-- edu.senex.de Training Platform - Database Schema
-- Run: docker exec -i postgres psql -U postgres -d edu < schema.sql

-- Users
CREATE TABLE IF NOT EXISTS users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(50) UNIQUE NOT NULL,
    password_hash VARCHAR(255) NOT NULL,
    display_name VARCHAR(100) NOT NULL,
    is_admin BOOLEAN DEFAULT false,
    created_at TIMESTAMP DEFAULT NOW()
);

-- Flashcard Decks
CREATE TABLE IF NOT EXISTS decks (
    id SERIAL PRIMARY KEY,
    slug VARCHAR(100) UNIQUE NOT NULL,
    name VARCHAR(200) NOT NULL,
    description TEXT DEFAULT '',
    card_count INT DEFAULT 0,
    sort_order INT DEFAULT 0,
    source_file VARCHAR(200),
    updated_at TIMESTAMP DEFAULT NOW()
);

-- Flashcards
CREATE TABLE IF NOT EXISTS cards (
    id SERIAL PRIMARY KEY,
    deck_id INT NOT NULL REFERENCES decks(id) ON DELETE CASCADE,
    question TEXT NOT NULL,
    answer TEXT NOT NULL,
    level VARCHAR(20) DEFAULT 'basis',
    sort_order INT DEFAULT 0,
    source_file VARCHAR(200),
    updated_at TIMESTAMP DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS idx_cards_deck ON cards(deck_id);

-- SM-2 Spaced Repetition Progress
CREATE TABLE IF NOT EXISTS card_progress (
    id SERIAL PRIMARY KEY,
    user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    card_id INT NOT NULL REFERENCES cards(id) ON DELETE CASCADE,
    ease_factor REAL DEFAULT 2.5,
    interval_days INT DEFAULT 0,
    repetitions INT DEFAULT 0,
    next_review DATE DEFAULT CURRENT_DATE,
    last_rating VARCHAR(10),
    last_reviewed_at TIMESTAMP,
    UNIQUE(user_id, card_id)
);
CREATE INDEX IF NOT EXISTS idx_card_progress_due ON card_progress(user_id, next_review);

-- Tutorials
CREATE TABLE IF NOT EXISTS tutorials (
    id SERIAL PRIMARY KEY,
    slug VARCHAR(100) UNIQUE NOT NULL,
    title VARCHAR(200) NOT NULL,
    description TEXT DEFAULT '',
    content_md TEXT NOT NULL,
    duration_min INT,
    sort_order INT DEFAULT 0,
    source_file VARCHAR(200),
    updated_at TIMESTAMP DEFAULT NOW()
);

-- Tutorial Progress
CREATE TABLE IF NOT EXISTS tutorial_progress (
    id SERIAL PRIMARY KEY,
    user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    tutorial_id INT NOT NULL REFERENCES tutorials(id) ON DELETE CASCADE,
    completed BOOLEAN DEFAULT false,
    completed_at TIMESTAMP,
    UNIQUE(user_id, tutorial_id)
);

-- Cheat Sheets
CREATE TABLE IF NOT EXISTS cheatsheets (
    id SERIAL PRIMARY KEY,
    slug VARCHAR(100) UNIQUE NOT NULL,
    title VARCHAR(200) NOT NULL,
    category VARCHAR(100) DEFAULT '',
    content_md TEXT NOT NULL,
    source_file VARCHAR(200),
    updated_at TIMESTAMP DEFAULT NOW()
);

-- Quiz Results
CREATE TABLE IF NOT EXISTS quiz_results (
    id SERIAL PRIMARY KEY,
    user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    deck_slug VARCHAR(100),
    quiz_type VARCHAR(50) DEFAULT 'multiple_choice',
    score_percent INT,
    total_questions INT,
    correct_answers INT,
    created_at TIMESTAMP DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS idx_quiz_results_user ON quiz_results(user_id, created_at DESC);