Migration is wrapped by transaction, so manual `commit_db_transaction` without transaction restarting causes "there is no transaction in progress" warnings. We should use `disable_ddl_transaction!` instead, if we can omit transaction completely.

* Allow hiding of reblogs from followed users

This adds a new entry to the account menu to allow users to hide
future reblogs from a user (and then if they've done that, to show
future reblogs instead).

This does not remove or add historical reblogs from/to the user's
timeline; it only affects new statuses.

The API for this operates by sending a "reblogs" key to the follow
endpoint. If this is sent when starting a new follow, it will be
respected from the beginning of the follow relationship (even if
the follow request must be approved by the followee). If this is
sent when a follow relationship already exists, it will simply
update the existing follow relationship. As with the notification
muting, this will now return an object ({reblogs: [true|false]}) or
false for each follow relationship when requesting relationship
information for an account. This should cause few issues due to an
object being truthy in many languages, but some modifications may
need to be made in pickier languages.

Database changes: adds a show_reblogs column (default true,
non-nullable) to the follows and follow_requests tables. Because
these are non-nullable, we use the existing MigrationHelpers to
perform this change without locking those tables, although the
tables are likely to be small anyway.

Tests included.

See also <https://github.com/glitch-soc/mastodon/pull/212>.

* Rubocop fixes

* Code review changes

* Test fixes

This patchset closes #648 and resolves #3271.

* Rubocop fix

* Revert reblogs defaulting in argument, fix tests

It turns out we needed this for the same reason we needed it in muting:
if nil gets passed in somehow (most usually by an API client not passing
any value), we need to detect and handle it.

We could specify a default in the parameter and then also catch nil, but
there's no great reason to duplicate the default value.

We added an index for `[account_id, reblog_of_id]`, but we already have a similar index for `reblog_of_id`. Those index will be bigger according to statuses count. For example, `reblog_of_id` index uses 800MB for 10GB statuses table.

So this patch swaps indexed columns like `[reblog_of_id, account_id]`, then it will covers both usage with single index.

Since those index creation may take a while, I've also disabled previous index creation.

* Add consumable invites

* Add UI for generating invite codes

* Add tests

* Display max uses and expiration in invites table, delete invite

* Remove unused column and redundant validator

- Default follows not used, probably bad idea
- InviteCodeValidator is redundant because RegistrationsController
  checks invite code validity

* Add admin setting to disable invites

* Add admin UI for invites, configurable role for invite creation

- Admin UI that lists everyone's invites, always available
- Admin setting min_invite_role to control who can invite people
- Non-admin invite UI only visible if users are allowed to

* Do not remove invites from database, expire them instantly

* Add logging of admin actions

* Update brakeman whitelist

* Log creates, updates and destroys with history of changes

* i18n: Update Polish translation (#5782)

Signed-off-by: Marcin Mikołajczak <me@m4sk.in>

* Split admin navigation into moderation and administration

* Redesign audit log page

*  (#5795)

* Add color coding to audit log

* Change dismiss->resolve, log all outcomes of report as resolve

* Update terminology (e-mail blacklist) (#5796)

* Update terminology (e-mail blacklist)

imho looks better

* Update en.yml

* Fix code style issues

* i18n-tasks normalize

* Serialize moved accounts into REST and ActivityPub APIs

* Parse federated moved accounts from ActivityPub

* Add note about moved accounts to public profiles

* Add moved account message to web UI

* Fix code style issues

* Add structure for lists

* Add list timeline streaming API

* Add list APIs, bind list-account relation to follow relation

* Add API for adding/removing accounts from lists

* Add pagination to lists API

* Add pagination to list accounts API

* Adjust scopes for new APIs

- Creating and modifying lists merely requires "write" scope
- Fetching information about lists merely requires "read" scope

* Add test for wrong user context on list timeline

* Clean up tests

* Add a hide_notifications column to mutes

* Add muting_notifications? and a notifications argument to mute!

* block notifications in notify_service from hard muted accounts

* Add specs for how mute! interacts with muting_notifications?

* specs testing that hide_notifications in mutes actually hides notifications

* Add support for muting notifications in MuteService

* API support for muting notifications (and specs)

* Less gross passing of notifications flag

* Break out a separate mute modal with a hide-notifications checkbox.

* Convert profile header mute to use mute modal

* Satisfy eslint.

* specs for MuteService notifications params

* add trailing newlines to files for Pork :)

* Put the label for the hide notifications checkbox in a label element.

* Add a /api/v1/mutes/details route that just returns the array of mutes.

* Define a serializer for /api/v1/mutes/details

* Add more specs for the /api/v1/mutes/details endpoint

* Expose whether a mute hides notifications in the api/v1/relationships endpoint

* Show whether muted users' notifications are muted in account lists

* Allow modifying the hide_notifications of a mute with the /api/v1/accounts/:id/mute endpoint

* make the hide/unhide notifications buttons work

* satisfy eslint

* In probably dead code, replace a dispatch of muteAccount that was skipping the modal with launching the mute modal.

* fix a missing import

* add an explanatory comment to AccountInteractions

* Refactor handling of default params for muting to make code cleaner

* minor code style fixes oops

* Fixed a typo that was breaking the account mute API endpoint

* Apply white-space: nowrap to account relationships icons

* Fix code style issues

* Remove superfluous blank line

* Rename /api/v1/mutes/details -> /api/v2/mutes

* Don't serialize "account" in MuteSerializer

Doing so is somewhat unnecessary since it's always the current user's account.

* Fix wrong variable name in api/v2/mutes

* Use Toggle in place of checkbox in the mute modal.

* Make the Toggle in the mute modal look better

* Code style changes in specs and removed an extra space

* Code review suggestions from akihikodaki

Also fixed a syntax error in tests for AccountInteractions.

* Make AddHideNotificationsToMute Concurrent

It's not clear how much this will benefit instances in practice, as the
number of mutes tends to be pretty small, but this should prevent any
blocking migrations nonetheless.

* Fix up migration things

* Remove /api/v2/mutes

* Add moderator role and add pundit policies for admin actions

* Add rake task for turning user into mod and revoking it again

* Fix handling of unauthorized exception

* Deliver new report e-mails to staff, not just admins

* Add promote/demote to admin UI, hide some actions conditionally

* Fix unused i18n

Fix #5597

We have changed how we store reblogs in the redis for bigint IDs. This process is done by 1) scan all entries in users feed, and 2) re-store reblogs by 3 write commands.

However, this operation is really slow for large instances. e.g. 1hrs on friends.nico (w/ 50k users). So I have tried below tweaks.

* It checked non-reblogs by `entry[0] == entry[1]`, but this condition won't work because `entry[0]` is String while `entry[1]` is Float. Changing `entry[0].to_i == entry[1]` seems work.
  -> about 4-20x faster (feed with less reblogs will be faster)
* Write operations can be batched by pipeline
  -> about 6x faster
* Wrap operation by Lua script and execute by EVALSHA command. This really reduces packets between Ruby and Redis.
  -> about 3x faster

I've taken Lua script way, though doing other optimizations may be enough.

Reported at
https://don.inux39.me/@inux39/1406082
https://don.inux39.me/@inux39/1406134

* Add foreign key constraint to column `account` in `account_moderation_notes`

* Change account_id and target_account_id to non-nullable in account_moderation_notes

* Add dependent: :destroy to account and target_account in account_moderation_notes

* Add moderation note

* Add frozen_string_literal

* Make rspec pass

* Encode custom emojis as resolveable objects in ActivityPub

* Improve code style

* Implement BlacklistedEmailDomain

* Use Faker::Internet.domain_name

* Remove note column

* Add frozen_string_literal comment

* Delete unnecessary codes

* Sort alphabetically

* Change of wording

* Rename BlacklistedEmailDomain to EmailDomainBlock

* Use non-serial IDs

This change makes a number of nontrivial tweaks to the data model in
Mastodon:

* All IDs are now 8 byte integers (rather than mixed 4- and 8-byte)
* IDs are now assigned as:
  * Top 6 bytes: millisecond-resolution time from epoch
  * Bottom 2 bytes: serial (within the millisecond) sequence number
  * See /lib/tasks/db.rake's `define_timestamp_id` for details, but
    note that the purpose of these changes is to make it difficult to
    determine the number of objects in a table from the ID of any
    object.
* The Redis sorted set used for the feed will have values used to look
  up toots, rather than scores. This is almost always the same as the
  existing behavior, except in the case of boosted toots. This change
  was made because Redis stores scores as double-precision floats,
  which cannot store the new ID format exactly. Note that this doesn't
  cause problems with sorting/pagination, because ZREVRANGEBYSCORE
  sorts lexicographically when scores are tied. (This will still cause
  sorting issues when the ID gains a new significant digit, but that's
  extraordinarily uncommon.)

Note a couple of tradeoffs have been made in this commit:

* lib/tasks/db.rake is used to enforce many/most column constraints,
  because this commit seems likely to take a while to bring upstream.
  Enforcing a post-migrate hook is an easier way to maintain the code
  in the interim.
* Boosted toots will appear in the timeline as many times as they have
  been boosted. This is a tradeoff due to the way the feed is saved in
  Redis at the moment, but will be handled by a future commit.

This would effectively close Mastodon's #1059, as it is a
snowflake-like system of generating IDs. However, given how involved
the changes were simply within Mastodon, it may have unexpected
interactions with some clients, if they store IDs as doubles
(or as 4-byte integers). This was a problem that Twitter ran into with
their "snowflake" transition, particularly in JavaScript clients that
treated IDs as JS integers, rather than strings. It therefore would be
useful to test these changes at least in the web interface and popular
clients before pushing them to all users.

* Fix JavaScript interface with long IDs

Somewhat predictably, the JS interface handled IDs as numbers, which in
JS are IEEE double-precision floats. This loses some precision when
working with numbers as large as those generated by the new ID scheme,
so we instead handle them here as strings. This is relatively simple,
and doesn't appear to have caused any problems, but should definitely
be tested more thoroughly than the built-in tests. Several days of use
appear to support this working properly.

BREAKING CHANGE:

The major(!) change here is that IDs are now returned as strings by the
REST endpoints, rather than as integers. In practice, relatively few
changes were required to make the existing JS UI work with this change,
but it will likely hit API clients pretty hard: it's an entirely
different type to consume. (The one API client I tested, Tusky, handles
this with no problems, however.)

Twitter ran into this issue when introducing Snowflake IDs, and decided
to instead introduce an `id_str` field in JSON responses. I have opted
to *not* do that, and instead force all IDs to 64-bit integers
represented by strings in one go. (I believe Twitter exacerbated their
problem by rolling out the changes three times: once for statuses, once
for DMs, and once for user IDs, as well as by leaving an integer ID
value in JSON. As they said, "If you’re using the `id` field with JSON
in a Javascript-related language, there is a very high likelihood that
the integers will be silently munged by Javascript interpreters. In most
cases, this will result in behavior such as being unable to load or
delete a specific direct message, because the ID you're sending to the
API is different than the actual identifier associated with the
message." [1]) However, given that this is a significant change for API
users, alternatives or a transition time may be appropriate.

1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html

* Restructure feed pushes/unpushes

This was necessary because the previous behavior used Redis zset scores
to identify statuses, but those are IEEE double-precision floats, so we
can't actually use them to identify all 64-bit IDs. However, it leaves
the code in a much better state for refactoring reblog handling /
coalescing.

Feed-management code has been consolidated in FeedManager, including:

* BatchedRemoveStatusService no longer directly manipulates feed zsets
* RemoveStatusService no longer directly manipulates feed zsets
* PrecomputeFeedService has moved its logic to FeedManager#populate_feed

(PrecomputeFeedService largely made lots of calls to FeedManager, but
didn't follow the normal adding-to-feed process.)

This has the effect of unifying all of the feed push/unpush logic in
FeedManager, making it much more tractable to update it in the future.

Due to some additional checks that must be made during, for example,
batch status removals, some Redis pipelining has been removed. It does
not appear that this should cause significantly increased load, but if
necessary, some optimizations are possible in batch cases. These were
omitted in the pursuit of simplicity, but a batch_push and batch_unpush
would be possible in the future.

Tests were added to verify that pushes happen under expected conditions,
and to verify reblog behavior (both on pushing and unpushing). In the
case of unpushing, this includes testing behavior that currently leads
to confusion such as Mastodon's #2817, but this codifies that the
behavior is currently expected.

* Rubocop fixes

I could swear I made these changes already, but I must have lost them
somewhere along the line.

* Address review comments

This addresses the first two comments from review of this feature:

https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735
https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931

This adds an optional argument to FeedManager#key, the subtype of feed
key to generate. It also tests to ensure that FeedManager's settings are
such that reblogs won't be tracked forever.

* Hardcode IdToBigints migration columns

This addresses a comment during review:
https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452

This means we'll need to make sure that all _id columns going forward
are bigints, but that should happen automatically in most cases.

* Additional fixes for stringified IDs in JSON

These should be the last two. These were identified using eslint to try
to identify any plain casts to JavaScript numbers. (Some such casts are
legitimate, but these were not.)

Adding the following to .eslintrc.yml will identify casts to numbers:

~~~
  no-restricted-syntax:
  - warn
  - selector: UnaryExpression[operator='+'] > :not(Literal)
    message: Avoid the use of unary +
  - selector: CallExpression[callee.name='Number']
    message: Casting with Number() may coerce string IDs to numbers
~~~

The remaining three casts appear legitimate: two casts to array indices,
one in a server to turn an environment variable into a number.

* Only implement timestamp IDs for Status IDs

Per discussion in #4801, this is only being merged in for Status IDs at
this point. We do this in a migration, as there is no longer use for
a post-migration hook. We keep the initialization of the timestamp_id
function as a Rake task, as it is also needed after db:schema:load (as
db/schema.rb doesn't store Postgres functions).

* Change internal streaming payloads to stringified IDs as well

This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from
#5019, with an extra change for the addition to FeedManager#unpush.

* Ensure we have a status_id_seq sequence

Apparently this is not a given when specifying a custom ID function,
so now we ensure it gets created. This uses the generic version of this
function to more easily support adding additional tables with timestamp
IDs in the future, although it would be possible to cut this down to a
less generic version if necessary. It is only run during db:schema:load
or the relevant migration, so the overhead is extraordinarily minimal.

* Transition reblogs to new Redis format

This provides a one-way migration to transition old Redis reblog entries
into the new format, with a separate tracking entry for reblogs.

It is not invertible because doing so could (if timestamp IDs are used)
require a database query for each status in each users' feed, which is
likely to be a significant toll on major instances.

* Address review comments from @akihikodaki

No functional changes.

* Additional review changes

* Heredoc cleanup

* Run db:schema:load hooks for test in development

This matches the behavior in Rails'
ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which
would otherwise break `rake db:setup` in development.

It also moves some functionality out to a library, which will be a good
place to put additional related functionality in the near future.

* Make IdsToBigints (mostly!) non-blocking

This pulls in GitLab's MigrationHelpers, which include code to make
column changes in ways that Postgres can do without locking. In general,
this involves creating a new column, adding an index and any foreign
keys as appropriate, adding a trigger to keep it populated alongside
the old column, and then progressively copying data over to the new
column, before removing the old column and replacing it with the new
one.

A few changes to GitLab's MigrationHelpers were necessary:

* Some changes were made to remove dependencies on other GitLab code.
* We explicitly wait for index creation before forging ahead on column
  replacements.
* We use different temporary column names, to avoid running into index
  name length limits.
* We rename the generated indices back to what they "should" be after
  replacing columns.
* We rename the generated foreign keys to use the new column names when
  we had to create them. (This allows the migration to be rolled back
  without incident.)

# Big Scary Warning

There are two things here that may trip up large instances:

1. The change for tables' "id" columns is not concurrent. In
   particular, the stream_entries table may be big, and does not
   concurrently migrate its id column. (On the other hand, x_id type
   columns are all concurrent.)
2. This migration will take a long time to run, *but it should not
   lock tables during that time* (with the exception of the "id"
   columns as described above). That means this should probably be run
   in `screen` or some other session that can be run for a long time.
   Notably, the migration will take *longer* than it would without
   these changes, but the website will still be responsive during that
   time.

These changes were tested on a relatively large statuses table (256k
entries), and the service remained responsive during the migration.
Migrations both forward and backward were tested.

* Rubocop fixes

* MigrationHelpers: Support ID columns in some cases

This doesn't work in cases where the ID column is referred to as a
foreign key by another table.

* MigrationHelpers: support foreign keys for ID cols

Note that this does not yet support foreign keys on non-primary-key
columns, but Mastodon also doesn't yet have any that we've needed to
migrate.

This means we can perform fully "concurrent" migrations to change ID
column types, and the IdsToBigints migration can happen with effectively
no downtime. (A few operations require a transaction, such as renaming
columns or deleting them, but these transactions should not block for
noticeable amounts of time.)

The algorithm for generating foreign key names has changed with this,
and therefore all of those changed in schema.rb.

* Provide status, allow for interruptions

The MigrationHelpers now allow restarting the rename of a column if it
was interrupted, by removing the old "new column" and re-starting the
process.

Along with this, they now provide status updates on the changes which
are happening, as well as indications about when the changes can be
safely interrupted (when there are at least 10 seconds estimated to be
left before copying data is complete).

The IdsToBigints migration now also sorts the columns it migrates by
size, starting with the largest tables. This should provide
administrators a worst-case scenario estimate for the length of
migrations: each successive change will get faster, giving admins a
chance to abort early on if they need to run the migration later. The
idea is that this does not force them to try to time interruptions
between smaller migrations.

* Fix column sorting in IdsToBigints

Not a significant change, but it impacts the order of columns in the
database and db/schema.rb.

* Actually pause before IdsToBigints

* Fix #117 - Add ability to specify alternative text for media attachments

- POST /api/v1/media accepts `description` straight away
- PUT /api/v1/media/:id to update `description` (only for unattached ones)
- Serialized as `name` of Document object in ActivityPub
- Uploads form adjusted for better performance and description input

* Add tests

* Change undo button blend mode to difference

* Fix the migration error when deprecated_preview_cards has deleted

* Re-run Travis CI

This addresses a comment during review:
https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452

This means we'll need to make sure that all _id columns going forward
are bigints, but that should happen automatically in most cases.

* Custom emoji

- In OStatus: `<link rel="emoji" name="coolcat" href="http://..." />`
- In ActivityPub: `{ type: "Emoji", name: ":coolcat:", href: "http://..." }`
- In REST API: Status object includes `emojis` array (`shortcode`, `url`)
- Domain blocks with reject media stop emojis
- Emoji file up to 50KB
- Web UI handles custom emojis
- Static pages render custom emojis as `<img />` tags

Side effects:

- Undo #4500 optimization, as I needed to modify it to restore
  shortcode handling in emojify()
- Formatter#plaintext should now make sure stripped out line-breaks
  and paragraphs are replaced with newlines

* Fix emoji at the start not being converted

* Improve OpenGraph tags for about pages

* Add thumbnail admin setting

* Fix error

* Fix up

* Decouple Status#local? from uri being nil

* Replace on-the-fly URI generation with stored URIs

- Generate URI in after_save hook for local statuses
- Use static value in TagManager when available, fallback to tag format
- Make TagManager use ActivityPub::TagManager to understand new format
- Adjust tests

* Use other heuristic for locality of old statuses, do not perform long query

* Exclude tombstone stream entries from Atom feed

* Prevent nil statuses from landing in Pubsubhubbub::DistributionWorker

* Fix URI not being saved (#4818)

* Add more specs for Status

* Save generated uri immediately

and also fix method order to minimize diff.

* Fix alternate HTML URL in Atom

* Fix tests

* Remove not-null constraint from statuses migration to speed it up

* Make PreviewCard records reuseable between statuses

**Warning!** Migration truncates preview_cards tablec

* Allow a wider thumbnail for link preview, display it in horizontal layout (#4648)

* Delete preview cards files before truncating

* Rename old table instead of truncating it

* Add mastodon:maintenance:remove_deprecated_preview_cards

* Ignore deprecated_preview_cards in schema definition

* Fix null behaviour

We only look up status_pins by account_id, or account_id and status_id,
never by status_id

* Allow multiple pinned statuses to be shown and make them be ordered by pinned date

* Set timestamps NOT NULL

* Make single-line pinned_statuses

* Spec for pinned_statuses

* Remove redundant empty line

* Pinned statuses

* yarn manage:translations