# SPDX-License-Identifier: GPL-3.0-or-later

# Haketilo proxy data and configuration (interface definition through abstract
# class).
#
# This file is part of Hydrilla&Haketilo.
#
# Copyright (C) 2022 Wojtek Kosior
#
# 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 <https://www.gnu.org/licenses/>.
#
#
# I, Wojtek Kosior, thereby promise not to sue for violation of this
# file's license. Although I request that you do not make use this code
# in a proprietary program, I am not going to enforce this in court.

"""
This module defines API for keeping track of all settings, rules, mappings and
resources.
"""

# Enable using with Python 3.7.
from __future__ import annotations

import dataclasses as dc
import typing as t

from pathlib import Path
from abc import ABC, abstractmethod
from enum import Enum

from immutables import Map

from ..versions import VerTuple
from ..url_patterns import ParsedPattern


class EnabledStatus(Enum):
    """
    ENABLED - User wished to always apply given mapping when it matched.

    DISABLED - User wished to never apply given mapping.

    AUTO_ENABLED - User has not configured given mapping but it will still be
        used when automatic application of mappings is turned on.

    NO_MARK - User has not configured given mapping and it won't be used.
    """
    ENABLED      = 'E'
    DISABLED     = 'D'
    AUTO_ENABLED = 'A'
    NO_MARK      = 'N'

@dc.dataclass(frozen=True, unsafe_hash=True)
class Ref:
    """...."""
    id: str


# mypy needs to be corrected:
# https://stackoverflow.com/questions/70999513/conflict-between-mix-ins-for-abstract-dataclasses/70999704#70999704
@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class RepoRef(Ref):
    """...."""
    @abstractmethod
    def remove(self, state: 'HaketiloState') -> None:
        """...."""
        ...

    @abstractmethod
    def update(
            self,
            state: 'HaketiloState',
            *,
            name: t.Optional[str] = None,
            url:  t.Optional[str] = None
    ) -> 'RepoRef':
        """...."""
        ...

    @abstractmethod
    def refresh(self, state: 'HaketiloState') -> 'RepoIterationRef':
        """...."""
        ...


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class RepoIterationRef(Ref):
    """...."""
    pass


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class MappingRef(Ref):
    """...."""
    @abstractmethod
    def disable(self, state: 'HaketiloState') -> None:
        """...."""
        ...

    @abstractmethod
    def forget_enabled(self, state: 'HaketiloState') -> None:
        """...."""
        ...


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class MappingVersionRef(Ref):
    """...."""
    @abstractmethod
    def enable(self, state: 'HaketiloState') -> None:
        """...."""
        ...

@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class ResourceRef(Ref):
    """...."""
    pass


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class ResourceVersionRef(Ref):
    """...."""
    pass


@dc.dataclass(frozen=True)
class PayloadKey:
    """...."""
    payload_ref: 'PayloadRef'

    mapping_identifier:     str
    # mapping_version:        VerTuple
    # mapping_repo:           str
    # mapping_repo_iteration: int
    pattern:                ParsedPattern

    def __lt__(self, other: 'PayloadKey') -> bool:
        """...."""
        return (
            self.mapping_identifier,
            # other.mapping_version,
            # self.mapping_repo,
            # other.mapping_repo_iteration,
            self.pattern
        ) < (
            other.mapping_identifier,
            # self.mapping_version,
            # other.mapping_repo,
            # self.mapping_repo_iteration,
            other.pattern
        )

@dc.dataclass(frozen=True)
class PayloadData:
    """...."""
    payload_ref: 'PayloadRef'

    mapping_installed:   bool
    explicitly_enabled:  bool
    unique_token:        str
    pattern:             ParsedPattern
    eval_allowed:        bool
    cors_bypass_allowed: bool

@dc.dataclass(frozen=True)
class FileData:
    type:     str
    name:     str
    contents: bytes

@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class PayloadRef(Ref):
    """...."""
    @abstractmethod
    def get_data(self, state: 'HaketiloState') -> PayloadData:
        """...."""
        ...

    @abstractmethod
    def get_mapping(self, state: 'HaketiloState') -> MappingVersionRef:
        """...."""
        ...        

    @abstractmethod
    def get_script_paths(self, state: 'HaketiloState') \
        -> t.Iterable[t.Sequence[str]]:
        """...."""
        ...

    @abstractmethod
    def get_file_data(self, state: 'HaketiloState', path: t.Sequence[str]) \
        -> t.Optional[FileData]:
        """...."""
        ...


class MappingUseMode(Enum):
    """
    AUTO - Apply mappings except for those explicitly disabled.
 
    WHEN_ENABLED - Only apply mappings explicitly marked as enabled. Don't apply
        unmarked nor explicitly disabled mappings.

    QUESTION - Automatically apply mappings that are explicitly enabled. Ask
        whether to enable unmarked mappings. Don't apply explicitly disabled
        ones.
    """
    AUTO         = 'A'
    WHEN_ENABLED = 'W'
    QUESTION     = 'Q'

@dc.dataclass(frozen=True)
class HaketiloGlobalSettings:
    """...."""
    mapping_use_mode:      MappingUseMode
    default_allow_scripts: bool
    repo_refresh_seconds:  int


class MissingItemError(ValueError):
    """...."""
    pass


class HaketiloState(ABC):
    """...."""
    @abstractmethod
    def get_repo(self, repo_id: str) -> RepoRef:
        """...."""
        ...

    @abstractmethod
    def get_repo_iteration(self, repo_iteration_id: str) -> RepoIterationRef:
        """...."""
        ...

    @abstractmethod
    def get_mapping(self, mapping_id: str) -> MappingRef:
        """...."""
        ...

    @abstractmethod
    def get_mapping_version(self, mapping_version_id: str) \
        -> MappingVersionRef:
        """...."""
        ...

    @abstractmethod
    def get_resource(self, resource_id: str) -> ResourceRef:
        """...."""
        ...

    @abstractmethod
    def get_resource_version(self, resource_version_id: str) \
        -> ResourceVersionRef:
        """...."""
        ...

    @abstractmethod
    def get_payload(self, payload_id: str) -> PayloadRef:
        """...."""
        ...

    @abstractmethod
    def add_repo(self, name: t.Optional[str], url:  t.Optional[str]) \
        -> RepoRef:
        """...."""
        ...

    @abstractmethod
    def get_settings(self) -> HaketiloGlobalSettings:
        """...."""
        ...

    @abstractmethod
    def update_settings(
            self,
            *,
            mapping_use_mode:      t.Optional[MappingUseMode] = None,
            default_allow_scripts: t.Optional[bool]           = None,
            repo_refresh_seconds:  t.Optional[int]            = None
    ) -> None:
        """...."""
        ...