"use strict";

const Promise = require("bluebird"),
  fs = require("fs"),
  config = require("config");

let scanning = 0;

let photoDB = null;

const picturesPath = config.get("picturesPath");

function scanFile(path, file, stats) {
  return new Promise(function(resolve, reject) {
    console.log("Scanning file: " + path + "/" + file);
    return resolve(true);
  });
}

function scanDir(path) {
  return new Promise(function(resolve, reject) {
    console.log("Scanning path " + path);

    fs.readdir(path, function(err, files) {
      if (err) {
        console.warn(" Could not readdir " + path);
        return resolve(null);
      }

      scanning++;

      return Promise.map(files, function(file) {
        let filepath = path + "/" + file;

        return new Promise(function(resolve, reject) {
          fs.stat(filepath, function(err, stats) {
            if (err) {
              console.warn("Could not stat " + filepath);
              return resolve(false);
            }

            if (stats.isDirectory()) {
              return scanDir(filepath, stats).then(function(entry) {
                return resolve(true);
              });
            }

            /* stats.isFile()  */
            return scanFile(path, file, stats).then(function(entry) {
              if (!entry) {
                return resolve(false);
              }

              const replacements = {
                path: path.slice(picturesPath.length),
                filename: file,
                added: new Date()
              };

              return photoDB.sequelize.query("SELECT id FROM photos WHERE path=:path AND filename=:filename", {
                replacements: replacements,
                type: photoDB.sequelize.QueryTypes.SELECT
              }).then(function(photo) {
                if (photo.length == 0) {
                  return photoDB.sequelize.query("INSERT INTO photos " +
                   "SET path=:path,filename=:filename,added=DATE(:added)", {
                    replacements: replacements
                  });
                }
              }).then(function() {
                return resolve(true);
              });
            });
          });
        });
      }, {
        concurrency: 10
      }).then(function() {
        scanning--;
        if (scanning == 0) {
          const endStamp = Date.now();
          console.log("Scanning completed in " + Math.round(((endStamp - startStamp))) + "ms.");
        }
      }).then(function() {
        return resolve();
      });
    });
  });
}

const startStamp = Date.now();

module.exports = {
  scan: function (db) {
    photoDB = db;
    return scanDir(picturesPath);
  }
};