/**
 * @fileoverview Disallows multiple blank lines.
 * implementation adapted from the no-trailing-spaces rule.
 * @author Greg Cochard
 * @deprecated in ESLint v8.53.0
 */
'use strict';

//------------------------------------------------------------------------------
// 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: 'no-multiple-empty-lines',
            url: 'https://eslint.style/rules/js/no-multiple-empty-lines',
          },
        },
      ],
    },
    type: 'layout',

    docs: {
      description: 'Disallow multiple empty lines',
      recommended: false,
      url: 'https://eslint.org/docs/latest/rules/no-multiple-empty-lines',
    },

    fixable: 'whitespace',

    schema: [
      {
        type: 'object',
        properties: {
          max: {
            type: 'integer',
            minimum: 0,
          },
          maxEOF: {
            type: 'integer',
            minimum: 0,
          },
          maxBOF: {
            type: 'integer',
            minimum: 0,
          },
        },
        required: ['max'],
        additionalProperties: false,
      },
    ],

    messages: {
      blankBeginningOfFile:
        'Too many blank lines at the beginning of file. Max of {{max}} allowed.',
      blankEndOfFile:
        'Too many blank lines at the end of file. Max of {{max}} allowed.',
      consecutiveBlank:
        'More than {{max}} blank {{pluralizedLines}} not allowed.',
    },
  },

  create(context) {
    // Use options.max or 2 as default
    let max = 2,
      maxEOF = max,
      maxBOF = max;

    if (context.options.length) {
      max = context.options[0].max;
      maxEOF =
        typeof context.options[0].maxEOF !== 'undefined' ?
          context.options[0].maxEOF
        : max;
      maxBOF =
        typeof context.options[0].maxBOF !== 'undefined' ?
          context.options[0].maxBOF
        : max;
    }

    const sourceCode = context.sourceCode;

    // Swallow the final newline, as some editors add it automatically and we don't want it to cause an issue
    const allLines =
      sourceCode.lines.at(-1) === '' ?
        sourceCode.lines.slice(0, -1)
      : sourceCode.lines;
    const templateLiteralLines = new Set();

    //--------------------------------------------------------------------------
    // Public
    //--------------------------------------------------------------------------

    return {
      TemplateLiteral(node) {
        node.quasis.forEach((literalPart) => {
          // Empty lines have a semantic meaning if they're inside template literals. Don't count these as empty lines.
          for (
            let ignoredLine = literalPart.loc.start.line;
            ignoredLine < literalPart.loc.end.line;
            ignoredLine++
          ) {
            templateLiteralLines.add(ignoredLine);
          }
        });
      },
      'Program:exit'(node) {
        return (
          allLines

            // Given a list of lines, first get a list of line numbers that are non-empty.
            .reduce((nonEmptyLineNumbers, line, index) => {
              if (line.trim() || templateLiteralLines.has(index + 1)) {
                nonEmptyLineNumbers.push(index + 1);
              }
              return nonEmptyLineNumbers;
            }, [])

            // Add a value at the end to allow trailing empty lines to be checked.
            .concat(allLines.length + 1)

            // Given two line numbers of non-empty lines, report the lines between if the difference is too large.
            .reduce((lastLineNumber, lineNumber) => {
              let messageId, maxAllowed;

              if (lastLineNumber === 0) {
                messageId = 'blankBeginningOfFile';
                maxAllowed = maxBOF;
              } else if (lineNumber === allLines.length + 1) {
                messageId = 'blankEndOfFile';
                maxAllowed = maxEOF;
              } else {
                messageId = 'consecutiveBlank';
                maxAllowed = max;
              }

              if (lineNumber - lastLineNumber - 1 > maxAllowed) {
                context.report({
                  node,
                  loc: {
                    start: {
                      line: lastLineNumber + maxAllowed + 1,
                      column: 0,
                    },
                    end: { line: lineNumber, column: 0 },
                  },
                  messageId,
                  data: {
                    max: maxAllowed,
                    pluralizedLines: maxAllowed === 1 ? 'line' : 'lines',
                  },
                  fix(fixer) {
                    const rangeStart = sourceCode.getIndexFromLoc({
                      line: lastLineNumber + 1,
                      column: 0,
                    });

                    /*
                     * The end of the removal range is usually the start index of the next line.
                     * However, at the end of the file there is no next line, so the end of the
                     * range is just the length of the text.
                     */
                    const lineNumberAfterRemovedLines = lineNumber - maxAllowed;
                    const rangeEnd =
                      lineNumberAfterRemovedLines <= allLines.length ?
                        sourceCode.getIndexFromLoc({
                          line: lineNumberAfterRemovedLines,
                          column: 0,
                        })
                      : sourceCode.text.length;

                    return fixer.removeRange([rangeStart, rangeEnd]);
                  },
                });
              }

              return lineNumber;
            }, 0)
        );
      },
    };
  },
};