#!/usr/bin/env bash
# BASH3 Boilerplate: parse_url
#
# This file:
#
#  - Takes a URL and parses protocol, user, pass, host, port, path.
#
# Based on:
#
#  - https://stackoverflow.com/a/6174447/151666
#
# Usage as a function:
#
#  source parse_url.sh
#  parse_url 'http://johndoe:abc123@example.com:8080/index.html' pass
#
# Usage as a command:
#
#  parse_url.sh 'http://johndoe:abc123@example.com:8080/index.html'
#
# Based on a template by BASH3 Boilerplate v2.8.0
# https://bash3boilerplate.sh/#authors
#
# The MIT License (MIT)
# Copyright (c) 2013 Kevin van Zonneveld and contributors
# You are not obligated to bundle the LICENSE file with your b3bp projects as long
# as you leave these references intact in the header comments of your source files.

function parse_url() (
  set -o errexit
  set -o errtrace
  set -o nounset
  set -o pipefail

  local parse="${1:-}"
  local need="${2:-}"

  local proto=""
  local url
  local userpass=""
  local user=""
  local pass=""
  local hostport
  local host=""
  local port=""
  local path=""

  url="${parse}"

  if [[ "${url}" = *"://"* ]]; then
    proto="${url%%://*}://"
    url="${url#*://}"
  fi

  if [[ "${url}" = *"@"* ]]; then
    userpass="${url%%@*}"
    url="${url#*@}"
  fi

  hostport="${url%%/*}"
  if [[ "${url}" = */* ]]; then
    path="${url#*/}"
  fi

  if [[ "${userpass}" = *":"* ]]; then
    user="${userpass%%:*}"
    pass="${userpass#*:}"
  else
    user="${userpass}"
  fi

  if [[ "${hostport}" = *":"* ]]; then
    host="${hostport%%:*}"
    port="${hostport#*:}"
  else
    host="${hostport}"
  fi

  [[ ! "${user}" ]] && user="${userpass}"
  [[ ! "${host}" ]] && host="${hostport}"
  if [[ ! "${port}" ]]; then
    [[ "${proto}" = "http://" ]] && port="80"
    [[ "${proto}" = "https://" ]] && port="443"
    [[ "${proto}" = "mysql://" ]] && port="3306"
    [[ "${proto}" = "redis://" ]] && port="6379"
  fi

  if [[ "${need}" ]]; then
    case "${need}" in
    proto | user | pass | host | port | path)
      echo "${!need}"
      ;;
    *)
      echo "parse_url: unknown field selector: ${need}" 1>&2
      return 1
      ;;
    esac
  else
    echo ""
    echo " Use second argument to return just 1 variable."
    echo " parse_url() demo: "
    echo ""
    echo "   proto: ${proto}"
    echo "   user:  ${user}"
    echo "   pass:  ${pass}"
    echo "   host:  ${host}"
    echo "   port:  ${port}"
    echo "   path:  ${path}"
    echo ""
  fi
)

if [[ "${BASH_SOURCE[0]:-}" != "${0}" ]]; then
  export -f parse_url
else
  parse_url "$@"
  exit
fi