#!/usr/bin/env bash

valid_inputs=(
  "v@example.com"
  "v@e.com"
  "v@e.me"
  "valid@123.com"
  "valid@example.com"
  "vali.d@example.com"
  "va-lid@example.com"
  "v-a-l-i-d@example.com"
  "v.a-lid@example.com"
  "v.ali-d@example.com"
  "v_ali-d@example.com"
  "va_li-d@example.com"
  "v_a_li_d@example.com"
  "v.ali-d@example.com"
  "v.ali.d@example.com"
  "v0.ali.d@example.com"
  "v0.ali.d1@example.com"
  "valid@e-x_ample.com"
  "valid@e.x-ample.c.om"
  "v.alid@e.xample.c.a.tw"
  "v.a.lid@e.xample.c.a.tw"
  "v.a+lid@e.xample.c.a.tw"
  "valid@e.xample.c.a.tw"
  "valid+alias@example.com"
  "valid01@example.com"
  "valid-01@example.com"
  "valid_01@example.com"
  "valid.01@example.com"
  "va-lid-0-1@example.com"
  "va.lid-0-1@example.com"
  "val-id.0-1@example.com"
)

invalid_inputs=(
  "-invalid@example.com"
  ".invalid@example.com"
  "_invalid@example.com"
  "inv alid@example.com"
  "invalid@exa mple.com"
  "inv.-alid@example.com"
  "inv-.-alid@example.com"
  "invali-.-d@example.com"
  "inval..id@example.com"
  "inva--lid@example.com"
  "inval_-id@example.com"
  "inval-.id@example.com"
  "invalid.@example.com"
  "invalid_@example.com"
  "invalid-@example.com"
  "0.invali.d@example.com"
  "0.invali.1@example.com"
  "invalid@_"
  "invalid@com"
  "invalid@example.c-.om"
  "invalid@example._com"
  "invalid@e-x._ample.com"
  "invalid@e-.x_ample.com"
  "invalid@e.-x_ample.com"
  "invalid@example.c"
  "invalid@example._"
  "invalid@exampl.0e"
  "invalid@exampl.e1"
  "invalid@exampl.1"
  "invalid@example."
  "invalid@example.com."
  "invalid++alias@example.com"
  "invalid+1+alias@example.com"
  "invalid+alias+user@example.com"
  "invalid+xyz+alias@example.com"
  "+alias@example.com"
  "invalid@-.com"
  "invalid@.com"
  "invalid@com"
  "@"
  ".@."
  "-@-"
  "_@_"
  "+@+"
  "a.@.."
  "@com"
  "@example.com"
  "_@example.com"
  ".@example.com"
  "invalid@_123.com"
  "invalid@example.123"
  "invalid@example.123.456"
)

regex="^([A-Za-z]+((\.|\-|\_)?[A-Za-z0-9])*\+?((\.|\-|\_)?[A-Za-z]+[A-Za-z0-9]*)*)@(([A-Za-z0-9]+)+((\.|\-|\_)?([A-Za-z0-9]+)+)*)+\.([A-Za-z]{2,})+$"

function validator {
  if [[ $1 =~ ${regex} ]]; then
    printf "* %-48s \e[1;32m[pass]\e[m\n" "${1}"
  else
    printf "* %-48s \e[1;31m[fail]\e[m\n" "${1}"
  fi
}

cat <<-EOF
a simple email validator in shell

online validator: http://emailregex.com/
RFC: http://emailregex.com/email-validation-summary/
EOF

echo
echo "### expected result: valid"
echo

for input in "${valid_inputs[@]}"; do
  validator "${input}"
done

echo
echo "### expected result: invalid"
echo

for input in "${invalid_inputs[@]}"; do
  validator "${input}"
done