/**
 * The SP-404MK2 panel. Presentational: it is told what is lit and reports
 * presses, holding no state of its own.
 */
import { panelLabel } from "../domain/format";
import type { ControlId, Entry } from "../domain/types";
import { cx } from "./cx";
import { CONTROL_GROUPS, FX_LEFT, FX_RIGHT, KNOBS, PAD_ROWS } from "./panelLayout";
import styles from "./Panel.module.css";

export interface ScreenText {
  readonly top: string;
  readonly right: string;
  readonly main: string;
  /** Inverted chips along the bottom of the LCD — the layer's functions. */
  readonly chips: readonly string[];
}

export interface PanelProps {
  /** Controls carrying a function on the current layer, and which entries. */
  readonly lit: ReadonlyMap<ControlId, Entry[]>;
  readonly held: readonly ControlId[];
  readonly screen: ScreenText;
  readonly onPress?: (id: ControlId) => void;
}

interface KeyProps extends Pick<PanelProps, "lit" | "held" | "onPress"> {
  readonly id: ControlId;
  /** Comes from a CSS module, so possibly undefined. See cx. */
  readonly className: string | undefined;
}

/** Pads print their number, not "PAD 7" — until a layer lights them up. */
const padNumber = (id: ControlId): string | undefined => /^p(\d+)$/.exec(id)?.[1];

function Key({ id, className, lit, held, onPress }: KeyProps) {
  const entries = lit.get(id);
  const isHeld = held.includes(id);
  const isLit = entries !== undefined && entries.length > 0;
  const number = padNumber(id);

  return (
    <button
      type="button"
      className={cx(className, isHeld && styles.held, !isHeld && isLit && styles.lit)}
      data-control={id}
      aria-label={panelLabel(id)}
      onClick={onPress ? () => onPress(id) : undefined}
    >
      {isLit ? (
        entries[0]!.short
      ) : number ? (
        <span className={styles.num}>{number}</span>
      ) : (
        panelLabel(id)
      )}
      {entries && entries.length > 1 ? (
        <span className={styles.badge}>{entries.length}</span>
      ) : null}
    </button>
  );
}

export function Panel({ lit, held, screen, onPress }: PanelProps) {
  const key = { lit, held, ...(onPress ? { onPress } : {}) };

  return (
    <div className={styles.panel}>
      <div className={styles.knobs}>
        {KNOBS.map((id) => (
          <Key key={id} id={id} className={styles.knob} {...key} />
        ))}
      </div>

      <div className={styles.screenRow}>
        <div className={styles.fxCol}>
          {FX_LEFT.map((id) => (
            <Key key={id} id={id} className={styles.fx} {...key} />
          ))}
        </div>

        {/* The circle sits behind the display and shows only as caps above and
            below it — no ring around the rectangle. */}
        <div className={styles.screenWrap}>
          <div className={styles.circle} aria-hidden="true" />
          <div className={styles.lcd}>
            <div className={styles.lcdRow}>
              <span>{screen.top}</span>
              <span>{screen.right}</span>
            </div>
            <div className={styles.lcdMain}>{screen.main}</div>
            <div className={styles.lcdRow}>
              {screen.chips.map((chip) => (
                <span key={chip} className={styles.chip}>
                  {chip}
                </span>
              ))}
            </div>
          </div>
        </div>

        <div className={styles.fxCol}>
          {FX_RIGHT.map((id) => (
            <Key key={id} id={id} className={styles.fx} {...key} />
          ))}
        </div>
      </div>

      <div className={styles.ctl}>
        {CONTROL_GROUPS.map((group) => (
          <div className={styles.group} key={group.left.join()}>
            <div className={styles.col}>
              <div className={styles.caption}>
                {group.leftCaption ? <span>{group.leftCaption}</span> : null}
                <i className={styles.rule} />
              </div>
              <div className={styles.btnRow}>
                {group.left.map((id) => (
                  <Key key={id} id={id} className={styles.key} {...key} />
                ))}
              </div>
            </div>

            <div className={styles.col}>
              <div className={styles.caption}>
                {group.rightCaption ? <span>{group.rightCaption}</span> : null}
                <i className={styles.rule} />
              </div>
              <div className={styles.btnRow}>
                {group.right.map((id) => (
                  <Key key={id} id={id} className={styles.key} {...key} />
                ))}
                {group.rightKnob ? (
                  <Key id={group.rightKnob} className={styles.valueKnob} {...key} />
                ) : null}
              </div>
            </div>
          </div>
        ))}
      </div>

      <div className={styles.pads}>
        {PAD_ROWS.map((row) => (
          <div className={styles.padRow} key={row.side}>
            {row.pads.map((id) => (
              <Key key={id} id={id} className={styles.pad} {...key} />
            ))}
            <Key id={row.side} className={styles.side} {...key} />
          </div>
        ))}
      </div>
    </div>
  );
}