import csv
import datetime
import os

from otree.api import *

doc = """
Consent page for the experiment.

PURPOSE
-------
Displays the participant information sheet, collects electronic consent via a
required checkbox, and writes a dedicated consent log entry that satisfies the
following electronic-consent storage requirement:

    "The log must contain at least: date, time, IP address, and user ID."

HOW IT WORKS
------------
1. The page renders the information sheet and a mandatory checkbox.
2. When the participant submits:
   - oTree validates that the checkbox is ticked (error if not).
   - `before_next_page` stamps the timestamp on the Player record and calls
     `_write_consent_log`, which appends one row to  consent_log.csv  in the
     project root.
3. The log file is created automatically on the first consent submission.

HOW TO USE
----------
Add 'Consent' as the FIRST entry in the `app_sequence` of every SESSION_CONFIG
in settings.py:

    'app_sequence': ['Consent', 'Combined_2lights', 'Pay'],
"""


# ─────────────────────────────────────────────────────────────────────────────
#  CONSTANTS / MODELS
# ─────────────────────────────────────────────────────────────────────────────

class C(BaseConstants):
    NAME_IN_URL = 'Consent'
    PLAYERS_PER_GROUP = None
    NUM_ROUNDS = 1


class Subsession(BaseSubsession):
    pass


class Group(BaseGroup):
    pass


class Player(BasePlayer):
    # ── Prolific ID (collected before consent, stored separately from Code.html) ─
    ID_consent = models.StringField(label="Please enter your Prolific ID")

    # ── Consent checkbox ──────────────────────────────────────────────────────
    # Set to True when the participant ticks the box and submits.
    consent_given = models.BooleanField(
        label="I have read the information above and agree to participate in this study.",
        widget=widgets.CheckboxInput,
        initial=False,
    )

    # ── Timestamp ─────────────────────────────────────────────────────────────
    # Stored as "YYYY-MM-DD HH:MM:SS" (set in before_next_page).
    consent_timestamp = models.StringField(blank=True)

    # ── IP address ────────────────────────────────────────────────────────────
    # Submitted as a hidden form field pre-filled by vars_for_template.
    # Listed in form_fields so oTree stores it automatically on submit.
    consent_ip = models.StringField(blank=True)


# ─────────────────────────────────────────────────────────────────────────────
#  CONSENT LOG
#  Writes/appends rows to  <project_root>/consent_log.csv
#  Each row records: date, time, participant_code (user ID), ip_address,
#  consent_given, session_code.
#
#  This file is the dedicated consent storage required by the protocol.
#  Keep it stored securely and back it up regularly.
# ─────────────────────────────────────────────────────────────────────────────

def _write_consent_log(player):
    """Append one consent record to consent_log.csv in the project root."""
    now = datetime.datetime.now()

    # Resolve the project root: two levels up from this file
    # (Consent/__init__.py  →  Consent/  →  project root)
    project_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
    log_path = os.path.join(project_root, 'consent_log.csv')

    file_exists = os.path.isfile(log_path)

    with open(log_path, 'a', newline='', encoding='utf-8') as f:
        writer = csv.writer(f)
        # Write header on the very first run
        if not file_exists:
            writer.writerow([
                'date',
                'time',
                'participant_code',   # oTree internal user ID
                'prolific_id',        # ID_consent from this page
                'ip_address',
                'consent_given',
                'session_code',
            ])
        writer.writerow([
            now.strftime('%Y-%m-%d'),
            now.strftime('%H:%M:%S'),
            player.participant.code,
            player.ID_consent or '',
            player.consent_ip or 'unknown',
            player.consent_given,
            player.session.code,
        ])


# ─────────────────────────────────────────────────────────────────────────────
#  PAGES
# ─────────────────────────────────────────────────────────────────────────────

class ConsentPage(Page):
    form_model = 'player'
    # consent_ip is included here so oTree saves the hidden field on submit.
    form_fields = ['ID_consent', 'consent_given', 'consent_ip']

    # NOTE: get_context_data is a standard Django CBV method that oTree does
    # NOT intercept with its own player-passing logic, so `self` here is the
    # real page view instance with access to self.request.
    # (oTree's own methods like vars_for_template receive the *player* as
    # their first argument, which is why we cannot use those to access
    # self.request.)
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        # oTree >= 5.10 uses Starlette (ASGI), so the request is a
        # starlette.requests.Request — not a Django WSGIRequest.
        # Headers are in request.headers (lowercase), and the direct client
        # IP is in request.client.host (not request.META['REMOTE_ADDR']).
        x_forwarded_for = self.request.headers.get('x-forwarded-for', '')
        if x_forwarded_for:
            ip = x_forwarded_for.split(',')[0].strip()
        else:
            ip = self.request.client.host if self.request.client else 'unknown'
        ctx['ip_address'] = ip
        return ctx

    @staticmethod
    def error_message(player, values):
        """Block form submission if the participant did not tick the box."""
        if not values.get('consent_given'):
            return 'You must check the box to confirm your consent before continuing.'

    @staticmethod
    def before_next_page(player, timeout_happened):
        # 1. Record the consent timestamp on the Player model
        player.consent_timestamp = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        # 2. Write the dedicated consent log entry
        _write_consent_log(player)


page_sequence = [ConsentPage]