// # Local File System Image Storage module
// The (default) module for storing images, using the local file system

var express   = require('express'),
    fs        = require('fs-extra'),
    path      = require('path'),
    util      = require('util'),
    Promise   = require('bluebird'),
    errors    = require('../errors'),
    config    = require('../config'),
    utils     = require('../utils'),
    baseStore = require('./base');

function LocalFileStore() {
}
util.inherits(LocalFileStore, baseStore);

// ### Save
// Saves the image to storage (the file system)
// - image is the express image object
// - returns a promise which ultimately returns the full url to the uploaded image
LocalFileStore.prototype.save = function (image, targetDir) {
    targetDir = targetDir || this.getTargetDir(config.paths.imagesPath);
    var targetFilename;

    return this.getUniqueFileName(this, image, targetDir).then(function (filename) {
        targetFilename = filename;
        return Promise.promisify(fs.mkdirs)(targetDir);
    }).then(function () {
        return Promise.promisify(fs.copy)(image.path, targetFilename);
    }).then(function () {
        // The src for the image must be in URI format, not a file system path, which in Windows uses \
        // For local file system storage can use relative path so add a slash
        var fullUrl = (config.paths.subdir + '/' + config.paths.imagesRelPath + '/' +
            path.relative(config.paths.imagesPath, targetFilename)).replace(new RegExp('\\' + path.sep, 'g'), '/');
        return fullUrl;
    }).catch(function (e) {
        errors.logError(e);
        return Promise.reject(e);
    });
};

LocalFileStore.prototype.exists = function (filename) {
    return new Promise(function (resolve) {
        fs.stat(filename, function (err) {
            var exists = !err;
            resolve(exists);
        });
    });
};

// middleware for serving the files
LocalFileStore.prototype.serve = function () {
    // For some reason send divides the max age number by 1000
    return express['static'](config.paths.imagesPath, {maxAge: utils.ONE_YEAR_MS});
};

module.exports = LocalFileStore;
