-- ============================================================
-- Schema: English Learning App (TOEIC Focus)
-- Run this FIRST before seed.sql
-- ============================================================

-- TOEIC questions (Part 1–7)
CREATE TABLE IF NOT EXISTS questions (
  id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  part        INT NOT NULL CHECK (part BETWEEN 1 AND 7),
  type        TEXT,
  content     TEXT NOT NULL,
  options     JSONB NOT NULL DEFAULT '[]',  -- ["A. ...", "B. ...", "C. ...", "D. ..."]
  answer      TEXT NOT NULL,                -- "A" | "B" | "C" | "D"
  explanation TEXT,
  audio_url   TEXT,                         -- Part 1–4 (listening)
  image_url   TEXT,                         -- Part 1 (photos)
  created_at  TIMESTAMPTZ DEFAULT now()
);

-- TOEIC vocabulary (6 topics)
CREATE TABLE IF NOT EXISTS vocab (
  id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  word        TEXT NOT NULL,
  phonetic    TEXT,
  meaning_vi  TEXT NOT NULL,
  topic       TEXT NOT NULL CHECK (topic IN ('Business', 'Office', 'Travel', 'Finance', 'HR', 'Marketing')),
  example     TEXT,
  created_at  TIMESTAMPTZ DEFAULT now()
);

-- Indexes for common query patterns
CREATE INDEX IF NOT EXISTS idx_questions_part ON questions(part);
CREATE INDEX IF NOT EXISTS idx_vocab_topic    ON vocab(topic);