-- 021_sessions.sql
-- Anonymous / session participants for workflow channels (v0.24.3)

CREATE TABLE IF NOT EXISTS session_participants (
    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    session_token TEXT NOT NULL UNIQUE,
    channel_id    UUID NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
    display_name  TEXT NOT NULL DEFAULT 'Visitor',
    fingerprint   TEXT,
    created_at    TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_session_participants_channel
    ON session_participants(channel_id);

CREATE INDEX IF NOT EXISTS idx_session_participants_token
    ON session_participants(session_token);

COMMENT ON TABLE session_participants IS 'Ephemeral identities for anonymous workflow channel visitors.';

-- Allow channels to opt in to anonymous session access.
ALTER TABLE channels ADD COLUMN IF NOT EXISTS allow_anonymous BOOLEAN NOT NULL DEFAULT FALSE;

COMMENT ON COLUMN channels.allow_anonymous IS 'When true, unauthenticated visitors can join via session token (workflow channels only).';