import { Router } from 'express';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { initScrabbleDictionary, isValidWord, chooseMove } from './scrabbleEngine.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const WORDLIST_PATH = path.join(__dirname, '../data/wordlists/enable1.txt');

// Common words used to build a player-friendly Wordle answer pool.
// These are well-known 5-letter English words that make fair Wordle puzzles.
const COMMON_WORDS = new Set([
  'ABOUT','ABOVE','ABUSE','ACTOR','ACUTE','ADMIT','ADOPT','ADULT','AFTER',
  'AGAIN','AGENT','AGREE','AHEAD','ALARM','ALBUM','ALERT','ALIGN','ALIVE',
  'ALLEY','ALLOW','ALONE','ALONG','ALTER','ANGEL','ANGLE','ANGRY','ANKLE',
  'ANNEX','ANNOY','APART','APPLE','APPLY','APRIL','ARENA','ARGUE','ARISE',
  'ARMOR','ARRAY','ARROW','ASIDE','ASKED','ASSET','AVOID','AWARD','AWARE',
  'AWFUL','BADLY','BAKER','BASIC','BASIS','BATCH','BEACH','BEGAN','BEGIN',
  'BEING','BELOW','BENCH','BIBLE','BIRTH','BLACK','BLADE','BLAME','BLAND',
  'BLANK','BLAST','BLAZE','BLEED','BLEND','BLESS','BLIND','BLOCK','BLOOD',
  'BLOWN','BOARD','BONUS','BOOST','BOUND','BRAIN','BRAND','BRAVE','BREAD',
  'BREAK','BREED','BRICK','BRIDE','BRIEF','BRING','BROAD','BROKE','BROOK',
  'BROWN','BRUSH','BUILD','BUILT','BUNCH','BURNT','BUYER','CACHE','CANDY',
  'CARGO','CARRY','CATCH','CAUSE','CHAIN','CHAIR','CHAOS','CHARM','CHASE',
  'CHEAP','CHECK','CHEEK','CHEER','CHESS','CHEST','CHIEF','CHILD','CHINA',
  'CIVIC','CIVIL','CLAIM','CLASS','CLEAN','CLEAR','CLERK','CLICK','CLIFF',
  'CLIMB','CLING','CLOCK','CLOSE','CLOUD','COACH','COAST','COULD','COUNT',
  'COURT','COVER','CRACK','CRAFT','CRASH','CRAZY','CREAM','CREEK','CRIME',
  'CRISP','CROSS','CROWD','CROWN','CRUEL','CRUSH','CURVE','CYCLE','DAILY',
  'DANCE','DEATH','DEBUT','DELAY','DENSE','DEPOT','DEPTH','DERBY','DEVIL',
  'DIGIT','DIRTY','DOING','DOUBT','DOUGH','DRAFT','DRAIN','DRAMA','DRANK',
  'DRAWN','DREAM','DRESS','DRIED','DRIFT','DRILL','DRINK','DRIVE','DROVE',
  'DRUGS','DRUMS','DRUNK','DWELL','DYING','EAGER','EARLY','EARTH','EIGHT',
  'ELECT','EMAIL','EMPTY','ENEMY','ENJOY','ENTER','ENTRY','EQUAL','ERROR',
  'ESSAY','EVERY','EVENT','EXACT','EXIST','EXTRA','FAINT','FAIRY','FAITH',
  'FALSE','FANCY','FAULT','FEAST','FENCE','FETCH','FEVER','FEWER','FIELD',
  'FIFTH','FIFTY','FIGHT','FINAL','FLAIR','FLAME','FLASH','FLEET','FLESH',
  'FLOAT','FLOOD','FLOOR','FLOUR','FLUID','FOCUS','FORCE','FORGE','FORUM',
  'FOUND','FRANK','FRAUD','FRESH','FRONT','FROST','FROZE','FRUIT','FULLY',
  'FUNDS','FUNNY','GHOST','GIANT','GIVEN','GLASS','GLOBE','GLOOM','GLOSS',
  'GLOVE','GOING','GRACE','GRADE','GRAIN','GRAND','GRANT','GRASP','GRASS',
  'GRAVE','GREAT','GREEN','GREET','GRIEF','GRIND','GROAN','GROSS','GROUP',
  'GROVE','GROWN','GUARD','GUESS','GUEST','GUIDE','GUILT','GUISE','GUSTO',
  'HABIT','HAPPY','HARSH','HEART','HEAVY','HENCE','HINGE','HONEY','HONOR',
  'HORSE','HOTEL','HOUSE','HUMAN','HUMOR','HURRY','IDEAL','IMAGE','IMPLY',
  'INBOX','INDEX','INNER','INPUT','INTER','INTRO','ISSUE','JAPAN','JOINT',
  'JOUST','JUDGE','JUICE','JUICY','JUMBO','KARMA','KNIFE','KNOCK','KNOWN',
  'LABEL','LARGE','LASER','LATER','LAUGH','LAYER','LEARN','LEASE','LEAVE',
  'LEGAL','LEVEL','LIGHT','LIMIT','LINEN','LIVER','LOCAL','LODGE','LOGIC',
  'LOOSE','LOVER','LOWER','LUCKY','LUNAR','LYING','MAGIC','MAJOR','MAKER',
  'MARCH','MATCH','MAYOR','MEDIA','MERIT','METAL','MIGHT','MINOR','MINUS',
  'MIXED','MODEL','MONEY','MONTH','MORAL','MOTOR','MOUNT','MOUSE','MOUTH',
  'MOVED','MOVIE','MUSIC','NAIVE','NEVER','NIGHT','NOISE','NORTH','NOTED',
  'NOVEL','NURSE','OCCUR','OFFER','OFTEN','ONSET','OPERA','ORBIT','ORDER',
  'OTHER','OUTER','OUNCE','OWNER','PAINT','PANEL','PAPER','PARTY','PASTA',
  'PATCH','PAUSE','PEACE','PEARL','PEDAL','PENNY','PERCH','PHASE','PHONE',
  'PHOTO','PIANO','PIECE','PILOT','PITCH','PIXEL','PIZZA','PLACE','PLAIN',
  'PLANE','PLANT','PLATE','PLAZA','PLEAD','PLUCK','PLUMB','PLUME','PLUMP',
  'PLUNGE','POINT','POKER','POLAR','POUND','POWER','PRESS','PRICE','PRIDE',
  'PRIME','PRINT','PRIOR','PRIZE','PROBE','PROOF','PROSE','PROUD','PROVE',
  'PROXY','PULSE','PUPIL','QUEEN','QUERY','QUEST','QUEUE','QUICK','QUIET',
  'QUITE','QUOTA','QUOTE','RADAR','RADIO','RAISE','RALLY','RANCH','RANGE',
  'RAPID','RATIO','REACH','READY','REALM','REBEL','REFER','REIGN','RELAX',
  'REPLY','RIGHT','RIGID','RISKY','RIVAL','RIVER','ROBOT','ROCKY','ROMAN',
  'ROUGH','ROUND','ROUTE','ROYAL','RULER','RUMOR','RURAL','SAINT','SALAD',
  'SAUCE','SCALE','SCALD','SCENE','SCOUT','SCREW','SEIZE','SENSE','SERVE',
  'SEVEN','SHADE','SHAKE','SHALL','SHAME','SHAPE','SHARE','SHARP','SHELF',
  'SHIFT','SHIRT','SHOCK','SHOOT','SHORT','SHOUT','SIGHT','SINCE','SIXTH',
  'SIXTY','SIZED','SKILL','SLEEP','SLICE','SLIDE','SLOPE','SLUMP','SMALL',
  'SMART','SMELL','SMILE','SMOKE','SOLAR','SOLID','SOLVE','SORRY','SOUND',
  'SOUTH','SPACE','SPARK','SPEAK','SPELL','SPEND','SPICE','SPILL','SPINE',
  'SPLIT','SPOKE','SPORT','SPRAY','SQUAD','STACK','STAFF','STAGE','STAIN',
  'STAKE','STALE','STALL','STAND','START','STATE','STEAL','STEEL','STEEP',
  'STICK','STILL','STOCK','STOOD','STORE','STORM','STORY','STRAP','STRAW',
  'STRIP','STUDY','STUFF','STYLE','SUGAR','SUITE','SUPER','SURGE','SWAMP',
  'SWEAR','SWEAT','SWEEP','SWEET','SWEPT','SWIFT','SWING','SWORE','SWORN',
  'TABLE','TAKEN','TASTE','TEACH','TEETH','TENSE','TERMS','THANK','THEIR',
  'THEME','THERE','THESE','THICK','THING','THINK','THIRD','THOSE','THREE',
  'THREW','THROW','TIGHT','TIMER','TIRED','TITLE','TODAY','TOKEN','TONAL',
  'TOPIC','TOTAL','TOUCH','TOUGH','TRACE','TRACK','TRADE','TRAIL','TRAIN',
  'TRAIT','TRASH','TREAT','TREND','TRIAL','TRIBE','TRICK','TRIED','TROOP',
  'TRUCK','TRULY','TRUMP','TRUNK','TRUTH','TUMOR','TWICE','TWIST','TYPICAL',
  'ULTRA','UNDER','UNION','UNITE','UNITY','UNTIL','UPPER','UPSET','URBAN',
  'USAGE','UTTER','VALID','VALUE','VALVE','VERSE','VIDEO','VIGOR','VIRAL',
  'VIRUS','VISIT','VITAL','VIVID','VOICE','VOTER','WAIST','WASTE','WATCH',
  'WATER','WEARY','WEIGH','WEIRD','WHILE','WHITE','WHOLE','WHOSE','WIDER',
  'WITCH','WOMAN','WOMEN','WORLD','WORRY','WORSE','WORST','WORTH','WOULD',
  'WOUND','WRIST','WRITE','WROTE','YOUNG','YOURS','YOUTH','ZONAL',
]);

// ── Load word sets at startup ─────────────────────────────────────────────────

let allFiveLetterWords = null; // Set<string> — all valid 5-letter ENABLE words
let answerPool = null;         // string[] — shuffleable answer list

function loadWordLists() {
  if (allFiveLetterWords) return;

  let raw = '';
  try {
    raw = fs.readFileSync(WORDLIST_PATH, 'utf8');
  } catch (err) {
    console.warn('[words] ENABLE word list not found, using fallback.');
    raw = [...COMMON_WORDS].join('\n');
  }

  const allWords = raw.split('\n').map(w => w.trim().toUpperCase());

  const enableFive = new Set(
    allWords.filter(w => w.length === 5 && /^[A-Z]{5}$/.test(w)),
  );

  allFiveLetterWords = enableFive;

  // Scrabble dictionary: every ENABLE word of legal play length (2–15 letters).
  const scrabbleWords = new Set(
    allWords.filter(w => w.length >= 2 && w.length <= 15 && /^[A-Z]+$/.test(w)),
  );
  initScrabbleDictionary(scrabbleWords);
  console.log(`[words] loaded ${scrabbleWords.size} Scrabble words (2–15 letters)`);

  // Answer pool: prefer curated common words that are also in ENABLE;
  // supplement with additional ENABLE words up to a healthy pool size.
  const curated = [...COMMON_WORDS].filter(w => enableFive.has(w));
  answerPool = curated.length >= 200 ? curated : [...enableFive];

  console.log(`[words] loaded ${enableFive.size} valid 5-letter words, ${answerPool.length} answer candidates`);
}

loadWordLists();

// ── Router ────────────────────────────────────────────────────────────────────

const router = Router();

// GET /api/words/wordle/start
// Returns a random answer word plus the full valid-word pool for the client.
router.get('/wordle/start', (_req, res) => {
  const answer = answerPool[Math.floor(Math.random() * answerPool.length)];
  res.json({ answer, validWords: [...allFiveLetterWords] });
});

// POST /api/words/wordle/validate  { word: string }
// Quick single-word validation (used as a lightweight alternative to the full pool).
router.post('/wordle/validate', (req, res) => {
  const word = (req.body?.word ?? '').trim().toUpperCase();
  if (!/^[A-Z]{5}$/.test(word)) {
    return res.json({ valid: false });
  }
  res.json({ valid: allFiveLetterWords.has(word) });
});

// ── Scrabble ──────────────────────────────────────────────────────────────────

// POST /api/words/scrabble/validate  { words: string[] }
// Validates every word a human move forms. Returns the list of invalid ones.
router.post('/scrabble/validate', (req, res) => {
  const words = Array.isArray(req.body?.words) ? req.body.words : [];
  const invalid = words
    .map(w => String(w).trim().toUpperCase())
    .filter(w => !isValidWord(w));
  res.json({ valid: invalid.length === 0, invalid });
});

// POST /api/words/scrabble/ai-move  { board, rack, skill, firstMove, bagCount }
// Returns the AI's chosen move: a play, an exchange, or a pass.
router.post('/scrabble/ai-move', (req, res) => {
  const { board, rack, skill, firstMove, bagCount } = req.body ?? {};
  if (!Array.isArray(board) || !Array.isArray(rack)) {
    return res.status(400).json({ error: 'board and rack are required' });
  }
  const move = chooseMove({
    board,
    rack,
    skill: Number(skill) || 3,
    firstMove: !!firstMove,
    bagCount: Number(bagCount) || 0,
  });
  res.json(move);
});

export default router;