#!/usr/bin/env python3

# common.py - PVC CLI client function library, Common functions
# Part of the Parallel Virtual Cluster (PVC) system
#
#    Copyright (C) 2018-2020 Joshua M. Boniface <joshua@boniface.me>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
###############################################################################

import os
import io
import math
import time
import requests
import click

def format_bytes(size_bytes):
    byte_unit_matrix = {
        'B': 1,
        'K': 1024,
        'M': 1024*1024,
        'G': 1024*1024*1024,
        'T': 1024*1024*1024*1024,
        'P': 1024*1024*1024*1024*1024
    }
    human_bytes = '0B'
    for unit in sorted(byte_unit_matrix, key=byte_unit_matrix.get):
        formatted_bytes = int(math.ceil(size_bytes / byte_unit_matrix[unit]))
        if formatted_bytes < 10000:
            human_bytes = '{}{}'.format(formatted_bytes, unit)
            break
    return human_bytes

class UploadProgressBar(object):
    def __init__(self, filename, end_message='', end_nl=True):
        file_size = os.path.getsize(filename)
        file_size_human = format_bytes(file_size)
        click.echo("Uploading file (total size {})...".format(file_size_human))

        self.length = file_size
        self.time_last = int(round(time.time() * 1000)) - 1000
        self.bytes_last = 0
        self.bytes_diff = 0
        self.is_end = False

        self.end_message = end_message
        self.end_nl = end_nl
        if not self.end_nl:
            self.end_suffix = ' '
        else:
            self.end_suffix = ''

        self.bar = click.progressbar(length=self.length, show_eta=True)

    def update(self, monitor):
        bytes_cur = monitor.bytes_read
        self.bytes_diff += bytes_cur - self.bytes_last
        if self.bytes_last == bytes_cur:
            self.is_end = True
        self.bytes_last = bytes_cur

        time_cur = int(round(time.time() * 1000))
        if (time_cur - 1000) > self.time_last:
            self.time_last = time_cur
            self.bar.update(self.bytes_diff)
            self.bytes_diff = 0

        if self.is_end:
            self.bar.update(self.bytes_diff)
            self.bytes_diff = 0
            click.echo()
            click.echo()
            if self.end_message:
                click.echo(self.end_message + self.end_suffix, nl=self.end_nl)

class ErrorResponse(requests.Response):
    def __init__(self, json_data, status_code):
        self.json_data = json_data
        self.status_code = status_code

    def json(self):
        return self.json_data

def call_api(config, operation, request_uri, headers={}, params=None, data=None, files=None):
    # Craft the URI
    uri = '{}://{}{}{}'.format(
        config['api_scheme'],
        config['api_host'],
        config['api_prefix'],
        request_uri
    )

    # Craft the authentication header if required
    if config['api_key']:
        headers['X-Api-Key'] = config['api_key']

    # Determine the request type and hit the API
    try:
        if operation == 'get':
            response = requests.get(
                uri,
                headers=headers,
                params=params,
                data=data
            )
        if operation == 'post':
            response = requests.post(
                uri,
                headers=headers,
                params=params,
                data=data,
                files=files
            )
        if operation == 'put':
            response = requests.put(
                uri,
                headers=headers,
                params=params,
                data=data,
                files=files
            )
        if operation == 'patch':
            response = requests.patch(
                uri,
                headers=headers,
                params=params,
                data=data
            )
        if operation == 'delete':
            response = requests.delete(
                uri,
                headers=headers,
                params=params,
                data=data
            )
    except Exception as e:
        message = 'Failed to connect to the API: {}'.format(e)
        response = ErrorResponse({'message':message}, 500)

    # Display debug output
    if config['debug']:
        click.echo('API endpoint: {}'.format(uri), err=True)
        click.echo('Response code: {}'.format(response.status_code), err=True)
        click.echo('Response headers: {}'.format(response.headers), err=True)
        click.echo(err=True)

    # Return the response object
    return response