/*
Copyright (c) 2012, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://yuilibrary.com/license/
*/

import fs from "fs";

const exists = fs.exists;

var walkFile = function (str, cb) {
  var data = [],
    item;

  ["end_of_record"].concat(str.split("\n")).forEach(function (line) {
    line = line.trim();
    var allparts = line.split(":"),
      parts = [allparts.shift(), allparts.join(":")],
      lines,
      fn;

    switch (parts[0].toUpperCase()) {
      case "TN":
        item.title = parts[1].trim();
        break;
      case "SF":
        item.file = parts.slice(1).join(":").trim();
        break;
      case "FNF":
        item.functions.found = Number(parts[1].trim());
        break;
      case "FNH":
        item.functions.hit = Number(parts[1].trim());
        break;
      case "LF":
        item.lines.found = Number(parts[1].trim());
        break;
      case "LH":
        item.lines.hit = Number(parts[1].trim());
        break;
      case "DA":
        lines = parts[1].split(",");
        item.lines.details.push({
          line: Number(lines[0]),
          hit: Number(lines[1]),
        });
        break;
      case "FN":
        fn = parts[1].split(",");
        item.functions.details.push({
          name: fn[1],
          line: Number(fn[0]),
        });
        break;
      case "FNDA":
        fn = parts[1].split(",");
        item.functions.details.some(function (i, k) {
          if (i.name === fn[1] && i.hit === undefined) {
            item.functions.details[k].hit = Number(fn[0]);
            return true;
          }
        });
        break;
      case "BRDA":
        fn = parts[1].split(",");
        item.branches.details.push({
          line: Number(fn[0]),
          block: Number(fn[1]),
          branch: Number(fn[2]),
          taken: fn[3] === "-" ? 0 : Number(fn[3]),
        });
        break;
      case "BRF":
        item.branches.found = Number(parts[1]);
        break;
      case "BRH":
        item.branches.hit = Number(parts[1]);
        break;
    }

    if (line.indexOf("end_of_record") > -1) {
      data.push(item);
      item = {
        lines: {
          found: 0,
          hit: 0,
          details: [],
        },
        functions: {
          hit: 0,
          found: 0,
          details: [],
        },
        branches: {
          hit: 0,
          found: 0,
          details: [],
        },
      };
    }
  });

  data.shift();

  if (data.length) {
    cb(null, data);
  } else {
    cb("Failed to parse string");
  }
};

const parseInternal = function (file, cb) {
  exists(file, function (x) {
    if (!x) {
      return walkFile(file, cb);
    }
    fs.readFile(file, "utf8", function (err, str) {
      walkFile(str, cb);
    });
  });
};

export const parse = (file) =>
  new Promise((resolve, reject) => {
    parseInternal(file, (error, coverage) => {
      error ? reject(error) : resolve(coverage);
    });
  });

export default parse;