import importlib
import logging
import os
import sys
from enum import Enum, auto
from typing import List, Iterable, Type, Optional, TypeVar

import click

from ..instance import Instance, Project, Services
from ..wstring import WParagraph, WAlignment

_logger = logging.getLogger(__name__)


class KiwiCLI(click.MultiCommand):
    """Command Line Interface spread over multiple files in this directory"""

    def list_commands(self, ctx: click.Context) -> List[str]:
        """list all the commands defined by cmd_*.py files in this directory"""

        return [
            filename[4:-3]
            for filename in os.listdir(os.path.abspath(os.path.dirname(__file__)))
            if filename.startswith("cmd_") and filename.endswith(".py")
        ]

    def get_command(self, ctx: click.Context, cmd_name: str) -> Optional[click.Command]:
        """import and return a specific command"""

        try:
            cmd_module = importlib.import_module(f"kiwi_scp.commands.cmd_{cmd_name}")

        except ImportError:
            return

        for cmd_name in dir(cmd_module):
            member = getattr(cmd_module, cmd_name)
            if isinstance(member, click.Command):
                return member


class KiwiCommandType(Enum):
    INSTANCE = auto()
    PROJECT = auto()
    PROJECTS = auto()
    SERVICES = auto()


T = TypeVar("T")


class KiwiCommand:
    type: KiwiCommandType = KiwiCommandType.SERVICES
    enabled_only: bool = False

    @staticmethod
    def print_header(header: str) -> None:
        click.secho(header, fg="green", bold=True)

    @staticmethod
    def print_error(error: str) -> None:
        click.secho(error, file=sys.stderr, fg="red", bold=True)

    @staticmethod
    def print_list(content: Iterable[str]) -> None:
        for item in content:
            click.echo(click.style("  - ", fg="green") + click.style(item, fg="blue"))

    @staticmethod
    def user_query(description: str, default: T, cast_to: Type[T] = str) -> T:
        # prompt user as per argument
        while True:
            try:
                prompt = \
                    click.style(f"Enter {description} [", fg="green") + \
                    click.style(default, fg="blue") + \
                    click.style("] ", fg="green")
                str_value = input(prompt).strip()
                if str_value:
                    return cast_to(str_value)
                else:
                    return default

            except EOFError:
                click.echo("Input aborted.")
                return default

            except Exception as e:
                click.echo(f"Invalid input: {e}")

    @staticmethod
    def danger_confirm(*prompt_lines: str, default: Optional[bool] = None) -> bool:
        if default is True:
            suffix = "[YES|no]"
            default_answer = "yes"

        elif default is False:
            suffix = "[yes|NO]"
            default_answer = "no"

        else:
            suffix = "[yes|no]"
            default_answer = None

        dumb = WParagraph.from_strings(
            click.style("WARNING", bold=True, underline=True, blink=True, fg="red"),
            click.style("ここにゴミ", fg="cyan"),
            click.style("を捨てないで下さい", fg="cyan"),
            click.style("DO NOT DUMB HERE", fg="yellow"),
            click.style("NO DUMB AREA", fg="yellow"),
        ).align(WAlignment.CENTER).surround("!")

        prompt = WParagraph.from_strings(*prompt_lines).align(WAlignment.LEFT).emphasize(3)

        answer = input(
            f"{dumb}\n\n"
            f"{prompt}\n\n"
            f"Are you sure you want to proceed? {suffix}: "
        ).strip().lower()

        if not answer:
            answer = default_answer

        while answer not in ["yes", "no"]:
            answer = input("Please type 'yes' or 'no' explicitly: ").strip().lower()

        return answer == "yes"

    @classmethod
    def run(cls, instance: Instance, project_names: List[str], service_names: List[str], **kwargs):

        _logger.debug(f"{instance.directory!r}: {project_names!r}, {service_names!r}")

        projects = [
            instance.get_project(project_name)
            for project_name in project_names
        ]

        if not projects:
            # run for whole instance
            _logger.debug(f"running for instance, kwargs={kwargs}")
            cls.run_for_instance(instance, **kwargs)

        elif not service_names:
            # run for entire project(s)
            for project_name, project in zip(project_names, projects):
                if project is None:
                    _logger.debug(f"running for new project {project_name}, kwargs={kwargs}")
                    cls.run_for_new_project(instance, project_name, **kwargs)

                else:
                    if cls.enabled_only and not project.project_config.enabled:
                        cls.print_error(f"Can't interact with disabled project {project_name}!")
                        return

                    _logger.debug(f"running for project {project.name}, kwargs={kwargs}")
                    cls.run_for_project(instance, project, **kwargs)

        else:
            # run for some services
            project_name = project_names[0]
            project = projects[0]

            if project is None:
                cls.print_error(f"Project '{project_name}' not in kiwi-scp instance at '{instance.directory}'!")

            else:
                if cls.enabled_only and not project.project_config.enabled:
                    cls.print_error(f"Can't interact with disabled project {project_name}!")
                    return

                _logger.debug(f"running for services {service_names} in project {project_name}, kwargs={kwargs}")
                cls.run_for_services(instance, project, service_names, **kwargs)

    @classmethod
    def run_for_instance(cls, instance: Instance, **kwargs) -> None:
        for project_config in instance.config.projects:
            if cls.enabled_only and not project_config.enabled:
                cls.print_header(f"Skipping disabled project {project_config.name}")
                continue

            project = instance.get_project(project_config.name)
            cls.run_for_project(instance, project, **kwargs)

    @classmethod
    def run_for_project(cls, instance: Instance, project: Project, **kwargs) -> None:
        service_names = [service.name for service in project.services.content]
        cls.run_for_services(instance, project, service_names, **kwargs)

    @classmethod
    def run_for_new_project(cls, instance: Instance, project_name: str, **kwargs) -> None:
        cls.print_error(f"Project '{project_name}' not in kiwi-scp instance at '{instance.directory}'!")

    @classmethod
    def run_for_services(cls, instance: Instance, project: Project, service_names: List[str], **kwargs) -> None:
        services = project.services.filter_existing(service_names)

        new_service_names = [
            service_name
            for service_name
            in service_names
            if service_name not in list(services.names)
        ]

        cls.run_for_filtered_services(instance, project, services, new_service_names, **kwargs)

    @classmethod
    def run_for_filtered_services(cls, instance: Instance, project: Project, services: Services,
                                  new_service_names: List[str], **kwargs) -> None:
        raise Exception