CREATE TABLE agent_settings (
  id smallint PRIMARY KEY DEFAULT 1 CHECK (id = 1),
  enabled boolean NOT NULL DEFAULT false,
  provider_name text NOT NULL DEFAULT '',
  provider_type text NOT NULL DEFAULT 'openai_compatible' CHECK (provider_type IN ('openai_compatible','openai','custom_http')),
  base_url text NOT NULL DEFAULT '',
  model text NOT NULL DEFAULT '',
  encrypted_api_key bytea,
  timeout_ms integer NOT NULL DEFAULT 30000 CHECK (timeout_ms BETWEEN 1000 AND 120000),
  max_tokens integer NOT NULL DEFAULT 2048 CHECK (max_tokens BETWEEN 1 AND 32768),
  temperature double precision NOT NULL DEFAULT 0.2 CHECK (temperature BETWEEN 0 AND 2),
  system_prompt text NOT NULL DEFAULT '',
  max_history integer NOT NULL DEFAULT 20 CHECK (max_history BETWEEN 1 AND 100),
  rate_limit integer NOT NULL DEFAULT 30 CHECK (rate_limit BETWEEN 1 AND 600),
  request_logging boolean NOT NULL DEFAULT false,
  tool_enabled boolean NOT NULL DEFAULT true,
  confirmation_required boolean NOT NULL DEFAULT true,
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now(),
  updated_by uuid REFERENCES users(id)
);

CREATE TABLE agent_sessions (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  admin_user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  title text NOT NULL DEFAULT 'OverCooked Admin Agent',
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now(),
  expires_at timestamptz NOT NULL DEFAULT (now() + interval '24 hours')
);
CREATE INDEX agent_sessions_admin_idx ON agent_sessions(admin_user_id, updated_at DESC);

CREATE TABLE agent_messages (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id uuid NOT NULL REFERENCES agent_sessions(id) ON DELETE CASCADE,
  role text NOT NULL CHECK (role IN ('system','user','assistant','tool')),
  content text NOT NULL,
  tool_name text,
  tool_call_id text,
  confirmation_state text NOT NULL DEFAULT 'none' CHECK (confirmation_state IN ('none','pending','confirmed','cancelled','expired')),
  created_at timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX agent_messages_session_idx ON agent_messages(session_id, created_at);

CREATE TABLE agent_audit (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id uuid REFERENCES agent_sessions(id) ON DELETE SET NULL,
  admin_user_id uuid NOT NULL REFERENCES users(id) ON DELETE RESTRICT,
  capability text NOT NULL,
  action text NOT NULL,
  target text NOT NULL DEFAULT '',
  request_summary text NOT NULL DEFAULT '',
  result jsonb NOT NULL DEFAULT '{}'::jsonb,
  status text NOT NULL CHECK (status IN ('planned','pending_confirmation','success','cancelled','failed')),
  error_code text NOT NULL DEFAULT '',
  trace_id text NOT NULL DEFAULT '',
  latency_ms bigint NOT NULL DEFAULT 0,
  created_at timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX agent_audit_admin_idx ON agent_audit(admin_user_id, created_at DESC);