#!/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>

# Last modified : Wed 22 May 2019 08:10:00 PM EDT

# By Sabarish Sivanath

# To support Python 3

from .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, score_option = 'closest', verbose = 1):

        '''

        Inputs:

            gts - ground truths

            res - predictions

            score_option - {shortest, closest, average}

            verbose - 1 or 0

        Outputs:

            Blue scores

        '''

        assert(gts.keys() == res.keys())

        imgIds = 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 = score_option, verbose =verbose)

        # return (bleu, bleu_info)

        return score, scores

    def method(self):

        return "Bleu"