CREATE TABLE events (
    id TEXT PRIMARY KEY,
    timestamp INTEGER NOT NULL,
    channel TEXT NOT NULL,
    content_types TEXT NOT NULL,  -- JSON array: ["text"], ["text", "image"]
    content TEXT,
    direction TEXT NOT NULL,      -- sent, received, observed
    thread_id TEXT,
    reply_to TEXT,
    source_adapter TEXT NOT NULL,
    source_id TEXT NOT NULL,
    UNIQUE(source_adapter, source_id)
);

CREATE TABLE persons (
    id TEXT PRIMARY KEY,
    canonical_name TEXT NOT NULL,
    display_name TEXT,
    is_me INTEGER DEFAULT 0,
    relationship_type TEXT
);

CREATE TABLE identities (
    id TEXT PRIMARY KEY,
    person_id TEXT NOT NULL REFERENCES persons(id),
    channel TEXT NOT NULL,
    identifier TEXT NOT NULL,
    UNIQUE(channel, identifier)
);

CREATE TABLE event_participants (
    event_id TEXT NOT NULL REFERENCES events(id),
    person_id TEXT NOT NULL REFERENCES persons(id),
    role TEXT NOT NULL,  -- sender, recipient, cc, observer
    PRIMARY KEY (event_id, person_id, role)
);

CREATE TABLE tags (
    id TEXT PRIMARY KEY,
    event_id TEXT NOT NULL REFERENCES events(id),
    tag_type TEXT NOT NULL,    -- topic, entity, emotion, project, context
    value TEXT NOT NULL,
    confidence REAL,
    source TEXT NOT NULL       -- user, analysis
);