/**
 * @fileoverview Rule to validate spacing before function paren.
 * @author Mathias Schreck <https://github.com/lo1tuma>
 * @deprecated in ESLint v8.53.0
 */
'use strict';

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const astUtils = require('./utils/ast-utils');

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

/** @type {import('../types').Rule.RuleModule} */
module.exports = {
  meta: {
    deprecated: {
      message: 'Formatting rules are being moved out of ESLint core.',
      url: 'https://eslint.org/blog/2023/10/deprecating-formatting-rules/',
      deprecatedSince: '8.53.0',
      availableUntil: '10.0.0',
      replacedBy: [
        {
          message:
            'ESLint Stylistic now maintains deprecated stylistic core rules.',
          url: 'https://eslint.style/guide/migration',
          plugin: {
            name: '@stylistic/eslint-plugin-js',
            url: 'https://eslint.style/packages/js',
          },
          rule: {
            name: 'space-before-function-paren',
            url: 'https://eslint.style/rules/js/space-before-function-paren',
          },
        },
      ],
    },
    type: 'layout',

    docs: {
      description:
        'Enforce consistent spacing before `function` definition opening parenthesis',
      recommended: false,
      url: 'https://eslint.org/docs/latest/rules/space-before-function-paren',
    },

    fixable: 'whitespace',

    schema: [
      {
        oneOf: [
          {
            enum: ['always', 'never'],
          },
          {
            type: 'object',
            properties: {
              anonymous: {
                enum: ['always', 'never', 'ignore'],
              },
              named: {
                enum: ['always', 'never', 'ignore'],
              },
              asyncArrow: {
                enum: ['always', 'never', 'ignore'],
              },
            },
            additionalProperties: false,
          },
        ],
      },
    ],

    messages: {
      unexpectedSpace: 'Unexpected space before function parentheses.',
      missingSpace: 'Missing space before function parentheses.',
    },
  },

  create(context) {
    const sourceCode = context.sourceCode;
    const baseConfig =
      typeof context.options[0] === 'string' ? context.options[0] : 'always';
    const overrideConfig =
      typeof context.options[0] === 'object' ? context.options[0] : {};

    /**
     * Determines whether a function has a name.
     * @param {ASTNode} node The function node.
     * @returns {boolean} Whether the function has a name.
     */
    function isNamedFunction(node) {
      if (node.id) {
        return true;
      }

      const parent = node.parent;

      return (
        parent.type === 'MethodDefinition' ||
        (parent.type === 'Property' &&
          (parent.kind === 'get' || parent.kind === 'set' || parent.method))
      );
    }

    /**
     * Gets the config for a given function
     * @param {ASTNode} node The function node
     * @returns {string} "always", "never", or "ignore"
     */
    function getConfigForFunction(node) {
      if (node.type === 'ArrowFunctionExpression') {
        // Always ignore non-async functions and arrow functions without parens, e.g. async foo => bar
        if (
          node.async &&
          astUtils.isOpeningParenToken(
            sourceCode.getFirstToken(node, { skip: 1 })
          )
        ) {
          return overrideConfig.asyncArrow || baseConfig;
        }
      } else if (isNamedFunction(node)) {
        return overrideConfig.named || baseConfig;

        // `generator-star-spacing` should warn anonymous generators. E.g. `function* () {}`
      } else if (!node.generator) {
        return overrideConfig.anonymous || baseConfig;
      }

      return 'ignore';
    }

    /**
     * Checks the parens of a function node
     * @param {ASTNode} node A function node
     * @returns {void}
     */
    function checkFunction(node) {
      const functionConfig = getConfigForFunction(node);

      if (functionConfig === 'ignore') {
        return;
      }

      const rightToken = sourceCode.getFirstToken(
        node,
        astUtils.isOpeningParenToken
      );
      const leftToken = sourceCode.getTokenBefore(rightToken);
      const hasSpacing = sourceCode.isSpaceBetweenTokens(leftToken, rightToken);

      if (hasSpacing && functionConfig === 'never') {
        context.report({
          node,
          loc: {
            start: leftToken.loc.end,
            end: rightToken.loc.start,
          },
          messageId: 'unexpectedSpace',
          fix(fixer) {
            const comments = sourceCode.getCommentsBefore(rightToken);

            // Don't fix anything if there's a single line comment between the left and the right token
            if (comments.some((comment) => comment.type === 'Line')) {
              return null;
            }
            return fixer.replaceTextRange(
              [leftToken.range[1], rightToken.range[0]],
              comments.reduce(
                (text, comment) => text + sourceCode.getText(comment),
                ''
              )
            );
          },
        });
      } else if (!hasSpacing && functionConfig === 'always') {
        context.report({
          node,
          loc: rightToken.loc,
          messageId: 'missingSpace',
          fix: (fixer) => fixer.insertTextAfter(leftToken, ' '),
        });
      }
    }

    return {
      ArrowFunctionExpression: checkFunction,
      FunctionDeclaration: checkFunction,
      FunctionExpression: checkFunction,
    };
  },
};