/**
 * 마작패 그림 (docs/games/mahjong.md §9): 직접 그린 SVG. 만수 = 숫자 + "만", 통수 = 동그라미, 삭수 = 막대, 자패 = 한글.
 * 작은 크기(버림패)에서는 숫자를 크게 쓴 간단한 그림으로 바꿔 휴대폰에서도 읽히게 한다. 수패는 종류마다 안쪽 테두리
 * 무늬(실선·점선·긴 점선)가 달라 색만으로 구별하지 않아도 된다.
 */
import type { CSSProperties } from 'react';

const SUIT_KO: Record<string, string> = { m: '만수', p: '통수', s: '삭수' };
const SUIT_SHORT: Record<string, string> = { m: '만', p: '통', s: '삭' };
const HONOR_KO = ['동', '남', '서', '북', '백', '발', '중'];

const INK = '#1c1e21';
const RED = '#c8202a';
const BLUE = '#1f5fbf';
const GREEN = '#17804a';

/** "5m0r" → { n: 5, suit: 'm', red: true }; honors use suit 'z' and n 1..7. */
export function parseCode(code: string): { n: number; suit: 'm' | 'p' | 's' | 'z'; red: boolean; kind: string } {
  return { n: Number(code[0]), suit: code[1] as 'm' | 'p' | 's' | 'z', red: code.endsWith('r'), kind: code.slice(0, 2) };
}

/** Screen-reader name: "만수 5", "적도라 통수 5", "동", "중". */
export function tileName(code: string): string {
  const t = parseCode(code);
  if (t.suit === 'z') return HONOR_KO[t.n - 1]!;
  return `${t.red ? '적도라 ' : ''}${SUIT_KO[t.suit]} ${t.n}`;
}
/** Short name: "5만", "3통", "7삭", "동" (kind codes like "5m" work too). */
export function tileShort(code: string): string {
  const t = parseCode(code);
  return t.suit === 'z' ? HONOR_KO[t.n - 1]! : `${t.n}${SUIT_SHORT[t.suit]}`;
}

/** Sort key: 만 → 통 → 삭 → 자, by number, red five first. */
export function tileOrder(code: string): number {
  const t = parseCode(code);
  return 'mpsz'.indexOf(t.suit) * 100 + t.n * 10 + (t.red ? 0 : 1) + Number(code[2] ?? 0) / 10;
}

const PIN_POS: Record<number, [number, number][]> = {
  1: [[30, 38]],
  2: [
    [30, 22],
    [30, 54],
  ],
  3: [
    [16, 18],
    [30, 38],
    [44, 58],
  ],
  4: [
    [18, 22],
    [42, 22],
    [18, 54],
    [42, 54],
  ],
  5: [
    [17, 18],
    [43, 18],
    [30, 38],
    [17, 58],
    [43, 58],
  ],
  6: [
    [19, 16],
    [41, 16],
    [19, 38],
    [41, 38],
    [19, 60],
    [41, 60],
  ],
  7: [
    [14, 13],
    [30, 21],
    [46, 29],
    [19, 46],
    [41, 46],
    [19, 63],
    [41, 63],
  ],
  8: [
    [19, 12],
    [41, 12],
    [19, 30],
    [41, 30],
    [19, 47],
    [41, 47],
    [19, 64],
    [41, 64],
  ],
  9: [
    [14, 16],
    [30, 16],
    [46, 16],
    [14, 38],
    [30, 38],
    [46, 38],
    [14, 60],
    [30, 60],
    [46, 60],
  ],
};

function pinColor(n: number, i: number, red: boolean): string {
  if (red) return RED;
  if (n === 1) return RED;
  if (n === 2) return i === 0 ? GREEN : BLUE;
  if (n === 3) return [BLUE, RED, GREEN][i]!;
  if (n === 4) return i === 0 || i === 3 ? BLUE : GREEN;
  if (n === 5) return i === 2 ? RED : i === 0 || i === 4 ? BLUE : GREEN;
  if (n === 6) return i < 2 ? GREEN : RED;
  if (n === 7) return i < 3 ? GREEN : RED;
  if (n === 8) return BLUE;
  return i < 3 ? BLUE : i < 6 ? RED : GREEN;
}

function Pins({ n, red }: { n: number; red: boolean }) {
  const pos = PIN_POS[n]!;
  const r = n === 1 ? 17 : n <= 3 ? 9.5 : n <= 5 ? 8.5 : n <= 7 ? 7 : 7;
  return (
    <>
      {pos.map(([x, y], i) => {
        const c = pinColor(n, i, red);
        return (
          <g key={i}>
            <circle cx={x} cy={y} r={r} fill="none" stroke={c} strokeWidth={n === 1 ? 4 : 2.6} />
            <circle cx={x} cy={y} r={r * 0.42} fill={c} />
          </g>
        );
      })}
    </>
  );
}

/** Bamboo sticks: rows of [x positions], with red sticks for some centres. */
const SOU_ROWS: Record<number, number[][]> = {
  2: [[30], [30]],
  3: [[30], [18, 42]],
  4: [
    [20, 40],
    [20, 40],
  ],
  5: [[18, 42], [30], [18, 42]],
  6: [
    [15, 30, 45],
    [15, 30, 45],
  ],
  7: [[30], [15, 30, 45], [15, 30, 45]],
  8: [
    [12, 24, 36, 48],
    [12, 24, 36, 48],
  ],
  9: [
    [15, 30, 45],
    [15, 30, 45],
    [15, 30, 45],
  ],
};

function Sticks({ n, red }: { n: number; red: boolean }) {
  if (n === 1) {
    // 1삭: one big stick with knots and a red top.
    return (
      <g>
        <rect x={24} y={12} width={12} height={54} rx={6} fill={GREEN} />
        <rect x={24} y={12} width={12} height={12} rx={6} fill={RED} />
        <line x1={24} y1={39} x2={36} y2={39} stroke="#fff" strokeWidth={2} />
        <line x1={24} y1={52} x2={36} y2={52} stroke="#fff" strokeWidth={2} />
      </g>
    );
  }
  const rows = SOU_ROWS[n]!;
  const top = 8;
  const bottom = 70;
  const gap = 4;
  const h = (bottom - top - gap * (rows.length - 1)) / rows.length;
  const w = rows.some((r) => r.length === 4) ? 7 : 8;
  return (
    <>
      {rows.map((xs, ri) =>
        xs.map((x, ci) => {
          const y = top + ri * (h + gap);
          const center = (n === 5 && ri === 1) || (n === 7 && ri === 0) || (n === 9 && ci === 1);
          const c = red ? RED : center ? RED : GREEN;
          return (
            <g key={`${ri}-${ci}`}>
              <rect x={x - w / 2} y={y} width={w} height={h} rx={w / 2} fill={c} />
              <line x1={x - w / 2} y1={y + h / 2} x2={x + w / 2} y2={y + h / 2} stroke="#fff" strokeWidth={1.4} />
            </g>
          );
        }),
      )}
    </>
  );
}

/** Inner frame pattern per suit (colour-blind help, §9). */
const FRAME_DASH: Record<string, string | undefined> = { m: undefined, p: '1.5 3', s: '6 3' };

function Face({ code, compact }: { code: string; compact: boolean }) {
  const t = parseCode(code);
  const frame = t.suit !== 'z' && (
    <rect x={5} y={5} width={50} height={66} rx={5} fill="none" stroke="#c9bfa8" strokeWidth={1.6} strokeDasharray={FRAME_DASH[t.suit]} />
  );
  if (t.suit === 'z') {
    const ch = HONOR_KO[t.n - 1]!;
    if (t.n === 5) {
      return (
        <>
          <rect x={10} y={10} width={40} height={56} rx={4} fill="none" stroke={BLUE} strokeWidth={4} />
          <text x={30} y={48} textAnchor="middle" fontSize={compact ? 28 : 22} fontWeight={800} fill={BLUE}>
            {ch}
          </text>
        </>
      );
    }
    const color = t.n === 6 ? GREEN : t.n === 7 ? RED : INK;
    return (
      <text x={30} y={compact ? 53 : 52} textAnchor="middle" fontSize={compact ? 40 : 36} fontWeight={900} fill={color}>
        {ch}
      </text>
    );
  }
  const numColor = t.red ? RED : INK;
  if (compact) {
    if (t.suit === 'm') {
      return (
        <>
          {frame}
          <text x={30} y={50} textAnchor="middle" fontSize={44} fontWeight={900} fill={numColor}>
            {t.n}
          </text>
          <rect x={14} y={58} width={32} height={7} rx={3.5} fill={RED} />
        </>
      );
    }
    if (t.suit === 'p') {
      return (
        <>
          {frame}
          <circle cx={30} cy={38} r={23} fill="none" stroke={t.red ? RED : BLUE} strokeWidth={4} />
          <text x={30} y={53} textAnchor="middle" fontSize={40} fontWeight={900} fill={t.red ? RED : BLUE}>
            {t.n}
          </text>
        </>
      );
    }
    return (
      <>
        {frame}
        <rect x={7} y={12} width={6} height={52} rx={3} fill={t.red ? RED : GREEN} />
        <rect x={47} y={12} width={6} height={52} rx={3} fill={t.red ? RED : GREEN} />
        <text x={30} y={53} textAnchor="middle" fontSize={40} fontWeight={900} fill={t.red ? RED : GREEN}>
          {t.n}
        </text>
      </>
    );
  }
  if (t.suit === 'm') {
    return (
      <>
        {frame}
        <text x={30} y={40} textAnchor="middle" fontSize={34} fontWeight={900} fill={numColor}>
          {t.n}
        </text>
        <text x={30} y={66} textAnchor="middle" fontSize={21} fontWeight={800} fill={RED}>
          만
        </text>
      </>
    );
  }
  return (
    <>
      {frame}
      {t.suit === 'p' ? <Pins n={t.n} red={t.red} /> : <Sticks n={t.n} red={t.red} />}
      <text x={52} y={14} textAnchor="end" fontSize={11} fontWeight={800} fill={t.red ? RED : '#6b6352'}>
        {t.n}
      </text>
    </>
  );
}

export interface TileProps {
  /** Tile code ("5m0r") or kind code ("5m"); null draws the back. */
  code: string | null;
  /** Width in px (height is 4:3). */
  w: number;
  sideways?: boolean;
  dim?: boolean;
  className?: string;
  style?: CSSProperties;
  /** aria-hidden by default: the parent describes the tile. */
  label?: string;
}

export function Tile({ code, w, sideways, dim, className, style, label }: TileProps) {
  const h = Math.round((w * 4) / 3);
  const compact = w < 30;
  const svg = (
    <svg viewBox="0 0 60 80" width={w} height={h} style={{ display: 'block', ...(sideways ? { transform: 'rotate(-90deg)' } : {}) }} aria-hidden>
      {code === null ? (
        <>
          <rect x={1} y={1} width={58} height={78} rx={8} fill="#1d5a8c" stroke="#123b5c" strokeWidth={2} />
          <rect x={7} y={7} width={46} height={62} rx={5} fill="#2a73ad" />
        </>
      ) : (
        <>
          <rect x={1} y={1} width={58} height={78} rx={8} fill="#d9cdb0" stroke="#9c8f72" strokeWidth={2} />
          <rect x={2} y={2} width={56} height={71} rx={7} fill="#fffcf3" />
          <Face code={code} compact={compact} />
        </>
      )}
    </svg>
  );
  const box: CSSProperties = sideways
    ? { width: h, height: w, display: 'inline-flex', alignItems: 'center', justifyContent: 'center', flex: 'none', ...style }
    : { width: w, height: h, display: 'inline-block', flex: 'none', ...style };
  return (
    <span className={`mj-tile${dim ? ' dim' : ''}${className ? ` ${className}` : ''}`} style={box} role={label ? 'img' : undefined} aria-label={label} aria-hidden={label ? undefined : true}>
      {svg}
    </span>
  );
}