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

ALTER TABLE students ADD COLUMN IF NOT EXISTS group_id INT REFERENCES groups(id);

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()
);

DO $$
BEGIN
  INSERT INTO students (name)
  SELECT DISTINCT student_name FROM entries WHERE student_name IS NOT NULL AND student_name <> ''
  ON CONFLICT (name) DO NOTHING;
END $$;

CREATE TABLE IF NOT EXISTS project_files (
  id SERIAL PRIMARY KEY,
  entry_id INT NOT NULL REFERENCES entries(id) ON DELETE CASCADE,
  token VARCHAR(64),
  path VARCHAR(255) NOT NULL,
  name VARCHAR(255) NOT NULL,
  created_at TIMESTAMPTZ DEFAULT now()
);

UPDATE project_files SET token = md5(random()::text || clock_timestamp()::text) WHERE token IS NULL;
ALTER TABLE project_files ALTER COLUMN token SET NOT NULL;
CREATE UNIQUE INDEX IF NOT EXISTS project_files_token_key ON project_files(token);

ALTER TABLE project_files ALTER COLUMN entry_id DROP NOT NULL;
ALTER TABLE project_files ADD COLUMN IF NOT EXISTS detached_at TIMESTAMPTZ;

ALTER TABLE entries ADD COLUMN IF NOT EXISTS deleted_at TIMESTAMPTZ;

CREATE TABLE IF NOT EXISTS branches (
  id SERIAL PRIMARY KEY,
  name VARCHAR(200) NOT NULL UNIQUE,
  address TEXT,
  phone VARCHAR(50),
  created_at TIMESTAMPTZ DEFAULT now()
);

ALTER TABLE groups ADD COLUMN IF NOT EXISTS branch_id INT REFERENCES branches(id) ON DELETE SET NULL;
ALTER TABLE groups ADD COLUMN IF NOT EXISTS day_of_week INT;
ALTER TABLE groups ADD COLUMN IF NOT EXISTS time_start TIME;
ALTER TABLE groups ADD COLUMN IF NOT EXISTS time_end TIME;
ALTER TABLE groups ADD COLUMN IF NOT EXISTS cover_path VARCHAR(255);

CREATE TABLE IF NOT EXISTS users (
  id SERIAL PRIMARY KEY,
  username VARCHAR(100) NOT NULL UNIQUE,
  password_hash VARCHAR(255) NOT NULL,
  name VARCHAR(150),
  role VARCHAR(20) NOT NULL DEFAULT 'tutor' CHECK (role IN ('admin','tutor')),
  is_active BOOLEAN DEFAULT true,
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE IF NOT EXISTS user_branches (
  user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  branch_id INT NOT NULL REFERENCES branches(id) ON DELETE CASCADE,
  PRIMARY KEY (user_id, branch_id)
);

CREATE TABLE IF NOT EXISTS sessions (
  id SERIAL PRIMARY KEY,
  user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  token VARCHAR(64) NOT NULL UNIQUE,
  created_at TIMESTAMPTZ DEFAULT now(),
  expires_at TIMESTAMPTZ NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_sessions_token ON sessions(token);
CREATE INDEX IF NOT EXISTS idx_sessions_expires_at ON sessions(expires_at);

ALTER TABLE audit_log ADD COLUMN IF NOT EXISTS user_id INT REFERENCES users(id) ON DELETE SET NULL;

CREATE TABLE IF NOT EXISTS group_photos (
  id SERIAL PRIMARY KEY,
  group_id INT NOT NULL REFERENCES groups(id) ON DELETE CASCADE,
  photo_path VARCHAR(255) NOT NULL,
  caption TEXT,
  taken_at DATE,
  created_at TIMESTAMPTZ DEFAULT now()
);

ALTER TABLE group_photos ADD COLUMN IF NOT EXISTS sort_order INT DEFAULT 0;

CREATE INDEX IF NOT EXISTS idx_group_photos_group_id ON group_photos(group_id);