#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2014, 2015 OpenMarket Ltd
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#

import logging
import os
from typing import Any

import attr

from synapse.config.server import generate_ip_set, parse_proxy_config
from synapse.types import JsonDict
from synapse.util.check_dependencies import check_requirements
from synapse.util.module_loader import load_module

from ._base import Config, ConfigError

logger = logging.getLogger(__name__)

DEFAULT_THUMBNAIL_SIZES = [
    {"width": 32, "height": 32, "method": "crop"},
    {"width": 96, "height": 96, "method": "crop"},
    {"width": 320, "height": 240, "method": "scale"},
    {"width": 640, "height": 480, "method": "scale"},
    {"width": 800, "height": 600, "method": "scale"},
]

THUMBNAIL_SIZE_YAML = """\
        #  - width: %(width)i
        #    height: %(height)i
        #    method: %(method)s
"""

# A map from the given media type to the type of thumbnail we should generate
# for it.
THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP = {
    "image/jpeg": "jpeg",
    "image/jpg": "jpeg",
    "image/webp": "jpeg",
    # Thumbnails can only be jpeg or png. We choose png thumbnails for gif
    # because it can have transparency.
    "image/gif": "png",
    "image/png": "png",
}

URL_PREVIEW_BLACKLIST_IGNORED_BECAUSE_HTTP_PROXY_SET_WARNING = """\
The Synapse config url_preview_ip_range_blacklist will be ignored as an HTTP(s) proxy is configured."""


@attr.s(frozen=True, slots=True, auto_attribs=True)
class ThumbnailRequirement:
    width: int
    height: int
    method: str
    media_type: str


@attr.s(frozen=True, slots=True, auto_attribs=True)
class MediaStorageProviderConfig:
    store_local: bool  # Whether to store newly uploaded local files
    store_remote: bool  # Whether to store newly downloaded remote files
    store_synchronous: bool  # Whether to wait for successful storage for local uploads


def parse_thumbnail_requirements(
    thumbnail_sizes: list[JsonDict],
) -> dict[str, tuple[ThumbnailRequirement, ...]]:
    """Takes a list of dictionaries with "width", "height", and "method" keys
    and creates a map from image media types to the thumbnail size, thumbnailing
    method, and thumbnail media type to precalculate

    Args:
        thumbnail_sizes: List of dicts with "width", "height", and "method" keys

    Returns:
        Dictionary mapping from media type string to list of ThumbnailRequirement.
    """
    requirements: dict[str, list[ThumbnailRequirement]] = {}
    for size in thumbnail_sizes:
        width = size["width"]
        height = size["height"]
        method = size["method"]

        for format, thumbnail_format in THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP.items():
            requirement = requirements.setdefault(format, [])
            if thumbnail_format == "jpeg":
                requirement.append(
                    ThumbnailRequirement(width, height, method, "image/jpeg")
                )
            elif thumbnail_format == "png":
                requirement.append(
                    ThumbnailRequirement(width, height, method, "image/png")
                )
            else:
                raise Exception(
                    "Unknown thumbnail mapping from %s to %s. This is a Synapse problem, please report!"
                    % (format, thumbnail_format)
                )
    return {
        media_type: tuple(thumbnails) for media_type, thumbnails in requirements.items()
    }


@attr.s(auto_attribs=True, slots=True, frozen=True)
class MediaUploadLimit:
    """
    Represents a limit on the amount of data a user can upload in a given time
    period.

    These can be configured through the `media_upload_limits` [config option](https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#media_upload_limits)
    or via the `get_media_upload_limits_for_user` module API [callback](https://element-hq.github.io/synapse/latest/modules/media_repository_callbacks.html#get_media_upload_limits_for_user).
    """

    max_bytes: int
    """The maximum number of bytes that can be uploaded in the given time period."""

    time_period_ms: int
    """The time period in milliseconds."""


class ContentRepositoryConfig(Config):
    section = "media"

    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
        # Only enable the media repo if either the media repo is enabled or the
        # current worker app is the media repo.
        if (
            config.get("enable_media_repo", True) is False
            and config.get("worker_app") != "synapse.app.media_repository"
        ):
            self.can_load_media_repo = False
            return
        else:
            self.can_load_media_repo = True

        # Whether this instance should be the one to run the background jobs to
        # e.g clean up old URL previews.
        self.media_instance_running_background_jobs = config.get(
            "media_instance_running_background_jobs",
        )

        self.max_upload_size = self.parse_size(config.get("max_upload_size", "50M"))
        self.max_image_pixels = self.parse_size(config.get("max_image_pixels", "32M"))
        self.max_spider_size = self.parse_size(config.get("max_spider_size", "10M"))

        self.prevent_media_downloads_from = config.get(
            "prevent_media_downloads_from", []
        )

        self.unused_expiration_time = self.parse_duration(
            config.get("unused_expiration_time", "24h")
        )

        self.max_pending_media_uploads = config.get("max_pending_media_uploads", 5)

        self.media_store_path = self.ensure_directory(
            config.get("media_store_path", "media_store")
        )

        # Whether to enable the local media storage provider. When disabled,
        # media will only be stored in configured storage providers and temp
        # files will be used for processing.
        self.enable_local_media_storage = config.get("enable_local_media_storage", True)

        backup_media_store_path = config.get("backup_media_store_path")

        synchronous_backup_media_store = config.get(
            "synchronous_backup_media_store", False
        )

        storage_providers = config.get("media_storage_providers", [])

        if backup_media_store_path:
            if storage_providers:
                raise ConfigError(
                    "Cannot use both 'backup_media_store_path' and 'storage_providers'"
                )

            storage_providers = [
                {
                    "module": "file_system",
                    "store_local": True,
                    "store_synchronous": synchronous_backup_media_store,
                    "store_remote": True,
                    "config": {"directory": backup_media_store_path},
                }
            ]

        # This is a list of config that can be used to create the storage
        # providers. The entries are tuples of (Class, class_config,
        # MediaStorageProviderConfig), where Class is the class of the provider,
        # the class_config the config to pass to it, and
        # MediaStorageProviderConfig are options for StorageProviderWrapper.
        #
        # We don't create the storage providers here as not all workers need
        # them to be started.
        self.media_storage_providers: list[tuple] = []

        for i, provider_config in enumerate(storage_providers):
            # We special case the module "file_system" so as not to need to
            # expose FileStorageProviderBackend
            if (
                provider_config["module"] == "file_system"
                or provider_config["module"] == "synapse.rest.media.v1.storage_provider"
            ):
                provider_config["module"] = (
                    "synapse.media.storage_provider.FileStorageProviderBackend"
                )

            provider_class, parsed_config = load_module(
                provider_config, ("media_storage_providers", "<item %i>" % i)
            )

            wrapper_config = MediaStorageProviderConfig(
                provider_config.get("store_local", False),
                provider_config.get("store_remote", False),
                provider_config.get("store_synchronous", False),
            )

            self.media_storage_providers.append(
                (provider_class, parsed_config, wrapper_config)
            )

        self.dynamic_thumbnails = config.get("dynamic_thumbnails", False)
        self.thumbnail_requirements = parse_thumbnail_requirements(
            config.get("thumbnail_sizes", DEFAULT_THUMBNAIL_SIZES)
        )
        self.url_preview_enabled = bool(config.get("url_preview_enabled", False))

        if self.url_preview_enabled:
            check_requirements("url-preview")

            proxy_config = parse_proxy_config(config)
            is_proxy_configured = (
                proxy_config.http_proxy is not None
                or proxy_config.https_proxy is not None
            )
            if "url_preview_ip_range_blacklist" in config:
                if is_proxy_configured:
                    logger.warning(
                        "".join(
                            URL_PREVIEW_BLACKLIST_IGNORED_BECAUSE_HTTP_PROXY_SET_WARNING
                        )
                    )
            else:
                if not is_proxy_configured:
                    raise ConfigError(
                        "For security, you must specify an explicit target IP address "
                        "blacklist in url_preview_ip_range_blacklist for url previewing "
                        "to work"
                    )

            # we always block '0.0.0.0' and '::', which are supposed to be
            # unroutable addresses.
            self.url_preview_ip_range_blocklist = generate_ip_set(
                config["url_preview_ip_range_blacklist"],
                ["0.0.0.0", "::"],
                config_path=("url_preview_ip_range_blacklist",),
            )

            self.url_preview_ip_range_allowlist = generate_ip_set(
                config.get("url_preview_ip_range_whitelist", ()),
                config_path=("url_preview_ip_range_whitelist",),
            )

            self.url_preview_url_blocklist = config.get("url_preview_url_blacklist", ())

            self.url_preview_accept_language = config.get(
                "url_preview_accept_language"
            ) or ["en"]

        media_retention = config.get("media_retention") or {}

        self.media_retention_local_media_lifetime_ms = None
        local_media_lifetime = media_retention.get("local_media_lifetime")
        if local_media_lifetime is not None:
            self.media_retention_local_media_lifetime_ms = self.parse_duration(
                local_media_lifetime
            )

        self.media_retention_remote_media_lifetime_ms = None
        remote_media_lifetime = media_retention.get("remote_media_lifetime")
        if remote_media_lifetime is not None:
            self.media_retention_remote_media_lifetime_ms = self.parse_duration(
                remote_media_lifetime
            )

        self.enable_authenticated_media = config.get("enable_authenticated_media", True)

        self.media_upload_limits: list[MediaUploadLimit] = []
        for limit_config in config.get("media_upload_limits", []):
            time_period_ms = self.parse_duration(limit_config["time_period"])
            max_bytes = self.parse_size(limit_config["max_size"])

            self.media_upload_limits.append(MediaUploadLimit(max_bytes, time_period_ms))

    def generate_config_section(self, data_dir_path: str, **kwargs: Any) -> str:
        assert data_dir_path is not None
        media_store = os.path.join(data_dir_path, "media_store")
        return f"media_store_path: {media_store}"
