#!/bin/python

"""
Browser select script.
Use this as the default browser to allow opening differnt browsers based on
URL patterns.

Controllable via TOML file
"""
import os
import sys
from subprocess import Popen
import re
import pathlib
import appdirs as app_dirs
import toml

HARDCODED_DEFAULT_BROWSER = "chromium"
CONFIG_FILE_NAME = "browser_select.toml"

# pylint: disable=too-few-public-methods
class Browser:
    """
    Represents an executable browser
    """
    def __init__(self, executable, working_dir=None):
        self.exec = executable
        self.working_dir = working_dir

    def start_browser(self, args):
        """
        Start a browser with command line arguments
        """
        popen_args = [self.exec, *args]
        with Popen(popen_args, cwd=self.working_dir) as proc:
            ret_code = proc.poll()
        return ret_code


class Site:
    """
    Website class that allows to match an url and provides the correct browser
    for this website
    """
    # pylint: disable=too-many-arguments
    def __init__(self, urls, www, protocols, browser, regex=None, name=None):
        self.name = "Unnamed Site"
        if name is not None:
            self.name = name

        urls = urls if isinstance(urls, list) else [urls]
        protocols = protocols if isinstance(protocols, list) else [protocols]

        if regex is None:
            self.regexes = []
            proto_regex = r'|'.join(protocols)
            www_regex = r'(?:www\.|)' if www else ''
            for url in urls:
                regex = r'^(?:'+proto_regex+r')://'+www_regex+url
                self.regexes.append(re.compile(regex))
        else:
            self.regexes = [re.compile(regex)]

        self.browser = browser

    def match_url(self, url) -> bool:
        """
        Checks if a given url matches the registered patterns for this website
        """
        for regex in self.regexes:
            if bool(regex.match(url)):
                return True
        return False

    def get_browser(self) -> Browser:
        """
        Get the assosciated browser for this website
        """
        return self.browser


def get_config():
    """
    Return the content of the configuration file.
    returns None if nothing is loaded
    """

    config_file_path = None

    # Check user directory
    user_dir = app_dirs.user_config_dir('browser_select', 'shimatta')
    user_config_file = os.path.join(user_dir, CONFIG_FILE_NAME)
    if os.path.exists(user_config_file):
        config_file_path = user_config_file

    # Check the location besides the script
    if config_file_path is None:
        cfg = os.path.join(pathlib.Path(
            __file__).parent.resolve(), CONFIG_FILE_NAME)
        if os.path.exists(cfg):
            config_file_path = cfg

    if config_file_path is None:
        # Config file not found.
        return None

    parsed_toml = toml.load(config_file_path)

    return parsed_toml


# pylint: disable=too-many-locals # Local variables needed. This is ugly, but I don't care
def parse_config(cfg_dict):
    """
    Parse the toml configuration
    """
    # Get the browser list
    browsers = {}

    cfg_browsers = cfg_dict['browsers']
    for key, value in cfg_browsers.items():
        wdir = value.get('working_dir', None)
        browsers[key] = Browser(value['exec'], wdir)

    # Get Sites
    sites = []
    cfg_pattens = cfg_dict['urlpatterns']
    for key, value in cfg_pattens.items():
        name = value.get('site_name', None)
        if name is None:
            name = key

        protocol = value.get('protocol', ['http', 'https'])
        url = value.get('site_url', None)
        site_regex = value.get('site_regex', None)
        www = value.get('www', True)
        site_browser = browsers[value['browser']]

        site = Site(url, www, protocol, site_browser,
                    regex=site_regex, name=name)
        sites.append(site)

    # Get default browser
    try:
        default_executable = cfg_dict['general']['default_browser']
    except KeyError as _ex:
        default_executable = HARDCODED_DEFAULT_BROWSER
    default_browser = Browser(default_executable)

    return sites, default_browser


def execute_browser():
    """
    Main function that checks which browser to use and then executes it
    """
    browser_to_execute = Browser(HARDCODED_DEFAULT_BROWSER)
    # Try read configuration TOML
    try:
        cfg = get_config()
        sites, default_browser = parse_config(cfg)

        browser_to_execute = default_browser

    # pylint: disable=broad-except # Catch all errors in config parsing. It has to be correct
    except Exception as ex:
        print(ex)

    if len(sys.argv) > 1:
        cmd_args = sys.argv[1:]
        url_param = sys.argv[1]
    else:
        cmd_args = []
        url_param = None

    if url_param is not None:
        for site in sites:
            if site.match_url(url_param):
                browser_to_execute = site.get_browser()
                break

    return browser_to_execute.start_browser(cmd_args)

if __name__ == '__main__':
    sys.exit(execute_browser())