-- Phase 10: relations (threads, edits, reactions, references) and
-- full-text search.

-- content.m.relates_to of each event, written out so that "the children of
-- this event" is an index lookup. Both are '' for an event that relates to
-- nothing, and are cleared when the event is redacted: the redaction
-- algorithm strips the content they came from.
ALTER TABLE roomserver_events ADD COLUMN relates_to_id TEXT NOT NULL DEFAULT '';
ALTER TABLE roomserver_events ADD COLUMN rel_type TEXT NOT NULL DEFAULT '';

-- The events already stored. Only a relation with both fields a string
-- counts, which is the rule the roomserver applies to new events.
UPDATE roomserver_events SET
    relates_to_id = json_extract(event_json, '$.content."m.relates_to".event_id'),
    rel_type      = json_extract(event_json, '$.content."m.relates_to".rel_type')
WHERE redacted_by = ''
  AND json_type(event_json, '$.content."m.relates_to".event_id') = 'text'
  AND json_type(event_json, '$.content."m.relates_to".rel_type') = 'text';

-- /relations, the bundled summaries and /threads all start from a parent
-- and read its children in stream order.
CREATE INDEX IF NOT EXISTS roomserver_events_relations_idx
    ON roomserver_events (room_id, relates_to_id, rel_type, stream_ordering);

-- The full-text index /search reads: one row per searchable event, keyed by
-- the event's stream ordering as its rowid, which is unique across the
-- server and is what a redaction finds the row by. Outliers are not here:
-- an event joins the index when it joins a timeline.
--
-- unicode61 with diacritics removed matches "cafe" against "café", which is
-- what a user searching a chat history expects.
CREATE VIRTUAL TABLE IF NOT EXISTS roomserver_event_search USING fts5(
    body,
    room_id    UNINDEXED,
    event_id   UNINDEXED,
    search_key UNINDEXED,
    sender     UNINDEXED,
    event_type UNINDEXED,
    tokenize = 'unicode61 remove_diacritics 2'
);

INSERT INTO roomserver_event_search (rowid, body, room_id, event_id, search_key, sender, event_type)
SELECT stream_ordering, json_extract(event_json, '$.content.body'), room_id, event_id,
       'content.body', sender, event_type
FROM roomserver_events
WHERE event_type = 'm.room.message' AND NOT outlier AND redacted_by = ''
  AND json_type(event_json, '$.content.body') = 'text';

INSERT INTO roomserver_event_search (rowid, body, room_id, event_id, search_key, sender, event_type)
SELECT stream_ordering, json_extract(event_json, '$.content.name'), room_id, event_id,
       'content.name', sender, event_type
FROM roomserver_events
WHERE event_type = 'm.room.name' AND NOT outlier AND redacted_by = ''
  AND json_type(event_json, '$.content.name') = 'text';

INSERT INTO roomserver_event_search (rowid, body, room_id, event_id, search_key, sender, event_type)
SELECT stream_ordering, json_extract(event_json, '$.content.topic'), room_id, event_id,
       'content.topic', sender, event_type
FROM roomserver_events
WHERE event_type = 'm.room.topic' AND NOT outlier AND redacted_by = ''
  AND json_type(event_json, '$.content.topic') = 'text';