DROP SCHEMA IF EXISTS edu_platform CASCADE;
CREATE SCHEMA edu_platform;

drop table if exists edu_platform.users;
CREATE TABLE edu_platform.users (
    id SERIAL PRIMARY KEY,
    name VARCHAR(100) NOT NULL,
    age INT NOT NULL,
    email VARCHAR(100) NOT NULL, 
    registration_date DATE NOT NULL
);

drop table if exists edu_platform.courses;
CREATE TABLE edu_platform.courses (
	id SERIAL PRIMARY KEY,
	title VARCHAR(100) NOT NULL,
	category VARCHAR(100) NOT NULL,
    created_at DATE not NULL
);

drop table if exists edu_platform.lessons;
create TABLE edu_platform.lessons (
	id SERIAL PRIMARY KEY,
	course_id INT NOT NULL,
	title VARCHAR(100) NOT NULL,
	duration_min INT NOT null,
	FOREIGN KEY (course_id) REFERENCES edu_platform.courses(id)
);

drop table if exists edu_platform.enrollments;
create TABLE edu_platform.enrollments (
	id SERIAL PRIMARY KEY,
	user_id	INT NOT NULL,
	course_id INT NOT NULL,
	enrolled_at DATE not null,
	foreign key (user_id) references edu_platform.users(id),
	foreign key (course_id) references edu_platform.courses(id)
);

drop table if exists edu_platform.lesson_views;
create table edu_platform.lesson_views (
	id SERIAL PRIMARY KEY,
	user_id	INT NOT NULL,
	lesson_id INT NOT NULL,
	viewed_at TIMESTAMP not null,
	foreign key (user_id) references edu_platform.users(id),
	foreign key (lesson_id) references edu_platform.lessons(id)
);