📚 ប្រវត្តិវិទ្យា បាក់ឌុប

-- Table 1: Questions Table
CREATE TABLE questions (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  year INT NOT NULL,
  chapter TEXT NOT NULL,
  question TEXT NOT NULL,
  option_a TEXT NOT NULL,
  option_b TEXT NOT NULL,
  option_c TEXT NOT NULL,
  option_d TEXT NOT NULL,
  answer VARCHAR(2) NOT NULL,
  explanation TEXT,
  image_url TEXT,
  keywords TEXT[],
  created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Table 2: Bookmarks Table
CREATE TABLE bookmarks (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES auth.users(id),
  question_id UUID REFERENCES questions(id),
  created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Table 3: Quiz Results Table
CREATE TABLE quiz_results (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES auth.users(id),
  score INT NOT NULL,
  total_questions INT NOT NULL,
  time_taken_seconds INT,
  created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);