-- ── Thread metadata ───────────────────────────────────────────────────────────
-- Conformance: thread lookups filter by community before event matching.

CREATE TABLE thread_metadata (
    community_id            UUID NOT NULL REFERENCES communities(id),
    event_created_at        TIMESTAMPTZ NOT NULL,
    event_id                BYTEA NOT NULL,
    channel_id              UUID NOT NULL,
    parent_event_id         BYTEA,
    parent_event_created_at TIMESTAMPTZ,
    root_event_id           BYTEA,
    root_event_created_at   TIMESTAMPTZ,
    depth                   INT NOT NULL DEFAULT 0,
    reply_count             INT NOT NULL DEFAULT 0,
    descendant_count        INT NOT NULL DEFAULT 0,
    last_reply_at           TIMESTAMPTZ,
    broadcast               BOOLEAN NOT NULL DEFAULT FALSE,
    PRIMARY KEY (community_id, event_created_at, event_id),
    FOREIGN KEY (community_id, channel_id) REFERENCES channels (community_id, id)
);

CREATE INDEX idx_thread_metadata_parent ON thread_metadata (community_id, parent_event_id);
CREATE INDEX idx_thread_metadata_root ON thread_metadata (community_id, root_event_id);
CREATE INDEX idx_thread_metadata_window
    ON thread_metadata (community_id, root_event_id, event_created_at DESC, event_id ASC);
CREATE INDEX idx_thread_metadata_channel_depth
    ON thread_metadata (community_id, channel_id, depth, event_created_at);
CREATE INDEX idx_thread_metadata_event_id ON thread_metadata (community_id, event_id);