#!/usr/bin/python3

# This script allows initialization and management of exams.

__author__ = "David Leoni"
__status__ = "Development"

#keep it first so we don't get deprecation warnings
import jupman_tools as jmt

import conf
import sys
import os
from contextlib import contextmanager

import shutil
import datetime
import glob
import re
import arghandler
from arghandler import ArgumentHandler
from arghandler import subcmd


from jupman_tools import info
from jupman_tools import fatal
from jupman_tools import warn

import logging

jm = conf.jm

@contextmanager
def CD(new_dir):
    prevdir = os.getcwd()
    info(f"Setting working dir to {new_dir}")
    os.chdir(os.path.expanduser(new_dir))
    try:
        yield
    finally:        
        os.chdir(prevdir)
        info(f"Restored working dir.")

def get_target_student(ld):
    return '_private/%s/student-zip/%s/'  % (ld, jm.get_exam_student_folder(ld))

def get_exam_text_filename(ld, extension):
    return 'exam-%s.%s' % (ld, extension)
    
cur_dir_names = os.listdir('.')    

if 'exam.py' not in cur_dir_names:
    fatal('You must execute exam.py from within the directory it is contained!')

def arg_date(parser, args):
    parser.add_argument('date', help="date in format 'yyyy-mm-dd'" )
    return jmt.parse_date_str(vars(parser.parse_args(args))['date'])    
    
@subcmd(help="Initializes a new exam")
def init(parser, context,args):
    
    parser.add_argument('date', help="date in format 'yyyy-mm-dd'" )
    #TODO parser.add_argument('--edit-notebook-mode')
    ld = jmt.parse_date_str(vars(parser.parse_args(args))['date'])    

    eld_admin = "_private/" + ld
    eld_solutions = "_private/%s/solutions" % ld
    pubeld = "exams/%s" % ld 
    exam_ipynb = '%s/exam-%s.ipynb' % (eld_solutions, ld)

    if os.path.exists(eld_admin):
        fatal("PRIVATE EXAM ADMIN ALREADY EXISTS: " + eld_admin)

    if os.path.exists(eld_solutions):
        fatal("PRIVATE EXAM SOLUTIONS ALREADY EXISTS: " + eld_solutions)
        
    if os.path.exists(pubeld):
        fatal("PUBLIC EXAM ALREADY EXISTS: " + pubeld)

    
    shutil.copytree("_templates/exam", 
                    eld_admin,
                    ignore=shutil.ignore_patterns('exam-yyyy-mm-dd.ipynb'))
    
    jmt.expand_JM(   '_templates/exam/solutions/exam-yyyy-mm-dd.ipynb', 
                    exam_ipynb,
                    ld,
                    conf)

    os.rename('%s/jupman-yyyy-mm-dd-grades.ods' % eld_admin,
              "%s/%s-%s-grades.ods" % (eld_admin, conf.jm.filename, ld))
    
    info()
    info("You can now edit Python solutions, tests, exercises and exam notebook here  : " )
    print()
    info("   " + eld_solutions)


                        
"""
jupman-2000-12-31-FIRSTNAME-LASTNAME-ID
    exercise1.py
    exercise2.py
    exercise3.py  
"""
@subcmd(help='Zips a builded exam, making it ready for deploy on the exam server')
def package(parser,context,args):
    
    parser.add_argument('date', help="date in format 'yyyy-mm-dd'" )
    parser.add_argument('-t','--site',  action='store_true', help="zips the site" )
    parser.add_argument('-r','--server', action='store_true',  help="zips the server" )
    
    vs = vars(parser.parse_args(args))
    ld = jmt.parse_date_str(vs['date'])
    
    zip_site = vs['site']
    zip_server = vs['server']
        
    eld_admin = '_private/' + ld 
    eld_solutions = '_private/%s/solutions' % ld
    eld_notebook = '%s/exam-%s.ipynb' % (eld_solutions, ld)    
    target_student = get_target_student(ld)
    target_student_pdf = '%s/%s' % (get_target_student(ld), get_exam_text_filename(ld, 'pdf'))    
    target_student_zip = "%s/server/%s-%s-exam" % (eld_admin,jm.filename,ld) # without '.zip'
    target_server_zip = "%s/%s-%s-server" % (eld_admin, jm.filename,ld) # without '.zip'


    if not os.path.exists(jm.build):
        fatal("%s WAS NOT BUILT !" % jm.build)

    if not os.path.exists(eld_solutions):
        fatal("MISSING SOURCE SOLUTION EXERCISES: " + eld_solutions)

    if os.path.exists(target_student):
        fatal("TARGET STUDENT EXERCISES DIRECTORY ALREADY EXISTS: " + target_student)


    try:
        dir_names = os.listdir(jm.build)    
    except Exception as e:        
        fatal("ERROR WITH DIR %s" % jm.build, ex=e)

    if len(dir_names) == 0:
        fatal("SITE DIRECTORY AT %s WAS NOT BUILT !" % jm.build)

    server_jupman = "%s/server/%s" % (eld_admin, jm.filename)

    if os.path.exists(server_jupman):
        jmt.delete_tree(server_jupman, "_private/%s/server" % ld)

    if zip_site:
        info("Copying built website ...")        
        shutil.copytree(jm.build, server_jupman)

    if not os.path.exists(target_student):
        os.makedirs(target_student)


    info("Copying exercises to " + str(target_student))
    jm.copy_code(eld_solutions, target_student, copy_solutions=False)

    
    info("Building pdf ..")
    import nbformat
    import nbconvert
    from nbconvert import PDFExporter    
    pdf_exporter = PDFExporter()    
    
    #Dav dic 2019:  couldn't make it work, keeps complaining about missing files
    #pdf_exporter.template_file = '_templates/classic.tplx
    # as a result we have stupid extra date and worse extra numbering in headers

    with open('%s/exam-%s.ipynb' % (target_student, ld)) as f:
        ex_nb = nbformat.read(f, as_version=4)
        old_title = jmt._replace_title(ex_nb, 
                                       eld_notebook, 
                                       "").strip('#').strip(jm.ipynb_exercises)

        ex_nb.cells = [cell for cell in ex_nb.cells \
                             if not ('nbsphinx' in cell.metadata \
                                     and cell.metadata['nbsphinx'] == 'hidden')]

        
        with CD(target_student): # needed otherwise doesn't find images
            info(f"  Exporting to {target_student_pdf}")    
            (body, resources) = pdf_exporter.from_notebook_node(ex_nb,
                                                                resources={'metadata': {'name': old_title}})    
        
        with open(target_student_pdf, 'wb') as pdf_f:        
            pdf_f.write(body)    
    
    info("Creating student exercises zip:  %s.zip" % target_student_zip)
    
    def remap(fname):
        if fname.startswith('_private/'):
            return fname[len('_private/YYYY-MM-DD/student-zip/'):]
        else:
            return '/%s/%s' % (jm.get_exam_student_folder(ld), fname)
            
    deglobbed_common_files, deglobbed_common_files_patterns = jm._common_files_maps(target_student_zip)
    
    jm.zip_paths([target_student] + deglobbed_common_files,
                  target_student_zip,  
                  patterns=deglobbed_common_files_patterns,
                  remap=remap)
    
    if zip_server:
        info("Creating server zip: %s.zip" % target_server_zip )
        shutil.make_archive(target_server_zip, 'zip', eld_admin + "/server")
        
    if zip_server and zip_site:
        print("")    
        info("You can now browse the website at:  %s" % (os.path.abspath(eld_admin + "/server/" + jm.filename + "/html/index.html")))
        print("")        
        

@subcmd(help='Set up grading for the provided exam')
def grade(parser,context,args):
    ld = arg_date(parser, args)
    eld_admin = "_private/%s" % ld
    shipped = "%s/shipped" % eld_admin
    graded = "%s/graded" % eld_admin

    if not os.path.exists(shipped):
        fatal("Couldn't find directory: " + shipped)

    try:
        dir_names = next(os.walk(shipped))[1]
    except Exception as e:        
        info("\n\n    ERROR! %s\n\n" % repr(e))
        exit(1)
    if len(dir_names) == 0:
        fatal("NOTHING TO GRADE IN %s" % shipped)
        
    for dn in dir_names:
        target = "%s/%s" % (graded, dn)
        
        if (os.path.exists("%s/shipped" % target)):
            fatal("DIRECTORY ALREADY EXISTS: %s/shipped\n\n" % target)
            
        if (os.path.exists("%s/graded" % target)):
            fatal("DIRECTORY ALREADY EXISTS: %s/graded\n\n" % target)

        info("Copying Python files to execute and eventually grade in %s/graded" % target)
        shutil.copytree('%s/shipped/%s' % (eld_admin, dn) , '%s/shipped' % target)
        info("Copying original shipped files (don't touch them!) in %s/shipped" % target)
        shutil.copytree('%s/shipped/%s' % (eld_admin, dn) , '%s/graded' % target)
    

@subcmd('zip-grades', help='Creates a separate zip for each student containing his graded sheet and code')
def zip_grades(parser,context,args):
    ld = arg_date(parser, args)
    eld_admin = "_private/" + ld 
    shipped = eld_admin + "/shipped"

    try:
        
        dir_names = next(os.walk(shipped))[1]
    except Exception as e:        
        info("\n\n    ERROR! " + repr(e) + "\n\n")
        exit(1)
    if len(dir_names) == 0:
        info("\n\n  ERROR! NOTHING TO ZIP!\n\n")
    for dn in dir_names:
        target = "%s/graded/%s" % (eld_admin, dn)
        shutil.make_archive(target, 'zip', target)
    print("")
    info("You can now find zips to send to students in %s/graded" % eld_admin)
    print("")

@subcmd('publish', help='Copies exam python files from private/ to exam/ (both exercises and solutions), and zips them')
def publish(parser,context,args):
    ld = arg_date(parser, args)
    source = "_private/%s" % ld  
    source_admin = source
    source_solutions =  '%s/solutions' % source
    student_pdf = get_target_student(ld) + '/' + get_exam_text_filename(ld, 'pdf')
    
    
    if not os.path.isdir(source_admin):
        fatal("SOURCE PRIVATE EXAM FOLDER %s DOES NOT EXISTS !" % source_admin)
    if not os.path.isdir(source_solutions):
        fatal("SOURCE PRIVATE EXAM FOLDER %s DOES NOT EXISTS !" % source_solutions)

    dest = 'exams/%s/solutions' % ld
    dest_zip = '_static/generated/%s-%s-exam'  % (jm.filename, ld)

    if os.path.exists(dest):
        fatal("TARGET PUBLIC EXAM FOLDER %s ALREADY EXISTS !" % dest)
    if os.path.exists(dest_zip):
        fatal("TARGET PUBLIC EXAM ZIP %s.zip ALREADY EXISTS !" % dest_zip)    

    info("Copying solutions to %s" % dest)
    shutil.copytree(source_solutions, dest)

    # better avoiding this, I often fix exams post-publication
    #info("Copying exam PDF text")
    #shutil.copyfile(student_pdf, '%s/%s' % (dest, get_exam_text_filename(ld, 'pdf')))
    
    info()
    info("Exam Python files copied.")
    info()
    info("You can now manually build and run the following git instructions to publish the exam.")
    
    info("  ./build.py")
    info("  git status  # just to check everything is ok")
    info("  git add .")
    info("  git commit -m 'published " + ld + " exam'")
    info("  git push")
    info()

        
@subcmd('delete', help="Deletes an existing exam")
def delete_exam(parser,context,args):
        
    ld = arg_date(parser, args)
    eld_admin = '_private/%s' % ld
    
    pubeld = 'exams/%s' % ld
    pubeldzip = '_static/generated/%s-%s-exam.zip' % (jm.filename, ld)

    deleted = []

    ans = ''
    while ans != 'Y' and ans != 'n':  
        print ('DO YOU *REALLY* WANT TO DELETE EXAM %s (NOTE: CANNOT BE UNDONE) [Y/n]? ' % ld),
        ans = input()

    if ans != 'Y':
        print("")
        info("User cancelled, no data was deleted.")
        return

    print("")
    
    def delete_stuff(path, confirm_path):
        """ Deletes path and logs deleted stuff 
        """
        if os.path.exists(path):
            if os.path.isfile(path): 
                jmt.delete_file(path, confirm_path)
            elif os.path.isdir(path):
                jmt.delete_tree(path, confirm_path)
            else:
                raise Exception("File is neither a directory nor a file: %s" % path)
            deleted.append(path)
            
    delete_stuff(eld_admin, "_private/%s" % ld)
    delete_stuff(pubeld, "exams/%s" % ld)
    delete_stuff(pubeldzip, '_static/generated/%s-%s-exam.zip' % (jm.filename, ld))

    if len(deleted) == 0:
        fatal("COULDN'T FIND ANY EXAM FILE TO DELETE FOR DATE: " + ld)


if __name__ == "__main__":
    logging.getLogger().setLevel(logging.INFO)

    handler = ArgumentHandler(description='Manages ' + jm.filename + ' exams.',
                         use_subcommand_help=True)
    handler.run()

    print("")
    info("DONE.\n")




