'use strict';

const fs = require('graceful-fs');
const path = require('path');
const copy = require('../copy').copy;
const remove = require('../remove').remove;
const mkdirp = require('../mkdirs').mkdirp;
const pathExists = require('../path-exists').pathExists;
const stat = require('../util/stat');

function move(src, dest, opts, cb) {
  if (typeof opts === 'function') {
    cb = opts;
    opts = {};
  }

  const overwrite = opts.overwrite || opts.clobber || false;

  stat.checkPaths(src, dest, 'move', (err, stats) => {
    if (err) return cb(err);
    const { srcStat } = stats;
    stat.checkParentPaths(src, srcStat, dest, 'move', (err) => {
      if (err) return cb(err);
      mkdirp(path.dirname(dest), (err) => {
        if (err) return cb(err);
        return doRename(src, dest, overwrite, cb);
      });
    });
  });
}

function doRename(src, dest, overwrite, cb) {
  if (overwrite) {
    return remove(dest, (err) => {
      if (err) return cb(err);
      return rename(src, dest, overwrite, cb);
    });
  }
  pathExists(dest, (err, destExists) => {
    if (err) return cb(err);
    if (destExists) return cb(new Error('dest already exists.'));
    return rename(src, dest, overwrite, cb);
  });
}

function rename(src, dest, overwrite, cb) {
  fs.rename(src, dest, (err) => {
    if (!err) return cb();
    if (err.code !== 'EXDEV') return cb(err);
    return moveAcrossDevice(src, dest, overwrite, cb);
  });
}

function moveAcrossDevice(src, dest, overwrite, cb) {
  const opts = {
    overwrite,
    errorOnExist: true,
  };
  copy(src, dest, opts, (err) => {
    if (err) return cb(err);
    return remove(src, cb);
  });
}

module.exports = move;