'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 = require('../middleware/resource-location').resourceLocation().concat('/');


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(jimp.FONT_SANS_16_BLACK);
           })
           .then((font) => {
             loadedImage.print(font, 118, 22, user.username);
           })
           .then(() => {
             return jimp.loadFont(__dirname + '/font/DEJAVU_SANS_13.fnt');
           })
           .then((font) => {
             loadedImage.print(font, 118, 49, user.squadId.name);
             return font;
           })
           .then((font) => {
             let rankH;
             let rankW;
             let rankX;
             let rankY;

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

               if (result) {
                 if (user.squadId.fraction === 'BLUFOR') {
                   rankW = 33;
                   rankH = 80;
                   rankX = 38;
                   rankY = 20;
                 } else {
                   rankW = 38;
                   rankH = 60;
                   rankX = 35;
                   rankY = 36;
                 }

                 jimp.read(resourceDir + 'rank/' + result._id + fileExt)
                     .then((rankImage) => {
                       rankImage.resize(rankW, rankH);
                       loadedImage
                         .print(font, 118, 69, result.name)
                         .composite(rankImage, rankX, rankY);
                     })
                     .then(() => {
                       addDecorationsAndSave(userId, loadedImage, res, next);
                     });
               } else {
                 // user has not any assignable rank in his fraction at this point,
                 // e.g. assigned rank has been deleted or switched fraction so rankLvl is not defined
                 addDecorationsAndSave(userId, loadedImage, res, next);
               }
             });
           })
           .catch((err) => {
             next(err);
           });
};


/**
 * query decorations according to user id and
 * add all graphics into given image
 *
 * @param {number} userId
 * @param {Object} loadedImage - background image
 * @param {function} res
 * @param {function} next
 */
let addDecorationsAndSave = (userId, loadedImage, res, next) => {
  const medalW = 21;
  const medalH = 40;
  const ribbonW = 53;
  const ribbonH = 15;
  let medalPx = 690;
  let medalPy = 9;
  let ribbonPx = 658;
  let ribbonPy = 107;

  AwardingModel.find({
    'userId': userId,
    'confirmed': 1,
  }, ['decorationId', 'date']).populate('decorationId', ['isMedal', 'fraction'])
               .exec((err, awardings) => {
                   if (err) {
                     return next(err);
                   }
                   if (awardings.length > 0) {
                     awardings.sort((a1, a2) => sortAwardingsForSignature(a1, a2));

                     // 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);
                               if (medalPy === 9) {
                                 medalPx = medalPx - 1 - medalW;
                               } else {
                                 medalPx = medalPx + 1 + medalW;
                               }
                               if (medalPx <= 300) {
                                 medalPx = medalPx + 1 + medalW;
                                 medalPy = medalPy + 3 + medalH;
                               }
                             } else {
                               decorationImage.resize(ribbonW, ribbonH);
                               loadedImage.composite(decorationImage, ribbonPx, ribbonPy);
                               ribbonPx = ribbonPx - 2 - ribbonW;
                               if (ribbonPx <= 200) {
                                 ribbonPy = ribbonPy - 3 - ribbonH;
                                 ribbonPx = 657;
                               }
                             }
                             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 {Object} image - Jimp image
 * @param {number} userId - user id of signature owner
 * @param {function} res - express response object
 * @param {function} 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();
    }).catch((error) => {
      console.log(error);
    });
  }, 3000);
};

const sortAwardingsForSignature = (a1, a2) => {
  if (!a1.decorationId.isMedal && !a2.decorationId.isMedal) {
    if (a1.decorationId.fraction === a2.decorationId.fraction) {
      if (a1.date !== a2.date) {
        if (a1.date < a2.date) {
          return -1;
        }
        if (a1.date > a2.date) {
          return 1;
        }
      }
      return 0;
    } else {
      if (a1.decorationId.fraction === 'GLOBAL' && a2.decorationId.fraction !== 'GLOBAL') {
        return -1;
      }
      if (a2.decorationId.fraction === 'GLOBAL' && a1.decorationId.fraction !== 'GLOBAL') {
        return 1;
      }
    }
  }
  if (a1.decorationId.isMedal !== a2.decorationId.isMedal) {
    if (a1.decorationId.isMedal && !a2.decorationId.isMedal) {
      return 1;
    }
    if (!a1.decorationId.isMedal && a2.decorationId.isMedal) {
      return -1;
    }
  }
  if (a1.decorationId.isMedal && a2.decorationId.isMedal) {
    if (a1.date !== a2.date) {
      if (a1.date < a2.date) {
        return -1;
      }
      if (a1.date > a2.date) {
        return 1;
      }
    }
    return 0;
  }
};


module.exports = createSignature;