import type { ActivityKind, ActivityRow, DispatchWithAuthor, EventKind, Role } from './db.js';

/** "2m ago" / "3h ago" / "5d ago" / "just now". */
export function relativeTime(iso: string, now: Date = new Date()): string {
  const ms = now.getTime() - new Date(iso).getTime();
  const m = Math.round(ms / 60_000);
  if (m < 1) return 'just now';
  if (m < 60) return `${m}m ago`;
  const h = Math.round(m / 60);
  if (h < 24) return `${h}h ago`;
  const d = Math.round(h / 24);
  return `${d}d ago`;
}

/** "Maya Rasmussen" → "Maya R." (single-word names unchanged). */
export function redactName(fullName: string): string {
  const parts = fullName.trim().split(/\s+/);
  if (parts.length === 1) return parts[0];
  const last = parts[parts.length - 1][0] ?? '';
  return `${parts[0]} ${last}.`;
}

/** Tenure as "2 years, 4 months" / "8 months" / "12 days". */
export function tenureSince(iso: string, now: Date = new Date()): string {
  const start = new Date(iso);
  const ms = now.getTime() - start.getTime();
  const days = Math.floor(ms / (24 * 60 * 60 * 1000));
  if (days < 31) return `${days} day${days === 1 ? '' : 's'}`;
  const months = Math.floor(days / 30.44);
  if (months < 12) return `${months} month${months === 1 ? '' : 's'}`;
  const years = Math.floor(months / 12);
  const remMonths = months % 12;
  if (remMonths === 0) return `${years} year${years === 1 ? '' : 's'}`;
  return `${years} year${years === 1 ? '' : 's'}, ${remMonths} month${remMonths === 1 ? '' : 's'}`;
}

/** "MONDAY · 11 MAY" — uppercase day-of-week + day + short month. */
export function pulseDateLabel(now: Date = new Date()): string {
  const day = new Intl.DateTimeFormat('en-GB', { weekday: 'long', timeZone: 'Europe/Copenhagen' }).format(now);
  const date = new Intl.DateTimeFormat('en-GB', { day: 'numeric', month: 'short', timeZone: 'Europe/Copenhagen' }).format(now);
  return `${day.toUpperCase()} · ${date.toUpperCase()}`;
}

/** Morning / afternoon / evening greeting based on Europe/Copenhagen hour. */
export function timeOfDay(now: Date = new Date()): 'morning' | 'afternoon' | 'evening' {
  const hour = Number(new Intl.DateTimeFormat('en-GB', {
    hour: 'numeric', hour12: false, timeZone: 'Europe/Copenhagen',
  }).format(now));
  if (hour < 12) return 'morning';
  if (hour < 18) return 'afternoon';
  return 'evening';
}

// ── Event kind labels + default action labels ──────────────────────

/** Human display label for an event kind. office_hours surfaces as 'Studio hours'. */
export function eventKindLabel(kind: EventKind): string {
  return ({
    dinner:           'Dinner',
    office_hours:     'Studio hours',
    summit:           'Summit',
    virtual:          'Virtual',
    working_session:  'Working session',
  } as const)[kind];
}

/** Default action label per event kind, used when event.action_label is null. */
export function defaultActionLabel(kind: EventKind): string {
  return ({
    dinner:           'Save your seat →',
    office_hours:     'Book a slot →',
    summit:           'RSVP →',
    virtual:          'Join →',
    working_session:  'RSVP →',
  } as const)[kind];
}

// ── Vote-count copy ────────────────────────────────────────────────

/**
 * "{votes} of {total} council member(s) ha(s|ve) weighed in."
 * Handles 0 (no members), 1 (singular), and 2+ (plural) correctly.
 */
export function voteCountSentence(votes: number, total: number): string {
  if (total === 0) return `${votes} of 0 council members have weighed in.`;
  if (total === 1) return `${votes} of 1 council member has weighed in.`;
  return `${votes} of ${total} council members have weighed in.`;
}

// ── Activity ticker mapping ────────────────────────────────────────

const ROLE_DOT: Record<Role, string> = {
  pilot: 'var(--pigment-copper)',
  cab:   'var(--pigment-terracotta)',
  fenja: 'var(--pigment-indigo)',
};

export function dotForRole(role: Role): string {
  return ROLE_DOT[role];
}

export interface TickerItem {
  dotColor: string;
  name: string;
  phrase: string;
  relative: string;
}

// ── Deterministic avatar pigment ─────────────────────────────────

/** Avatar pigment palette — the same five used elsewhere in the portal. */
export const AVATAR_PIGMENTS = [
  { name: 'terracotta', token: 'var(--pigment-terracotta)', hex: '#b96b58' },
  { name: 'copper',     token: 'var(--pigment-copper)',     hex: '#6d8c7c' },
  { name: 'walnut',     token: 'var(--secondary)',          hex: '#785f53' },
  { name: 'indigo',     token: 'var(--pigment-indigo)',     hex: '#5a6d83' },
  { name: 'heather',    token: 'var(--pigment-heather)',    hex: '#8d7a85' },
] as const;

export type AvatarPigment = (typeof AVATAR_PIGMENTS)[number];

/** Deterministic avatar pigment for a given user id. Same id → same pigment everywhere. */
export function pigmentForId(id: number): AvatarPigment {
  return AVATAR_PIGMENTS[Math.abs(id) % AVATAR_PIGMENTS.length];
}

/** Initials from a name. "Mette Hansen" → "MH". "Jonathan" → "J". */
export function initialsFromName(name: string): string {
  const parts = name.trim().split(/\s+/);
  if (parts.length === 1) return (parts[0][0] ?? '').toUpperCase();
  return ((parts[0][0] ?? '') + (parts[parts.length - 1][0] ?? '')).toUpperCase();
}

// ── Focus tags parser ────────────────────────────────────────────

/**
 * Parse a comma-separated input string into a normalised tag list.
 * Rules: trim, strip ASCII control chars, collapse internal whitespace to a
 * single space, drop empties, dedupe (case-sensitive after normalisation),
 * cap at 3 entries × 24 chars each. Deterministic; safe to call on every save.
 */
export function parseFocusTags(input: string): string[] {
  if (!input) return [];
  return input
    .split(',')
    // eslint-disable-next-line no-control-regex
    .map(s => s.replace(/[ -]/g, '').replace(/\s+/g, ' ').trim())
    .filter(s => s.length > 0)
    .filter((s, i, arr) => arr.indexOf(s) === i)
    .slice(0, 3)
    .map(s => s.slice(0, 24));
}

/** Read a focus_tags JSON blob from the DB safely. Returns [] on any malformed input. */
export function readFocusTags(json: string | null): string[] {
  if (!json) return [];
  try {
    const v = JSON.parse(json);
    return Array.isArray(v) ? v.map(String).filter(Boolean) : [];
  } catch { return []; }
}

// ── Dispatches ───────────────────────────────────────────────────

const KEBAB_SAFE = /[^a-z0-9]+/g;

/** {{id}}-{{kebab-cased-title}}. Stable on title rename only if the id leads. */
export function dispatchSlug(d: { id: number; title: string }): string {
  const slug = d.title
    .toLowerCase()
    .normalize('NFKD').replace(/[̀-ͯ]/g, '')
    .replace(KEBAB_SAFE, '-')
    .replace(/^-+|-+$/g, '');
  return `${d.id}-${slug || 'dispatch'}`;
}

/** Pull the leading id out of a dispatch slug. Returns null if malformed. */
export function parseDispatchSlug(slug: string): number | null {
  const m = slug.match(/^(\d+)(?:-|$)/);
  if (!m) return null;
  const n = Number(m[1]);
  return Number.isInteger(n) && n > 0 ? n : null;
}

/** Title-case the kind value for display. */
export function dispatchKindLabel(kind: DispatchWithAuthor['kind']): string {
  return ({
    decision:           'Decision',
    update:             'Update',
    behind_the_scenes:  'Behind the scenes',
    note:               'Note',
  } as const)[kind];
}

/** Friendly role label, falls back to title-case role name. */
export function roleLabel(role: Role): string {
  return ({ pilot: 'Pilot', cab: 'Council', fenja: 'Fenja team' } as const)[role];
}

/** Pigment token for a dispatch kind, used by pill backgrounds. */
export function dispatchKindPigment(kind: DispatchWithAuthor['kind']): string {
  return ({
    decision:           'var(--pigment-terracotta)',
    update:             'var(--pigment-indigo)',
    behind_the_scenes:  'var(--pigment-ochre)',
    note:               'var(--pigment-heather)',
  } as const)[kind];
}

/** Strip a small amount of markdown for body excerpts. */
export function stripMarkdownLight(md: string): string {
  return md
    .replace(/`{1,3}[^`]*`{1,3}/g, '')
    .replace(/!\[[^\]]*\]\([^)]*\)/g, '')
    .replace(/\[([^\]]+)\]\([^)]*\)/g, '$1')
    .replace(/[*_]{1,3}([^*_]+)[*_]{1,3}/g, '$1')
    .replace(/^>+\s?/gm, '')
    .replace(/^#+\s?/gm, '')
    .replace(/\n+/g, ' ')
    .trim();
}

/** Longer single-paragraph preview (for /pulse hero placement). Defaults to ~520 chars cut on the nearest sentence boundary. */
export function dispatchLongPreview(d: { excerpt: string | null; body: string }, maxChars = 520): string {
  const source = stripMarkdownLight(d.body);
  if (source.length <= maxChars) return source;
  const window = source.slice(0, maxChars + 100);
  const dotPos = Math.max(
    window.lastIndexOf('. '),
    window.lastIndexOf('? '),
    window.lastIndexOf('! '),
  );
  return (dotPos > maxChars - 120 ? window.slice(0, dotPos + 1) : window.slice(0, maxChars)).trim() + '…';
}

/** Two-paragraph dispatch excerpt: { lead, trail | null }. */
export function dispatchExcerptParas(d: { excerpt: string | null; body: string }): { lead: string; trail: string | null } {
  const source = d.excerpt && d.excerpt.trim().length > 0
    ? d.excerpt.trim()
    : stripMarkdownLight(d.body);
  if (source.length <= 200) return { lead: source, trail: null };

  // Find the nearest sentence boundary within ~200 chars
  const window = source.slice(0, 240);
  const lastDot = Math.max(
    window.lastIndexOf('. '),
    window.lastIndexOf('? '),
    window.lastIndexOf('! '),
  );
  const cut = lastDot > 80 ? lastDot + 1 : 200;
  return {
    lead: source.slice(0, cut).trim(),
    trail: source.slice(cut).trim().slice(0, 120).replace(/\s+\S*$/, '') + '…',
  };
}

export function tickerItem(row: ActivityRow, subjectLabel: string | null): TickerItem {
  const phrases: Record<ActivityKind, string> = {
    voted:               subjectLabel ? `weighed in on “${subjectLabel}”` : 'cast a pulse vote',
    rsvped:              subjectLabel ? `is coming to ${subjectLabel}`    : 'RSVP’d to an event',
    booked_office_hours: 'booked office hours',
    roadmap_shipped:    subjectLabel ? `shipped ${subjectLabel}`          : 'shipped a roadmap item',
    pulse_opened:       subjectLabel ? `opened: “${subjectLabel}”`        : 'opened a new pulse',
  };
  return {
    dotColor: dotForRole(row.actor_role),
    name: redactName(row.actor_name),
    phrase: phrases[row.kind],
    relative: relativeTime(row.created_at),
  };
}