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

# Haketilo proxy data and configuration (ResourceStore and MappingStore
# implementations).
#
# 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 provides an interface to interact with mappings, and resources
inside Haketilo.
"""

# Enable using with Python 3.7.
from __future__ import annotations

import sqlite3
import typing as t
import dataclasses as dc

from ... import item_infos
from .. import state as st
from . import base

def _set_installed_status(cursor: sqlite3.Cursor, id: str, new_status: str) \
    -> None:
    cursor.execute(
         'UPDATE item_versions SET installed = ? WHERE item_version_id = ?;',
        (new_status, id)
    )

def _get_statuses(cursor: sqlite3.Cursor, id: str) -> t.Tuple[str, str]:
    cursor.execute(
        '''
        SELECT
                installed, active
        FROM
                item_versions
        WHERE
                item_version_id = ?;
        ''',
        (id,)
    )

    rows = cursor.fetchall()

    if rows == []:
        raise st.MissingItemError()

    (installed_status, active_status), = rows

    return installed_status, active_status

VersionRefVar = t.TypeVar(
    'VersionRefVar',
    'ConcreteResourceVersionRef',
    'ConcreteMappingVersionRef'
)

def _install_version(ref: VersionRefVar) -> None:
    with ref.state.cursor(transaction=True) as cursor:
        installed_status, _ = _get_statuses(cursor, ref.id)

        if installed_status == 'I':
            return

        _set_installed_status(cursor, ref.id, 'I')

        ref.state.pull_missing_files()

def _uninstall_version(ref: VersionRefVar) -> t.Optional[VersionRefVar]:
    with ref.state.cursor(transaction=True) as cursor:
        installed_status, active_status = _get_statuses(cursor, ref.id)

        if installed_status == 'N':
            return ref

        _set_installed_status(cursor, ref.id, 'N')

        ref.state.prune_orphans()

        if active_status == 'R':
            ref.state.recompute_dependencies()

        cursor.execute(
            'SELECT COUNT(*) FROM item_versions WHERE item_version_id = ?;',
            (ref.id,)
        )

        (version_still_present,), = cursor.fetchall()
        return ref if version_still_present else None


@dc.dataclass(frozen=True, unsafe_hash=True)
class ConcreteMappingRef(st.MappingRef):
    state: base.HaketiloStateWithFields = dc.field(hash=False, compare=False)

    def get_version_display_infos(self) \
        -> t.Sequence[st.MappingVersionDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                '''
                SELECT
                        ive.item_version_id,
                        ive.definition,
                        ive.repo,
                        ive.repo_iteration,
                        ive.installed,
                        ive.active,
                        ive.is_orphan,
                        ive.is_local,
                        ms.frozen,
                        ms.enabled
                FROM
                             item_versions_extra AS ive
                        JOIN mapping_statuses    AS ms USING (item_id)
                WHERE
                        ive.item_id = ?;
                ''',
                (self.id,)
            )

            rows = cursor.fetchall()

        if rows == []:
            raise st.MissingItemError()

        result = []

        for (item_version_id, definition, repo, repo_iteration,
             installed_status, active_status, is_orphan, is_local,
             frozen_status, enabled_status) in rows:
            ref = ConcreteMappingVersionRef(str(item_version_id), self.state)

            item_info = item_infos.MappingInfo.load(
                definition,
                repo,
                repo_iteration
            )

            display_info = st.MappingVersionDisplayInfo(
                ref             = ref,
                info            = item_info,
                installed       = st.InstalledStatus(installed_status),
                active          = st.ActiveStatus(active_status),
                is_orphan       = is_orphan,
                is_local        = is_local,
                mapping_enabled = st.EnabledStatus(enabled_status),
                mapping_frozen  = st.FrozenStatus.make(frozen_status)
            )
            result.append(display_info)

        return sorted(result, key=(lambda di: di.info))


@dc.dataclass(frozen=True)
class ConcreteMappingStore(st.MappingStore):
    state: base.HaketiloStateWithFields

    def get(self, id: str) -> st.MappingRef:
        return ConcreteMappingRef(str(int(id)), self.state)

    def get_display_infos(self) -> t.Sequence[st.MappingDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                '''
                WITH available_item_ids AS (
                        SELECT DISTINCT item_id FROM item_versions
                )
                SELECT
                        i.item_id,
                        i.identifier,
                        ive.item_version_id,
                        ive.definition,
                        ive.repo,
                        ive.repo_iteration,
                        ive.installed,
                        ive.active,
                        ive.is_orphan,
                        ive.is_local,
                        ms.enabled,
                        ms.frozen
                FROM
                                  items                 AS i
                        JOIN      mapping_statuses      AS ms
                                USING (item_id)
                        LEFT JOIN item_versions_extra   AS ive
                                ON ms.active_version_id = ive.item_version_id
                WHERE
                        i.item_id IN available_item_ids;
                '''
            )

            rows = cursor.fetchall()

        result = []

        for (item_id, identifier, item_version_id, definition, repo,
             repo_iteration, installed_status, active_status, is_orphan,
             is_local, enabled_status, frozen_status) in rows:
            ref = ConcreteMappingRef(str(item_id), self.state)

            active_version: t.Optional[st.MappingVersionDisplayInfo] = None

            if item_version_id is not None:
                active_version_ref = ConcreteMappingVersionRef(
                    id    = str(item_version_id),
                    state = self.state
                )

                active_version_info = item_infos.MappingInfo.load(
                    definition,
                    repo,
                    repo_iteration
                )

                active_version = st.MappingVersionDisplayInfo(
                    ref             = active_version_ref,
                    info            = active_version_info,
                    installed       = st.InstalledStatus(installed_status),
                    active          = st.ActiveStatus(active_status),
                    is_orphan       = is_orphan,
                    is_local        = is_local,
                    mapping_enabled = st.EnabledStatus(enabled_status),
                    mapping_frozen  = st.FrozenStatus.make(frozen_status)
                )

            display_info = st.MappingDisplayInfo(
                ref            = ref,
                identifier     = identifier,
                enabled        = st.EnabledStatus(enabled_status),
                frozen         = st.FrozenStatus.make(frozen_status),
                active_version = active_version
            )

            result.append(display_info)

        return sorted(result, key=(lambda di: di.identifier))


@dc.dataclass(frozen=True, unsafe_hash=True)
class ConcreteMappingVersionRef(st.MappingVersionRef):
    state: base.HaketiloStateWithFields

    def install(self) -> None:
        return _install_version(self)

    def uninstall(self) -> t.Optional['ConcreteMappingVersionRef']:
        return _uninstall_version(self)

    def get_all_version_display_infos(self) \
        -> t.Sequence[st.MappingVersionDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                '''
                SELECT
                        item_id
                FROM
                        item_versions
                WHERE
                        item_version_id = ?;
                ''',
                (self.id,)
            )

            rows = cursor.fetchall()
            if rows == []:
                raise st.MissingItemError()

            (mapping_id,), = rows

            mapping_ref = ConcreteMappingRef(str(mapping_id), self.state)

            return mapping_ref.get_version_display_infos()


@dc.dataclass(frozen=True)
class ConcreteMappingVersionStore(st.MappingVersionStore):
    state: base.HaketiloStateWithFields

    def get(self, id: str) -> st.MappingVersionRef:
        return ConcreteMappingVersionRef(str(int(id)), self.state)


@dc.dataclass(frozen=True, unsafe_hash=True)
class ConcreteResourceRef(st.ResourceRef):
    state: base.HaketiloStateWithFields = dc.field(hash=False, compare=False)

    def get_version_display_infos(self) \
        -> t.Sequence[st.ResourceVersionDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                '''
                SELECT
                        ive.item_version_id,
                        ive.definition,
                        ive.repo,
                        ive.repo_iteration,
                        ive.installed,
                        ive.active,
                        ive.is_orphan,
                        ive.is_local
                FROM
                             item_versions_extra AS ive
                        JOIN items               AS i USING (item_id)
                WHERE
                        i.type = 'R' AND ive.item_id = ?;
                ''',
                (self.id,)
            )

            rows = cursor.fetchall()

        if rows == []:
            raise st.MissingItemError()

        result = []

        for (item_version_id, definition, repo, repo_iteration,
             installed_status, active_status, is_orphan, is_local) in rows:
            ref = ConcreteResourceVersionRef(str(item_version_id), self.state)

            item_info = item_infos.ResourceInfo.load(
                definition,
                repo,
                repo_iteration
            )

            display_info = st.ResourceVersionDisplayInfo(
                ref             = ref,
                info            = item_info,
                installed       = st.InstalledStatus(installed_status),
                active          = st.ActiveStatus(active_status),
                is_orphan       = is_orphan,
                is_local        = is_local
            )
            result.append(display_info)

        return sorted(result, key=(lambda di: di.info))


@dc.dataclass(frozen=True)
class ConcreteResourceStore(st.ResourceStore):
    state: base.HaketiloStateWithFields

    def get(self, id: str) -> st.ResourceRef:
        return ConcreteResourceRef(str(int(id)), self.state)

    def get_display_infos(self) -> t.Sequence[st.ResourceDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                "SELECT item_id, identifier FROM items WHERE type = 'R';"
            )

            rows = cursor.fetchall()

        result = []

        for item_id, identifier in rows:
            ref = ConcreteResourceRef(str(item_id), self.state)

            result.append(st.ResourceDisplayInfo(ref, identifier))

        return sorted(result, key=(lambda di: di.identifier))


@dc.dataclass(frozen=True, unsafe_hash=True)
class ConcreteResourceVersionRef(st.ResourceVersionRef):
    state: base.HaketiloStateWithFields

    def install(self) -> None:
        return _install_version(self)

    def uninstall(self) -> t.Optional['ConcreteResourceVersionRef']:
        return _uninstall_version(self)

    def get_all_version_display_infos(self) \
        -> t.Sequence[st.ResourceVersionDisplayInfo]:
        with self.state.cursor() as cursor:
            cursor.execute(
                '''
                SELECT
                        item_id
                FROM
                        item_versions
                WHERE
                        item_version_id = ?;
                ''',
                (self.id,)
            )

            rows = cursor.fetchall()
            if rows == []:
                raise st.MissingItemError()

            (resource_id,), = rows

            resource_ref = ConcreteResourceRef(str(resource_id), self.state)

            return resource_ref.get_version_display_infos()


@dc.dataclass(frozen=True)
class ConcreteResourceVersionStore(st.ResourceVersionStore):
    state: base.HaketiloStateWithFields

    def get(self, id: str) -> st.ResourceVersionRef:
        return ConcreteResourceVersionRef(str(int(id)), self.state)