CREATE TABLE contacto_emergencia(id_contacto SERIAL UNIQUE,
  telefono_emergencia BIGINT NOT NULL CHECK (telefono_emergencia > 99999999 AND telefono_emergencia < 100000000000),
  nombre_emergencia VARCHAR(50) NOT NULL,
  PRIMARY KEY (id_contacto)
);

CREATE TABLE enfermedad(id_enfermedad SMALLSERIAL UNIQUE,
  descripcion_enfermedad TEXT NOT NULL,
  PRIMARY KEY (id_enfermedad)
);

CREATE TABLE empresa(rut_empresa VARCHAR(9) NOT NULL UNIQUE,
  nombre_empresa VARCHAR(50) NOT NULL,
  contacto VARCHAR(50) NOT NULL,
  telefono BIGINT NOT NULL CHECK (telefono > 99999999 AND telefono < 100000000000),
  PRIMARY KEY (rut_empresa)
);

CREATE TABLE especialidad(id_especialidad SMALLSERIAL UNIQUE,
  descripcion_especialidad TEXT NOT NULL,
  PRIMARY KEY (id_especialidad)
);

CREATE TABLE categoria(id_categoria SMALLSERIAL UNIQUE,
  descripcion_categoria TEXT NOT NULL,
  PRIMARY KEY (id_categoria)
);

CREATE TABLE vehiculo(patente VARCHAR(6) NOT NULL UNIQUE,
  ano_vehiculo SMALLINT NOT NULL,
  marca VARCHAR(20) NOT NULL,
  capacidad SMALLINT NOT NULL,
  PRIMARY KEY (patente)
);

CREATE TABLE region(id_region SMALLSERIAL UNIQUE,
  nombre_region VARCHAR(20) NOT NULL,
  PRIMARY KEY (id_region)
);

CREATE TABLE ciudad(id_ciudad SMALLSERIAL UNIQUE,
  nombre_ciudad VARCHAR(20) NOT NULL,
  id_region SMALLINT,
  PRIMARY KEY (id_ciudad),
  FOREIGN KEY (id_region) REFERENCES region (id_region) ON DELETE CASCADE
);

CREATE TABLE guia(rut_guia VARCHAR(9) NOT NULL UNIQUE,
  nombre_guia VARCHAR(50) NOT NULL,
  calle VARCHAR(20) NOT NULL,
  numero SMALLINT NOT NULL,
  id_ciudad SMALLINT,
  PRIMARY KEY (rut_guia),
  FOREIGN KEY (id_ciudad) REFERENCES ciudad (id_ciudad) ON DELETE CASCADE
);

CREATE TABLE tour(id_tour SERIAL UNIQUE,
  nombre_tour VARCHAR(50) NOT NULL,
  costo_indiv INT NOT NULL CHECK (costo_indiv > costo_grupal),
  costo_grupal INT NOT NULL CHECK (costo_grupal > 0),
  minima_personas INT NOT NULL CHECK (minima_personas > 0),
  id_ciudad SMALLINT,
  PRIMARY KEY (id_tour),
  FOREIGN KEY (id_ciudad) REFERENCES ciudad (id_ciudad) ON DELETE CASCADE
);

CREATE TABLE lugar(id_lugar SMALLSERIAL UNIQUE,
  nombre_lugar VARCHAR(50) NOT NULL,
  valor_entrada INT NOT NULL CHECK (valor_entrada >= 0),
  nivel SMALLINT NOT NULL CHECK (nivel >= 0),
  id_ciudad SMALLINT,
  PRIMARY KEY (id_lugar),
  FOREIGN KEY (id_ciudad) REFERENCES ciudad (id_ciudad) ON DELETE CASCADE
);

CREATE TABLE turista(rut_turista VARCHAR(9) NOT NULL UNIQUE,
  nombre_turista VARCHAR(50) NOT NULL,
  fecha_nacimento DATE NOT NULL,
  id_contacto INT,
  PRIMARY KEY (rut_turista),
  FOREIGN KEY (id_contacto) REFERENCES contacto_emergencia (id_contacto) ON DELETE CASCADE
);

CREATE TABLE tiene_enfermedad(rut_turista VARCHAR(9) NOT NULL,
  id_enfermedad SMALLINT NOT NULL,
  FOREIGN KEY (rut_turista) REFERENCES turista (rut_turista) ON DELETE CASCADE,
  FOREIGN KEY (id_enfermedad) REFERENCES enfermedad (id_enfermedad) ON DELETE CASCADE
);

CREATE TABLE descuento(id_descuento SMALLSERIAL UNIQUE,
  descripcion_descuento TEXT NOT NULL,
  porcentaje DECIMAL(3,2) NOT NULL CHECK (porcentaje BETWEEN 0 AND 1),
  PRIMARY KEY (id_descuento)
);

CREATE TABLE realiza(id_tour INT NOT NULL,
  rut_turista VARCHAR(9) NOT NULL,
  id_descuento SMALLINT NOT NULL,
  FOREIGN KEY (id_tour) REFERENCES tour (id_tour) ON DELETE CASCADE,
  FOREIGN KEY (rut_turista) REFERENCES turista (rut_turista) ON DELETE CASCADE,
  FOREIGN KEY (id_descuento) REFERENCES descuento (id_descuento) ON DELETE CASCADE
);

CREATE TABLE arrienda(patente VARCHAR(6) NOT NULL,
  rut_empresa VARCHAR(9) NOT NULL,
  precio INT NOT NULL CHECK (precio > 0),
  fecha_devolucion DATE NOT NULL,
  FOREIGN KEY (patente) REFERENCES vehiculo (patente) ON DELETE CASCADE,
  FOREIGN KEY (rut_empresa) REFERENCES empresa (rut_empresa) ON DELETE CASCADE
);

CREATE TABLE posee(rut_guia VARCHAR(9) NOT NULL,
  id_especialidad SMALLINT NOT NULL,
  nivel_especialidad SMALLINT NOT NULL CHECK (nivel_especialidad >= 0),
  FOREIGN KEY (rut_guia) REFERENCES guia (rut_guia) ON DELETE CASCADE,
  FOREIGN KEY (id_especialidad) REFERENCES especialidad (id_especialidad) ON DELETE CASCADE
);

CREATE TABLE participa(id_tour INT NOT NULL,
  rut_guia VARCHAR(9) NOT NULL,
  id_categoria SMALLINT NOT NULL,
  FOREIGN KEY (id_tour) REFERENCES tour (id_tour) ON DELETE CASCADE,
  FOREIGN KEY (rut_guia) REFERENCES guia (rut_guia) ON DELETE CASCADE,
  FOREIGN KEY (id_categoria) REFERENCES categoria (id_categoria) ON DELETE CASCADE
);

CREATE TABLE asociado(id_tour INT NOT NULL,
  id_lugar SMALLINT NOT NULL,
  fecha_llegada DATE,
  hora_llegada TIME,
  fecha_salida DATE,
  hora_salida TIME,
  FOREIGN KEY (id_tour) REFERENCES tour (id_tour) ON DELETE CASCADE,
  FOREIGN KEY (id_lugar) REFERENCES lugar (id_lugar) ON DELETE CASCADE
);

CREATE TABLE requerir_auto(id_tour INT NOT NULL,
  patente VARCHAR(6) NOT NULL,
  chofer VARCHAR(50) NOT NULL,
  FOREIGN KEY (id_tour) REFERENCES tour (id_tour) ON DELETE CASCADE,
  FOREIGN KEY (patente) REFERENCES vehiculo (patente) ON DELETE CASCADE
);