/**
 * @fileoverview Check that common.hasCrypto is used if crypto, tls,
 * https, or http2 modules are required.
 * @author Daniel Bevenius <daniel.bevenius@gmail.com>
 */
'use strict';

const utils = require('./rules-utils.js');

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
const msg = 'Please add a hasCrypto check to allow this test to be skipped ' +
            'when Node is built "--without-ssl".';

const cryptoModules = ['crypto', 'http2'];
const requireModules = cryptoModules.concat(['tls', 'https']);
const bindingModules = cryptoModules.concat(['tls_wrap']);

module.exports = {
  meta: {
    fixable: 'code',
  },
  create(context) {
    const missingCheckNodes = [];
    const requireNodes = [];
    let commonModuleNode = null;
    let hasSkipCall = false;

    function testCryptoUsage(node) {
      if (utils.isRequired(node, requireModules) ||
          utils.isBinding(node, bindingModules)) {
        requireNodes.push(node);
      }

      if (utils.isCommonModule(node)) {
        commonModuleNode = node;
      }
    }

    function testIfStatement(node) {
      if (node.test.argument === undefined) {
        return;
      }
      if (isCryptoCheck(node.test.argument)) {
        checkCryptoCall(node);
      }
    }

    function isCryptoCheck(node) {
      return utils.usesCommonProperty(node, ['hasCrypto', 'hasFipsCrypto']);
    }

    function checkCryptoCall(node) {
      if (utils.inSkipBlock(node)) {
        hasSkipCall = true;
      } else {
        missingCheckNodes.push(node);
      }
    }

    function testMemberExpression(node) {
      if (isCryptoCheck(node)) {
        checkCryptoCall(node);
      }
    }

    function reportIfMissingCheck() {
      if (hasSkipCall) {
        // There is a skip, which is good, but verify that the require() calls
        // in question come after at least one check.
        if (missingCheckNodes.length > 0) {
          requireNodes.forEach((requireNode) => {
            const beforeAllChecks = missingCheckNodes.every((checkNode) => {
              return requireNode.range[0] < checkNode.range[0];
            });

            if (beforeAllChecks) {
              context.report({
                node: requireNode,
                message: msg,
              });
            }
          });
        }
        return;
      }

      if (requireNodes.length > 0) {
        if (missingCheckNodes.length > 0) {
          report(missingCheckNodes);
        } else {
          report(requireNodes);
        }
      }
    }

    function report(nodes) {
      nodes.forEach((node) => {
        context.report({
          node,
          message: msg,
          fix: (fixer) => {
            if (commonModuleNode) {
              return fixer.insertTextAfter(
                commonModuleNode,
                '\nif (!common.hasCrypto) {' +
                ' common.skip("missing crypto");' +
                '}',
              );
            }
          },
        });
      });
    }

    return {
      'CallExpression': (node) => testCryptoUsage(node),
      'IfStatement:exit': (node) => testIfStatement(node),
      'MemberExpression:exit': (node) => testMemberExpression(node),
      'Program:exit': () => reportIfMissingCheck(),
    };
  },
};