# CodeQ: an online programming tutor.
# Copyright (C) 2015 UL FRI
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

import os
import pickle
import sys

from termcolor import colored

from db.util import make_identifier
from db.models import Problem, Solution
from . import fix, fix_hints
from prolog.util import parse, stringify, used_predicates
from server.problems import get_facts, load_group, load_problem, solutions_for_problems
from .util import indent

# Get problem id from commandline.
if len(sys.argv) < 2:
    print('usage: ' + sys.argv[0] + ' <pid>')
    sys.exit(1)

problem = Problem.get(id=sys.argv[1])
problem_name = load_problem(problem.language, problem.group, problem.identifier, 'en').name

problem_module = load_problem(problem.language, problem.group, problem.identifier, 'common')
other_problems = [p for p in Problem.filter_language(problem.language)
                    if p.identifier != problem.identifier]
facts = get_facts(problem.language, problem_module)

# Testing function.
def test(code):
    # Find solutions to other problems that are used by this program.
    used_predicate_identifiers = {make_identifier(name) for name in used_predicates(code)}
    dependencies = sorted([p[2:] for p in other_problems
                                 if p.identifier in used_predicate_identifiers])
    aux_code = '\n' + solutions_for_problems('prolog', dependencies) + '\n' + facts
    correct, hints = problem_module.test(code, aux_code)
    return correct

traces = [s.trace for s in Solution.filter(problem_id=problem.id)]

# Load hint database stored in edits.pickle.
edits, submissions, queries = pickle.load(open('edits.pickle', 'rb'))
edits, submissions, queries = edits[problem.id], submissions[problem.id], queries[problem.id]

# Load current status (programs for which a hint was found).
try:
    done = pickle.load(open('status-'+str(problem.id)+'.pickle', 'rb'))
except:
    done = []

def print_hint(code, solution, steps, fix_time, n_tested):
    if solution:
        print(colored('Hint found! Tested {} programs in {:.1f} s.'.format(n_tested, fix_time), 'green'))
        print(colored(' Edits', 'blue'))
        for idx, a, b in steps:
            print('  {}: {} → {}'.format(idx, stringify(a), stringify(b)))
        print(colored(' Hints', 'blue'))
        for hint in fix_hints(code, steps):
            print('  {}'.format(hint))
        print(colored(' Final version', 'blue'))
        print(indent(stringify(parse(solution)), 2))
    else:
        print(colored('Hint not found! Tested {} programs in {:.1f} s.'.format(n_tested, fix_time), 'red'))

# Run interactive loop.
if len(sys.argv) == 2:
    while True:
        # Read the program from stdin.
        print('Enter program, end with empty line:')
        code = ''
        try:
            while True:
                line = input()
                if not line:
                    break
                code += line + '\n'
        except EOFError:
            break

        # Try finding a fix.
        print(colored('Analyzing program…', 'yellow'))
        solution, steps, fix_time, n_tested = fix(code, edits, test, debug=True)
        print_hint(code, solution, steps, fix_time, n_tested)

# Test fix() on incorrect student submissions.
elif sys.argv[2] == 'test':
    timeout = int(sys.argv[3]) if len(sys.argv) == 4 else 10
    incorrect = []
    for (code, correct), count in sorted(submissions.items()):
        # Skip syntactically-incorrect submissions.
        if parse(code) is None:
            continue
        if not correct:
            incorrect += [code] * count

    print('Fixing {}/{} programs (timeout={})…'.format(
        len([code for code in incorrect if code not in done]),
        len(incorrect), timeout))

    undone = []
    for i, program in enumerate(sorted(incorrect)):
        if program in done:
            done.append(program)
            continue
        if program in undone:
            continue

        print(colored('Analyzing program {0}/{1}…'.format(i+1, len(incorrect)), 'yellow'))
        solution, steps, fix_time, n_tested = fix(program, edits, test, timeout=timeout, debug=True)
        print_hint(program, solution, steps, fix_time, n_tested)
        print()

        if solution:
            done.append(program)
        else:
            undone.append(program)
        pickle.dump(done, open('status-'+str(problem.id)+'.pickle', 'wb'))

    print('Found hints for ' + str(len(done)) + ' of ' + str(len(incorrect)) + ' incorrect programs')

# Print info for this problem.
elif sys.argv[2] == 'info':
    # With no additional arguments, print some stats.
    if len(sys.argv) == 3:
        print('Problem {} ({}): {} edits and {} different submissions in {} traces'.format(
            problem.id, colored(problem_name, 'yellow'),
            colored(str(len(edits)), 'yellow'),
            colored(str(len(submissions)), 'yellow'),
            colored(str(len(traces)), 'yellow')))

    # Print all observed edits and their costs.
    elif sys.argv[3] == 'edits':
        for (path, before, after), cost in sorted(edits.items(), key=lambda x: x[1]):
            print(' {:.4f}\t{} → {}'.format(cost, stringify(before) if before else 'ε',
                                                  stringify(after) if after else 'ε'))
    # Print all observed edits and their costs.
    elif sys.argv[3] == 'names':
        for name, count in sorted(names.items(), key=lambda x: x[1]):
            print(' {:.4f}\t{}'.format(count,  name))

    # Print all student queries and their counts.
    elif sys.argv[3] == 'queries':
        for query, count in queries.most_common():
            print('  ' + str(count) + '\t' + query)

    # Print all student submissions and their counts.
    elif sys.argv[3] == 'submissions':
        which = None
        if len(sys.argv) > 4:
            which = sys.argv[4] == 'good'
        for (code, correct), count in submissions.most_common():
            if which is None or correct == which:
                print('{}\t{}'.format(count, code))