import React from 'react';
import PropTypes from 'prop-types';
import styled from 'styled-components';
import SimpleHighlight from '../SimpleHighlight';
import Title from '../Title';
import { FORBIDDEN_PROPS } from '../shared';

const MainTitle = styled(Title)`
  padding: 0;
  margin: 25px 0;
`;

const formatJSON = (key, value) => {
  if (typeof value === 'function') return '() => {}';
  if (typeof value === 'string') return `'${value}'`;

  return value;
};

const INDENTATION_SIZE = 2;
const spaces = size => ' '.repeat(size);
const jsonStr = (json, indentation) =>
  JSON.stringify(json, formatJSON, INDENTATION_SIZE)
    .replace(/\n/g, `\n${indentation}${spaces(INDENTATION_SIZE)}`)
    .replace(/"/g, '');

const renderPropValue = (propValue, indentation) => {
  if (typeof propValue === 'object' && propValue instanceof RegExp) {
    return `{${propValue}}`;
  }

  const types = {
    function: () => '{() => {}}',
    string: prop => `"${prop}"`,
    number: prop => `{${prop}}`,
    object: prop => `{${jsonStr(prop, indentation)}}`,
    instanceOf: prop => `{${prop}}`
  };

  const fn = types[typeof propValue];

  return fn ? fn(propValue) : propValue;
};

function getProps(props, indentation) {
  const breakline = `\n${indentation}${spaces(INDENTATION_SIZE)}`;

  return Object.entries(props)
    .filter(([name, value]) => value && !FORBIDDEN_PROPS.includes(name))
    .map(([prop, value], index) => {
      const propText =
        typeof value === 'boolean'
          ? prop
          : `${prop}=${renderPropValue(value, indentation)}`;

      return `${index === 0 ? breakline : ''}${propText}`;
    })
    .join(breakline);
}

const componentToString = (component, state, level = 0) => {
  let content;
  const indentation = spaces(level);

  if (typeof component === 'object') {
    const { type, props } = component;
    const name = type.displayName || type.name || type;
    const children = props ? props.children : null;

    content = `${indentation}<${name}${
      Object.keys(state).length ? getProps(state, indentation) : ''
    }`;
    content += children
      ? `>\n${React.Children.map(children, child =>
          componentToString(child, child.props, level + INDENTATION_SIZE)
        ).join('\n')}\n${indentation}</${name}>`
      : `\n${indentation}/>`;
  } else {
    content = component ? `${indentation}${component}` : '';
  }

  return content;
};

const msg = importModules =>
  `import ${'{'} ${importModules} ${'}'} from '@catho/quantum';\n\n`;

const CodeExample = ({ component, state, code, withImport, title }) => {
  const codeStr =
    code || componentToString(component, state || component.props);

  return (
    <>
      {title && <MainTitle as="h2">{title}</MainTitle>}
      <SimpleHighlight>
        {withImport && msg(withImport)}
        {codeStr}
      </SimpleHighlight>
    </>
  );
};

CodeExample.defaultProps = {
  code: '',
  title: '',
  withImport: '',
  state: null,
  component: {}
};

CodeExample.propTypes = {
  component: PropTypes.instanceOf(Object),
  state: PropTypes.instanceOf(Object),
  code: PropTypes.string,
  title: PropTypes.string,
  withImport: PropTypes.string
};

export default CodeExample;