#!/usr/bin/env bash

abort() {
  echo "$@"
  exit 1
}

url="$1"
test -z "$url" && url=$(git remote get-url origin 2> /dev/null) && origin=true
# validate repo url
test -z "$url" && abort "github repo needs to be specified as an argument"

# validate user
echo "Enter your github username"
read user
[ -n "$user" ] || abort "git username required"
# personal access token
# config name is github-personal-access-token '_' is not allowed in git config

github_personal_access_token=$(git config git-extras.github-personal-access-token)

test -z "$github_personal_access_token" && abort "git config git-extras.github-personal-access-token required"

# extract owner + project from repo url
project=${url##*/}
owner=${url%/$project}
project=${project%.git}
if [[ $owner == git@* ]]; then
  owner=${owner##*:}
else
  owner=${owner##*/}
fi

# validate
[ -z "$project" -o -z "$owner" ] && abort "github repo needs to be specified as an argument"

# create fork
curl -qsf \
  -X POST \
  -u "$user:$github_personal_access_token" \
  -H "X-GitHub-OTP: $MFA_CODE" \
  "https://api.github.com/repos/$owner/$project/forks"

[ $? = 0 ] || abort "fork failed"

echo "Add GitHub remote branch via SSH (you will be prompted to verify the server's credentials)? (y/n)"
read use_ssh
# Check if user has ssh configured with GitHub
if [ -n "$use_ssh" ] && ssh -T git@github.com 2>&1 | grep -qi 'success'; then
  remote_prefix="git@github.com:"
else
  remote_prefix="https://github.com/"
fi

if [ "$origin" = true ]; then
    git remote rename origin upstream
    git remote add origin "${remote_prefix}${user}/${project}.git"
    git fetch origin
else
    # clone forked repo into current dir
    git clone "${remote_prefix}${user}/${project}.git" "$project"
    # add reference to origin fork so can merge in upstream changes
    cd "$project"
    git remote add upstream "${remote_prefix}${owner}/${project}.git"
    git fetch upstream
fi