from otree.api import Page, cu
from .models import Constants as C  # C.SEQUENCES_BY_INFOSET and C.OPTION_BY_OUTCOME must exist

class Page1(Page):
    # --- helpers ---
    def _get_tg(self):
        tg = self.participant.vars.get('tg') or getattr(self.player, 'tg', None)
        return int(tg) if tg is not None else None

    def _get_info_set(self):
        iset = self.participant.vars.get('info_set') or getattr(self.player, 'info_set', None)
        if iset is None:
            raise RuntimeError('participant.vars["info_set"] must be set before this app.')
        return int(iset)

    def _get_seq(self, info_set: int):
        seq = C.SEQUENCES_BY_INFOSET.get(info_set)
        if seq is None:
            raise RuntimeError(f'No sequence for info_set={info_set}.')
        if len(seq) != C.num_rounds:
            raise RuntimeError(f'Sequence for info_set={info_set} must have {C.num_rounds} items.')
        return seq

    def _get_cents(self, seq, round_no: int) -> int:
        return int(seq[round_no - 1])  # 6, 2, or 0

    # --- oTree hooks ---
    def vars_for_template(self):
        r = self.subsession.round_number
        tg = self._get_tg()
        info_set = self._get_info_set()
        seq = self._get_seq(info_set)

        cents = self._get_cents(seq, r)
        which_option = C.OPTION_BY_OUTCOME.get(cents)  # e.g., {6:1, 0:1, 2:2}
        if which_option is None:
            raise RuntimeError(
                f'Unexpected outcome {cents}; expected one of {list(C.OPTION_BY_OUTCOME.keys())}.'
            )

        added = cu(cents / 100)
        current_total = self.participant.payoff
        total_after = current_total + added

        # Build history including current round (round 1 => one item)
        history = []
        if tg == 4:
            for i in range(r):  # 0..r-1
                c = int(seq[i])
                opt = C.OPTION_BY_OUTCOME.get(c)
                if opt is None:
                    raise RuntimeError(f'Unexpected outcome {c}')
                history.append(f"L{opt}: {c}")

        return dict(
            round_no=r,
            tg=tg,
            info_set=info_set,
            outcome_cents=cents,
            which_option=which_option,
            added=added,
            current_total=current_total,
            total_after=total_after,
            history=history,  # always a list (possibly empty if tg != 4, but you only render for tg==4)
        )

    def before_next_page(self, timeout_happened=False):
        r = self.subsession.round_number
        tg = self._get_tg()
        info_set = self._get_info_set()
        seq = self._get_seq(info_set)
        cents = self._get_cents(seq, r)
        if tg == 3 and cents:
            self.participant.payoff += cu(cents / 100)

page_sequence = [Page1]