// src/services/renderers/voiceDiagRenderer.js
//
// Renders the /voicediag CheckResult array into Webex-friendly
// markdown. Pure function — no I/O — so it's usable from both the
// chat command and (later) HTTP surfaces without recomputing.
//
// Layout:
//
//   **Voice Diagnostic - Store 12345** (user: ae12345@ae.com — Store 12345)
//
//   Errors (1)  Warnings (2)  Skipped (1)  OK (5)
//
//   **ERRORS**
//   - **Call Intercept**: Call intercept is ACTIVE — inbound calls...
//     • incomingType: INTERCEPT_ALL, outgoingType: ALLOW_ALL
//
//   **WARNINGS**
//   - **Do Not Disturb**: DND is enabled — incoming calls silenced.
//   - **Call Forwarding**: 1 forwarding variant is active: ...
//
//   **SKIPPED**
//   - **Call Waiting**: 403 on Call Waiting — likely missing scope ...
//
//   **OK** (5 — hidden; pass `detailed` to see them)
//
//   Fixable issues (2) — see confirmation cards below.
//
// Options
//   storeNum  (required) header text
//   detailed  (default false) — expands OK checks + shows the
//             `details` block under every check
//   emitFooter (default true) — trailing italic timestamp
//
// The renderer never emits an adaptive card itself. The caller
// (commands/voiceDiag.js) walks the same results array to post cards.

const SEVERITY_ORDER = ['error', 'warn', 'skipped', 'ok'];
const SEVERITY_LABEL = {
  error: 'ERRORS',
  warn: 'WARNINGS',
  skipped: 'SKIPPED',
  ok: 'OK',
};

/**
 * @param {Array<{id, label, status, message, details, remediation}>} results
 * @param {{
 *   storeNum: string,
 *   personLabel?: string,
 *   email?: string,
 *   detailed?: boolean,
 *   emitFooter?: boolean,
 *   wanWindowMinutes?: number,
 * }} [opts]
 * @returns {string} markdown, whitespace-trimmed
 */
export function renderVoiceDiagMarkdown(results, opts = {}) {
  const {
    storeNum,
    personLabel = null,
    email = null,
    detailed = false,
    emitFooter = true,
    wanWindowMinutes = null,
  } = opts;

  const list = Array.isArray(results) ? results : [];

  let reply = `**Voice Diagnostic - Store ${storeNum}**`;
  if (personLabel || email) {
    const who = [personLabel, email].filter(Boolean).join(' — ');
    reply += ` (user: ${who})`;
  }
  reply += '\n\n';

  if (list.length === 0) {
    reply += '_No checks were executed. Verify the store number and re-run._\n';
    return reply.trim();
  }

  const counts = countBySeverity(list);
  reply += summaryLine(counts) + '\n';
  const hasWanCheck = list.some((r) => /^wan/i.test(r?.id || ''));
  if (hasWanCheck && Number.isFinite(wanWindowMinutes)) {
    reply += `_WAN window: ${humanWindow(wanWindowMinutes)}_\n`;
  }
  reply += '\n';

  for (const severity of SEVERITY_ORDER) {
    const bucket = list.filter((r) => r.status === severity);
    if (bucket.length === 0) continue;

    // Hide the OK bucket from the console body unless detailed —
    // keeps the default output focused on what's actionable.
    if (severity === 'ok' && !detailed) continue;

    reply += `**${SEVERITY_LABEL[severity]}**\n`;
    for (const r of bucket) {
      reply += `- **${r.label}**: ${r.message}\n`;
      if (detailed && r.details && Object.keys(r.details).length > 0) {
        const detailBlock = renderDetails(r.details);
        if (detailBlock) reply += detailBlock + '\n';
      }
    }
    reply += '\n';
  }

  const fixable = list.filter((r) => r.status !== 'ok' && r.remediation);
  if (fixable.length > 0) {
    reply +=
      `**Fixable issues (${fixable.length})** — see confirmation cards below.\n\n` +
      fixable.map((r) => `- ${r.label}: ${r.remediation.title}`).join('\n') +
      '\n\n';
  }

  if (!detailed && counts.ok > 0) {
    reply += `_${counts.ok} OK check(s) hidden — pass \`detailed\` to include them._\n\n`;
  }

  if (emitFooter) {
    const now = new Date();
    reply += `_Last checked: ${now.toISOString()}_\n`;
  }

  return reply.trim();
}

function countBySeverity(list) {
  const counts = { error: 0, warn: 0, skipped: 0, ok: 0 };
  for (const r of list) {
    if (Object.prototype.hasOwnProperty.call(counts, r.status)) {
      counts[r.status] += 1;
    }
  }
  return counts;
}

function summaryLine({ error, warn, skipped, ok }) {
  return `Errors (${error}) · Warnings (${warn}) · Skipped (${skipped}) · OK (${ok})`;
}

/**
 * Human-friendly window label: 15m / 1h / 6h / 24h.
 */
function humanWindow(minutes) {
  if (!Number.isFinite(minutes) || minutes <= 0) return `${minutes}m`;
  if (minutes >= 1440 && minutes % 1440 === 0) return `${minutes / 1440}d`;
  if (minutes >= 60 && minutes % 60 === 0) return `${minutes / 60}h`;
  return `${minutes}m`;
}

/**
 * Detail rendering. Recognises common check-result shapes and
 * produces multiline markdown with icons/tables instead of a raw
 * `key: value` dump — which for WAN checks in particular looks
 * like an unreadable stringified JSON blob.
 *
 * Falls back to the compact key:value renderer for shapes we
 * don't know how to format specially. Returns null when the
 * details object contains nothing user-visible after formatting
 * (e.g. WAN threshold constants that are already in the message).
 *
 * The shape detectors are ordered from most-specific to
 * least-specific. Each returns a multiline string (with leading
 * indent to nest under the parent bullet) or null to fall through.
 */
function renderDetails(details) {
  if (details === null || details === undefined) return null;
  if (typeof details !== 'object') return `  - ${String(details)}`;

  // ── Shape-aware formatters (best-fit wins) ────────────────────
  if (Array.isArray(details.perLink)) {
    return renderPerLinkDetails(details);
  }
  if ('up' in details && 'down' in details && 'unknown' in details) {
    return renderLinkStateDetails(details);
  }
  if ('critical' in details && 'major' in details && 'minor' in details) {
    return renderAlarmsDetails(details);
  }
  if ('siteId' in details && 'siteName' in details) {
    return renderSiteDetails(details);
  }
  // Per-app audio MOS/loss/jitter summary — has
  // {avg,min,max,worst,badSampleCount,badSamplePct,appName,samples,
  //  validSamples,interval,warnThresh,errorThresh}. Match on the
  // combination unique to that shape.
  if ('appName' in details && 'worst' in details && 'validSamples' in details) {
    return renderAppAudioDetails(details);
  }
  if ('value' in details && 'warnThresh' in details && 'errorThresh' in details) {
    return renderThresholdDetails(details);
  }

  // ── Fallback: compact key:value dump ─────────────────────────
  const parts = [];
  for (const [k, v] of Object.entries(details)) {
    parts.push(`${k}: ${formatValue(v)}`);
  }
  return parts.length > 0 ? `  - ${parts.join(', ')}` : null;
}

const VERDICT_ICON = { ok: '✅', warn: '⚠️', error: '❌', unknown: '❓' };

function verdictIcon(v) {
  return VERDICT_ICON[v] || '·';
}

/**
 * WAN latency/jitter/loss/mos etc. Produces:
 *
 *   - Threshold: warn > 150ms, error > 400ms
 *   - Per link:
 *     - ✅ Inet1-00782: 22.2 ms
 *     - ✅ Inet2-00782: 13.5 ms
 *     - ⚠️ 5G-LTE-00782: 165 ms
 *     - Roll-up: 3 total · 2 ok · 1 warn · 0 error
 */
function renderPerLinkDetails(details) {
  const { perLink, warnThresh, errorThresh, standardLabel, total, ok, warn, error } = details;
  const lines = [];
  if (standardLabel) {
    lines.push(`  - Threshold: ${standardLabel}`);
  } else if (Number.isFinite(warnThresh) && Number.isFinite(errorThresh)) {
    lines.push(`  - Threshold: warn @ ${warnThresh}, error @ ${errorThresh}`);
  }
  if (Array.isArray(perLink) && perLink.length > 0) {
    lines.push('  - Per link:');
    for (const p of perLink) {
      const val = p?.value == null || Number.isNaN(p.value) ? '—' : String(p.value);
      lines.push(`    - ${verdictIcon(p?.verdict)} ${p?.link}: ${val}`);
    }
  }
  const rollup = [`${total ?? '?'} total`];
  if (Number.isFinite(ok))    rollup.push(`${ok} ok`);
  if (Number.isFinite(warn))  rollup.push(`${warn} warn`);
  if (Number.isFinite(error)) rollup.push(`${error} error`);
  if (rollup.length > 1) lines.push(`  - Roll-up: ${rollup.join(' · ')}`);
  return lines.length > 0 ? lines.join('\n') : null;
}

/**
 * WAN Link State — {total, up, down, unknown, offenders, unknownLabels}.
 */
function renderLinkStateDetails(details) {
  const { total, up, down, unknown, offenders = [], unknownLabels = [] } = details;
  const lines = [`  - Roll-up: ${total ?? '?'} total · ${up ?? 0} up · ${down ?? 0} down · ${unknown ?? 0} unknown`];
  if (offenders.length > 0) {
    lines.push(`  - Down: ${offenders.join(', ')}`);
  }
  if (unknownLabels.length > 0) {
    lines.push(`  - Unknown: ${unknownLabels.join(', ')}`);
  }
  return lines.join('\n');
}

/**
 * Per-app audio-quality (MOS/loss/jitter) detail formatter.
 * The summary carries: {appName, worst, avg, min, max, p95,
 * samples, validSamples, interval, warnThresh, errorThresh,
 * badSampleCount, badSamplePct, standardLabel, unit}.
 *
 * Output (example, MOS):
 *
 *   - App: Webex_Calling_RTP (voice traffic, DPI)
 *   - Threshold: warn < 4, error < 3.5
 *   - Worst window: 1.85 · Avg: 4.03 · p95: 4.28
 *   - Range: 1.85 – 4.41 across 288/288 samples @ 5min
 *   - Time in warn/error: 42 samples (15%)
 */
function renderAppAudioDetails(details) {
  const {
    appName, worst, avg, min, max, p95,
    samples, validSamples, interval,
    warnThresh, errorThresh, standardLabel, unit,
    badSampleCount, badSamplePct,
    detailsUrl,
  } = details;

  const u = unit || '';
  const lines = [`  - App: ${appName || 'voice'} (voice traffic, DPI)`];

  if (standardLabel) {
    lines.push(`  - Threshold: ${standardLabel}`);
  } else if (Number.isFinite(warnThresh) || Number.isFinite(errorThresh)) {
    lines.push(`  - Threshold: warn @ ${warnThresh ?? '?'}, error @ ${errorThresh ?? '?'}`);
  }

  const worstStr = worst == null ? '—' : `${worst}${u}`;
  const avgStr   = avg   == null ? '—' : `${avg}${u}`;
  const p95Str   = p95   == null ? '—' : `${p95}${u}`;
  lines.push(`  - Worst window: **${worstStr}** · Avg: ${avgStr} · p95: ${p95Str}`);

  if (min != null && max != null) {
    lines.push(`  - Range: ${min}${u} – ${max}${u} across ${validSamples}/${samples} samples @ ${interval || '5min'}`);
  }

  if (Number.isFinite(badSampleCount) && Number.isFinite(badSamplePct)) {
    if (badSampleCount > 0) {
      lines.push(`  - Time in warn/error: ${badSampleCount} sample${badSampleCount === 1 ? '' : 's'} (~${badSamplePct}% of window)`);
    } else {
      lines.push(`  - Time in warn/error: 0 samples (clean throughout window)`);
    }
  }

  // SCM UI deep-link — always the last row so it acts as a "next
  // step" for anyone inspecting the details. Only rendered when the
  // enrichment layer was able to build a URL (needs both site.id +
  // appAudio.appId — either missing → null skips this line cleanly).
  if (detailsUrl) {
    lines.push(`  - [View in Prisma UI](${detailsUrl})`);
  }

  return lines.join('\n');
}

/**
 * Alarm counts + optional category breakdown + rolled-up recent
 * samples. Handles both the old shape (bare `critical/major/minor +
 * recentSamples` array of raw events) and the new shape emitted by
 * wanAlarmsCheck (`byCategory`, rollups with `humanized`, `count`,
 * `age`).
 */
function renderAlarmsDetails(details) {
  const {
    critical = 0, major = 0, minor = 0,
    byCategory, recentSamples = [],
  } = details;

  const lines = [
    `  - Counts: 🔴 ${critical} critical · 🟠 ${major} major · 🟡 ${minor} minor`,
  ];

  if (byCategory && typeof byCategory === 'object') {
    const parts = [];
    if (byCategory.overlay > 0)  parts.push(`${byCategory.overlay} overlay/VPN`);
    if (byCategory.physical > 0) parts.push(`${byCategory.physical} physical WAN`);
    if (byCategory.device > 0)   parts.push(`${byCategory.device} device`);
    if (byCategory.other > 0)    parts.push(`${byCategory.other} other`);
    if (parts.length > 0) lines.push(`  - Category: ${parts.join(' · ')}`);
  }

  if (Array.isArray(recentSamples) && recentSamples.length > 0) {
    lines.push('  - Recent:');
    for (const a of recentSamples) {
      // Prefer humanized label + code; fall back gracefully for
      // pre-humanized (raw event) shapes.
      const label = a?.humanized || a?.type || a?.code || a?.alarm_type || 'unknown';
      const code  = a?.code && a?.humanized ? ` \`${a.code}\`` : '';
      const sev   = a?.severity ? ` (${a.severity})` : '';
      const count = Number.isFinite(a?.count) && a.count > 1 ? ` ×${a.count}` : '';
      const age   = a?.age ? ` — ${a.age}` : '';
      lines.push(`    - ${label}${code}${sev}${count}${age}`);
    }
  }

  return lines.join('\n');
}

/**
 * WAN Site — {siteId, siteName, elementCount, connectedElementCount, linkCount}.
 * Rendered as a compact one-liner since siteName is usually already
 * in the message.
 */
function renderSiteDetails(details) {
  const { siteId, elementCount, connectedElementCount, linkCount } = details;
  const parts = [];
  if (siteId) parts.push(`id: \`${siteId}\``);
  if (Number.isFinite(elementCount)) {
    parts.push(
      `${elementCount} element(s)` +
        (Number.isFinite(connectedElementCount)
          ? ` (${connectedElementCount} connected)`
          : ''),
    );
  }
  if (Number.isFinite(linkCount)) parts.push(`${linkCount} link(s)`);
  return parts.length > 0 ? `  - ${parts.join(' · ')}` : null;
}

/**
 * Single value + thresholds — {value, warnThresh, errorThresh, breakdown}.
 * The message already contains value + thresholds, so the details
 * block just shows the sub-score breakdown (if any) and skips the
 * redundant info.
 */
function renderThresholdDetails(details) {
  const { breakdown } = details;
  if (breakdown && typeof breakdown === 'object' && Object.keys(breakdown).length > 0) {
    const parts = Object.entries(breakdown).map(([k, v]) => `${k}: ${v}`);
    return `  - Breakdown: ${parts.join(' · ')}`;
  }
  return null;
}

function formatValue(v) {
  if (v === null || v === undefined) return '—';
  if (typeof v === 'boolean' || typeof v === 'number' || typeof v === 'string') {
    return String(v);
  }
  if (Array.isArray(v)) {
    if (v.length === 0) return '[]';
    if (v.length <= 3) return `[${v.map(formatValue).join(', ')}]`;
    return `[${v.slice(0, 3).map(formatValue).join(', ')}, …+${v.length - 3}]`;
  }
  // Fall through: nested object — collapse to a JSON snippet.
  try {
    const s = JSON.stringify(v);
    return s.length > 120 ? `${s.slice(0, 117)}…` : s;
  } catch {
    return '[object]';
  }
}