/**
   * @fileoverview A rule to choose between single and double quote marks
   * @author Matt DuVall <http://www.mattduvall.com/>, Brandon Payton
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Requirements
  //------------------------------------------------------------------------------
  
  const astUtils = require("../ast-utils");
  
  //------------------------------------------------------------------------------
  // Constants
  //------------------------------------------------------------------------------
  
  const QUOTE_SETTINGS = {
      double: {
          quote: "\"",
          alternateQuote: "'",
          description: "doublequote"
      },
      single: {
          quote: "'",
          alternateQuote: "\"",
          description: "singlequote"
      },
      backtick: {
          quote: "`",
          alternateQuote: "\"",
          description: "backtick"
      }
  };
  
  // An unescaped newline is a newline preceded by an even number of backslashes.
  const UNESCAPED_LINEBREAK_PATTERN = new RegExp(String.raw`(^|[^\\])(\\\\)*[${Array.from(astUtils.LINEBREAKS).join("")}]`);
  
  /**
   * Switches quoting of javascript string between ' " and `
   * escaping and unescaping as necessary.
   * Only escaping of the minimal set of characters is changed.
   * Note: escaping of newlines when switching from backtick to other quotes is not handled.
   * @param {string} str - A string to convert.
   * @returns {string} The string with changed quotes.
   * @private
   */
  QUOTE_SETTINGS.double.convert =
  QUOTE_SETTINGS.single.convert =
  QUOTE_SETTINGS.backtick.convert = function(str) {
      const newQuote = this.quote;
      const oldQuote = str[0];
  
      if (newQuote === oldQuote) {
          return str;
      }
      return newQuote + str.slice(1, -1).replace(/\\(\${|\r
  ?|
  |.)|["'`]|\${|(\r
  ?|
  )/g, (match, escaped, newline) => {
          if (escaped === oldQuote || oldQuote === "`" && escaped === "${") {
              return escaped; // unescape
          }
          if (match === newQuote || newQuote === "`" && match === "${") {
              return `\\${match}`; // escape
          }
          if (newline && oldQuote === "`") {
              return "\
  "; // escape newlines
          }
          return match;
      }) + newQuote;
  };
  
  const AVOID_ESCAPE = "avoid-escape";
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = {
      meta: {
          docs: {
              description: "enforce the consistent use of either backticks, double, or single quotes",
              category: "Stylistic Issues",
              recommended: false
          },
  
          fixable: "code",
  
          schema: [
              {
                  enum: ["single", "double", "backtick"]
              },
              {
                  anyOf: [
                      {
                          enum: ["avoid-escape"]
                      },
                      {
                          type: "object",
                          properties: {
                              avoidEscape: {
                                  type: "boolean"
                              },
                              allowTemplateLiterals: {
                                  type: "boolean"
                              }
                          },
                          additionalProperties: false
                      }
                  ]
              }
          ]
      },
  
      create(context) {
  
          const quoteOption = context.options[0],
              settings = QUOTE_SETTINGS[quoteOption || "double"],
              options = context.options[1],
              allowTemplateLiterals = options && options.allowTemplateLiterals === true,
              sourceCode = context.getSourceCode();
          let avoidEscape = options && options.avoidEscape === true;
  
          // deprecated
          if (options === AVOID_ESCAPE) {
              avoidEscape = true;
          }
  
          /**
           * Determines if a given node is part of JSX syntax.
           *
           * This function returns `true` in the following cases:
           *
           * - `<div className="foo"></div>` ... If the literal is an attribute value, the parent of the literal is `JSXAttribute`.
           * - `<div>foo</div>` ... If the literal is a text content, the parent of the literal is `JSXElement`.
           *
           * In particular, this function returns `false` in the following cases:
           *
           * - `<div className={"foo"}></div>`
           * - `<div>{"foo"}</div>`
           *
           * In both cases, inside of the braces is handled as normal JavaScript.
           * The braces are `JSXExpressionContainer` nodes.
           *
           * @param {ASTNode} node The Literal node to check.
           * @returns {boolean} True if the node is a part of JSX, false if not.
           * @private
           */
          function isJSXLiteral(node) {
              return node.parent.type === "JSXAttribute" || node.parent.type === "JSXElement";
          }
  
          /**
           * Checks whether or not a given node is a directive.
           * The directive is a `ExpressionStatement` which has only a string literal.
           * @param {ASTNode} node - A node to check.
           * @returns {boolean} Whether or not the node is a directive.
           * @private
           */
          function isDirective(node) {
              return (
                  node.type === "ExpressionStatement" &&
                  node.expression.type === "Literal" &&
                  typeof node.expression.value === "string"
              );
          }
  
          /**
           * Checks whether or not a given node is a part of directive prologues.
           * See also: http://www.ecma-international.org/ecma-262/6.0/#sec-directive-prologues-and-the-use-strict-directive
           * @param {ASTNode} node - A node to check.
           * @returns {boolean} Whether or not the node is a part of directive prologues.
           * @private
           */
          function isPartOfDirectivePrologue(node) {
              const block = node.parent.parent;
  
              if (block.type !== "Program" && (block.type !== "BlockStatement" || !astUtils.isFunction(block.parent))) {
                  return false;
              }
  
              // Check the node is at a prologue.
              for (let i = 0; i < block.body.length; ++i) {
                  const statement = block.body[i];
  
                  if (statement === node.parent) {
                      return true;
                  }
                  if (!isDirective(statement)) {
                      break;
                  }
              }
  
              return false;
          }
  
          /**
           * Checks whether or not a given node is allowed as non backtick.
           * @param {ASTNode} node - A node to check.
           * @returns {boolean} Whether or not the node is allowed as non backtick.
           * @private
           */
          function isAllowedAsNonBacktick(node) {
              const parent = node.parent;
  
              switch (parent.type) {
  
                  // Directive Prologues.
                  case "ExpressionStatement":
                      return isPartOfDirectivePrologue(node);
  
                  // LiteralPropertyName.
                  case "Property":
                  case "MethodDefinition":
                      return parent.key === node && !parent.computed;
  
                  // ModuleSpecifier.
                  case "ImportDeclaration":
                  case "ExportNamedDeclaration":
                  case "ExportAllDeclaration":
                      return parent.source === node;
  
                  // Others don't allow.
                  default:
                      return false;
              }
          }
  
          return {
  
              Literal(node) {
                  const val = node.value,
                      rawVal = node.raw;
                  let isValid;
  
                  if (settings && typeof val === "string") {
                      isValid = (quoteOption === "backtick" && isAllowedAsNonBacktick(node)) ||
                          isJSXLiteral(node) ||
                          astUtils.isSurroundedBy(rawVal, settings.quote);
  
                      if (!isValid && avoidEscape) {
                          isValid = astUtils.isSurroundedBy(rawVal, settings.alternateQuote) && rawVal.indexOf(settings.quote) >= 0;
                      }
  
                      if (!isValid) {
                          context.report({
                              node,
                              message: "Strings must use {{description}}.",
                              data: {
                                  description: settings.description
                              },
                              fix(fixer) {
                                  return fixer.replaceText(node, settings.convert(node.raw));
                              }
                          });
                      }
                  }
              },
  
              TemplateLiteral(node) {
  
                  // If backticks are expected or it's a tagged template, then this shouldn't throw an errors
                  if (
                      allowTemplateLiterals ||
                      quoteOption === "backtick" ||
                      node.parent.type === "TaggedTemplateExpression" && node === node.parent.quasi
                  ) {
                      return;
                  }
  
                  // A warning should be produced if the template literal only has one TemplateElement, and has no unescaped newlines.
                  const shouldWarn = node.quasis.length === 1 && !UNESCAPED_LINEBREAK_PATTERN.test(node.quasis[0].value.raw);
  
                  if (shouldWarn) {
                      context.report({
                          node,
                          message: "Strings must use {{description}}.",
                          data: {
                              description: settings.description
                          },
                          fix(fixer) {
                              if (isPartOfDirectivePrologue(node)) {
  
                                  /*
                                   * TemplateLiterals in a directive prologue aren't actually directives, but if they're
                                   * in the directive prologue, then fixing them might turn them into directives and change
                                   * the behavior of the code.
                                   */
                                  return null;
                              }
                              return fixer.replaceText(node, settings.convert(sourceCode.getText(node)));
                          }
                      });
                  }
              }
          };
  
      }
  };