#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2015 GNS3 Technologies Inc.
#
# 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 <http://www.gnu.org/licenses/>.


import hashlib
import json
import os
import re
import urllib.request

from gns3registry.image import Image

class Registry:
    def __init__(self):
        pass

    def detect_image(self, image_path):
        """
        :returns: Array of configuration corresponding to the image
        """

        image = Image(image_path)
        configurations = []

        #TODO: Manage open error
        for config in self._all_configs():
            if self._image_match(image, config):
                configurations.append(config)

        return configurations

    def download_image(self, sha1sum, images_dir):
        for config in self._all_configs():
            for image_type in config.get("images", {}):
                for file in config["images"].get(image_type, []):
                    if file["sha1sum"] == sha1sum:
                        path = os.path.join(images_dir, "QEMU", file["filename"])

                        if "direct_download_url" in file:
                            print("Download {} to {}".format(file["direct_download_url"], path))
                            #TODO: Skip download if file already exist with same sha1
                            urllib.request.urlretrieve(file["direct_download_url"], path)
                            return path
                        else:
                            print("You need to manually download the image {filename} from:\n{download_url}\n\nAnd run: ./bin/gns3-get --add {filename}".format(filename=file["filename"], download_url=file["download_url"]))
                            return None

    def search_device(self, query):
        results = []
        for config in self._all_configs():
            if re.match(r".*{}.*".format(query), config["name"], flags=re.IGNORECASE):
                results.append(config)
        return results

    def _all_configs(self):
        """
        Iterate on all configs available on devices
        """
        devices_path = self._get_devices_path()
        for (dirpath, dirnames, filenames) in os.walk(devices_path):
            for filename in filenames:
                file = os.path.join(dirpath, filename)
                if file.endswith(".json"):
                    with open(os.path.join(devices_path, file)) as f:
                        config = json.load(f)
                        yield config

    def _image_match(self, image, config):
        """
        :returns: True if image is present in configuration
        """
        for image_type in config.get("images", {}):
            for file in config["images"].get(image_type, []):
                if file.get("sha1sum", None) == image.sha1sum:
                    image.version = file["version"]
                    config["images"][image_type] = image
                    return True
            return False

    def _get_devices_path(self):
        """
        Get the path where the registry files are located
        """
        path = os.path.abspath(os.path.dirname(__file__))
        return os.path.join(path, "..", "devices")