"use strict";

const _ = require("lodash");
const isStandardSyntaxRule = require("../../utils/isStandardSyntaxRule");
const parseSelector = require("../../utils/parseSelector");
const report = require("../../utils/report");
const ruleMessages = require("../../utils/ruleMessages");
const styleSearch = require("style-search");
const validateOptions = require("../../utils/validateOptions");

const ruleName = "selector-attribute-brackets-space-inside";

const messages = ruleMessages(ruleName, {
  expectedOpening: 'Expected single space after "["',
  rejectedOpening: 'Unexpected whitespace after "["',
  expectedClosing: 'Expected single space before "]"',
  rejectedClosing: 'Unexpected whitespace before "]"'
});

const rule = function(expectation, options, context) {
  return (root, result) => {
    const validOptions = validateOptions(result, ruleName, {
      actual: expectation,
      possible: ["always", "never"]
    });

    if (!validOptions) {
      return;
    }

    root.walkRules(rule => {
      if (!isStandardSyntaxRule(rule)) {
        return;
      }

      if (rule.selector.indexOf("[") === -1) {
        return;
      }

      const selector = rule.raws.selector
        ? rule.raws.selector.raw
        : rule.selector;

      let hasFixed;
      const fixedSelector = parseSelector(
        selector,
        result,
        rule,
        selectorTree => {
          selectorTree.walkAttributes(attributeNode => {
            const attributeSelectorString = attributeNode.toString();

            styleSearch(
              { source: attributeSelectorString, target: "[" },
              match => {
                const nextCharIsSpace =
                  attributeSelectorString[match.startIndex + 1] === " ";
                const index = attributeNode.sourceIndex + match.startIndex + 1;

                if (nextCharIsSpace && expectation === "never") {
                  if (context.fix) {
                    hasFixed = true;
                    fixBefore(attributeNode);

                    return;
                  }

                  complain(messages.rejectedOpening, index);
                }

                if (!nextCharIsSpace && expectation === "always") {
                  if (context.fix) {
                    hasFixed = true;
                    fixBefore(attributeNode);

                    return;
                  }

                  complain(messages.expectedOpening, index);
                }
              }
            );

            styleSearch(
              { source: attributeSelectorString, target: "]" },
              match => {
                const prevCharIsSpace =
                  attributeSelectorString[match.startIndex - 1] === " ";
                const index = attributeNode.sourceIndex + match.startIndex - 1;

                if (prevCharIsSpace && expectation === "never") {
                  if (context.fix) {
                    hasFixed = true;
                    fixAfter(attributeNode);

                    return;
                  }

                  complain(messages.rejectedClosing, index);
                }

                if (!prevCharIsSpace && expectation === "always") {
                  if (context.fix) {
                    hasFixed = true;
                    fixAfter(attributeNode);

                    return;
                  }

                  complain(messages.expectedClosing, index);
                }
              }
            );
          });
        }
      );

      if (hasFixed) {
        if (!rule.raws.selector) {
          rule.selector = fixedSelector;
        } else {
          rule.raws.selector.raw = fixedSelector;
        }
      }

      function complain(message, index) {
        report({
          message,
          index,
          result,
          ruleName,
          node: rule
        });
      }
    });
  };

  function fixBefore(attributeNode) {
    const rawAttrBefore = _.get(attributeNode, "raws.spaces.attribute.before");
    const { attrBefore, setAttrBefore } = rawAttrBefore
      ? {
          attrBefore: rawAttrBefore,
          setAttrBefore(fixed) {
            attributeNode.raws.spaces.attribute.before = fixed;
          }
        }
      : {
          attrBefore: _.get(attributeNode, "spaces.attribute.before", ""),
          setAttrBefore(fixed) {
            _.set(attributeNode, "spaces.attribute.before", fixed);
          }
        };

    if (expectation === "always") {
      setAttrBefore(attrBefore.replace(/^\s*/, " "));
    } else if (expectation === "never") {
      setAttrBefore(attrBefore.replace(/^\s*/, ""));
    }
  }

  function fixAfter(attributeNode) {
    let key;

    if (attributeNode.operator) {
      if (attributeNode.insensitive) {
        key = "insensitive";
      } else {
        key = "value";
      }
    } else {
      key = "attribute";
    }

    const rawAfter = _.get(attributeNode, `raws.spaces.${key}.after`);
    const { after, setAfter } = rawAfter
      ? {
          after: rawAfter,
          setAfter(fixed) {
            attributeNode.raws.spaces[key].after = fixed;
          }
        }
      : {
          after: _.get(attributeNode, `spaces.${key}.after`, ""),
          setAfter(fixed) {
            _.set(attributeNode, `spaces.${key}.after`, fixed);
          }
        };

    if (expectation === "always") {
      setAfter(after.replace(/\s*$/, " "));
    } else if (expectation === "never") {
      setAfter(after.replace(/\s*$/, ""));
    }
  }
};

rule.ruleName = ruleName;
rule.messages = messages;
module.exports = rule;