# -*- coding: utf-8 -*-

# 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 2 of the License, or
# (at your option) any later version.

# This is a copy and paste of various parts of kobo 0.4.2-1 needed to support the
# creation of kobo commands

import sys
import os
import optparse
from optparse import Option
import sqlite3 as lite
from git import Repo

def username_prompt(prompt=None, default_value=None):
    """Ask for a username."""
    if default_value is not None:
        return default_value

    prompt = prompt or "Enter your username: "
    print >>sys.stderr, prompt,
    return sys.stdin.readline()


def password_prompt(prompt=None, default_value=None):
    """Ask for a password."""
    import getpass

    if default_value is not None:
        return default_value

    prompt = prompt or "Enter your password: "
    try:
        # try to use stderr stream
        result = getpass.getpass(prompt, stream=sys.stderr)
    except TypeError:
        # fall back to stdout
        result = getpass.getpass(prompt)
    return result


def yes_no_prompt(prompt, default_value=None):
    """Give a yes/no (y/n) question."""
    if default_value is not None:
        if default_value not in ("Y", "N"):
            raise ValueError("Invalid default value: %s" % default_value)
        default_value = default_value.upper()

    prompt = "%s [%s/%s]: " % (prompt, ("y", "Y")[default_value == "Y"], ("n", "N")[default_value == "N"])
    print >>sys.stderr, prompt,

    while True:
        user_input = sys.stdin.readline().strip().upper()
        if user_input == "" and default_value is not None:
            user_input = default_value

        if user_input == "Y":
            return True
        if user_input == "N":
            return False

def are_you_sure_prompt(prompt=None):
    """Give a yes/no (y/n) question."""
    prompt = prompt or "Are you sure? Enter 'YES' to continue: "
    print >>sys.stderr, prompt,
    user_input = sys.stdin.readline().strip()

    if user_input == "YES":
        return True

    return False


class Plugin(object):
    """A plugin base class."""

    author = None
    version = None
    enabled = False

    def __getattr__(self, name):
        """
        Get missing attribute from a container.
        This is quite hackish but it allows to define settings and methods per container.
        """
        return getattr(self.container, name)


class Command(Plugin):
    """An abstract class representing a command for CommandOptionParser."""

    enabled = False
    admin = False

    username_prompt = staticmethod(username_prompt)
    password_prompt = staticmethod(password_prompt)
    yes_no_prompt = staticmethod(yes_no_prompt)
    are_you_sure_prompt = staticmethod(are_you_sure_prompt)

    def __init__(self, parser):
        Plugin.__init__(self)
        self.parser = parser

    def options(self):
        """Add options to self.parser."""
        pass

    def run(self, *args, **kwargs):
        """Run a command. Arguments contain parsed options."""
        raise NotImplementedError()

    def set_repo(self, **kwargs):
        self.container.set_repo(**kwargs)

    def set_taskrepo(self, **kwargs):
        self.container.set_taskrepo(**kwargs)


class PluginContainer(object):
    """A plugin container.

    Usage: Inherit PluginContainer and register plugins to the new class.
    """

    def __getitem__(self, name):
        return self._get_plugin(name)

    def __iter__(self):
        return self.plugins.iterkeys()

    @classmethod
    def normalize_name(cls, name):
        return name

    @classmethod
    def _get_plugins(cls):
        """Return dictionary of registered plugins."""

        result = {}
        parent_plugins = cls._get_parent_plugins(cls.normalize_name).items()
        class_plugins = getattr(cls, "_class_plugins", {}).items()
        for name, plugin_class in parent_plugins + class_plugins:
            result[name] = type(plugin_class.__name__, (plugin_class, ), {"__doc__": plugin_class.__doc__})
        return result

    @classmethod
    def _get_parent_plugins(cls, normalize_function):
        result = {}
        for parent in cls.__bases__:
            if parent is PluginContainer:
                # don't use PluginContainer itself - plugins have to be registered to subclasses
                continue

            if not issubclass(parent, PluginContainer):
                # skip parents which are not PluginContainer subclasses
                continue

            # read inherited plugins first (conflicts are resolved recursively)
            plugins = parent._get_parent_plugins(normalize_function)

            # read class plugins, override inherited on name conflicts
            if hasattr(parent, "_class_plugins"):
                for plugin_class in parent._class_plugins.values():
                    normalized_name = normalize_function(plugin_class.__name__)
                    plugins[normalized_name] = plugin_class

            for name, value in plugins.iteritems():
                if result.get(name, value) != value:
                   raise RuntimeError("Cannot register plugin '%s'. Another plugin with the same normalized name (%s) is already in the container." % (str(value), normalized_name))

            result.update(plugins)

        return result

    @property
    def plugins(self):
        if not hasattr(self, "_plugins"):
            self._plugins = self.__class__._get_plugins()
        return self._plugins

    def _get_plugin(self, name):
        """Return a plugin or raise KeyError."""
        normalized_name = self.normalize_name(name)

        if normalized_name not in self.plugins:
            raise KeyError("Plugin not found: %s" % normalized_name)

        plugin = self.plugins[normalized_name]
        plugin.container = self
        plugin.normalized_name = normalized_name
        return plugin

    @classmethod
    def register_plugin(cls, plugin):
        """Register a new plugin. Return normalized plugin name."""

        if cls is PluginContainer:
            raise TypeError("Can't register plugin to the PluginContainer base class.")

        if "_class_plugins" not in cls.__dict__:
            cls._class_plugins = {}

        if not getattr(plugin, "enabled", False):
            return

        normalized_name = cls.normalize_name(plugin.__name__)
        cls._class_plugins[normalized_name] = plugin
        return normalized_name

    @classmethod
    def register_module(cls, module, prefix=None, skip_broken=False):
        """Register all plugins in a module's sub-modules.

        @param module: a python module that contains plugin sub-modules
        @type  module: module
        @param prefix: if specified, only modules with this prefix will be processed
        @type  prefix: str
        @param skip_broken: skip broken sub-modules and print a warning
        @type  skip_broken: bool
        """
        path = os.path.dirname(module.__file__)
        module_list = []

        for fn in os.listdir(path):
            if not fn.endswith(".py"):
                continue
            if fn.startswith("_"):
                continue
            if prefix and not fn.startswith(prefix):
                continue
            if not os.path.isfile(os.path.join(path, fn)):
                continue
            module_list.append(fn[:-3])

        if skip_broken:
            for mod in module_list[:]:
                try:
                    __import__(module.__name__, {}, {}, [mod])
                except:
                    import sys
                    print >> sys.stderr, "WARNING: Skipping broken plugin module: %s.%s" % (module.__name__, mod)
                    module_list.remove(mod)
        else:
            __import__(module.__name__, {}, {}, module_list)

        for mn in module_list:
            mod = getattr(module, mn)
            for pn in dir(mod):
                plugin = getattr(mod, pn)
                if type(plugin) is type and issubclass(plugin, Plugin) and plugin is not Plugin:
                    cls.register_plugin(plugin)


class CommandContainer(PluginContainer):
    """Container for Command classes."""

    @classmethod
    def normalize_name(cls, name):
        """Replace some characters in command names."""
        return name.lower().replace('_', '-').replace(' ', '-')

    def set_repo(self, **kwargs):
        self.repo = Repo(os.getcwd(), search_parent_directories=True)

    def set_taskrepo(self, init=False, **kwargs):
        # do some work to find the default location for the db

        db_location = os.path.join(self.repo.working_tree_dir, "taskrepo.db")
        if not init and not os.path.exists(db_location):
            raise ValueError(u'Not a valid taskrepo, please init first! (git taskrepo init)')
        conn = lite.connect(db_location)
        self.taskrepo = conn

class CommandOptionParser(optparse.OptionParser):
    """Enhanced OptionParser with plugin support."""
    def __init__(self,
            usage=None,
            option_list=None,
            option_class=Option,
            version=None,
            conflict_handler="error",
            description=None,
            formatter=None,
            add_help_option=True,
            prog=None,
            command_container=None,
            default_command="help",
            add_username_password_options=False):

        usage = usage or "%prog <command> [args] [--help]"
        self.container = command_container
        self.default_command = default_command
        self.command = None
        formatter = formatter or optparse.IndentedHelpFormatter(max_help_position=33)

        optparse.OptionParser.__init__(self, usage, option_list, option_class, version, conflict_handler, description, formatter, add_help_option, prog)

        if add_username_password_options:
            option_list = [
                optparse.Option("--username", help="specify user"),
                optparse.Option("--password", help="specify password"),
            ]
            self._populate_option_list(option_list, add_help=False)

    def print_help(self, file=None, admin=False):
        if file is None:
            file = sys.stdout
        file.write(self.format_help())
        if self.command in (None, "help", "help-admin"):
            file.write("\n")
            file.write(self.format_help_commands(admin=admin))

    def format_help_commands(self, admin=False):
        commands = []
        admin_commands = []

        for name, plugin in sorted(self.container.plugins.iteritems()):
            is_admin = getattr(plugin, "admin", False)
            text = "  %-30s %s" % (name, plugin.__doc__ or "")
            if is_admin:
                if admin:
                    admin_commands.append(text)
            else:
                commands.append(text)

        if commands:
            commands.insert(0, "commands:")
            commands.append("")

        if admin_commands:
            admin_commands.insert(0, "admin commands:")
            admin_commands.append("")

        return "\n".join(commands + admin_commands)

    def parse_args(self, args=None, values=None):
        """return (command_instance, opts, args)"""
        args = self._get_args(args)
        command = None

        if len(args) > 0 and not args[0].startswith("-"):
            command = args[0]
            args = args[1:]
        else:
            command = self.default_command
            # keep args as is

        if not command in self.container.plugins:
            self.error("unknown command: %s" % command)

        CommandClass = self.container[command]
        cmd = CommandClass(self)
        if self.command != cmd.normalized_name:
            self.command = cmd.normalized_name
            cmd.options()
        cmd_opts, cmd_args = optparse.OptionParser.parse_args(self, args, values)
        return (cmd, cmd_opts, cmd_args)

    def run(self, args=None, values=None):
        """parse arguments and run a command"""
        cmd, cmd_opts, cmd_args = self.parse_args(args, values)
        cmd_kwargs = cmd_opts.__dict__
        cmd.run(*cmd_args, **cmd_kwargs)

class Help(Command):
    """show this help message and exit"""
    enabled = True

    def options(self):
        pass

    def run(self, *args, **kwargs):
        self.parser.print_help(admin=False)


class Help_Admin(Command):
    """show help message about administrative commands and exit"""
    enabled = True

    def options(self):
        # override default --help option
        opt = self.parser.get_option("--help")
        opt.action = "store_true"
        opt.dest = "help"

    def run(self, *args, **kwargs):
        self.parser.print_help(admin=True)

CommandContainer.register_plugin(Help)
CommandContainer.register_plugin(Help_Admin)