'use strict';

/**
 * Slot ↔ Planning Center position matching for the Band Lineup module.
 *
 * A "slot" is a mic/pack label the operator wrote for a spot on stage, e.g.
 * "[LEADER, VOX 1, ACOUSTIC] MIX 1". A scheduled person carries their PCO
 * team-position name, e.g. "Vox 1" or "Acoustic / Worship Leader". We assign
 * people to slots by loose token overlap — the same logic the backstage
 * Electron app used, lifted here unchanged so the board matches what the booth
 * is used to. Pure functions only: no I/O, so this file is unit-testable.
 */

function normalizeTeamName(value) {
  return String(value || '').trim().toLowerCase();
}

/** Does a person's PCO team count as a band/stage team we display? `keywords` comes from admin config. */
function isAllowedTeamName(value, keywords) {
  const normalized = normalizeTeamName(value);
  if (!normalized) return false;
  return (keywords || []).some((kw) => {
    const k = normalizeTeamName(kw);
    return k && (normalized === k || normalized.includes(k));
  });
}

function normalizeLabel(value) {
  return String(value || '')
    .trim()
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, ' ')
    .replace(/\s+/g, ' ')
    .trim();
}

/** Fold a single token to a canonical instrument/role word (drops mic/pack noise, pluralises down). */
function normalizeToken(token) {
  const normalized = String(token || '').trim().toLowerCase();
  if (!normalized) return '';
  if (/^\d+$/.test(normalized)) return '';
  if (['mix', 'mic', 'slot', 'channel', 'ch', 'pack', 'wireless', 'input', 'headset'].includes(normalized)) return '';
  if (['vox', 'vocal', 'vocalist', 'vocalists', 'vocals', 'singer', 'singers'].includes(normalized)) return 'vocals';
  if (['keys', 'keyboard', 'keyboards'].includes(normalized)) return 'keys';
  if (['drum', 'drums', 'drummer', 'drummers'].includes(normalized)) return 'drums';
  if (['perc', 'percussionist', 'percussionists'].includes(normalized)) return 'percussion';
  if (['gtr', 'guitar', 'guitars'].includes(normalized)) return 'guitar';
  if (['electric', 'electricguitar'].includes(normalized)) return 'electric';
  if (['acoustic', 'acousticguitar'].includes(normalized)) return 'acoustic';
  if (['b', 'bandleader', 'leader', 'lead'].includes(normalized)) return normalized === 'b' ? '' : 'leader';
  if (['worship', 'calltoworship'].includes(normalized)) return normalized === 'calltoworship' ? 'call' : normalized;
  if (normalized.endsWith('s') && normalized.length > 4) return normalized.slice(0, -1);
  return normalized;
}

function labelTokens(value) {
  const normalized = normalizeLabel(value);
  if (!normalized) return [];
  const tokens = normalized.split(' ').map((t) => normalizeToken(t)).filter(Boolean);
  if (!tokens.length && normalized) return [normalized];
  return [...new Set(tokens)];
}

/**
 * The role part of a slot label to match on: the bracketed content when present
 * ("[VOX 2] MIX 2" → "VOX 2, "), else the whole label ("STAGE MANAGER"). This
 * drops the "MIX n / MC n / HEADSET" mic-assignment noise so a mic number can't
 * be mistaken for a position number.
 */
function slotRoleText(label) {
  const brackets = String(label || '').match(/\[([^\]]*)\]/g);
  if (brackets && brackets.length) return brackets.map((b) => b.slice(1, -1)).join(', ');
  return String(label || '');
}

/** The set of standalone numbers in a label ("vox 2" → {"2"}). */
function numbersIn(value) {
  return new Set(normalizeLabel(value).split(' ').filter((t) => /^\d+$/.test(t)));
}

/** 0–~140 similarity between a slot label and a PCO position name; higher is a better fit. */
function scoreMatch(slotLabel, positionLabel) {
  const slotNormalized = normalizeLabel(slotLabel);
  const positionNormalized = normalizeLabel(positionLabel);
  if (!slotNormalized || !positionNormalized) return 0;
  // A numbered role only matches the same number: "Vox 3" must not take "Vox 2".
  const slotNums = numbersIn(slotLabel);
  const posNums = numbersIn(positionLabel);
  if (slotNums.size && posNums.size && ![...posNums].some((n) => slotNums.has(n))) return 0;
  if (slotNormalized === positionNormalized) return 120;
  if (slotNormalized.includes(positionNormalized) || positionNormalized.includes(slotNormalized)) return 95;

  const slotTokens = labelTokens(slotLabel);
  const positionTokens = labelTokens(positionLabel);
  if (!slotTokens.length || !positionTokens.length) return 0;

  const positionSet = new Set(positionTokens);
  const slotSet = new Set(slotTokens);
  const overlap = slotTokens.filter((t) => positionSet.has(t));
  if (!overlap.length) return 0;

  const overlapCount = overlap.length;
  const slotCoverage = overlapCount / slotSet.size;
  const positionCoverage = overlapCount / positionSet.size;
  const sharedPhrase = overlap.join(' ');

  let score = Math.round(slotCoverage * 70 + positionCoverage * 20 + overlapCount * 4);
  if (slotCoverage === 1) score += 18;
  if (positionCoverage === 1) score += 10;
  if (sharedPhrase && slotNormalized.includes(sharedPhrase) && positionNormalized.includes(sharedPhrase)) score += 8;
  return score;
}

/**
 * Assign scheduled members to the ordered slot list. Greedy by best score, each
 * member used once. Returns an array aligned to `slots`, each entry the chosen
 * member or null. `MIN_SCORE` keeps a weak coincidence from claiming a slot.
 */
const MIN_SCORE = 60;

/** The mix numbers a label names ("[VOX 5] MIX 8" → {"8"}; "Mix 8, VOX 5" → {"8"}). */
function mixNumbers(value) {
  const out = new Set(); const re = /\bmix\s*(\d+)\b/gi; let m;
  while ((m = re.exec(String(value || '')))) out.add(m[1]);
  return out;
}

/**
 * How well a person's Planning Center note names a spot. The booth writes the mic/role into each
 * vocalist's and the leader's note every week ("Mix 8, VOX 5", "DP48, Drums"), because those
 * change week to week and the position name ("Vocalist") doesn't say which mic. A note that names a
 * different mix than the spot is never a match; the role part ("VOX 5") is scored like a position.
 * 0 means the note says nothing usable about this spot ("NA", blank, or no overlap).
 */
function noteScore(slotLabel, note) {
  const text = String(note || '').trim();
  if (!text || /^n\/?a$/i.test(text)) return 0;
  const slotMix = mixNumbers(slotLabel); const noteMix = mixNumbers(text);
  let mixBonus = 0;
  if (noteMix.size && slotMix.size) {
    if (![...noteMix].some((n) => slotMix.has(n))) return 0;
    mixBonus = 100;
  }
  const role = text.replace(/\bmix\s*\d+\b/gi, ' ');
  const roleScore = scoreMatch(slotRoleText(slotLabel), role);
  if (!roleScore && !mixBonus) return 0;
  if (noteMix.size && slotMix.size && roleScore === 0 && role.replace(/[^a-z0-9]/gi, '')) {
    // The mix agrees but the role contradicts it (e.g. "Mix 8, Keys" on a VOX spot) — trust neither.
    const roleTokens = labelTokens(role);
    if (roleTokens.length) return 0;
  }
  return mixBonus + roleScore;
}

function assignMembersToSlots(slots, members) {
  const pool = members.slice();
  const result = slots.map(() => null);
  const take = (chosen) => {
    // One spot per person: someone scheduled twice (Leader + Acoustic) must not fill a second spot.
    const key = chosen.personId || '';
    for (let i = pool.length - 1; i >= 0; i -= 1) if (pool[i] === chosen || (key && pool[i].personId === key)) pool.splice(i, 1);
  };
  // Pass 1 — people whose note names their spot go exactly there, best-fitting pairs first.
  const pairs = [];
  slots.forEach((slotLabel, s) => pool.forEach((m) => { const sc = noteScore(slotLabel, m.note); if (sc >= MIN_SCORE) pairs.push({ s, m, sc }); }));
  pairs.sort((a, b) => b.sc - a.sc);
  for (const { s, m } of pairs) {
    if (result[s] || !pool.includes(m)) continue;
    result[s] = m; take(m);
  }
  // Pass 2 — everyone else by Planning Center position, into the spots still open.
  return result.map((placed, s) => {
    if (placed) return placed;
    const slotLabel = slots[s];
    const role = slotRoleText(slotLabel);
    let bestIndex = -1;
    let bestScore = MIN_SCORE - 1;
    for (let i = 0; i < pool.length; i += 1) {
      const score = scoreMatch(role, pool[i].label);
      if (score > bestScore) { bestScore = score; bestIndex = i; }
    }
    if (bestIndex < 0) return null;
    const chosen = pool[bestIndex];
    take(chosen);
    return chosen;
  });
}

/* ── photos by instrument ──────────────────────────────────────────────
 * A person can have a photo per instrument, named "Name - Instrument" ("DJ - Drums.jpg",
 * "DJ - Vocals.jpg"); a photo with no instrument word is their everyday one. Sync picks the photo
 * whose instrument matches the spot the person is in that week. Instruments group into families so
 * the usual shorthands agree: Vox/Vocals/Singer, Keys/Piano/Pad/Synth, Drums/Perc, Bass,
 * Guitar/Electric/Acoustic/Rhythm, Leader. */
const ROLE_FAMILY = {
  vocals: 'vocals', keys: 'keys', piano: 'keys', pad: 'keys', synth: 'keys', organ: 'keys',
  drums: 'drums', percussion: 'drums', bass: 'bass',
  guitar: 'guitar', electric: 'guitar', acoustic: 'guitar', rhythm: 'guitar', leader: 'leader',
};
/** The instrument families a label names ("[LEADER, VOX 1, ACOUSTIC] MIX 1" → leader, vocals, guitar). */
function roleFamilies(text) {
  const out = new Set();
  for (const t of normalizeLabel(text).split(' ')) { const f = ROLE_FAMILY[normalizeToken(t)]; if (f) out.add(f); }
  return out;
}
/** The instrument families a SPOT is for: its bracketed role, else the PCO position it was filled by. */
function spotFamilies(slotLabel, positionLabel) {
  const fromSlot = roleFamilies(slotRoleText(slotLabel));
  return fromSlot.size ? fromSlot : roleFamilies(positionLabel || '');
}
/** Split a photo's name into the person and the instruments it shows: "DJ Drums" → "DJ" + {drums}.
 *  The first word is always the person; instrument words after it are read off, other words
 *  ("action", "2") are just part of the photo's description. */
function photoParts(libName) {
  const words = normalizeLabel(libName).split(' ').filter(Boolean);
  const roles = new Set(); const person = [];
  words.forEach((w, i) => {
    const f = i > 0 ? ROLE_FAMILY[normalizeToken(w)] : null;
    if (f) roles.add(f); else if (!roles.size) person.push(w);
  });
  return { person: person.join(' '), roles };
}
/** The key a remembered photo pick is stored under: per person AND instrument, so DJ's drum pick
 *  never overrides his vocal photo. A spot naming several ("Leader, Vox 1, Acoustic") files under
 *  its most specific: leader, then vocals, drums, keys, bass, guitar. No family → everyday pick. */
const ROLE_PRIORITY = ['leader', 'vocals', 'drums', 'keys', 'bass', 'guitar'];
function photoKey(personId, families) {
  const f = ROLE_PRIORITY.find((r) => families && families.has(r)) || '';
  return f ? `${personId}|${f}` : String(personId || '');
}

/**
 * Best library photo for a Planning Center person, matched by name so Sync can use the folder
 * photo instead of the PCO headshot. Handles full names, "First L" and first-name-only files,
 * preferring the most specific. Returns the entry, or null when no library photo is a confident
 * match — only then is PCO's headshot used. Several equally good photos ("Mike" and "mike") is
 * not a reason to fall back to PCO: the first of them wins (the booth prefers its own photos).
 * `entries` is [{ ...whatever, name }]. `want` (optional) is the set of instrument families the
 * person is on this week: a photo for that instrument beats their everyday photo, which beats a
 * photo of them on something else — but any photo of theirs still beats PCO's headshot.
 */
function bestLibraryMatch(pcoName, entries, want) {
  const target = normalizeLabel(pcoName);
  if (!target) return null;
  const T = target.split(' ').filter(Boolean);
  const scoreOf = (name) => {
    const ln = normalizeLabel(name);
    if (!ln) return 0;
    if (ln === target) return 100; // exact full name
    const L = ln.split(' ').filter(Boolean);
    if (!L.length || !T.length) return 0;
    // Align the library name against a leading run of the person's name, token by token.
    // Every library token must equal the person's token in that position — except the LAST
    // library token, which may be an initial/prefix ("m" of "Moniz"). This makes "Brian M"
    // match "Brian Moniz" and "Alex" match "Alex Gaitan", but NOT "Alex" → "Alexander Zinni".
    let ok = true; let exact = 0; let usedPrefix = false;
    for (let k = 0; k < L.length; k += 1) {
      const lt = L[k]; const tt = T[k];
      if (!tt) { ok = false; break; }
      if (lt === tt) { exact += 1; continue; }
      if (k === L.length - 1 && tt.startsWith(lt)) { usedPrefix = true; continue; }
      ok = false; break;
    }
    if (ok) {
      if (L.length >= 2) return usedPrefix ? 86 : 92;   // "brian m" / "alex gaitan"
      if (exact === 1) return 90;                        // first name matches exactly ("alex")
      if (usedPrefix) return 45;                         // "alex" vs "alexander" — too ambiguous
    }
    // Otherwise: a library surname that appears anywhere in the person's name.
    const last = L[L.length - 1];
    if (last && last.length >= 3 && T.includes(last)) return 78;
    return 0;
  };
  const wanted = want && want.size ? want : null;
  let best = null;
  let bestScore = 0;
  for (const e of entries) {
    const parts = photoParts(e.name);
    let s = scoreOf(parts.roles.size ? parts.person : e.name);
    if (s < 60) continue; // not them
    if (parts.roles.size && wanted) s += [...parts.roles].some((f) => wanted.has(f)) ? 20 : -20;
    if (s > bestScore) { bestScore = s; best = e; }
  }
  if (!best) return null; // no confident match → PCO photo
  return best;
}

/**
 * Could this library photo be of this Planning Center person? Used when someone drops a photo onto
 * a synced person's spot, to tell "this is their photo" (remember it) from "put someone else here".
 * A name match, the same first name ("DJ action" → "DJ McLean"), or first names sharing their
 * first three letters (a nickname: "Rose" → "Rosaliz").
 */
function samePerson(pcoName, libName) {
  if (bestLibraryMatch(pcoName, [{ name: libName }])) return true;
  const a = normalizeLabel(pcoName).split(' ')[0] || ''; const b = photoParts(libName).person.split(' ')[0] || '';
  if (a && a === b) return true;
  return a.length >= 3 && b.length >= 3 && a.slice(0, 3) === b.slice(0, 3);
}

module.exports = {
  samePerson,
  roleFamilies,
  spotFamilies,
  photoParts,
  photoKey,
  normalizeTeamName,
  isAllowedTeamName,
  bestLibraryMatch,
  normalizeLabel,
  normalizeToken,
  labelTokens,
  slotRoleText,
  numbersIn,
  scoreMatch,
  assignMembersToSlots,
  noteScore,
  mixNumbers,
  MIN_SCORE,
};