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

# Haketilo proxy data and configuration (update of dependency tree in the db).
#
# 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.

"""
....
"""

# Enable using with Python 3.7.
from __future__ import annotations

import sqlite3
import typing as t

from urllib.parse import urlparse, urljoin

import requests

from .... import item_infos
from ... import simple_dependency_satisfying as sds
from ... import state


AnyInfoVar = t.TypeVar(
    'AnyInfoVar',
    item_infos.ResourceInfo,
    item_infos.MappingInfo
)

def _get_infos_of_type(cursor: sqlite3.Cursor, info_type: t.Type[AnyInfoVar],) \
    -> t.Mapping[int, AnyInfoVar]:
    cursor.execute(
        '''
        SELECT
                i.item_id, iv.definition, r.name, ri.iteration
        FROM
                     item_versions   AS iv
                JOIN items           AS i  USING (item_id)
                JOIN repo_iterations AS ri USING (repo_iteration_id)
                JOIN repos           AS r  USING (repo_id)
        WHERE
                i.type = ?;
        ''',
        (info_type.type_name[0].upper(),)
    )

    result: dict[int, AnyInfoVar] = {}

    for item_id, definition, repo_name, repo_iteration in cursor.fetchall():
        info = info_type.load(definition, repo_name, repo_iteration)
        result[item_id] = info

    return result

def _mark_version_installed(cursor: sqlite3.Cursor, version_id: int) -> None:
    cursor.execute(
        '''
        UPDATE
                item_versions
        SET
                installed = 'I'
        WHERE
                item_version_id = ?;
        ''',
        (version_id,)
    )

def _recompute_dependencies_no_state_update_no_pull_files(
        cursor:             sqlite3.Cursor,
        extra_requirements: t.Iterable[sds.MappingRequirement]
) -> None:
    cursor.execute('DELETE FROM payloads;')

    ids_to_resources = _get_infos_of_type(cursor, item_infos.ResourceInfo)
    ids_to_mappings  = _get_infos_of_type(cursor, item_infos.MappingInfo)

    resources = ids_to_resources.items()
    resources_to_ids = dict((info.identifier, id) for id, info in resources)

    mappings = ids_to_mappings.items()
    mappings_to_ids = dict((info.identifier, id) for id, info in mappings)

    requirements = [*extra_requirements]

    cursor.execute(
        '''
        SELECT
                i.identifier
        FROM
                     mapping_statuses AS ms
                JOIN items            AS i  USING(item_id)
        WHERE
                ms.enabled = 'E' AND ms.frozen = 'N';
        '''
    )

    for mapping_identifier, in cursor.fetchall():
        requirements.append(sds.MappingRequirement(mapping_identifier))

    cursor.execute(
        '''
        SELECT
                active_version_id, frozen
        FROM
                mapping_statuses
        WHERE
                enabled = 'E' AND frozen IN ('R', 'E');
        '''
    )

    for active_version_id, frozen in cursor.fetchall():
        info = ids_to_mappings[active_version_id]

        requirement: sds.MappingRequirement

        if frozen == 'R':
            requirement = sds.MappingRepoRequirement(info.identifier, info.repo)
        else:
            requirement = sds.MappingVersionRequirement(info.identifier, info)

        requirements.append(requirement)

    mapping_choices = sds.compute_payloads(
        ids_to_resources.values(),
        ids_to_mappings.values(),
        requirements
    )

    cursor.execute(
        '''
        UPDATE
                mapping_statuses
        SET
                required          = FALSE,
                active_version_id = NULL
        WHERE
                enabled != 'E';
        '''
    )

    cursor.execute('DELETE FROM payloads;')

    for choice in mapping_choices.values():
        mapping_ver_id = mappings_to_ids[choice.info.identifier]

        _mark_version_installed(cursor, mapping_ver_id)

        cursor.execute(
            '''
            SELECT
                    item_id
            FROM
                    item_versions
            WHERE
                    item_version_id = ?;
            ''',
            (mapping_ver_id,)
        )

        (mapping_item_id,), = cursor.fetchall()

        cursor.execute(
            '''
            UPDATE
                    mapping_statuses
            SET
                    required          = ?,
                    active_version_id = ?
            WHERE
                    item_id = ?;
            ''',
            (choice.required, mapping_ver_id, mapping_item_id)
        )

        for num, (pattern, payload) in enumerate(choice.payloads.items()):
            cursor.execute(
                '''
                INSERT INTO payloads(
                        mapping_item_id,
                        pattern,
	                    eval_allowed,
                        cors_bypass_allowed
                )
                VALUES (?, ?, ?, ?);
                ''',
                (
                    mapping_ver_id,
                    pattern.orig_url,
                    payload.allows_eval,
                    payload.allows_cors_bypass
                )
            )

            cursor.execute(
                '''
                SELECT
                        payload_id
                FROM
                        payloads
                WHERE
                        mapping_item_id = ? AND pattern = ?;
                ''',
                (mapping_ver_id, pattern.orig_url)
            )

            (payload_id,), = cursor.fetchall()

            for res_num, resource_info in enumerate(payload.resources):
                resource_ver_id = resources_to_ids[resource_info.identifier]

                _mark_version_installed(cursor, resource_ver_id)

                cursor.execute(
                    '''
                    INSERT INTO resolved_depended_resources(
                            payload_id,
                            resource_item_id,
                            idx
                    )
                    VALUES(?, ?, ?);
                    ''',
                    (payload_id, resource_ver_id, res_num)
                )

def _pull_missing_files(cursor: sqlite3.Cursor) -> None:
    cursor.execute(
        '''
        SELECT DISTINCT
                f.file_id, f.sha256,
                r.repo_id, r.url
        FROM
                     repos           AS R
                JOIN repo_iterations AS ri USING (repo_id)
                JOIN item_versions   AS iv USING (repo_iteration_id)
                JOIN file_uses       AS fu USING (item_version_id)
                JOIN files           AS f  USING (file_id)
        WHERE
                iv.installed = 'I' AND f.data IS NULL;
        '''
    )

    rows = cursor.fetchall()

    for file_id, sha256, repo_id, repo_url in rows:
        try:
            response = requests.get(urljoin(repo_url, f'file/sha256/{sha256}'))
            assert response.ok
        except:
            raise state.FileInstallationError(
                repo_id = str(repo_id),
                sha256  = sha256
            )

        cursor.execute(
            '''
            UPDATE
                    files
            SET
                    data = ?
            WHERE
                    file_id = ?;
            ''',
            (response.content, file_id)
        )

def _recompute_dependencies_no_state_update(
        cursor:             sqlite3.Cursor,
        extra_requirements: t.Iterable[sds.MappingRequirement]
) -> None:
    _recompute_dependencies_no_state_update_no_pull_files(
        cursor,
        extra_requirements
    )
    _pull_missing_files(cursor)