# 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 curses
import pickle
import sys

from monkey.action import parse, expand
from db.models import Problem, Solution

if len(sys.argv) > 1:
    if sys.argv[1].endswith('.pickle'):
        with open(sys.argv[1], 'rb') as f:
            attempts = pickle.load(f)
    else:
        pid = int(sys.argv[1])
        attempts = sorted(Solution.filter(problem_id=pid), key=lambda s: s.codeq_user_id)
else:
    # print all problem ids
    print('problems:')
    for problem in Problem.list():
        print('  {}\t{}'.format(problem.id, problem.identifier))
    print()
    pid = int(input('enter problem id: '))
    attempts = sorted(Solution.filter(problem_id=pid), key=lambda s: s.codeq_user_id)

def get_actions(trace):
    try:
        actions = parse(trace)
        expand(actions)
        return actions
    except Exception as ex:
        sys.stderr.write('Error parsing action log: {}\n'.format(ex))
        return []

def main(stdscr):
    def draw_code(win, text, highlight_pos=None, highlight_color=0):
        win.erase()
        win.border()
        y = x = 0
        for n, char in enumerate(text + ' '):
            attr = curses.color_pair(highlight_color if n == highlight_pos else 1)
            if char == '\t':
                char = ' '

            if char != '\n':
                win.addstr(y+1, x+1, char, attr)
                x += 1
            else:
                # add an empty cell at end of each line for highlighting
                win.addstr(y+1, x+1, ' ', attr)
                x = 0
                y += 1
        win.refresh()

    def draw_status(win, uid, action_idx):
        win.erase()
        text = 'usr {}, act {}/{}: {}'.format(uid, action_idx, len(actions),
                                              actions[min(len(actions)-1, index)])
        win.addstr(0, 0, text[:79])
        win.refresh()

    stdscr.clear()
    if curses.has_colors():
        curses.init_pair(1, curses.COLOR_WHITE, 0)
        curses.init_pair(2, curses.COLOR_BLACK, curses.COLOR_GREEN)
        curses.init_pair(3, curses.COLOR_WHITE, curses.COLOR_RED)
    curses.init_color(0, 0, 0, 0)
    curses.curs_set(0)

    stdscr.attrset(curses.color_pair(1))
    statuswin = stdscr.derwin(1, 80, 0, 0)
    codewin = stdscr.derwin(22, 80, 1, 0)

    attempt_idx = 0
    if len(sys.argv) > 2:
        uid = int(sys.argv[2])
        for attempt_idx, a in enumerate(attempts):
            if a.codeq_user_id == uid:
                break
    attempt = attempts[attempt_idx]
    actions = get_actions(attempt.trace)
    index = 0
    code = ''

    draw_status(statuswin, attempt.codeq_user_id, index)
    draw_code(codewin, code, 0, 2)
    while True:
        c = stdscr.getch()
        if 0 < c < 256:
            c = chr(c)

        if c == curses.KEY_HOME:
            # go to first action
            index = 0
            code = ''
        elif c == curses.KEY_LEFT:
            # go to previous action
            if index > 0:
                index -= 1
                action = actions[index]
                code = action.unapply(code)
        elif c == curses.KEY_RIGHT:
            # go to next action
            if index < len(actions):
                action = actions[index]
                code = action.apply(code)
                index += 1
        elif c == 'n':
            # go to next solution
            if attempt_idx < len(attempts)-1:
                attempt_idx += 1
                attempt = attempts[attempt_idx]
                actions = get_actions(attempt.trace)
                code = ''
                index = 0
        elif c == 'N':
            # go to previous solution
            if attempt_idx > 0:
                attempt_idx -= 1
                attempt = attempts[attempt_idx]
                actions = get_actions(attempt.trace)
                code = ''
                index = 0
        elif c == 'q':
            # quit
            break
        elif c == 't':
            # go to next 'test' action
            if index < len(actions) and actions[index].type == 'test':
                index += 1
            while index < len(actions) and actions[index].type != 'test':
                code = actions[index].apply(code)
                index += 1
        elif c == 'T':
            # go to previous 'test' action
            while index > 0 and actions[index-1].type != 'test':
                code = actions[index-1].unapply(code)
                index -= 1
            if index > 0 and actions[index-1].type == 'test':
                index -= 1

        # if active action is 'remove' or 'insert', highlight the character
        action = actions[index] if index < len(actions) else actions[-1]
        if action.type in {'insert', 'remove'}:
            highlight_pos = action.offset
            highlight_color = 2 if action.type == 'insert' else 3
        else:
            highlight_pos = None
            highlight_color = 0

        draw_status(statuswin, attempt.codeq_user_id, index)
        draw_code(codewin, code, highlight_pos, highlight_color)

curses.wrapper(main)