import multiprocessing
import time
import traceback

import cv2
import numpy as np

from core import mplib
from core.interact import interact as io
from core.joblib import SubprocessGenerator, ThisThreadGenerator
from facelib import LandmarksProcessor
from samplelib import (SampleGeneratorBase, SampleLoader, SampleProcessor,
                       SampleType)


'''
arg
output_sample_types = [
                        [SampleProcessor.TypeFlags, size, (optional) {} opts ] ,
                        ...
                      ]
'''
class SampleGeneratorFaceTest(SampleGeneratorBase):
    def __init__ (self, samples_path, debug=False, batch_size=1,
                        random_ct_samples_path=None,
                        sample_process_options=SampleProcessor.Options(),
                        output_sample_types=[],
                        uniform_yaw_distribution=False,
                        generators_count=4,
                        raise_on_no_data=True,                        
                        **kwargs):

        super().__init__(debug, batch_size)
        self.initialized = False
        self.sample_process_options = sample_process_options
        self.output_sample_types = output_sample_types
        
        if self.debug:
            self.generators_count = 1
        else:
            self.generators_count = max(1, generators_count)

        samples = SampleLoader.load (SampleType.FACE, samples_path)
        self.samples_len = len(samples)
        
        if self.samples_len == 0:
            if raise_on_no_data:
                raise ValueError('No training data provided.')
            else:
                return
                
        if uniform_yaw_distribution:
            samples_pyr = [ ( idx, sample.get_pitch_yaw_roll() ) for idx, sample in enumerate(samples) ]
            
            grads = 128
            #instead of math.pi / 2, using -1.2,+1.2 because actually maximum yaw for 2DFAN landmarks are -1.2+1.2
            grads_space = np.linspace (-1.2, 1.2,grads)

            yaws_sample_list = [None]*grads
            for g in io.progress_bar_generator ( range(grads), "Sort by yaw"):
                yaw = grads_space[g]
                next_yaw = grads_space[g+1] if g < grads-1 else yaw

                yaw_samples = []
                for idx, pyr in samples_pyr:
                    s_yaw = -pyr[1]
                    if (g == 0          and s_yaw < next_yaw) or \
                    (g < grads-1     and s_yaw >= yaw and s_yaw < next_yaw) or \
                    (g == grads-1    and s_yaw >= yaw):
                        yaw_samples += [ idx ]
                if len(yaw_samples) > 0:
                    yaws_sample_list[g] = yaw_samples
            
            yaws_sample_list = [ y for y in yaws_sample_list if y is not None ]
            
            index_host = mplib.Index2DHost( yaws_sample_list )
        else:
            index_host = mplib.IndexHost(self.samples_len)

        if random_ct_samples_path is not None:
            ct_samples = SampleLoader.load (SampleType.FACE, random_ct_samples_path)
            ct_index_host = mplib.IndexHost( len(ct_samples) )
        else:
            ct_samples = None
            ct_index_host = None

        if self.debug:
            self.generators = [ThisThreadGenerator ( self.batch_func, (samples, index_host.create_cli(), ct_samples, ct_index_host.create_cli() if ct_index_host is not None else None) )]
        else:
            self.generators = []
            self.comm_qs = []
            for i in range(self.generators_count):
                comm_q = multiprocessing.Queue()
                
                gen = SubprocessGenerator ( self.batch_func, (comm_q, samples, index_host.create_cli(), ct_samples, ct_index_host.create_cli() if ct_index_host is not None else None), start_now=False )
            
                self.comm_qs.append(comm_q)
                self.generators.append(gen)
                               
            SubprocessGenerator.start_in_parallel( self.generators )

        self.generator_counter = -1
        
        self.initialized = True
        
    #overridable
    def is_initialized(self):
        return self.initialized
        
    def send_start(self):
        for comm_q in self.comm_qs:
            comm_q.put( ('start', 0) )
         
         
    def set_face_scale(self, scale):
        
        for comm_q in self.comm_qs:
            comm_q.put( ('face_scale', scale) )
            
        
    def __iter__(self):
        return self

    def __next__(self):
        if not self.initialized:
            return []
            
        self.generator_counter += 1
        generator = self.generators[self.generator_counter % len(self.generators) ]
        return next(generator)

    def batch_func(self, param ):
        comm_q, samples, index_host, ct_samples, ct_index_host = param
 
        bs = self.batch_size
        face_scale = 1.0
        
        while True:
            if not comm_q.empty():
                cmd, param = comm_q.get()
                if cmd == 'face_scale':
                    face_scale = param 
                    
                if cmd == 'start':
                    break

        while True:
            
            while not comm_q.empty():
                cmd, param = comm_q.get()
                if cmd == 'face_scale':
                    face_scale = param         
            
            batches = None

            indexes = index_host.multi_get(bs)
            ct_indexes = ct_index_host.multi_get(bs) if ct_samples is not None else None

            t = time.time()
            for n_batch in range(bs):
                sample_idx = indexes[n_batch]
                sample = samples[sample_idx]

                ct_sample = None
                if ct_samples is not None:
                    ct_sample = ct_samples[ct_indexes[n_batch]]

                try:
                    x, = SampleProcessor.process ([sample], self.sample_process_options, self.output_sample_types, self.debug, ct_sample=ct_sample, face_scale=face_scale)
                except:
                    raise Exception ("Exception occured in sample %s. Error: %s" % (sample.filename, traceback.format_exc() ) )

                if batches is None:
                    batches = [ [] for _ in range(len(x)) ]

                for i in range(len(x)):
                    batches[i].append ( x[i] )

            yield [ np.array(batch) for batch in batches]