmd
    else 
      >&2 echo remote copy failed
      >&2 echo $cmd
      return 1
    fi
   }

  alias fcopy="copy -r -q -m -n -a "
  # for copying chromium profile use
  #  --exclude=Singleton*