CREATE TYPE particle_type AS ENUM (
  'stream', 'folder', 'media', 'file', 'text', 'quest', 'paper', 'think'
);

CREATE TYPE visibility_mode AS ENUM ('network_all', 'custom');

CREATE TABLE particles (
  id TEXT PRIMARY KEY,
  type particle_type NOT NULL,
  network_id TEXT NOT NULL REFERENCES networks(id) ON DELETE CASCADE,
  parent_id TEXT REFERENCES particles(id) ON DELETE CASCADE,
  created_by_email VARCHAR(255) NOT NULL,
  visibility visibility_mode NOT NULL DEFAULT 'network_all',
  data JSONB NOT NULL DEFAULT '{}',
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE TABLE particle_members (
  particle_id TEXT NOT NULL REFERENCES particles(id) ON DELETE CASCADE,
  email VARCHAR(255) NOT NULL,
  added_at TIMESTAMPTZ DEFAULT NOW(),
  PRIMARY KEY (particle_id, email)
);

-- Indexes
CREATE INDEX idx_particles_parent_updated ON particles(parent_id, updated_at DESC);
CREATE INDEX idx_particles_network_root ON particles(network_id, updated_at DESC) WHERE parent_id IS NULL;
CREATE INDEX idx_particles_open_streams ON particles(network_id) WHERE type = 'stream' AND data->>'status' = 'open';
CREATE INDEX idx_particle_members_email ON particle_members(email, particle_id);