-- Session history table for tracking all RADIUS connections
-- This table persists session data that was previously only in memory

CREATE TABLE IF NOT EXISTS sesiones (
  id SERIAL PRIMARY KEY,

  -- RADIUS session identifiers
  session_id VARCHAR(64) UNIQUE NOT NULL,    -- Acct-Session-Id from FreeRADIUS
  username VARCHAR(64) NOT NULL,             -- User-Name
  dispositivo_id INTEGER REFERENCES dispositivos(id) ON DELETE SET NULL,

  -- NAS (Network Access Server) information
  nas_ip VARCHAR(45),                        -- NAS-IP-Address
  nas_id VARCHAR(64),                        -- NAS-Identifier
  calling_station_id VARCHAR(32),            -- MAC address of client device
  called_station_id VARCHAR(64),             -- SSID or AP identifier

  -- Session timestamps
  started_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  ended_at TIMESTAMPTZ,                      -- NULL if session is active
  last_update TIMESTAMPTZ NOT NULL DEFAULT NOW(),

  -- Session state: active, stopped, stale
  status VARCHAR(16) NOT NULL DEFAULT 'active',
  stop_reason VARCHAR(64),                   -- Acct-Terminate-Cause

  -- Traffic statistics (from Interim-Updates and Stop)
  bytes_in BIGINT DEFAULT 0,                 -- Acct-Input-Octets
  bytes_out BIGINT DEFAULT 0,                -- Acct-Output-Octets
  packets_in BIGINT DEFAULT 0,               -- Acct-Input-Packets
  packets_out BIGINT DEFAULT 0,              -- Acct-Output-Packets
  session_time INTEGER DEFAULT 0,            -- Acct-Session-Time (seconds)

  -- For stale detection
  interim_interval INTEGER                   -- Expected Acct-Interim-Interval
);

-- Indexes for efficient queries
CREATE INDEX IF NOT EXISTS idx_sesiones_username ON sesiones(username);
CREATE INDEX IF NOT EXISTS idx_sesiones_dispositivo ON sesiones(dispositivo_id);
CREATE INDEX IF NOT EXISTS idx_sesiones_status ON sesiones(status);
CREATE INDEX IF NOT EXISTS idx_sesiones_started ON sesiones(started_at DESC);
CREATE INDEX IF NOT EXISTS idx_sesiones_last_update ON sesiones(last_update);
CREATE INDEX IF NOT EXISTS idx_sesiones_calling_station ON sesiones(calling_station_id);

-- Partial index for active sessions (frequently queried)
CREATE INDEX IF NOT EXISTS idx_sesiones_active
  ON sesiones(username, dispositivo_id)
  WHERE status = 'active';