#!/usr/bin/env python

import sys,os
class AnnoFile:
    def __init__(self):
        self.anno={}
        
    def load(self, filename):
        f=open(filename)
        for l in f:
            tok=l.split()
            self.anno[tok[0]]=map(lambda x: float(x), tok[1:])
        f.close()

class Classes:
    def __init__(self):
        self.no2name={}
        self.name2no={}
    def load(self, filename):
        f=open(filename)
        first=True
        for l in f:
            if first:
                first=False
            else:
                tok=l.split()
                self.no2name[int(tok[0])]=tok[1]
                self.name2no[tok[1]]=int(tok[0])

# get the EER for a pair of classes
def EERcls(toEval, GT, cls):
    ranking=[]

    Npos=0
    Nneg=0

    EERfound=False
    for img in toEval.anno:
        # get the right columns, and count number of positive and negative images in groudtruth
        ranking+=[(toEval.anno[img][cls], GT.anno[img][cls])]
        if GT.anno[img][cls]==1:
            Npos+=1
        else:
            Nneg+=1
        
    # sort the ranking        
    ranking.sort()
    eer=-1
    pos=0
    neg=0
    
    # determine TPR and FPR
    oldtp=0
    roc=[]
    for i in ranking:
        if i[1]==1:
            pos+=1
        else:
            neg+=1

        fpr=float(neg)/float(Nneg)
        tpr=float(pos)/float(Npos)
        
        roc+=[(tpr,fpr)]

        # find the crossing point=EER
        if  not EERfound and ( (abs(tpr-(1-fpr))<=0.05) or (1-tpr)<fpr ):
            eer=min(1-fpr,tpr) # optimistic EER
            EERfound=True

    return (eer,roc)
     
# get the EER for each class in an annotation file
def EERall(toEval, GT, classes,writeROCs,fname):
    rocs=[]
    for cls in classes.no2name:
        (eercls,roccls)=EERcls(toEval,GT,cls)
        rocs+=[roccls]
        print "%20s: %f" %(classes.no2name[cls],eercls)


    if writeROCs:
        cls=0
        for i in rocs:
            f=open("roc-%s-%i.txt"%(fname,cls),'w')
            cls+=1
            for j in i:
                print >>f,j[0],j[1]

        f=open("plot-%s.gpl"%fname,'w')
        print >>f,"set title \"%s\""%fname

        first=True
        for i in classes.no2name:
            if first:
                print>>f, "plot \\"
                print>>f, "\"roc-%s-%i.txt\" title \"%s\" with lines \\"%(fname,i,classes.no2name[i])
                first=False
            else:
                print>>f, ",\"roc-%s-%i.txt\" title \"%s\" with lines \\"%(fname,i,classes.no2name[i])

        print >>f
        print >>f,"pause(-1)"
        
trainGT=AnnoFile()
#trainGT.load("test.anno.txt")
trainGT.load("train.anno.txt")

cls=Classes()
cls.load("classes.txt")

if "-roc" in sys.argv:
    writeROCs=True
    sys.argv.pop(sys.argv.index("-roc"))

for evalf in sys.argv[1:]:
    toEval=AnnoFile()
    toEval.load(evalf)
    print evalf
    EERall(toEval, trainGT,cls,writeROCs,os.path.basename(evalf))