from otree.api import (
    models, widgets, BaseConstants, BaseSubsession, BaseGroup, BasePlayer,
    Currency as c, currency_range
)
import random

doc = """
This is a task that requires real effort from participants.
Subjects are shown two images of incomprehensible text.
Subjects are required to transcribe (copy) the text into a text entry field.
The quality of a subject's transcription is measured by the
<a href="http://en.wikipedia.org/wiki/Levenshtein_distance">Levenshtein distance</a>.
"""


def levenshtein(a, b):
    """Calculates the Levenshtein distance between a and b."""
    n, m = len(a), len(b)
    if n > m:
        # Make sure n <= m, to use O(min(n,m)) space
        a, b = b, a
        n, m = m, n

    current = range(n + 1)
    for i in range(1, m + 1):
        previous, current = current, [i] + [0] * n
        for j in range(1, n + 1):
            add, delete = previous[j] + 1, current[j - 1] + 1
            change = previous[j - 1]
            if a[j - 1] != b[i - 1]:
                change = change + 1
            current[j] = min(add, delete, change)

    return current[n]


def distance_and_ok(transcribed_text, reference_text, max_error_rate):
    error_threshold = len(reference_text) * max_error_rate
    distance = levenshtein(transcribed_text, reference_text)
    ok = distance <= error_threshold
    return distance, ok


class Constants(BaseConstants):
    name_in_url = 'real_effort'
    players_per_group = None

    # payoff if  player's transcribtion is correct""",
    gt_payoff = c(0.05)

    reference_texts = [
        "Revealed preference",
        "Nel mezzo del cammin di nostra vita mi ritrovai per una selva oscura che la diritta via era smarrita",
    ]

    num_rounds = len(reference_texts)

    allowed_error_rates = [0.1, 0.5]


class Subsession(BaseSubsession):
    pass


class Group(BaseGroup):
    pass


class Player(BasePlayer):
    prolific_id = models.StringField()

    age = models.IntegerField(
        label='What is your age?',
        min=13, max=125)

    gender = models.StringField(
        choices=['Male', 'Female'],
        label='What is your gender?',
        widget=widgets.RadioSelectHorizontal)

    statedcomplexity = models.IntegerField(
    label='What do you think is the level of complexity of the previous task on a 0 - 10 scale?".',
    choices=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
    widget=widgets.RadioSelectHorizontal)
    transcribed_text = models.LongStringField()
    levenshtein_distance = models.IntegerField()

    is_correct = models.BooleanField()

    def current_question(self):
        return self.session.vars['questions'][self.round_number - 1]

    def check_correct(self):
        self.is_correct = (self.submitted_answer == self.solution)