"use strict"

// modules used for graphic manipulation
const jimp = require('jimp');
const imagemin = require('imagemin');
const imageminpngquant = require('imagemin-pngquant');
const SHA1 = require('node-sha1');
const async = require('async');

// Mongoose Model using mongoDB
const UserModel = require('../models/user');
const AwardingModel = require('../models/awarding');
const RankModel = require('../models/rank');

// http error code table
const codes = require('../routes/http-codes');

// standard input/output file extension
const fileExt = '.png';
const resourceDir = __dirname + '/../resource/';


let createSignature = (userId, res, next) => {

  let loadedImage;
  let user;

  if (!String(userId).match(/^[0-9a-fA-F]{24}$/)) {
    let error = new Error('no valid ID ' + userId);
    error.status = codes.wrongdatatyperequest;
    return next(error);
  }
  UserModel.findById(userId, ['username', 'rankLvl', 'squadId'])
    .populate('squadId', ['name', 'fraction'])
    .exec()
    .then((resUser) => {
      user = resUser;
      let platePath;
      if (resUser && resUser.squadId && resUser.squadId.fraction === 'BLUFOR') {
        platePath = __dirname + '/backplate/blufor' + fileExt;
      } else if (resUser && resUser.squadId && resUser.squadId.fraction === 'OPFOR') {
        platePath = __dirname + '/backplate/opfor' + fileExt;
      }

      // kill process on undefined platePath
      if (!platePath) {
        throw new Error('Fraction not defined for user with id ' + userId);
      }
      return jimp.read(platePath)
    })
    .then((image) => {
      loadedImage = image;
    }).then(() => {
    return jimp.loadFont(__dirname + '/font/DEVAJU_SANS_19.fnt');
  })
    .then((font) => {
      loadedImage.print(font, 128, 8, user.username)
    })
    .then(() => {
      return jimp.loadFont(__dirname + '/font/DEJAVU_SANS_13.fnt');
    })
    .then((font) => {
      loadedImage.print(font, 128, 35, user.squadId.name);
      return font;
    })
    .then((font) => {
      let rankH, rankW, rankX, rankY;

      RankModel.findOne({'level': user.rankLvl, 'fraction': user.squadId.fraction}, (err, result) => {
        if (err) {
          return next(err)
        }

        if (user.squadId.fraction === 'BLUFOR') {
          rankW = 25;
          rankH = 60;
          rankX = 36;
          rankY = 34;
        } else {
          rankW = 61;
          rankH = 61;
          rankX = 19;
          rankY = 36;
        }

        jimp.read(resourceDir + 'rank/' + result._id + fileExt)
          .then((rankImage) => {
            rankImage.resize(rankW, rankH);
            loadedImage
              .print(font, 128, 55, result.name)
              .composite(rankImage, rankX, rankY)
          })
          .then(() => {
            addDecorationsAndSave(userId, loadedImage, res, next);
          })
      })
    })
    .catch((err) => {
      next(err);
    })
};


/**
 * query decorations according to user id and
 * add all graphics into given image
 *
 * @param userId
 * @param loadedImage - background image
 * @param res
 * @param next
 */
let addDecorationsAndSave = (userId, loadedImage, res, next) => {
  const medalW = 21;
  const medalH = 40;
  const ribbonW = 53;
  const ribbonH = 15;
  let medalPx = 630;
  let medalPy = 5;
  let ribbonPx = 598;
  let ribbonPy = 95;

  AwardingModel.find({'userId': userId}, ['decorationId', 'date'],
    {sort: {date: 'asc'}}).populate('decorationId', ['isMedal'])
    .exec((err, awardings) => {
        if (err) {
          return next(err);
        }
        if (awardings.length > 0) {
          // use synchronized call to keep correct order of decorations
          async.eachSeries(awardings, (award, callback) => {
            jimp.read(resourceDir + 'decoration/' + award.decorationId._id + fileExt).then((decorationImage) => {

              if (award.decorationId.isMedal) {
                decorationImage.resize(medalW, medalH);
                loadedImage.composite(decorationImage, medalPx, medalPy);
                medalPx = medalPx - 1 - medalW;
                if (medalPx <= 300) {
                  medalPy = medalPy + 3 + medalH;
                  medalPx = 621;
                }
              } else {
                decorationImage.resize(ribbonW, ribbonH);
                loadedImage.composite(decorationImage, ribbonPx, ribbonPy);
                ribbonPx = ribbonPx - 2 - ribbonW;
                if (ribbonPx <= 174) {
                  ribbonPy = ribbonPy - 3 - ribbonH;
                  ribbonPx = 598;
                }
              }
              callback();
            })
          }, (err) => {
            if (err) {
              throw err;
            }
            compareImagesAndSave(loadedImage, userId, res, next);
          });
        } else {
          compareImagesAndSave(loadedImage, userId, res, next);
        }
      }
    )
};

let compareImagesAndSave = (generatedImage, userId, res, next) => {

  return jimp.read(resourceDir + 'signature/big/' + userId + fileExt)
    .then((oldImage) => {
      // compare hashes of image map to recognize difference
      const sig1 = SHA1(generatedImage.bitmap.data);
      const sig2 = SHA1(oldImage.bitmap.data);
      if (sig1 !== sig2) {
        saveJimpImageAndCompress(generatedImage, userId, res, next)
      } else {
        res.locals.items = {status: 'nothing to do'};
        next();
      }
    })
    .catch((err) => {
      saveJimpImageAndCompress(generatedImage, userId, res, next);
    })

};

/**
 *
 * Write Jimp image to file system
 * Gets minified after 3 seconds timeout
 *
 * @param image - Jimp image
 * @param userId - user id of signature owner
 * @param res - express response object
 * @param next - express next-function
 */
let saveJimpImageAndCompress = (image, userId, res, next) => {
  image.write(resourceDir + 'signature/big/' + userId + fileExt);
  setTimeout(() => {
    imagemin([resourceDir + 'signature/big/' + userId + fileExt], resourceDir + 'signature/', {
      plugins: [
        imageminpngquant({quality: '65-80'})
      ]
    }).then((files) => {
      res.locals.items = {status: 'success'};
      return next();
    })
  }, 3000);
};


module.exports = createSignature;