/**
 * ReadingSettingsPanel — slide-in drawer from the right for customizing
 * the reading experience: theme, font, sizing, orientation.
 */

import type { KeyboardEvent as ReactKeyboardEvent } from "react";
import { useTranslation } from "react-i18n-lite";
import type {
  FontFamily,
  OrientationLock,
  ReadingSettings,
  ThemePreset,
} from "../../types/reader";
import type { SettingsPersistMode } from "../../hooks/useReadingSettings";

interface ReadingSettingsPanelProps {
  settings: ReadingSettings;
  isOpen: boolean;
  onClose: () => void;
  onUpdate: (
    partial: Partial<ReadingSettings>,
    persist?: SettingsPersistMode,
  ) => void;
  onFlush: () => Promise<void>;
}

const THEME_OPTIONS: { value: ThemePreset; labelKey: string }[] = [
  { value: "sepia", labelKey: "reader.themeSepia" },
  { value: "dark", labelKey: "reader.themeDark" },
  { value: "light", labelKey: "reader.themeLight" },
  { value: "paper", labelKey: "reader.themePaper" },
];

const FONT_OPTIONS: { value: FontFamily; labelKey: string }[] = [
  { value: "sans-serif", labelKey: "reader.fontSans" },
  { value: "serif", labelKey: "reader.fontSerif" },
  { value: "monospace", labelKey: "reader.fontMonospace" },
];

const ORIENTATION_OPTIONS: { value: OrientationLock; labelKey: string }[] = [
  { value: "auto", labelKey: "reader.orientationAuto" },
  { value: "portrait", labelKey: "reader.orientationPortrait" },
  { value: "landscape", labelKey: "reader.orientationLandscape" },
];

export default function ReadingSettingsPanel({
  settings,
  isOpen,
  onClose,
  onUpdate,
  onFlush,
}: ReadingSettingsPanelProps) {
  const { t } = useTranslation();

  const handleClose = () => {
    void onFlush();
    onClose();
  };

  const handleSlider = (key: keyof ReadingSettings, value: number) => {
    onUpdate({ [key]: value } as Partial<ReadingSettings>, "debounced");
  };

  const handleDiscrete = (key: keyof ReadingSettings, value: string | number) => {
    onUpdate({ [key]: value } as Partial<ReadingSettings>, "immediate");
  };

  return (
    <>
      {isOpen && (
        <div
          className="settings-overlay"
          onClick={handleClose}
          onKeyDown={(e: ReactKeyboardEvent) => {
            if (e.key === "Escape") handleClose();
          }}
          role="presentation"
        />
      )}

      <aside
        className={`settings-drawer ${isOpen ? "settings-drawer--open" : ""}`}
      >
        <div className="settings-header">
          <h2 className="settings-title">{t("reader.settingsTitle")}</h2>
          <button
            type="button"
            className="settings-close-btn"
            onClick={handleClose}
            aria-label={t("reader.closeSettingsAria")}
          >
            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
              <line x1="18" y1="6" x2="6" y2="18" />
              <line x1="6" y1="6" x2="18" y2="18" />
            </svg>
          </button>
        </div>

        <div className="settings-body">
          <section className="settings-section">
            <h3 className="settings-section-title">{t("reader.theme")}</h3>
            <div className="theme-grid">
              {THEME_OPTIONS.map((opt) => (
                <button
                  key={opt.value}
                  type="button"
                  className={`theme-btn ${
                    settings.theme === opt.value ? "theme-btn--active" : ""
                  }`}
                  onClick={() => handleDiscrete("theme", opt.value)}
                >
                  {t(opt.labelKey)}
                </button>
              ))}
            </div>
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">{t("reader.font")}</h3>
            <div className="font-grid">
              {FONT_OPTIONS.map((opt) => (
                <button
                  key={opt.value}
                  type="button"
                  className={`font-btn ${
                    settings.font_family === opt.value ? "font-btn--active" : ""
                  }`}
                  onClick={() => handleDiscrete("font_family", opt.value)}
                >
                  {t(opt.labelKey)}
                </button>
              ))}
            </div>
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">
              {t("reader.fontSize", { size: String(settings.font_size) })}
            </h3>
            <input
              type="range"
              min="12"
              max="32"
              value={settings.font_size}
              onChange={(e) =>
                handleSlider("font_size", Number(e.target.value))
              }
              className="settings-slider"
              aria-label={t("reader.fontSizeAria")}
            />
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">
              {t("reader.lineHeight", { value: settings.line_height.toFixed(1) })}
            </h3>
            <input
              type="range"
              min="1.2"
              max="2.0"
              step="0.1"
              value={settings.line_height}
              onChange={(e) =>
                handleSlider("line_height", Number(e.target.value))
              }
              className="settings-slider"
              aria-label={t("reader.lineHeightAria")}
            />
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">
              {t("reader.margins", { value: String(settings.margin_width) })}
            </h3>
            <input
              type="range"
              min="8"
              max="48"
              value={settings.margin_width}
              onChange={(e) =>
                handleSlider("margin_width", Number(e.target.value))
              }
              className="settings-slider"
              aria-label={t("reader.marginWidthAria")}
            />
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">
              {t("reader.brightness", { value: String(settings.brightness) })}
            </h3>
            <input
              type="range"
              min="0"
              max="100"
              value={settings.brightness}
              onChange={(e) =>
                handleSlider("brightness", Number(e.target.value))
              }
              className="settings-slider"
              aria-label={t("reader.brightnessAria")}
            />
          </section>

          <section className="settings-section">
            <h3 className="settings-section-title">{t("reader.orientation")}</h3>
            <div className="orientation-grid">
              {ORIENTATION_OPTIONS.map((opt) => (
                <button
                  key={opt.value}
                  type="button"
                  className={`orientation-btn ${
                    settings.orientation_lock === opt.value
                      ? "orientation-btn--active"
                      : ""
                  }`}
                  onClick={() => handleDiscrete("orientation_lock", opt.value)}
                >
                  {t(opt.labelKey)}
                </button>
              ))}
            </div>
          </section>
        </div>
      </aside>
    </>
  );
}
