#!/bin/bash
#
# Copyright 2014 Red Hat, Inc.
#
# NAME
#     lab - wrapper for RHCE lab grading scripts
#
# SYNOPSIS
#     lab {-h|--help}
#     lab PROBLEM {setup|grade}
#
# DESCRIPTION
#     This script is a wrapper for the RHCE lab setup/grading scripts.
#     If they aren't found locally, it downloads the helper functions
#     provided by labtool.shlib and the grading script, lab-PROBLEM,
#     from the content.example.com server. After they are downloaded,
#     the library functions are sourced, then the particular grading
#     script is executed with the action to be taken passed as a
#     parameter.
#
# CHANGELOG
#   * Mon Jul  6 2015 George Hacker <ghacker@redhat.com>
#   - finished incomplete comment in program header
#   * Wed May 21 2014 George Hacker <ghacker@redhat.com>
#   - added copyright notice and added PATH definition
#   * Thu Apr 24 2014 George Hacker <ghacker@redhat.com>
#   - disabled sanity-checking code & sudo for grading
#   * Sun Apr 20 2014 George Hacker <ghacker@redhat.com>
#   - original code

PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/sbin

problem_name="$1"
problem_script="lab-$1"
setup_grade="$2"

function_lib=labtool.shlib
content=content.example.com

# Get RHT_* variable definitions
[[ -f /etc/rht ]] && source /etc/rht

# Additional functions for this shell script
function panic {
  error_code=$1 ; shift
  echo "Error: $@" 1>&2
  echo 'Please contact your instructor.' 1>&2
  exit ${error_code}
}

function print_usage {
  cat 1>&2 <<EOF
This script controls the setup and grading of labs.

Usage: lab $1 COMMAND
       lab $1 {-h|--help}

COMMAND is one of:
    setup - perform any setup steps for this lab on this machine
    grade - perform any grading steps and report on this machine
EOF
}

# Main area

# This program will not function if RHT_COURSE has not been defined
[[ -z "${RHT_COURSE}" ]] && panic 1 'RHT_COURSE not set!'

# If not root, use sudo to give necessary privileges (when needed)
[[ $(id -u) -ne 0 ]] && sudo=sudo

cd /usr/local/bin
url_prefix=http://${content}/courses/${RHT_COURSE}/${RHT_VMTREE%/*}/grading-scripts
# If functions are not found locally, download them
if [[ ! -f ${function_lib} ]] ; then
  if ! ${sudo} curl -s -f -O ${url_prefix}/${function_lib} ; then
    panic 2 'unable to download grading functions!'
  fi
fi

# If grading script is not found locally, download it
if [[ ! -f ${problem_script} ]] ; then
  if ${sudo} curl -s -f -O ${url_prefix}/${problem_script} ; then
    ${sudo} chmod 755 /usr/local/bin/${problem_script}
  else
    echo "Error: unknown problem specified and not found, ${problem_name}" 1>&2
    print_usage PROBLEM
    exit 2
  fi
fi
cd - &> /dev/null

# Source library of functions
source /usr/local/bin/${function_lib}

## Process command line
#case "${setup_grade}" in
#  setup|grade)
#    ;;
#  -h|--help)
#    print_usage "${problem_name}"
#    exit 0
#    ;;
#  *)
#    echo "Bad option ${setup_grade}" 1>&2
#    print_usage PROBLEM
#    exit 1
#    ;;
#esac

# Validation
[[ -z "${setup_grade}" ]] && debug 'Missing command' && print_usage "${problem_name}" && exit 1

"${problem_script}" "${setup_grade}"