// A text field of the device sheet. Java takes a field's text when it loses
// the focus or Enter is pressed, and colours a text its rule refuses red
// while it is typed. A refused text stays here, marked, with what the device
// keeps meanwhile, instead of being replaced without a word as Java does;
// Escape gives it up. A value the device already holds that the rule
// refuses (from a file, or written by someone else) is marked, never mended
// (plan I6).

import { useId, useState, type KeyboardEvent } from 'react';
import { checkField, type CheckedField, type FieldRule } from '@mdg-filius/doc';
import { useTranslate } from '../i18n/i18n.js';

export interface SheetFieldProps {
  readonly label: string;
  /** What the device holds. */
  readonly value: string;
  readonly rule: FieldRule;
  /** Gives the text to the device; says whether it was taken. */
  readonly onCommit: (text: string) => CheckedField;
  readonly disabled?: boolean;
  readonly readOnly?: boolean;
  /** A name for the browser tests and the label's input mode. */
  readonly name: string;
  readonly inputMode?: 'text' | 'decimal' | 'numeric';
  /** A field still to be filled (a new row's cell): empty and untouched, it is not marked. */
  readonly unfilled?: boolean;
}

export function SheetField({ label, value, rule, onCommit, disabled = false, readOnly = false, name, inputMode = 'text', unfilled = false }: SheetFieldProps) {
  const t = useTranslate();
  const id = useId();
  // What is typed and not yet taken; null shows the device's value.
  const [draft, setDraft] = useState<string | null>(null);
  const [refused, setRefused] = useState(false);
  const shown = draft ?? value;
  const marked = !readOnly && !(unfilled && draft === null && shown === '') && 'invalid' in checkField(rule, shown);

  const commit = () => {
    if (draft === null || readOnly) return;
    if (draft === value) {
      setDraft(null);
      setRefused(false);
      return;
    }
    const result = onCommit(draft);
    if ('value' in result) {
      setDraft(null);
      setRefused(false);
    } else {
      setRefused(true);
    }
  };

  const key = (event: KeyboardEvent<HTMLInputElement>) => {
    if (event.key === 'Enter') commit();
    if (event.key === 'Escape') {
      setDraft(null);
      setRefused(false);
    }
  };

  const hint = refused && draft !== null ? t('sheet.notTaken', { value: value === '' ? t('sheet.empty') : value }) : draft === null && marked ? t('sheet.invalidValue') : null;
  return (
    <label className="sheet-field" htmlFor={id}>
      <span>{label}</span>
      <input
        id={id}
        name={name}
        value={shown}
        disabled={disabled}
        readOnly={readOnly}
        inputMode={inputMode}
        autoComplete="off"
        spellCheck={false}
        aria-invalid={marked}
        aria-describedby={hint === null ? undefined : `${id}-hint`}
        onChange={(event) => {
          setDraft(event.target.value);
          setRefused(false);
        }}
        onBlur={commit}
        onKeyDown={key}
      />
      {hint === null ? null : (
        <span id={`${id}-hint`} className="sheet-hint" role="status">
          {hint}
        </span>
      )}
    </label>
  );
}

export function SheetCheck({
  label,
  checked,
  onChange,
  disabled = false,
  name,
}: {
  readonly label: string;
  readonly checked: boolean;
  readonly onChange: (checked: boolean) => void;
  readonly disabled?: boolean;
  readonly name: string;
}) {
  return (
    <label className={disabled ? 'sheet-check disabled' : 'sheet-check'}>
      <input type="checkbox" name={name} checked={checked} disabled={disabled} onChange={(event) => onChange(event.target.checked)} />
      {label}
    </label>
  );
}