"use strict";

const fs = require("fs");
const path = require("path");

const flatten = require("lodash/flatten");
const flattenDeep = require("lodash/flattenDeep");
const mapValues = require("lodash/mapValues");
const pluginFeatures = require("../data/plugin-features");
const builtInFeatures = require("../data/built-in-features");

const renameTests = (tests, getName) =>
  tests.map((test) => Object.assign({}, test, { name: getName(test.name) }));

const es6Data = require("compat-table/data-es6");
const es6PlusData = require("compat-table/data-es2016plus");
const envs = require("compat-table/environments");

const environments = [
  "chrome",
  "opera",
  "edge",
  "firefox",
  "safari",
  "node",
  "ie",
  "android",
  "ios",
  "phantom"
];

const envMap = {
  safari51: "safari5",
  safari71_8: "safari8",
  safari10_1: "safari10.1",
  firefox3_5: "firefox3",
  firefox3_6: "firefox3",
  node010: "node0.10",
  node012: "node0.12",
  iojs: "node3.3",
  node64: "node6",
  node65: "node6.5",
  node76: "node7.6",
  android40: "android4.0",
  android41: "android4.1",
  android42: "android4.2",
  android43: "android4.3",
  android44: "android4.4",
  android50: "android5.0",
  android51: "android5.1",
  ios51: "ios5.1",
};

const invertedEqualsEnv = Object.keys(envs)
  .filter((b) => envs[b].equals)
  .reduce((a, b) => {
    const checkEnv = envMap[envs[b].equals] || envs[b].equals;
    environments.some((env) => {
      // go through all environment names to find the the current one
      // and try to get the version as integer
      const version = parseInt(checkEnv.replace(env, ""), 10);
      if (!isNaN(version)) {
        Object.keys(envs).forEach((equals) => {
          // Go through all envs from compat-table and get int version
          const equalsVersion = parseInt(equals.replace(env, ""), 10);
          // If the current version is smaller than the version that was mentioned
          // in `equals` we can add an entry, as older versions should include features
          // that newer ones have
          if (!isNaN(equalsVersion) && equalsVersion <= version) {
            if (!a[equals]) a[equals] = [];
            a[equals].push(b);
          }
        });
        return true;
      }
    });

    return a;
  }, {});

invertedEqualsEnv.safari8 = ["ios9"];

const compatibilityTests = flattenDeep([
  es6Data,
  es6PlusData,
].map((data) =>
  data.tests.map((test) => {
    return test.subtests ?
      [test, renameTests(test.subtests, (name) => test.name + " / " + name)] :
      test;
  })
));

const getLowestImplementedVersion = ({ features }, env) => {
  const tests = flatten(compatibilityTests
    .filter((test) => {
      return features.indexOf(test.name) >= 0 ||
      // for features === ["DataView"]
      // it covers "DataView (Int8)" and "DataView (UInt8)"
      features.length === 1 && test.name.indexOf(features[0]) === 0;
    })
    .map((test) => {
      const isBuiltIn = test.category === "built-ins" || test.category === "built-in extensions";

      return test.subtests ?
        test.subtests.map((subtest) => ({
          name: `${test.name}/${subtest.name}`,
          res: subtest.res,
          isBuiltIn
        })) :
      {
        name: test.name,
        res: test.res,
        isBuiltIn
      };
    })
  );

  const envTests = tests
    .map(({ res: test, name, isBuiltIn }, i) => {
      // Babel itself doesn't implement the feature correctly,
      // don't count against it
      // only doing this for built-ins atm
      if (!test.babel && isBuiltIn) {
        return "-1";
      }

      // `equals` in compat-table
      Object.keys(test).forEach((t) => {
        const invertedEnvs = invertedEqualsEnv[envMap[t] || t];
        if (invertedEnvs) {
          invertedEnvs.forEach((inv) => {
            test[inv] = test[t];
          });
        }
      });

      return Object.keys(test)
      .filter((t) => t.startsWith(env))
      // Babel assumes strict mode
      .filter((test) => tests[i].res[test] === true || tests[i].res[test] === "strict")
      // normalize some keys
      .map((test) => envMap[test] || test)
      .filter((test) => !isNaN(parseInt(test.replace(env, ""))))
      .shift();
    });

  const envFiltered = envTests.filter((t) => t);
  if (envTests.length > envFiltered.length || envTests.length === 0) {
    // envTests.forEach((test, i) => {
    //   if (!test) {
    //     // print unsupported features
    //     if (env === 'node') {
    //       console.log(`ENV(${env}): ${tests[i].name}`);
    //     }
    //   }
    // });
    return null;
  }

  return envTests
    .map((str) => Number(str.replace(env, "")))
    .reduce((a, b) => { return (a < b) ? b : a; });
};

const generateData = (environments, features) => {
  return mapValues(features, (options) => {
    if (!options.features) {
      options = {
        features: [options]
      };
    }

    const plugin = {};
    environments.forEach((env) => {
      const version = getLowestImplementedVersion(options, env);
      if (version !== null) {
        plugin[env] = version;
      }
    });

    // add opera
    if (plugin.chrome) {
      if (plugin.chrome >= 28) {
        plugin.opera = plugin.chrome - 13;
      } else if (plugin.chrome === 5) {
        plugin.opera = 12;
      }
    }

    return plugin;
  });
};

fs.writeFileSync(
  path.join(__dirname, "../data/plugins.json"),
  JSON.stringify(generateData(environments, pluginFeatures), null, 2) + "\n"
);

fs.writeFileSync(
  path.join(__dirname, "../data/built-ins.json"),
  JSON.stringify(generateData(environments, builtInFeatures), null, 2) + "\n"
);