#!/user/bin/env python

import json
import os
import time
import sys
from argparse import ArgumentParser

from flask import (Flask, Response, redirect, request, send_file,
                   send_from_directory)

import visualdl
import visualdl.server
import visualdl.server.graph as vdl_graph
from visualdl.server import lib
from visualdl.server.log import logger
from visualdl.server.mock import data as mock_data
from visualdl.server.mock import data as mock_tags
from visualdl.python.cache import MemCache
from visualdl.python.storage import (LogWriter, LogReader)

try:
    import exceptions
except:
    pass
    
app = Flask(__name__, static_url_path="")
# set static expires in a short time to reduce browser's memory usage.
app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 30

error_retry_times = 3
error_sleep_time = 2  # seconds

SERVER_DIR = os.path.join(visualdl.ROOT, 'server')


def try_call(function, *args, **kwargs):
    res = lib.retry(error_retry_times, function, error_sleep_time, *args,
                    **kwargs)
    if not res:
        logger.error("server temporary error, will retry latter.")
    return res


def parse_args():
    """
    :return:
    """
    parser = ArgumentParser(
        description="VisualDL, a tool to visualize deep learning.")
    parser.add_argument(
        "-p",
        "--port",
        type=int,
        default=8040,
        action="store",
        dest="port",
        help="api service port")
    parser.add_argument(
        "-t",
        "--host",
        type=str,
        default="0.0.0.0",
        action="store",
        help="api service ip")
    parser.add_argument(
        "-m",
        "--model_pb",
        type=str,
        action="store",
        help="model proto in ONNX format")
    parser.add_argument(
        "--logdir",
        required=True,
        action="store",
        dest="logdir",
        help="log file directory")
    parser.add_argument(
        "--cache_timeout",
        action="store",
        dest="cache_timeout",
        type=float,
        default=20,
        help="memory cache timeout duration in seconds, default 20",
    )
    args = parser.parse_args()
    if not args.logdir:
        parser.print_help()
        sys.exit(-1)
    return args


args = parse_args()
server_path = os.path.abspath(os.path.dirname(sys.argv[0]))
static_file_path = os.path.join(SERVER_DIR, "./dist")
mock_data_path = os.path.join(SERVER_DIR, "./mock_data/")

log_reader = LogReader(args.logdir)

# mannully put graph's image on this path also works.
graph_image_path = os.path.join(args.logdir, 'graph.jpg')
# use a memory cache to reduce disk reading frequency.
CACHE = MemCache(timeout=args.cache_timeout)
cache_get = lib.cache_get(CACHE)


# status, msg, data
def gen_result(status, msg, data):
    """
    :param status:
    :param msg:
    :return:
    """
    result = dict()
    result['status'] = status
    result['msg'] = msg
    result['data'] = data
    return result


@app.route("/")
def index():
    return redirect('/static/index.html', code=302)


@app.route('/static/<path:filename>')
def serve_static(filename):
    return send_from_directory(
        os.path.join(server_path, static_file_path), filename)


@app.route('/graphs/image')
def serve_graph():
    return send_file(os.path.join(os.getcwd(), graph_image_path))


@app.route('/data/logdir')
def logdir():
    result = gen_result(0, "", {"logdir": args.logdir})
    return Response(json.dumps(result), mimetype='application/json')


@app.route('/data/runs')
def runs():
    data = cache_get('/data/runs', lib.get_modes, log_reader)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route("/data/plugin/scalars/tags")
def scalar_tags():
    data = cache_get("/data/plugin/scalars/tags", try_call,
                     lib.get_scalar_tags, log_reader)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route("/data/plugin/images/tags")
def image_tags():
    data = cache_get("/data/plugin/images/tags", try_call, lib.get_image_tags,
                     log_reader)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route("/data/plugin/histograms/tags")
def histogram_tags():
    data = cache_get("/data/plugin/histograms/tags", try_call,
                     lib.get_histogram_tags, log_reader)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route('/data/plugin/scalars/scalars')
def scalars():
    run = request.args.get('run')
    tag = request.args.get('tag')
    key = os.path.join('/data/plugin/scalars/scalars', run, tag)
    data = cache_get(key, try_call, lib.get_scalar, log_reader, run, tag)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route('/data/plugin/images/images')
def images():
    mode = request.args.get('run')
    tag = request.args.get('tag')
    key = os.path.join('/data/plugin/images/images', mode, tag)

    data = cache_get(key, try_call, lib.get_image_tag_steps, log_reader, mode,
                     tag)
    result = gen_result(0, "", data)

    return Response(json.dumps(result), mimetype='application/json')


@app.route('/data/plugin/images/individualImage')
def individual_image():
    mode = request.args.get('run')
    tag = request.args.get('tag')  # include a index
    step_index = int(request.args.get('index'))  # index of step

    key = os.path.join('/data/plugin/images/individualImage', mode, tag,
                       str(step_index))
    data = cache_get(key, try_call, lib.get_invididual_image, log_reader, mode,
                     tag, step_index)
    response = send_file(
        data, as_attachment=True, attachment_filename='img.png')
    return response


@app.route('/data/plugin/histograms/histograms')
def histogram():
    run = request.args.get('run')
    tag = request.args.get('tag')
    key = os.path.join('/data/plugin/histograms/histograms', run, tag)
    data = cache_get(key, try_call, lib.get_histogram, log_reader, run, tag)
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


@app.route('/data/plugin/graphs/graph')
def graph():
    # TODO(ChunweiYan) need to add a config for whether have graph.
    if graph_image_path is None or not os.path.isfile(graph_image_path):
        data = {'url': ''}
    else:
        data = {'url': '/graphs/image'}
    result = gen_result(0, "", data)
    return Response(json.dumps(result), mimetype='application/json')


if __name__ == '__main__':
    logger.info(" port=" + str(args.port))
    if args.model_pb:
        # draw graph
        image_dir = os.path.join(args.logdir, "graphs")
        if not os.path.isdir(image_dir):
            os.mkdir(image_dir)
        graph_image_path = vdl_graph.draw_graph(args.model_pb, image_dir)

    app.run(debug=False, host=args.host, port=args.port, threaded=True)