#!/usr/bin/env python

import sys
import logging
import importlib

import csv

from blocks.model import Model

from fuel.transformers import Batch
from fuel.streams import DataStream
from fuel.schemes import ConstantScheme, ShuffledExampleScheme

from blocks.algorithms import GradientDescent, AdaDelta, Momentum
from blocks.graph import ComputationGraph
from blocks.main_loop import MainLoop
from blocks.extensions import Printing, FinishAfter
from blocks.extensions.saveload import Dump, LoadFromDump, Checkpoint
from blocks.extensions.monitoring import DataStreamMonitoring, TrainingDataMonitoring
from blocks.extensions.plot import Plot

from data import transformers
from data.hdf5 import TaxiDataset, TaxiStream
import apply_model

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print >> sys.stderr, 'Usage: %s config' % sys.argv[0]
        sys.exit(1)
    model_name = sys.argv[1]
    config = importlib.import_module('.%s' % model_name, 'config')

def compile_valid_trip_ids():
    valid = TaxiDataset(config.valid_set, 'valid.hdf5', sources=('trip_id',))
    ids = valid.get_data(None, slice(0, valid.num_examples))
    return set(ids[0])

def setup_train_stream(req_vars, valid_trips_ids):
    train = TaxiDataset('train')
    train = DataStream(train, iteration_scheme=ShuffledExampleScheme(train.num_examples))

    train = transformers.TaxiExcludeTrips(valid_trips_ids, train)
    train = transformers.TaxiGenerateSplits(train, max_splits=100)

    train = transformers.TaxiAddDateTime(train)
    train = transformers.TaxiAddFirstLastLen(config.n_begin_end_pts, train)
    train = transformers.Select(train, tuple(req_vars))

    train_stream = Batch(train, iteration_scheme=ConstantScheme(config.batch_size))

    return train_stream

def setup_valid_stream(req_vars):
    valid = TaxiStream(config.valid_set, 'valid.hdf5')

    valid = transformers.TaxiAddDateTime(valid)
    valid = transformers.TaxiAddFirstLastLen(config.n_begin_end_pts, valid)
    valid = transformers.Select(valid, tuple(req_vars))

    valid_stream = Batch(valid, iteration_scheme=ConstantScheme(1000))
    
    return valid_stream

def setup_test_stream(req_vars):
    test = TaxiStream('test')
    
    test = transformers.TaxiAddDateTime(test)
    test = transformers.TaxiAddFirstLastLen(config.n_begin_end_pts, test)
    test = transformers.TaxiAddLast(config.n_begin_end_pts, test)
    test = transformers.Select(test, tuple(req_vars))

    test_stream = Batch(test, iteration_scheme=ConstantScheme(1000))

    return test_stream


def main():
    model = config.model.Model(config)

    cost = model.cost
    outputs = model.outputs

    req_vars = model.require_inputs + model.pred_vars
    req_vars_test = model.require_inputs + [ 'trip_id' ]

    valid_trips_ids = compile_valid_trip_ids()
    train_stream = setup_train_stream(req_vars, valid_trips_ids)
    valid_stream = setup_valid_stream(req_vars)

    # Training
    cg = ComputationGraph(cost)
    params = cg.parameters
    algorithm = GradientDescent(
        cost=cost,
        # step_rule=AdaDelta(decay_rate=0.5),
        step_rule=Momentum(learning_rate=config.learning_rate, momentum=config.momentum),
        params=params)

    extensions=[TrainingDataMonitoring(model.monitor, prefix='train', every_n_batches=1000),
                DataStreamMonitoring(model.monitor, valid_stream,
                                     prefix='valid',
                                     every_n_batches=1000),
                Printing(every_n_batches=1000),
                Plot(model_name, channels=[['valid_cost']], every_n_batches=1000),
                # Checkpoint('model.pkl', every_n_batches=100),
                Dump('model_data/' + model_name, every_n_batches=1000),
                LoadFromDump('model_data/' + model_name),
                # FinishAfter(after_epoch=42),
                ]

    main_loop = MainLoop(
        model=Model([cost]),
        data_stream=train_stream,
        algorithm=algorithm,
        extensions=extensions)
    main_loop.run()
    main_loop.profile.report()

    # Produce an output on the test data
    test_stream = setup_test_stream(req_vars_test)

    outfile = open("output/test-output-%s.csv" % model_name, "w")
    outcsv = csv.writer(outfile)
    if model.pred_vars == ['travel_time']:
        outcsv.writerow(["TRIP_ID", "TRAVEL_TIME"])
        for out in apply_model.Apply(outputs=outputs, stream=test_stream, return_vars=['trip_id', 'outputs']):
            time = out['outputs']
            for i, trip in enumerate(out['trip_id']):
                outcsv.writerow([trip, int(time[i])])
    else:
        outcsv.writerow(["TRIP_ID", "LATITUDE", "LONGITUDE"])
        for out in apply_model.Apply(outputs=outputs, stream=test_stream, return_vars=['trip_id', 'outputs']):
            dest = out['outputs']
            for i, trip in enumerate(out['trip_id']):
                outcsv.writerow([trip, repr(dest[i, 0]), repr(dest[i, 1])])
    outfile.close()


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    main()