/*
 * Copyright 2014 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

"use strict";

var fs = require("fs");
var path = require("path");
var spawn = require("child_process").spawn;

var ttxResourcesHome = path.join(__dirname, "..", "ttx");

var nextTTXTaskId = Date.now();

function runTtx(ttxResourcesHome, fontPath, registerOnCancel, callback) {
  fs.realpath(ttxResourcesHome, function(err, ttxResourcesHome) {
    var fontToolsHome = path.join(ttxResourcesHome, "fonttools-code");
    fs.realpath(fontPath, function(err, fontPath) {
      var ttxPath = path.join("Tools", "ttx");
      if (!fs.existsSync(path.join(fontToolsHome, ttxPath))) {
        callback("TTX was not found, please checkout PDF.js submodules");
        return;
      }
      var ttxEnv = {
        PYTHONPATH: path.join(fontToolsHome, "Lib"),
        PYTHONDONTWRITEBYTECODE: true,
      };
      var ttxStdioMode = "ignore";
      var ttx = spawn("python", [ttxPath, fontPath], {
        cwd: fontToolsHome,
        stdio: ttxStdioMode,
        env: ttxEnv,
      });
      var ttxRunError;
      registerOnCancel(function(reason) {
        ttxRunError = reason;
        callback(reason);
        ttx.kill();
      });
      ttx.on("error", function(err) {
        ttxRunError = err;
        callback("Unable to execute ttx");
      });
      ttx.on("close", function(code) {
        if (ttxRunError) {
          return;
        }
        callback();
      });
    });
  });
}

exports.translateFont = function translateFont(
  content,
  registerOnCancel,
  callback
) {
  var buffer = Buffer.from(content, "base64");
  var taskId = (nextTTXTaskId++).toString();
  var fontPath = path.join(ttxResourcesHome, taskId + ".otf");
  var resultPath = path.join(ttxResourcesHome, taskId + ".ttx");

  fs.writeFileSync(fontPath, buffer);
  runTtx(ttxResourcesHome, fontPath, registerOnCancel, function(err) {
    fs.unlinkSync(fontPath);
    if (err) {
      console.error(err);
      callback(err);
    } else if (!fs.existsSync(resultPath)) {
      callback("Output was not generated");
    } else {
      callback(null, fs.readFileSync(resultPath));
      fs.unlinkSync(resultPath);
    }
  });
};