'use strict';

/**
 * THE VYNDR REPORT (Session S7, a1 board) — daily newsletter assembly + send.
 *
 * Assembly is deterministic templating over EXISTING pipeline data (the Data
 * Semantics Rule extends to marketing — numbers come only from the pipeline,
 * never composed):
 *   - Signals:      snapshot:{sport}:latest (the locked pre-graded slate)
 *   - STREAK WATCH: rosterLogs → streaksService → streakLens (the lens IS the content)
 *   - THE RECORD:   ledgerService.getModelAggregate() — the n≥20 gate lives in
 *                   the aggregate (hit_pct is null below MIN_AGG_SAMPLE); this
 *                   template renders a percentage ONLY when hit_pct != null.
 *
 * VOICE v1.1: deadpan, no exclamation points, misses-included record, o/u for
 * sides, ET timestamps. Template linting (unit tests) asserts the banned list.
 *
 * Send is Listmonk (self-hosted, same box — zero out-of-pocket), env-gated:
 * without LISTMONK_* env every send path is a graceful no-op. One-click unsub
 * is Listmonk-native — the literal {{ UnsubscribeURL }} placeholder below is
 * substituted by Listmonk at send time, not by us.
 *
 * NOTHING here is scheduled. The send is operator-triggered via
 * POST /api/internal/newsletter/send until Kev arms a cron.
 */

const { cacheGet } = require('../utils/redis');

const DEFAULT_SPORTS = ['mlb', 'wnba'];
const SIGNALS_PER_SPORT = 5;
const STREAKS_TOTAL = 3;

// ---------------------------------------------------------------- helpers

function listmonkConfig(env = process.env) {
  const url = (env.LISTMONK_URL || '').replace(/\/+$/, '');
  const user = env.LISTMONK_USER || '';
  const token = env.LISTMONK_TOKEN || '';
  const listId = parseInt(env.LISTMONK_LIST_ID || '', 10);
  if (!url || !user || !token || !Number.isFinite(listId)) return null;
  return { url, user, token, listId };
}

function authHeaders(cfg) {
  // Listmonk API-user scheme (v2.4+): Authorization: token user:token
  return {
    'Content-Type': 'application/json',
    Authorization: `token ${cfg.user}:${cfg.token}`,
  };
}

function esc(s) {
  return String(s == null ? '' : s)
    .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
}

/** "total_bases" → "total bases" — display form for stat keys. */
function statLabel(stat) {
  return String(stat || '').toLowerCase().replace(/_/g, ' ').trim();
}

const sideChar = (dir) => (String(dir || 'over').toLowerCase() === 'under' ? 'u' : 'o');

function etDateParts(now) {
  const d = now instanceof Date ? now : new Date(now);
  const fmt = new Intl.DateTimeFormat('en-US', {
    timeZone: 'America/New_York', weekday: 'short', month: 'short', day: 'numeric',
  });
  return fmt.format(d); // e.g. "Sat, Jul 11"
}

function etDateKey(now) {
  const d = now instanceof Date ? now : new Date(now);
  return new Intl.DateTimeFormat('en-CA', {
    timeZone: 'America/New_York', year: 'numeric', month: '2-digit', day: '2-digit',
  }).format(d);
}

// ---------------------------------------------------------------- assembly

const GRADE_ORDER = { 'A+': 0, A: 1, 'A-': 2, 'B+': 3, B: 4, 'B-': 5, 'C+': 6, C: 7, 'C-': 8, D: 9 };
const gradeRank = (g) => (GRADE_ORDER[String(g || '').toUpperCase()] ?? 99);

/** One signal line: "Judge — total bases o1.5 · A+ · BOMBER" */
function signalLine(g) {
  const stat = statLabel(g.stat_type || g.stat);
  const side = sideChar(g.direction);
  const bits = [`${g.player || g.player_name} — ${stat} ${side}${g.line}`, String(g.grade || '').toUpperCase()];
  if (g.archetype) bits.push(String(g.archetype).toUpperCase());
  return bits.join(' · ');
}

/** Pick each sport's top graded reads (best grade first, confidence tiebreak). */
function topSignals(grades, cap = SIGNALS_PER_SPORT) {
  const rows = (Array.isArray(grades) ? grades : []).filter((g) => g && g.grade && (g.player || g.player_name));
  rows.sort((a, b) => (gradeRank(a.grade) - gradeRank(b.grade)) || ((b.confidence || 0) - (a.confidence || 0)));
  return rows.slice(0, cap);
}

/** One streak line, lens included: the streak + what it was built against + tonight. */
function streakLine(row) {
  const read = row.lens && row.lens.read ? row.lens.read : row.description;
  return `${row.player} — ${read}`;
}

/** THE RECORD line. The n≥20 gate is upstream (hit_pct null below sample). */
function recordLine(agg) {
  if (!agg) return 'RECORD BUILDING · 0 pending';
  if (agg.hit_pct == null) return `RECORD BUILDING · ${agg.pending || 0} pending`;
  const decided = (agg.hits || 0) + (agg.misses || 0);
  let line = `Last ${agg.window_days || 30} days: ${agg.hits}-${agg.misses} (${agg.hit_pct}%), misses included, n=${decided}`;
  if (agg.beat_close_pct != null) line += ` · beat the close ${agg.beat_close_pct}%`;
  return line;
}

/** RG + unsubscribe footer — baked into every send, html and text. */
const RG_TEXT_FOOTER = [
  '21+. Gambling problem? Call or text 1-800-GAMBLER.',
  'VYNDR is a data and analysis tool, not a sportsbook. No outcome is promised.',
  'You are receiving this because you confirmed a subscription at vyndr.app.',
  'One click to leave, no questions: {{ UnsubscribeURL }}',
].join('\n');

function rgHtmlFooter() {
  return `
  <div style="margin-top:28px;padding-top:14px;border-top:1px solid #1c2a26;color:#5b6f68;font-size:11px;line-height:1.7;">
    21+. Gambling problem? Call or text 1-800-GAMBLER.<br/>
    VYNDR is a data and analysis tool, not a sportsbook. No outcome is promised.<br/>
    You are receiving this because you confirmed a subscription at vyndr.app.<br/>
    One click to leave, no questions: <a href="{{ UnsubscribeURL }}" style="color:#5b6f68;">unsubscribe</a>
  </div>`;
}

function sectionHtml(title, lines) {
  if (!lines.length) return '';
  const rows = lines.map((l) => `<div style="padding:3px 0;">${esc(l)}</div>`).join('\n');
  return `
  <div style="margin-top:22px;">
    <div style="color:#00d4a0;font-size:11px;letter-spacing:0.14em;margin-bottom:8px;">${esc(title)}</div>
    ${rows}
  </div>`;
}

/**
 * Assemble the daily report from pipeline data. Every dependency is
 * injectable; fixtures drive the unit tests, no network, no Redis.
 *
 * Returns { subject, html, text, counts: { signals, streaks, sports } }.
 */
async function buildDailyReport(sports = DEFAULT_SPORTS, deps = {}) {
  const d = {
    cacheGet,
    loadRosterLogs: (sp) => require('./rosterLogs').loadRosterLogs(sp),
    computeStreaks: (roster, sp, opts) => require('./streaksService').computeStreaks(roster, sp, opts),
    applyLens: (rows, ctx) => require('./streakLens').applyLens(rows, ctx),
    getModelAggregate: (opts) => require('./ledgerService').getModelAggregate(opts),
    now: () => new Date(),
    ...deps,
  };
  const now = d.now();
  const dateLabel = etDateParts(now);

  // --- Signals: the locked snapshot per sport (cache-only, never triggers a run).
  const signalSections = [];
  let signalCount = 0;
  const slateCounts = [];
  for (const sport of sports) {
    const sp = String(sport).toLowerCase();
    let snap = null;
    try { snap = await d.cacheGet(`snapshot:${sp}:latest`); } catch { snap = null; }
    const grades = (snap && Array.isArray(snap.grades)) ? snap.grades : [];
    if (grades.length > 0) slateCounts.push(`${grades.length} ${sp.toUpperCase()}`);
    const top = topSignals(grades);
    if (top.length > 0) {
      signalCount += top.length;
      signalSections.push({ title: `SIGNALS — ${sp.toUpperCase()}`, lines: top.map(signalLine) });
    }
  }

  // --- STREAK WATCH: pure engines over cached logs, interpreted through the lens.
  // Lens context is cache-only (schedule) — absent context = the lens says less.
  let streakRows = [];
  for (const sport of sports) {
    const sp = String(sport).toLowerCase();
    try {
      const roster = await d.loadRosterLogs(sp);
      const streaks = d.computeStreaks(roster, sp, { stat: 'all' });
      let scheduleGames = [];
      try {
        const sched = await d.cacheGet(`schedule:${sp}:${etDateKey(now)}`);
        if (Array.isArray(sched)) scheduleGames = sched;
      } catch { /* say less */ }
      streakRows = streakRows.concat(d.applyLens(streaks, { scheduleGames, pitcherGames: [] }));
    } catch { /* an empty sport is a valid state */ }
  }
  streakRows.sort((a, b) => (b.currentStreak || 0) - (a.currentStreak || 0));
  // One row per player (their longest streak wins) — signal-dense, no repeats.
  const seenPlayers = new Set();
  const streakLines = [];
  for (const row of streakRows) {
    const p = String(row.player || '').toLowerCase();
    if (!p || seenPlayers.has(p)) continue;
    seenPlayers.add(p);
    streakLines.push(streakLine(row));
    if (streakLines.length >= STREAKS_TOTAL) break;
  }

  // --- THE RECORD: n≥20 gate enforced upstream (hit_pct null below sample).
  let agg = null;
  try { agg = await d.getModelAggregate({}); } catch { agg = null; }
  const record = recordLine(agg);

  // --- Compose. Subject carries a number only when the pipeline gave us one.
  const subject = signalCount > 0
    ? `THE VYNDR REPORT — ${dateLabel} · ${signalCount} signals`
    : `THE VYNDR REPORT — ${dateLabel}`;

  const wireLine = slateCounts.length > 0
    ? `THE WIRE — ${dateLabel}. ${slateCounts.join('. ')}.`
    : `THE WIRE — ${dateLabel}. No graded slate at send time.`;

  const textParts = [wireLine];
  for (const s of signalSections) textParts.push('', s.title, ...s.lines);
  if (streakLines.length) textParts.push('', 'STREAK WATCH', ...streakLines);
  textParts.push('', 'THE RECORD', record, '', 'The slate, the signals, the settle. vyndr.app', '', RG_TEXT_FOOTER);
  const text = textParts.join('\n');

  const html = `
<div style="background:#07100d;color:#c9d8d2;font-family:'JetBrains Mono',ui-monospace,Menlo,monospace;font-size:13px;line-height:1.6;padding:28px 24px;max-width:560px;margin:0 auto;">
  <div style="color:#e8fff4;font-size:15px;letter-spacing:0.18em;">THE VYNDR REPORT</div>
  <div style="color:#5b6f68;font-size:11px;margin-top:2px;">${esc(wireLine)}</div>
  ${signalSections.map((s) => sectionHtml(s.title, s.lines)).join('\n')}
  ${sectionHtml('STREAK WATCH', streakLines)}
  ${sectionHtml('THE RECORD', [record])}
  <div style="margin-top:22px;">
    <a href="https://vyndr.app" style="color:#00d4a0;">The slate, the signals, the settle. vyndr.app</a>
  </div>
  ${rgHtmlFooter()}
</div>`;

  return {
    subject,
    html,
    text,
    counts: { signals: signalCount, streaks: streakLines.length, sports: sports.length },
  };
}

// ------------------------------------------------------------------- send

/**
 * Subscribe one email through Listmonk with double opt-in
 * (preconfirm_subscriptions: false → Listmonk sends the confirmation).
 * Env-gated: no LISTMONK_* env → { ok: false, reason: 'not configured' }.
 * A 409 (already subscribed) is ok — idempotent, no enumeration.
 */
async function subscribe(email, opts = {}) {
  const cfg = listmonkConfig(opts.env);
  if (!cfg) return { ok: false, reason: 'not configured' };
  const fetchImpl = opts.fetchImpl || globalThis.fetch;
  try {
    const res = await fetchImpl(`${cfg.url}/api/subscribers`, {
      method: 'POST',
      headers: authHeaders(cfg),
      body: JSON.stringify({
        email: String(email).toLowerCase().trim(),
        name: '',
        status: 'enabled',
        lists: [cfg.listId],
        preconfirm_subscriptions: false,
      }),
    });
    if (res.ok || res.status === 409) return { ok: true };
    return { ok: false, reason: `listmonk ${res.status}` };
  } catch (err) {
    return { ok: false, reason: err && err.message ? err.message : 'listmonk unreachable' };
  }
}

/**
 * Assemble today's report and send it as a Listmonk campaign (create, then
 * start). Refuses to send an empty report — absent beats hollow. Env-gated
 * no-op without Listmonk config. NOT scheduled anywhere; the internal route
 * is the only caller until Kev arms a cron.
 */
async function sendDailyReport(opts = {}) {
  const cfg = listmonkConfig(opts.env);
  if (!cfg) return { ok: false, reason: 'not configured' };
  const fetchImpl = opts.fetchImpl || globalThis.fetch;

  const report = await buildDailyReport(opts.sports || DEFAULT_SPORTS, opts.deps || {});
  if (report.counts.signals === 0 && report.counts.streaks === 0) {
    return { ok: false, reason: 'empty report', report: { subject: report.subject, counts: report.counts } };
  }

  try {
    const createRes = await fetchImpl(`${cfg.url}/api/campaigns`, {
      method: 'POST',
      headers: authHeaders(cfg),
      body: JSON.stringify({
        name: report.subject,
        subject: report.subject,
        lists: [cfg.listId],
        type: 'regular',
        content_type: 'html',
        body: report.html,
        altbody: report.text,
      }),
    });
    if (!createRes.ok) return { ok: false, reason: `listmonk create ${createRes.status}` };
    const created = await createRes.json().catch(() => ({}));
    const campaignId = created && created.data && created.data.id;
    if (!campaignId) return { ok: false, reason: 'listmonk create: no campaign id' };

    const startRes = await fetchImpl(`${cfg.url}/api/campaigns/${campaignId}/status`, {
      method: 'PUT',
      headers: authHeaders(cfg),
      body: JSON.stringify({ status: 'running' }),
    });
    if (!startRes.ok) return { ok: false, reason: `listmonk start ${startRes.status}`, campaignId };

    return { ok: true, campaignId, subject: report.subject, counts: report.counts };
  } catch (err) {
    return { ok: false, reason: err && err.message ? err.message : 'listmonk unreachable' };
  }
}

module.exports = {
  buildDailyReport,
  sendDailyReport,
  subscribe,
  __internals: {
    listmonkConfig, authHeaders, statLabel, signalLine, topSignals,
    streakLine, recordLine, etDateParts, etDateKey, RG_TEXT_FOOTER,
    DEFAULT_SPORTS,
  },
};