import { useState } from 'react';
import type { MapStyleSettings, MapLabelLanguage, DepthFontSize, DepthColorStop } from './types';
import { DEFAULT_MAP_STYLE_SETTINGS } from './types';

interface MapSettingsPanelProps {
  value: MapStyleSettings;
  onChange: (next: MapStyleSettings) => void;
}

const LANGUAGES: { value: MapLabelLanguage; label: string }[] = [
  { value: 'ko', label: '한국어' },
  { value: 'en', label: 'English' },
  { value: 'ja', label: '日本語' },
  { value: 'zh', label: '中文' },
  { value: 'local', label: '현지어' },
];

const FONT_SIZES: { value: DepthFontSize; label: string }[] = [
  { value: 'small', label: '소' },
  { value: 'medium', label: '중' },
  { value: 'large', label: '대' },
];

function depthLabel(depth: number): string {
  return `${Math.abs(depth).toLocaleString()}m`;
}

function hexToRgb(hex: string): [number, number, number] {
  return [
    parseInt(hex.slice(1, 3), 16),
    parseInt(hex.slice(3, 5), 16),
    parseInt(hex.slice(5, 7), 16),
  ];
}

function rgbToHex(r: number, g: number, b: number): string {
  return `#${[r, g, b].map((c) => Math.round(Math.max(0, Math.min(255, c))).toString(16).padStart(2, '0')).join('')}`;
}

function interpolateGradient(stops: DepthColorStop[]): DepthColorStop[] {
  if (stops.length < 2) return stops;
  const sorted = [...stops].sort((a, b) => a.depth - b.depth);
  const first = sorted[0];
  const last = sorted[sorted.length - 1];
  const [r1, g1, b1] = hexToRgb(first.color);
  const [r2, g2, b2] = hexToRgb(last.color);
  return sorted.map((stop, i) => {
    if (i === 0 || i === sorted.length - 1) return stop;
    const t = i / (sorted.length - 1);
    return {
      depth: stop.depth,
      color: rgbToHex(
        r1 + (r2 - r1) * t,
        g1 + (g2 - g1) * t,
        b1 + (b2 - b1) * t,
      ),
    };
  });
}

export function MapSettingsPanel({ value, onChange }: MapSettingsPanelProps) {
  const [open, setOpen] = useState(false);
  const [autoGradient, setAutoGradient] = useState(false);

  const update = <K extends keyof MapStyleSettings>(key: K, val: MapStyleSettings[K]) => {
    onChange({ ...value, [key]: val });
  };

  const updateDepthStop = (index: number, color: string) => {
    const next = value.depthStops.map((s, i) => (i === index ? { ...s, color } : s));
    if (autoGradient && (index === 0 || index === next.length - 1)) {
      update('depthStops', interpolateGradient(next));
    } else {
      update('depthStops', next);
    }
  };

  const toggleAutoGradient = () => {
    const next = !autoGradient;
    setAutoGradient(next);
    if (next) {
      update('depthStops', interpolateGradient(value.depthStops));
    }
  };

  return (
    <>
      <button
        className={`map-settings-gear${open ? ' open' : ''}`}
        onClick={() => setOpen((p) => !p)}
        title="지도 설정"
        type="button"
      >
        ⚙
      </button>

      {open && (
        <div className="map-settings-panel">
          <div className="ms-title">지도 설정</div>

          {/* ── Language ──────────────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label">레이블 언어</div>
            <select
              value={value.labelLanguage}
              onChange={(e) => update('labelLanguage', e.target.value as MapLabelLanguage)}
            >
              {LANGUAGES.map((l) => (
                <option key={l.value} value={l.value}>
                  {l.label}
                </option>
              ))}
            </select>
          </div>

          {/* ── Land color ────────────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label">육지 색상</div>
            <div className="ms-row">
              <input
                type="color"
                className="ms-color-input"
                value={value.landColor}
                onChange={(e) => update('landColor', e.target.value)}
              />
              <span className="ms-hex">{value.landColor}</span>
            </div>
          </div>

          {/* ── Water color ───────────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label">물 기본색</div>
            <div className="ms-row">
              <input
                type="color"
                className="ms-color-input"
                value={value.waterBaseColor}
                onChange={(e) => update('waterBaseColor', e.target.value)}
              />
              <span className="ms-hex">{value.waterBaseColor}</span>
            </div>
          </div>

          {/* ── Depth gradient ────────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label" style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
              수심 구간 색상
              <span
                className={`tog-btn${autoGradient ? ' on' : ''}`}
                style={{ fontSize: 8, padding: '1px 5px', marginLeft: 8 }}
                onClick={toggleAutoGradient}
                title="최소/최대 색상 기준으로 중간 구간을 자동 보간합니다"
              >
                자동채우기
              </span>
            </div>
            {value.depthStops.map((stop, i) => {
              const isEdge = i === 0 || i === value.depthStops.length - 1;
              const dimmed = autoGradient && !isEdge;
              return (
                <div className="ms-row" key={stop.depth} style={dimmed ? { opacity: 0.5 } : undefined}>
                  <span className="ms-depth-label">{depthLabel(stop.depth)}</span>
                  <input
                    type="color"
                    className="ms-color-input"
                    value={stop.color}
                    onChange={(e) => updateDepthStop(i, e.target.value)}
                    disabled={dimmed}
                  />
                  <span className="ms-hex">{stop.color}</span>
                </div>
              );
            })}
          </div>

          {/* ── Depth font size ───────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label">수심 폰트 크기</div>
            <div className="tog" style={{ gap: 3 }}>
              {FONT_SIZES.map((fs) => (
                <div
                  key={fs.value}
                  className={`tog-btn${value.depthFontSize === fs.value ? ' on' : ''}`}
                  onClick={() => update('depthFontSize', fs.value)}
                >
                  {fs.label}
                </div>
              ))}
            </div>
          </div>

          {/* ── Depth font color ──────────────────────────── */}
          <div className="ms-section">
            <div className="ms-label">수심 폰트 색상</div>
            <div className="ms-row">
              <input
                type="color"
                className="ms-color-input"
                value={value.depthFontColor}
                onChange={(e) => update('depthFontColor', e.target.value)}
              />
              <span className="ms-hex">{value.depthFontColor}</span>
            </div>
          </div>

          {/* ── Reset ─────────────────────────────────────── */}
          <button
            className="ms-reset"
            type="button"
            onClick={() => {
              onChange(DEFAULT_MAP_STYLE_SETTINGS);
              setAutoGradient(false);
            }}
          >
            초기화
          </button>
        </div>
      )}
    </>
  );
}