[feature] Conversations API (#3013)

* Implement conversations API

* Sort and page conversations by last status ID

* Appease linter

* Fix deleting conversations and statuses

* Refactor to make migrations automatic

* Lint

* Update tests post-merge

* Fixes from live-fire testing

* Linter caught a format problem

* Refactor tests, fix cache

* Negative test for non-DMs

* Run conversations advanced migration on testrig startup as well as regular server startup

* Document (lack of) side effects of API method for deleting a conversation

* Make not-found check less nested for readability

* Rename PutConversation to UpsertConversation

* Use util.Ptr instead of IIFE

* Reduce cache used by conversations

* Remove unnecessary TableExpr/ColumnExpr

* Use struct tags for both unique constraints on Conversation

* Make it clear how paging with GetDirectStatusIDsBatch should be used

* Let conversation paging skip conversations it can't render

* Use Bun NewDropTable

* Convert delete raw query to Bun

* Convert update raw query to Bun

* Convert latestConversationStatusesTempTable raw query partially to Bun

* Convert conversationStatusesTempTable raw query partially to Bun

* Rename field used to store result of MaxDirectStatusID

* Move advanced migrations to their own tiny processor

* Catch up util function name with main

* Remove json.… wrappers

* Remove redundant check

* Combine error checks

* Replace map with slice of structs

* Address processor/type converter comments

- Add context info for errors
- Extract some common processor code into shared methods
- Move conversation eligibility check ahead of populating conversation

* Add error context when dropping temp tables

1 files changed, 12 insertions, 0 deletions

diff --git a/internal/db/status.go b/internal/db/status.go
index 88ae12a12..ade900728 100644
--- a/internal/db/status.go
+++ b/internal/db/status.go
@@ -78,4 +78,16 @@ type Status interface {
 
 	// GetStatusChildren gets the child statuses of a given status.
 	GetStatusChildren(ctx context.Context, statusID string) ([]*gtsmodel.Status, error)
+
+	// MaxDirectStatusID returns the newest ID across all DM statuses.
+	// Returns the empty string with no error if there are no DM statuses yet.
+	// It is used only by the conversation advanced migration.
+	MaxDirectStatusID(ctx context.Context) (string, error)
+
+	// GetDirectStatusIDsBatch returns up to count DM status IDs strictly greater than minID
+	// and less than or equal to maxIDInclusive. Note that this is different from most of our paging,
+	// which uses a maxID and returns IDs strictly less than that, because it's called with the result of
+	// MaxDirectStatusID, and expects to eventually return the status with that ID.
+	// It is used only by the conversation advanced migration.
+	GetDirectStatusIDsBatch(ctx context.Context, minID string, maxIDInclusive string, count int) ([]string, error)
 }