CREATE TABLE IF NOT EXISTS groups (
  id SERIAL PRIMARY KEY,
  name VARCHAR(100) NOT NULL UNIQUE,
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE IF NOT EXISTS students (
  id SERIAL PRIMARY KEY,
  name VARCHAR(150) NOT NULL UNIQUE,
  group_id INT REFERENCES groups(id),
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE IF NOT EXISTS entries (
  id SERIAL PRIMARY KEY,
  student_name VARCHAR(150) NOT NULL,
  group_id INT NOT NULL REFERENCES groups(id),
  description TEXT NOT NULL,
  photo_path VARCHAR(255),
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE IF NOT EXISTS settings (
  key TEXT PRIMARY KEY,
  value TEXT
);

INSERT INTO settings (key, value) VALUES ('spam_interval_min', '30')
ON CONFLICT (key) DO NOTHING;

CREATE TABLE IF NOT EXISTS share_links (
  id SERIAL PRIMARY KEY,
  token VARCHAR(40) UNIQUE NOT NULL,
  name VARCHAR(200) NOT NULL,
  group_id INT REFERENCES groups(id),
  student_name VARCHAR(150),
  date_from DATE,
  date_to DATE,
  created_at TIMESTAMPTZ DEFAULT now()
);

INSERT INTO groups (name) VALUES
  ('Beginner'),
  ('Intermediate'),
  ('Advanced')
ON CONFLICT (name) DO NOTHING;

CREATE TABLE IF NOT EXISTS project_files (
  id SERIAL PRIMARY KEY,
  entry_id INT NOT NULL REFERENCES entries(id) ON DELETE CASCADE,
  path VARCHAR(255) NOT NULL,
  name VARCHAR(255) NOT NULL,
  created_at TIMESTAMPTZ DEFAULT now()
);