#!/usr/bin/env python

## Version 2.1
## Written by Peter Sinclair, based on code by Ting Chan

## Previous Versions:
## 1.0  Original script
## 1.1  Documentation added
## 1.2  Updated to accommodate both Scheme and Python
## 1.3  Updated to accommodate any course number
## 2.0  Added "simple" mode (and named previous mode "standard")
## 2.1  Added automatic course detection and permission changing for answers folder

## SAMPLE INPUT for STANDARD MODE (all of the following formats will work):
##
## Single line value:
##
## value = 1
## value = {1}
## value = "1"
##
## Multi-line values:
##
## output = {One Line}
## output =
## {More than
## one line}
## output = {Also more
## than one
## line}
##
## Multi-line value with filename:
##
## file = filename
## {Content
## of
## file}
## file = {filename}
## {Content of File}

import os, pwd, shutil, stat, sys
from subprocess import call
## Assigns user input to variables, or prints error message if user input has problems
if len(sys.argv)!=4:
    print "Usage:", sys.argv[0], "assignment, question #, file"
    sys.exit(1)
else:
    asst_num = sys.argv[1]
    question = sys.argv[2]
    filename = sys.argv[3]

## Checks for course number in script path; if not present, prompts the user.
try:
    course = pwd.getpwuid(os.getuid())[0]
except:
    course = raw_input("Please enter the course code (ex: cs116): ")

## Tries to open filename; if filename does not exist in course/marking/asst_num/test.1
##    then the script prints an error message and terminates.
try:
    infile=file('/u/%s/marking/%s/test.1/%s' % (course, asst_num, filename),'r')
    lines = infile.readlines()
    infile.close()
except:
    print '/u/%s/marking/%s/test.1/%s file doesn\'t exist; no files created.' % (course, asst_num, filename)
    sys.exit(1)

## Variables to navigate lines:
##   n is the current position in lines
##   line is reset to lines[n] each time n changes, but is often reduced
##     to only the important part of the line while processing.
n=0
while lines[n] == "\n":
    n += 1
line = lines[n]

## Function to handle multi-line values
def multi_line_value():
    global line
    global n
    temp = ""
    if '{' in line and '}' in line:
        temp += line[line.index('{')+1:line.index('}')]
    else:
        while '{' not in line:
            n += 1
            line = lines[n]
        temp += line[line.index('{')+1:]
        n += 1
        line = lines[n]
        while '}' not in line:
            temp += line
            n += 1
            line = lines[n]
        temp += line[:line.index('}')]
#       if temp[0] == "\n": temp=temp[1:]       # Uncomment these lines if you want to remove a
#       if temp[-1] == "\n": temp=temp[:-1]     # single newline from the start/end of temp
    return temp

## Initialize variables for /in/question/options.rkt
options, value, desc, language, loadcode, mode = '', '', '', '', '', ''

## Loop to collect information /in/question/options.rkt as follows:
##    If line[0] does not equal 'q', the loop terminates
##    Otherwise, options, value, loadcode, or desc will update to equal
##       the remainder of the line.
while line[0] == 'q':
    if line.startswith('q_options'):
        line = line[7:]
        options += multi_line_value()
    elif line.startswith('q_value'):
        line = line[7:].strip('= \n\r{}\'\"')
        value = '(value %s)\n' % line
    elif line.startswith('q_loadcode'):
        line = line[10:].strip('= \n\r{}\'\"')
        loadcode = '(loadcode "%s")\n' % line
    elif line.startswith('q_desc'):
        line = line[6:].strip('= \n\r{}\'\"')
        desc = '(desc "%s")\n' % line
    elif line.startswith('q_language'):
        line = line[10:].strip('= \n\r{}\'\"')
        language = '(language %s)' % line
    elif line.startswith('q_mode'):
        mode = line[6:].strip('= \n\r{}\'\"')
    n += 1
    line = lines[n]

## Checks that a language has been specified either in filename or test.1/in/options.rkt;
##   If it hasn't, prints an error message and aborts
##   If it has, sets extension to either .rkt or .py depending on the language specified
extension = ""
if language == "":
    F = file('/u/%s/marking/%s/test.1/in/options.rkt' % (course, asst_num))
    big_options = F.read()
    F.close()
    if "scheme" in big_options:   extension = "rkt"
    elif "python" in big_options: extension = "py"
else:
    if "scheme" in language:   extension = "rkt"
    elif "python" in language: extension = "py"
if extension == "":
    print 'No language specified in test.1/%s or in test.1/in/options.rkt; no files created' % filename
    sys.exit(1)

## Prompts the user for an appropriate mode until a recognised mode is entered.
while mode not in ["simple", "standard", ""]:
    mode = raw_input("Mode not recognised. Please enter either simple or standard: ")

## Deletes test.1/in/question (if it exists) and creates a new, more empty test.1/in/question
try:    shutil.rmtree('/u/%s/marking/%s/test.1/in/%s' % (course, asst_num, question))
except: None
os.mkdir('/u/%s/marking/%s/test.1/in/%s' % (course, asst_num, question))
os.chdir('/u/%s/marking/%s/test.1/in/%s' % (course, asst_num, question))

## Writes desc, loadcode, value, and options to /in/question/options.rkt
## loadcode is set to aXqY.rkt or aXqY.py if it was not set in filename
if loadcode == "":
    loadcode = '(loadcode "%sq%s.%s")\n' % (asst_num, question, extension)
optionsfile = file('options.rkt', 'w')
optionsfile.writelines([desc, loadcode, value, options])
optionsfile.close()

## Skip any blank lines between question information and tests
while lines[n] == "\n":
    n += 1

test_num = 1 ## The current test
## name_test_dir produces an appropriate name for the current testing directory
##    based on test_num:
##    * If test_num is a one-digit number, then produces t0X, where X is test_num
##    * If test_num is longer than one digit, then produces tX, where X is test_num
def name_test_dir():
    if test_num < 10:
        return 't0%d' % test_num
    else:
        return 't%d' % test_num
test_dir = name_test_dir()

## Variables used in write_test() and following loop
value, desc, options, test_text, input, output = '', '', '', '', '', ''
files, duplicate_files = {}, []

## Function for writing necessary test files (if a field is empty, it is not written):
##    IMPORTANT: This function begins by deleting /in/asst_num and all subdirectories
##               and creating a new, empty /in/asst_num
##    test_text will be written to /in/question/test_dir/test.py (or test.rkt)
##    desc, value, and options will be written to /in/question/test_dir/options.rkt
##    input will be written to /in/question/test_dir/input
##    output will be written to /answers/question_test_dir.out
##    The value of each filename in files will be written to /provided/filename
## The function also displays what files are written for the test
def write_test():
    os.mkdir('/u/%s/marking/%s/test.1/in/%s/%s' % (course, asst_num, question, test_dir))
    os.chdir('/u/%s/marking/%s/test.1/in/%s/%s' % (course, asst_num, question, test_dir))
    test_file = file('test.%s' % extension, 'w')
    test_file.write(test_text)
    test_file.close()
    files_created = ['test.%s' % extension]
    
    if options or value or desc:
        F = file('options.rkt', 'w')
        F.writelines([desc, value, options])
        F.close
        files_created.append("options.rkt")
    if input:
        F = file('input', 'w')
        F.write(input)
        F.close
        files_created.append('input')
    if output:
        os.chdir('/u/%s/marking/%s/test.1/' % (course, asst_num))
        call('chmod -R 700 answers', shell=True)
        os.chdir('answers')
        F = file('%s_%s.out' % (question, test_dir), 'w')
        F.write(output)
        F.close
        files_created.append('%s_%s.out' % (question, test_dir))
    if files:
        os.chdir('/u/%s/marking/%s/test.1/provided' % (course, asst_num))
        for filename in files:
            F = file(filename, 'w')
            F.write(files[filename])
            F.close
            files_created.append(filename)
    
    ## English is a silly language, so it takes this much code to display
    ##    which files were created in a correctly punctuated fashion
    print_message = test_dir + ": Created "
    if len(files_created) == 1:
        print_message += files_created[0]
        files_created = []
    elif len(files_created) == 2:
        print_message += files_created[0] + ' and ' + files_created[1]
        files_created = []
    while len(files_created) > 2:
        print_message += files_created[0] + ', '
        files_created = files_created[1:]
    if len(files_created) == 2:
        print_message += files_created[0] + ', and ' + files_created[1]
    print print_message
    for name in sorted(duplicate_files):
        print "Attempted to create multiple files named %s; only the first was created" % name

## Loop to take data in from lines and call write_test() as follows:
##    If line == '\n' then the information for that test is complete, and the
##       loop will call write_test() before resetting all variables
##    If line begins with value, desc, options, input, output, or file,
##       then the appropriate field will be updated.
##    Otherwise, the information will be stored in test_text
##       (which will be written verbatim to test.py or test.rkt)
##    The loop will finish with the final test unwritten; the if statement
##       following the loop writes the final test.

while n < len(lines):
    line = lines[n]
    if line == '\n':
        try:    write_test()
        except: raise #print "Error writing", test_dir
        test_num += 1
        test_dir = name_test_dir()
        value, desc, options, test_text, input, output = '', '', '', '', '', ''
        files, duplicate_files = {}, []
    elif line.startswith('value'):
        line = line[5:].strip('= \n\r{}\'\"')
        value = '(value %s)\n' % line
    elif line.startswith('desc'):
        line = line[4:].strip('= \n\r{}\'\"')
        desc = '(desc "%s")\n' % line
    elif line.startswith('options'):
        line = line[7:]
        options += multi_line_value()
    elif line.startswith('input'):
        line = line[5:]
        input += multi_line_value()
    elif line.startswith('output'):
        line = line[6:]
        output += multi_line_value()
    elif line.startswith('file'):
        line = line[4:].strip('= \n\r{}\'\"')
        name = line
        n += 1
        line = lines[n]
        body = ""
        body += multi_line_value()
        if files.has_key(name):
            duplicate_files.append(name)
        else:
            files[name] = body
    elif mode == "simple" and extension == "py":
        test_text += "result = " + line
        n += 1
        line = lines[n]
        test_text += "expected = " + line
    elif mode == "simple" and extension == "rkt":
        line = line.strip()
        test_text += "(result " + line + ")\n"
        n += 1
        line = lines[n].strip()
        test_text += "(expected " + line + ")\n"
    else:
        test_text += line
    n += 1

## This if statement writes the final test  
if test_text != '':
    try:    write_test()
    except: print "Error writing", test_dir