import * as React from 'react';
import PropTypes from 'prop-types';
import clsx from 'clsx';
import { isFilled, isAdornedStart } from '../InputBase/utils';
import withStyles from '../styles/withStyles';
import capitalize from '../utils/capitalize';
import isMuiElement from '../utils/isMuiElement';
import FormControlContext from './FormControlContext';

export const styles = {
  /* Styles applied to the root element. */
  root: {
    display: 'inline-flex',
    flexDirection: 'column',
    position: 'relative',
    // Reset fieldset default style.
    minWidth: 0,
    padding: 0,
    margin: 0,
    border: 0,
    verticalAlign: 'top', // Fix alignment issue on Safari.
  },
  /* Styles applied to the root element if `margin="normal"`. */
  marginNormal: {
    marginTop: 16,
    marginBottom: 8,
  },
  /* Styles applied to the root element if `margin="dense"`. */
  marginDense: {
    marginTop: 8,
    marginBottom: 4,
  },
  /* Styles applied to the root element if `fullWidth={true}`. */
  fullWidth: {
    width: '100%',
  },
};

/**
 * Provides context such as filled/focused/error/required for form inputs.
 * Relying on the context provides high flexibility and ensures that the state always stays
 * consistent across the children of the `FormControl`.
 * This context is used by the following components:
 *
 *  - FormLabel
 *  - FormHelperText
 *  - Input
 *  - InputLabel
 *
 * You can find one composition example below and more going to [the demos](/components/text-fields/#components).
 *
 * ```jsx
 * <FormControl>
 *   <InputLabel htmlFor="my-input">Email address</InputLabel>
 *   <Input id="my-input" aria-describedby="my-helper-text" />
 *   <FormHelperText id="my-helper-text">We'll never share your email.</FormHelperText>
 * </FormControl>
 * ```
 *
 * ⚠️Only one input can be used within a FormControl.
 */
const FormControl = React.forwardRef(function FormControl(props, ref) {
  const {
    children,
    classes,
    className,
    color = 'primary',
    component: Component = 'div',
    disabled = false,
    error = false,
    fullWidth = false,
    focused: visuallyFocused,
    hiddenLabel = false,
    margin = 'none',
    required = false,
    size,
    variant = 'standard',
    ...other
  } = props;

  const [adornedStart, setAdornedStart] = React.useState(() => {
    // We need to iterate through the children and find the Input in order
    // to fully support server-side rendering.
    let initialAdornedStart = false;

    if (children) {
      React.Children.forEach(children, (child) => {
        if (!isMuiElement(child, ['Input', 'Select'])) {
          return;
        }

        const input = isMuiElement(child, ['Select']) ? child.props.input : child;

        if (input && isAdornedStart(input.props)) {
          initialAdornedStart = true;
        }
      });
    }
    return initialAdornedStart;
  });

  const [filled, setFilled] = React.useState(() => {
    // We need to iterate through the children and find the Input in order
    // to fully support server-side rendering.
    let initialFilled = false;

    if (children) {
      React.Children.forEach(children, (child) => {
        if (!isMuiElement(child, ['Input', 'Select'])) {
          return;
        }

        if (isFilled(child.props, true)) {
          initialFilled = true;
        }
      });
    }

    return initialFilled;
  });

  const [focusedState, setFocused] = React.useState(false);
  const focused = visuallyFocused !== undefined ? visuallyFocused : focusedState;

  if (disabled && focused) {
    setFocused(false);
  }

  let registerEffect;
  if (process.env.NODE_ENV !== 'production') {
    // eslint-disable-next-line react-hooks/rules-of-hooks
    const registeredInput = React.useRef(false);
    registerEffect = () => {
      if (registeredInput.current) {
        console.error(
          [
            'Material-UI: There are multiple InputBase components inside a FormControl.',
            'This is not supported. It might cause infinite rendering loops.',
            'Only use one InputBase.',
          ].join('\n'),
        );
      }

      registeredInput.current = true;
      return () => {
        registeredInput.current = false;
      };
    };
  }

  const onFilled = React.useCallback(() => {
    setFilled(true);
  }, []);

  const onEmpty = React.useCallback(() => {
    setFilled(false);
  }, []);

  const childContext = {
    adornedStart,
    setAdornedStart,
    color,
    disabled,
    error,
    filled,
    focused,
    fullWidth,
    hiddenLabel,
    margin: (size === 'small' ? 'dense' : undefined) || margin,
    onBlur: () => {
      setFocused(false);
    },
    onEmpty,
    onFilled,
    onFocus: () => {
      setFocused(true);
    },
    registerEffect,
    required,
    variant,
  };

  return (
    <FormControlContext.Provider value={childContext}>
      <Component
        className={clsx(
          classes.root,
          {
            [classes[`margin${capitalize(margin)}`]]: margin !== 'none',
            [classes.fullWidth]: fullWidth,
          },
          className,
        )}
        ref={ref}
        {...other}
      >
        {children}
      </Component>
    </FormControlContext.Provider>
  );
});

FormControl.propTypes = {
  // ----------------------------- Warning --------------------------------
  // | These PropTypes are generated from the TypeScript type definitions |
  // |     To update them edit the d.ts file and run "yarn proptypes"     |
  // ----------------------------------------------------------------------
  /**
   * The contents of the form control.
   */
  children: PropTypes.node,
  /**
   * Override or extend the styles applied to the component.
   * See [CSS API](#css) below for more details.
   */
  classes: PropTypes.object,
  /**
   * @ignore
   */
  className: PropTypes.string,
  /**
   * The color of the component. It supports those theme colors that make sense for this component.
   */
  color: PropTypes.oneOf(['primary', 'secondary']),
  /**
   * The component used for the root node.
   * Either a string to use a HTML element or a component.
   */
  component: PropTypes /* @typescript-to-proptypes-ignore */.elementType,
  /**
   * If `true`, the label, input and helper text should be displayed in a disabled state.
   */
  disabled: PropTypes.bool,
  /**
   * If `true`, the label should be displayed in an error state.
   */
  error: PropTypes.bool,
  /**
   * If `true`, the component will be displayed in focused state.
   */
  focused: PropTypes.bool,
  /**
   * If `true`, the component will take up the full width of its container.
   */
  fullWidth: PropTypes.bool,
  /**
   * If `true`, the label will be hidden.
   * This is used to increase density for a `FilledInput`.
   * Be sure to add `aria-label` to the `input` element.
   */
  hiddenLabel: PropTypes.bool,
  /**
   * If `dense` or `normal`, will adjust vertical spacing of this and contained components.
   */
  margin: PropTypes.oneOf(['dense', 'none', 'normal']),
  /**
   * If `true`, the label will indicate that the input is required.
   */
  required: PropTypes.bool,
  /**
   * The size of the text field.
   */
  size: PropTypes.oneOf(['medium', 'small']),
  /**
   * The variant to use.
   */
  variant: PropTypes.oneOf(['filled', 'outlined', 'standard']),
};

export default withStyles(styles, { name: 'MuiFormControl' })(FormControl);
