from django.conf import settings
from ldt.ldt_utils.models import Segment
import datetime

def update_stat_content(content):
    
    nb_division = settings.DIVISIONS_FOR_STAT_ANNOTATION
    
    segments = Segment.objects.filter(content=content)
    buckets = [0] * nb_division 
    
    size_division = content.duration / nb_division
    limits = [x * size_division for x in range(nb_division+1)]
    nb_annotation = len(segments)

    for segment in segments:
        
        begin = segment.start_ts
        end = segment.start_ts + segment.duration
        
        buckets = find_buckets(buckets, limits, begin, end)
        
    content.stat_annotation = get_string_from_buckets(buckets)
    content.nb_annotation = nb_annotation
    
    content.save()     
 
   
def update_stat_project(project, contents_only=[]):
        if project.state != 2:
            return None
    
        if contents_only:
            contents = contents_only
        else:
            contents = project.contents.all()
            
        for c in contents:
            update_stat_content(c)
            
        return True
    

def add_annotation_to_stat(content, begin, end):
    
    if not content.nb_annotation or not content.stat_annotation:
        content.nb_annotation = 1
        content.stat_annotation = get_empty_stat_vector()
    
    buckets = find_buckets(content.stat_annotation, begin, end)
    content.stat_annotation = get_string_from_buckets(buckets)
    content.last_annotated = datetime.datetime.now()
    
    content.save()        
    

def get_string_from_buckets(buckets):
    s = "%s" % buckets
    s = s[1:-1].replace(' ', '')
    return s


def get_buckets_from_string(string):
    return [int(x) for x in string.split(',')]

def get_empty_stat_vector():
    return [0] * (settings.DIVISIONS_FOR_STAT_ANNOTATION + 4)


def find_buckets(buckets, limits, begin, end):
    
    if len(buckets)+1 != len(limits):
        raise ValueError("There should be as many buckets as those defined by limits.")
    
    has_started = False  
        
    for i in range(len(limits)-1):
        if not has_started:
            if limits[i] <= begin and begin <= limits[i+1]:
                buckets[i] += 1
                has_started = True
                #print "Starts after timecode %s" % limits[i]
        elif limits[i] > end:
            #print "Ends before timecode %s" % limits[i]
            break
        else:
            buckets[i] += 1
            
    return buckets