import { Response } from 'miragejs';
import Ember from 'ember';
import fetch from 'fetch';

export default function (server) {
  // initial auth response cache -- lookup by mfa_request_id key
  const authResponses = {};
  // mfa requirement cache -- lookup by mfa_request_id key
  const mfaRequirement = {};
  // generate different constraint scenarios and return mfa_requirement object
  const generateMfaRequirement = (req, res) => {
    const { user } = req.params;
    // uses_passcode automatically set to true in factory for totp type
    const m = (type, uses_passcode = false) => server.create('mfa-method', { type, uses_passcode });
    let mfa_constraints = {};
    let methods = []; // flat array of methods for easy lookup during validation

    function generator() {
      const methods = [];
      const constraintObj = [...arguments].reduce((obj, methodArray, index) => {
        obj[`test_${index}`] = { any: methodArray };
        methods.push(...methodArray);
        return obj;
      }, {});
      return [constraintObj, methods];
    }

    if (user === 'mfa-a') {
      [mfa_constraints, methods] = generator([m('totp')]); // 1 constraint 1 passcode
    } else if (user === 'mfa-b') {
      [mfa_constraints, methods] = generator([m('okta')]); // 1 constraint 1 non-passcode
    } else if (user === 'mfa-c') {
      [mfa_constraints, methods] = generator([m('totp'), m('duo', true)]); // 1 constraint 2 passcodes
    } else if (user === 'mfa-d') {
      [mfa_constraints, methods] = generator([m('okta'), m('duo')]); // 1 constraint 2 non-passcode
    } else if (user === 'mfa-e') {
      [mfa_constraints, methods] = generator([m('okta'), m('totp')]); // 1 constraint 1 passcode 1 non-passcode
    } else if (user === 'mfa-f') {
      [mfa_constraints, methods] = generator([m('totp')], [m('duo', true)]); // 2 constraints 1 passcode for each
    } else if (user === 'mfa-g') {
      [mfa_constraints, methods] = generator([m('okta')], [m('duo')]); // 2 constraints 1 non-passcode for each
    } else if (user === 'mfa-h') {
      [mfa_constraints, methods] = generator([m('totp')], [m('okta')]); // 2 constraints 1 passcode 1 non-passcode
    } else if (user === 'mfa-i') {
      [mfa_constraints, methods] = generator([m('okta'), m('totp')], [m('totp')]); // 2 constraints 1 passcode/1 non-passcode 1 non-passcode
    } else if (user === 'mfa-j') {
      [mfa_constraints, methods] = generator([m('pingid')]); // use to test push failures
    }
    const numbers = (length) =>
      Math.random()
        .toString()
        .substring(2, length + 2);
    const mfa_request_id = `${numbers(8)}-${numbers(4)}-${numbers(4)}-${numbers(4)}-${numbers(12)}`;
    const mfa_requirement = {
      mfa_request_id,
      mfa_constraints,
    };
    // cache mfa requests to test different validation scenarios
    mfaRequirement[mfa_request_id] = { methods };
    // cache auth response to be returned later by sys/mfa/validate
    authResponses[mfa_request_id] = { ...res };
    return mfa_requirement;
  };
  // passthrough original request, cache response and return mfa stub
  const passthroughLogin = async (schema, req) => {
    // test totp not configured scenario
    if (req.params.user === 'totp-na') {
      return new Response(400, {}, { errors: ['TOTP mfa required but not configured'] });
    }
    const mock = req.params.user ? req.params.user.includes('mfa') : null;
    // bypass mfa for users that do not match type
    if (!mock) {
      req.passthrough();
    } else if (Ember.testing) {
      // use root token in test environment
      const res = await fetch('/v1/auth/token/lookup-self', { headers: { 'X-Vault-Token': 'root' } });
      if (res.status < 300) {
        const json = res.json();
        if (Ember.testing) {
          json.auth = {
            ...json.data,
            policies: [],
            metadata: { username: 'foobar' },
          };
          json.data = null;
        }
        return { auth: { mfa_requirement: generateMfaRequirement(req, json) } };
      }
      return new Response(500, {}, { errors: ['Mirage error fetching root token in testing'] });
    } else {
      const xhr = req.passthrough();
      xhr.onreadystatechange = () => {
        if (xhr.readyState === 4 && xhr.status < 300) {
          // XMLHttpRequest response prop only has a getter -- redefine as writable and set value
          Object.defineProperty(xhr, 'response', {
            writable: true,
            value: JSON.stringify({
              auth: { mfa_requirement: generateMfaRequirement(req, JSON.parse(xhr.responseText)) },
            }),
          });
        }
      };
    }
  };
  server.post('/auth/:method/login/:user', passthroughLogin);

  server.post('/sys/mfa/validate', (schema, req) => {
    try {
      const { mfa_request_id, mfa_payload } = JSON.parse(req.requestBody);
      const mfaRequest = mfaRequirement[mfa_request_id];

      if (!mfaRequest) {
        return new Response(404, {}, { errors: ['MFA Request ID not found'] });
      }
      // validate request body
      for (let constraintId in mfa_payload) {
        // ensure ids were passed in map
        const method = mfaRequest.methods.find(({ id }) => id === constraintId);
        if (!method) {
          return new Response(
            400,
            {},
            { errors: [`Invalid MFA constraint id ${constraintId} passed in map`] }
          );
        }
        // test non-totp validation by rejecting all pingid requests
        if (method.type === 'pingid') {
          return new Response(403, {}, { errors: ['PingId MFA validation failed'] });
        }
        // validate totp passcode
        const passcode = mfa_payload[constraintId][0];
        if (method.uses_passcode) {
          if (passcode !== 'test') {
            const error =
              passcode === 'used'
                ? 'code already used; new code is available in 30 seconds'
                : 'failed to validate';
            return new Response(403, {}, { errors: [error] });
          }
        } else if (passcode) {
          // for okta and duo, reject if a passcode was provided
          return new Response(400, {}, { errors: ['Passcode should only be provided for TOTP MFA type'] });
        }
      }
      return authResponses[mfa_request_id];
    } catch (error) {
      console.log(error);
      return new Response(500, {}, { errors: ['Mirage Handler Error: /sys/mfa/validate'] });
    }
  });
}