'use strict';
var jsTokens = require('js-tokens').default;
var processEnvRe = /\bprocess\.env\.[_$a-zA-Z][$\w]+\b/;
var spaceOrCommentRe = /^(?:\s|\/[/*])/;
function replace(src, envs) {
if (!processEnvRe.test(src)) {
return src;
}
var out = [];
var purge = envs.some(function(env) {
return env._ && env._.indexOf('purge') !== -1;
});
jsTokens.lastIndex = 0
var parts = src.match(jsTokens);
for (var i = 0; i < parts.length; i++) {
if (parts[i ] === 'process' &&
parts[i + 1] === '.' &&
parts[i + 2] === 'env' &&
parts[i + 3] === '.') {
var prevCodeToken = getAdjacentCodeToken(-1, parts, i);
var nextCodeToken = getAdjacentCodeToken(1, parts, i + 4);
var replacement = getReplacementString(envs, parts[i + 4], purge);
if (prevCodeToken !== '.' &&
nextCodeToken !== '.' &&
nextCodeToken !== '=' &&
typeof replacement === 'string') {
out.push(replacement);
i += 4;
continue;
}
}
out.push(parts[i]);
}
return out.join('');
}
function getAdjacentCodeToken(dir, parts, i) {
while (true) {
var part = parts[i += dir];
if (!spaceOrCommentRe.test(part)) {
return part;
}
}
}
function getReplacementString(envs, name, purge) {
for (var j = 0; j < envs.length; j++) {
var env = envs[j];
if (typeof env[name] !== 'undefined') {
return JSON.stringify(env[name]);
}
}
if (purge) {
return 'undefined';
}
}
module.exports = replace;