#!/usr/bin/env python
#
# File Name : bleu.py
#
# Description : Wrapper for BLEU scorer.
#
# Creation Date : 06-01-2015
# Last Modified : Thu 19 Mar 2015 09:13:28 PM PDT
# Authors : Hao Fang <hfang@uw.edu> and Tsung-Yi Lin <tl483@cornell.edu>

from c2nl.eval.bleu.bleu_scorer import BleuScorer


class Bleu:
    def __init__(self, n=4):
        # default compute Blue score up to 4
        self._n = n
        self._hypo_for_image = {}
        self.ref_for_image = {}

    def compute_score(self, gts, res, verbose):
        assert (sorted(gts.keys()) == sorted(res.keys()))
        imgIds = list(gts.keys())

        bleu_scorer = BleuScorer(n=self._n)
        for id in imgIds:
            hypo = res[id]
            ref = gts[id]

            # Sanity check.
            assert (type(hypo) is list)
            assert (len(hypo) == 1)
            assert (type(ref) is list)
            assert (len(ref) >= 1)

            bleu_scorer += (hypo[0], ref)

        # score, scores = bleu_scorer.compute_score(option='shortest')
        score, scores, bleu = bleu_scorer.compute_score(option='closest', verbose=verbose)
        # score, scores = bleu_scorer.compute_score(option='average', verbose=1)

        return score, scores, bleu

    def method(self):
        return "Bleu"
