CREATE TABLE collaboration_federation_identity (
    singleton boolean PRIMARY KEY DEFAULT true CHECK(singleton),
    instance_id uuid NOT NULL UNIQUE,
    key_id uuid NOT NULL,
    public_key text NOT NULL,
    private_key_cipher jsonb NOT NULL,
    created_at timestamptz NOT NULL DEFAULT now()
);
CREATE TABLE collaboration_partners (
    tenant_id bigint NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
    origin text NOT NULL,
    instance_id uuid NOT NULL,
    key_id uuid NOT NULL,
    public_key text NOT NULL,
    active boolean NOT NULL DEFAULT true,
    updated_at timestamptz NOT NULL DEFAULT now(),
    PRIMARY KEY(tenant_id,origin)
);
CREATE TABLE collaboration_federation_nonces (
    origin text NOT NULL,
    nonce uuid NOT NULL,
    expires_at timestamptz NOT NULL,
    PRIMARY KEY(origin,nonce)
);
CREATE TABLE collaboration_remote_bindings (
    id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id bigint NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
    principal_id uuid NOT NULL REFERENCES collaboration_principals(id) ON DELETE CASCADE,
    origin text NOT NULL,
    room_id uuid NOT NULL,
    invitation_id uuid NOT NULL,
    status text NOT NULL DEFAULT 'pending' CHECK(status IN ('pending','active','revoked','declined')),
    invitation jsonb NOT NULL,
    snapshot jsonb,
    revision bigint NOT NULL DEFAULT 0,
    last_read_seq bigint NOT NULL DEFAULT 0,
    sync_seq bigint NOT NULL DEFAULT 0,
    sync_at timestamptz,
    last_error text,
    UNIQUE(principal_id,origin,room_id)
);
CREATE TABLE collaboration_remote_messages (
    binding_id uuid NOT NULL REFERENCES collaboration_remote_bindings(id) ON DELETE CASCADE,
    id uuid NOT NULL,
    seq bigint NOT NULL,
    payload jsonb NOT NULL,
    PRIMARY KEY(binding_id,id),
    UNIQUE(binding_id,seq)
);
CREATE TABLE collaboration_outbox (
    id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    dedup_key text NOT NULL UNIQUE,
    tenant_id bigint NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
    principal_id uuid NOT NULL REFERENCES collaboration_principals(id),
    origin text NOT NULL,
    binding_id uuid REFERENCES collaboration_remote_bindings(id) ON DELETE CASCADE,
    room_id uuid REFERENCES collaboration_rooms(id) ON DELETE CASCADE,
    action text NOT NULL,
    payload jsonb NOT NULL,
    status text NOT NULL DEFAULT 'pending' CHECK(status IN ('pending','sent','failed')),
    attempts integer NOT NULL DEFAULT 0,
    next_attempt_at timestamptz NOT NULL DEFAULT now(),
    lease_until timestamptz,
    last_error text,
    created_at timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX collaboration_outbox_pending ON collaboration_outbox(next_attempt_at) WHERE status='pending';