#!/usr/bin/env bash

unset GREP_OPTIONS

source "$rvm_scripts_path/base"

usage() {
  echo "Usage: rvm migrate from to" >&2
  echo "Moves all gemsets from one ruby to another." >&2
}

confirm() {
  printf "$1 (Y/n): "
  local confirmation_response
  read -r confirmation_response
  [[ -z "$confirmation_response" ]] || echo "$confirmation_response" | \grep -qi '^y'
}

die_with_error() {
  "$rvm_scripts_path/log" "fail" "$1"
  exit "${2:-1}"
}

expand_ruby_name() {
  "$rvm_scripts_path/tools" strings "$1" | awk -F"$rvm_gemset_separator" '{print $1}'
}

migrate_rubies() {
  expanded_source="$(expand_ruby_name "$source_ruby")"
  expanded_destination="$(expand_ruby_name "$destination_ruby")"

  if [[ -z "$expanded_source" ]]; then
    die_with_error "Could not expand source ruby '$source_ruby'"
  elif [[ -z "$expanded_destination" ]]; then
    die_with_error "Could not expand destination ruby '$destination_ruby'"
  elif [[ "$expanded_destination" = "$expanded_source" ]]; then
    die_with_error "Source and Destination Ruby are the same ($expanded_destination)"
  elif [[ ! -d "$rvm_rubies_path/$expanded_source" ]]; then
    die_with_error "Ruby '$expanded_source' is not installed - please install it first."
  elif [[ ! -d "$rvm_rubies_path/$expanded_destination" ]]; then
    die_with_error "Ruby '$expanded_destination' is not installed - please install it first."
  fi

  echo "Are you sure you wish to MOVE gems from $expanded_source to $expanded_destination?"
  confirm "This will overwrite existing gems in $expanded_destination and remove them from $expanded_source" || return 1

  echo "Moving gemsets..."

  while read -r origin_gemset; do
    [[ "$origin_gemset" = "$expanded_source" || "$origin_gemset" = "$expanded_source$rvm_gemset_separator"* ]] || continue
    gemset_name="${origin_gemset/*${rvm_gemset_separator}/}"
    destination_gemset="$expanded_destination"
    if [[ -n "$gemset_name" ]]; then
      destination_gemset="$destination_gemset$rvm_gemset_separator$gemset_name"
    fi
    echo "Moving $origin_gemset to $destination_gemset"

    \rm -rf "$rvm_gems_path/$destination_gemset"
    result="$?"
    [[ "$result" -gt "0" ]] && die_with_error "Unable to remove gem directory '$rvm_gems_path/$destination_gemset'" "$result"

    mv "$rvm_gems_path/$origin_gemset" "$rvm_gems_path/$destination_gemset"
    result="$?"
    [[ "$result" -gt "0" ]] && die_with_error "Unable to move '$rvm_gems_path/$origin_gemset' to '$rvm_gems_path/$destination_gemset'" "$result"

    echo "Making gemset $destination_gemset pristine."
    __rvm_run_with_env "gemset.pristine" "$destination_gemset" "rvm gemset pristine"
  done < <("$rvm_scripts_path/list" gemsets strings | \grep "^$expanded_source")
  unset origin_gemset destination_gemset gemset_name

  if confirm 'Do you wish to move over aliases?' ; then
    while read -r alias_pair; do
      migrate_ruby_name="${alias_pair/*=/}"
      migrate_alias_name="${alias_pair/=*/}"
      if [[ "$migrate_ruby_name" = "$expanded_source" || "$migrate_ruby_name" = "$expanded_source$rvm_gemset_separator"* ]]; then
        migrate_new_alias_name="${migrate_ruby_name/$expanded_source/$expanded_destination}"
        echo "Updating alias $migrate_alias_name to point to $migrate_new_alias_name"
        "$rvm_scripts_path/alias" delete "$migrate_alias_name" >/dev/null 2>&1
        "$rvm_scripts_path/alias" create "$migrate_alias_name" "$migrate_new_alias_name" >/dev/null 2>&1
      fi
    done < "$rvm_config_path/alias"
    unset migrate_ruby_name migrate_alias_name migrate_new_alias_name
  fi

  if confirm "Do you wish to move over wrappers?" ; then
    origin_wrappers_path="$rvm_wrappers_path/$expanded_source"
    for binary_name in $(\ls "$rvm_bin_path") ; do
      full_bin_path="$rvm_bin_path/$binary_name"
      [[ ! -L "$full_bin_path" ]] && continue
      expanded_symlink="$(readlink "$full_bin_path")"
      [[ "$expanded_symlink" != "$origin_wrappers_path/"* ]] && continue
      linked_binary_name="$(basename "$expanded_symlink")"
      [[ "$binary_name" = "$linked_binary_name-$expanded_source" || "$binary_name" = "$expanded_source" ]] && continue
      new_wrapper_destination="${expanded_symlink/$expanded_source/$expanded_destination}"
      ln -sf "$new_wrapper_destination" "$full_bin_path"
    done
    unset origin_wrappers_path full_bin_path expanded_symlink linked_binary_name new_wrapper_destination
  fi

  if confirm "Do you also wish to completely remove $expanded_source (inc. archive)?" ; then
    __rvm_run_with_env "rvm.remove" "$expanded_source" "rvm remove $expanded_source --archive --gems"
  fi

  echo "Successfully migrated $expanded_source to $expanded_destination"

}

args=($*)
source_ruby="${args[0]}"
destination_ruby="${args[1]}"
args="$(echo ${args[@]:2}) " # Strip trailing / leading / extra spacing.

if [[ -z "$source_ruby" || -z "$destination_ruby" ]]; then
  usage ; exit 1
fi

source_ruby="$1"; shift
destination_ruby="$1"; shift

migrate_rubies