/**
 * VoiceOver/TalkBack accessibility label generators for common UI patterns.
 *
 * Returns A11yProps objects compatible with React Native accessibilityLabel/Role.
 * Web apps can map to aria-label / role.
 * Pure client-side TS — no backend dependency.
 */

import type { A11yProps } from './types.js';

export function buttonLabel(label: string, hint?: string): A11yProps {
  return {
    accessible: true,
    accessibilityLabel: label,
    accessibilityHint: hint,
    accessibilityRole: 'button',
  };
}

export function timerLabel(status: string, elapsedText: string, context?: string): A11yProps {
  const parts = [`Timer ${status}`, elapsedText];
  if (context) parts.push(context);
  return {
    accessible: true,
    accessibilityLabel: parts.join(', '),
    accessibilityRole: 'timer',
  };
}

export function progressLabel(name: string, percent: number, description?: string): A11yProps {
  const clamped = Math.max(0, Math.min(100, Math.round(percent)));
  const label = description
    ? `${name}: ${clamped} percent complete. ${description}`
    : `${name}: ${clamped} percent complete`;
  return {
    accessible: true,
    accessibilityLabel: label,
    accessibilityRole: 'progressbar',
    accessibilityValue: { min: 0, max: 100, now: clamped, text: `${clamped}%` },
  };
}

export function sliderLabel(metric: string, value: number, max?: number): A11yProps {
  const label = max !== undefined ? `${metric}: ${value} of ${max}` : `${metric}: ${value}`;
  return {
    accessible: true,
    accessibilityLabel: label,
    accessibilityRole: 'adjustable',
    accessibilityValue: { now: value, max, text: String(value) },
  };
}

export function alertLabel(severity: string, message: string): A11yProps {
  return {
    accessible: true,
    accessibilityLabel: `${severity} alert: ${message}`,
    accessibilityRole: 'alert',
  };
}

export function achievementLabel(name: string, description: string, earned: boolean): A11yProps {
  const status = earned ? 'Earned' : 'Locked';
  return {
    accessible: true,
    accessibilityLabel: `${status} achievement: ${name}. ${description}`,
    accessibilityRole: 'image',
    accessibilityState: { selected: earned },
  };
}

export function streakLabel(current: number, longest: number): A11yProps {
  return {
    accessible: true,
    accessibilityLabel: `Current streak: ${current} days. Longest streak: ${longest} days`,
    accessibilityRole: 'text',
  };
}

export function listItemLabel(title: string, subtitle?: string, badge?: string): A11yProps {
  const parts = [title];
  if (subtitle) parts.push(subtitle);
  if (badge) parts.push(badge);
  return {
    accessible: true,
    accessibilityLabel: parts.join(', '),
  };
}

export function formatDurationForA11y(ms: number): string {
  const safeMs = Math.max(0, ms);
  const totalSeconds = Math.floor(safeMs / 1000);
  const hours = Math.floor(totalSeconds / 3600);
  const minutes = Math.floor((totalSeconds % 3600) / 60);
  const seconds = totalSeconds % 60;

  const parts: string[] = [];
  if (hours > 0) parts.push(`${hours} ${hours === 1 ? 'hour' : 'hours'}`);
  if (minutes > 0) parts.push(`${minutes} ${minutes === 1 ? 'minute' : 'minutes'}`);
  if (seconds > 0 || parts.length === 0)
    parts.push(`${seconds} ${seconds === 1 ? 'second' : 'seconds'}`);

  return parts.join(' ');
}

const ONES = ['', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];
const TEENS = [
  'ten',
  'eleven',
  'twelve',
  'thirteen',
  'fourteen',
  'fifteen',
  'sixteen',
  'seventeen',
  'eighteen',
  'nineteen',
];
const TENS = ['', '', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety'];

function numberToWords(n: number): string {
  if (n < 0) return `negative ${numberToWords(-n)}`;
  if (n === 0) return 'zero';

  const parts: string[] = [];
  let remaining = n;

  if (remaining >= 1_000_000) {
    parts.push(`${numberToWords(Math.floor(remaining / 1_000_000))} million`);
    remaining %= 1_000_000;
  }
  if (remaining >= 1000) {
    parts.push(`${numberToWords(Math.floor(remaining / 1000))} thousand`);
    remaining %= 1000;
  }
  if (remaining >= 100) {
    parts.push(`${ONES[Math.floor(remaining / 100)]} hundred`);
    remaining %= 100;
  }
  if (remaining >= 20) {
    const t = TENS[Math.floor(remaining / 10)];
    const o = ONES[remaining % 10];
    parts.push(o ? `${t} ${o}` : t);
  } else if (remaining >= 10) {
    parts.push(TEENS[remaining - 10]);
  } else if (remaining > 0) {
    parts.push(ONES[remaining]);
  }

  return parts.join(' ');
}

export function formatNumberForA11y(n: number): string {
  return numberToWords(Math.round(n));
}

export function buildAnnouncement(headline: string, detail: string): string {
  return `${headline}. ${detail}`;
}

const POSITIVE_BREAK_MESSAGES = [
  'Every bit of progress counts!',
  'You showed up today — that matters!',
  'Rest is part of the journey. You are doing great!',
  'You can always come back — no pressure!',
  'Progress, not perfection. Well done!',
];

export function getPositiveBreakMessage(progressPercent: number): string {
  const clamped = Math.max(0, Math.min(100, progressPercent));
  const index = Math.floor((clamped / 100) * (POSITIVE_BREAK_MESSAGES.length - 1));
  return POSITIVE_BREAK_MESSAGES[index];
}