/*
The MIT License (MIT)

Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (sindresorhus.com)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

*/

'use strict';

var os = require('os');
var hasFlag = require('./has-flag.js');

var env = process.env;

var forceColor = void 0;
if (hasFlag('no-color') || hasFlag('no-colors') || hasFlag('color=false')) {
  forceColor = false;
} else if (hasFlag('color') || hasFlag('colors') || hasFlag('color=true')
           || hasFlag('color=always')) {
  forceColor = true;
}
if ('FORCE_COLOR' in env) {
  forceColor = env.FORCE_COLOR.length === 0
    || parseInt(env.FORCE_COLOR, 10) !== 0;
}

function translateLevel(level) {
  if (level === 0) {
    return false;
  }

  return {
    level: level,
    hasBasic: true,
    has256: level >= 2,
    has16m: level >= 3,
  };
}

function supportsColor(stream) {
  if (forceColor === false) {
    return 0;
  }

  if (hasFlag('color=16m') || hasFlag('color=full')
      || hasFlag('color=truecolor')) {
    return 3;
  }

  if (hasFlag('color=256')) {
    return 2;
  }

  if (stream && !stream.isTTY && forceColor !== true) {
    return 0;
  }

  var min = forceColor ? 1 : 0;

  if (process.platform === 'win32') {
    // Node.js 7.5.0 is the first version of Node.js to include a patch to
    // libuv that enables 256 color output on Windows. Anything earlier and it
    // won't work. However, here we target Node.js 8 at minimum as it is an LTS
    // release, and Node.js 7 is not. Windows 10 build 10586 is the first
    // Windows release that supports 256 colors. Windows 10 build 14931 is the
    // first release that supports 16m/TrueColor.
    var osRelease = os.release().split('.');
    if (Number(process.versions.node.split('.')[0]) >= 8
        && Number(osRelease[0]) >= 10 && Number(osRelease[2]) >= 10586) {
      return Number(osRelease[2]) >= 14931 ? 3 : 2;
    }

    return 1;
  }

  if ('CI' in env) {
    if (['TRAVIS', 'CIRCLECI', 'APPVEYOR', 'GITLAB_CI'].some(function(sign) {
      return sign in env;
    }) || env.CI_NAME === 'codeship') {
      return 1;
    }

    return min;
  }

  if ('TEAMCITY_VERSION' in env) {
    return (/^(9\.(0*[1-9]\d*)\.|\d{2,}\.)/.test(env.TEAMCITY_VERSION) ? 1 : 0
    );
  }

  if ('TERM_PROGRAM' in env) {
    var version = parseInt((env.TERM_PROGRAM_VERSION || '').split('.')[0], 10);

    switch (env.TERM_PROGRAM) {
      case 'iTerm.app':
        return version >= 3 ? 3 : 2;
      case 'Hyper':
        return 3;
      case 'Apple_Terminal':
        return 2;
      // No default
    }
  }

  if (/-256(color)?$/i.test(env.TERM)) {
    return 2;
  }

  if (/^screen|^xterm|^vt100|^rxvt|color|ansi|cygwin|linux/i.test(env.TERM)) {
    return 1;
  }

  if ('COLORTERM' in env) {
    return 1;
  }

  if (env.TERM === 'dumb') {
    return min;
  }

  return min;
}

function getSupportLevel(stream) {
  var level = supportsColor(stream);
  return translateLevel(level);
}

module.exports = {
  supportsColor: getSupportLevel,
  stdout: getSupportLevel(process.stdout),
  stderr: getSupportLevel(process.stderr),
};