#!/usr/bin/env python
from __future__ import print_function

import os
import sys
import json
import struct
import subprocess

VERSION = '7.0'

try:
        sys.stdin.buffer

        # Python 3.x version
        # Read a message from stdin and decode it.
        def getMessage():
                rawLength = sys.stdin.buffer.read(4)
                if len(rawLength) == 0:
                        sys.exit(0)
                messageLength = struct.unpack('@I', rawLength)[0]
                message = sys.stdin.buffer.read(messageLength).decode('utf-8')
                return json.loads(message)

        # Send an encoded message to stdout
        def sendMessage(messageContent):
                encodedContent = json.dumps(messageContent).encode('utf-8')
                encodedLength = struct.pack('@I', len(encodedContent))

                sys.stdout.buffer.write(encodedLength)
                sys.stdout.buffer.write(encodedContent)
                sys.stdout.buffer.flush()

except AttributeError:
        # Python 2.x version (if sys.stdin.buffer is not defined)
        # Read a message from stdin and decode it.
        def getMessage():
                rawLength = sys.stdin.read(4)
                if len(rawLength) == 0:
                        sys.exit(0)
                messageLength = struct.unpack('@I', rawLength)[0]
                message = sys.stdin.read(messageLength)
                return json.loads(message)

        # Send an encoded message to stdout
        def sendMessage(messageContent):
                encodedContent = json.dumps(messageContent)
                encodedLength = struct.pack('@I', len(encodedContent))

                sys.stdout.write(encodedLength)
                sys.stdout.write(encodedContent)
                sys.stdout.flush()


def install():
        home_path = os.getenv('HOME')

        manifest = {
                'name': 'open_with',
                'description': 'Open With native host',
                'path': os.path.realpath(__file__),
                'type': 'stdio',
        }
        locations = {
                'chrome': os.path.join(home_path, '.config', 'google-chrome', 'NativeMessagingHosts'),
                'chromium': os.path.join(home_path, '.config', 'chromium', 'NativeMessagingHosts'),
                'firefox': os.path.join(home_path, '.mozilla', 'native-messaging-hosts'),
        }
        filename = 'open_with.json'

        for browser, location in locations.items():
                if os.path.exists(os.path.dirname(location)):
                        if not os.path.exists(location):
                                os.mkdir(location)

                        browser_manifest = manifest.copy()
                        if browser == 'firefox':
                                browser_manifest['allowed_extensions'] = ['[email protected]']
                        else:
                                browser_manifest['allowed_origins'] = ['chrome-extension://cogjlncmljjnjpbgppagklanlcbchlno/']

                        with open(os.path.join(location, filename), 'w') as file:
                                file.write(
                                        json.dumps(browser_manifest, indent=2, separators=(',', ': '), sort_keys=True).replace('  ', '\t') + '\n'
                                )


def _read_desktop_file(path):
        with open(path, 'r') as desktop_file:
                current_section = None
                name = None
                command = None
                for line in desktop_file:
                        if line[0] == '[':
                                current_section = line[1:-2]
                        if current_section != 'Desktop Entry':
                                continue

                        if line.startswith('Name='):
                                name = line[5:].strip()
                        elif line.startswith('Exec='):
                                command = line[5:].strip()

                return {
                        'name': name,
                        'command': command
                }


def find_browsers():
        apps = [
                'Chrome',
                'Chromium',
                'chromium-browser',
                'firefox',
                'Firefox',
                'Google Chrome',
                'google-chrome',
                'opera',
                'Opera',
                'SeaMonkey',
                'seamonkey',
        ]
        paths = [
                os.path.join(os.getenv('HOME'), '.local/share/applications'),
                '/usr/local/share/applications',
                '/usr/share/applications'
        ]
        suffix = '.desktop'

        results = []
        for p in paths:
                for a in apps:
                        fp = os.path.join(p, a) + suffix
                        if os.path.exists(fp):
                                results.append(_read_desktop_file(fp))
        return results


def listen():
        receivedMessage = getMessage()
        if receivedMessage == 'ping':
                sendMessage({
                        'version': VERSION,
                        'file': os.path.realpath(__file__)
                })
        elif receivedMessage == 'find':
                sendMessage(find_browsers())
        else:
                for k, v in os.environ.items():
                        if k.startswith('MOZ_'):
                                try:
                                        os.unsetenv(k)
                                except:
                                        os.environ[k] = ''

                devnull = open(os.devnull, 'w')
                subprocess.Popen(receivedMessage, stdout=devnull, stderr=devnull)
                sendMessage(None)


if __name__ == '__main__':
        if len(sys.argv) == 2:
                if sys.argv[1] == 'install':
                        install()
                        sys.exit(0)
                elif sys.argv[1] == 'find_browsers':
                        print(find_browsers())
                        sys.exit(0)

        if '[email protected]' in sys.argv or 'chrome-extension://cogjlncmljjnjpbgppagklanlcbchlno/' in sys.argv:
                listen()
                sys.exit(0)

        print('Open With native helper, version %s.' % VERSION)