var gulp = require('gulp');
var sass = require('gulp-sass');
var babel = require('gulp-babel');
var concat = require('gulp-concat');
var rename = require('gulp-rename');
var uglify = require('gulp-uglify');
var rollup = require('rollup-stream');
var sourcemaps = require('gulp-sourcemaps');
var browserSync = require('browser-sync');
var jsonld = require('jsonld');
var source = require('vinyl-source-stream');
var buffer = require('vinyl-buffer');
var exec = require('child_process').exec;


var through = require('through2')
// todo: rollup for d3 & possibly jsonld


const server = browserSync.create();

function reload(done) {
  server.reload();
  done();
}

var paths = {
  "styles": {
    "src": "./src/scss/*.scss",
    "dest": "./assets/css/"
  },
  "scripts": {
    "src": "./src/js/portfolio.js",
    "dest": "./assets/js/",
    "d3src": "./src/js/d3.bundle.js",
    "d3destDir": "./assets/js/"
  },
  "data": {
    "src": "./rubenvandeven.jsonld",
    "dest": "./assets/js/"
  }
};

gulp.task('styles', function(done) {
  // console.log(done);
  return gulp.src(paths.styles.src, { sourcemaps: true })
      .pipe(sass().on('error', sass.logError))
      .pipe(gulp.dest(paths.styles.dest))
      .pipe(server.reload({ stream: true }));
});


gulp.task('scripts', function() {
    return gulp.src(paths.scripts.src)
      .pipe(sourcemaps.init())
      .pipe(babel({
            ignore: [
                './src/js/d3.v5.js',
            ]
          }))
      .pipe(concat('portfolio.js'))
      .pipe(gulp.dest(paths.scripts.dest)) // save .js
      .pipe(uglify())
      .pipe(rename({ extname: '.min.js' }))
      // .pipe(sourcemaps.write('maps'))
      .pipe(sourcemaps.write(''))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .min.js
      // .pipe(server.reload())
});

gulp.task('d3', function() {
    return rollup( 'rollup.config.js' )
      .pipe(source('d3.bundle.js'))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .js
      .pipe(buffer())
      .pipe(uglify())
      .pipe(rename({ extname: '.min.js' }))
      .pipe(sourcemaps.write('maps'))
      .pipe(gulp.dest(paths.scripts.d3destDir)) // save .min.js
});

function createHtaccessFromFlattenedJsonld(flattened) {
  let contentLines = [
    "# Don't edit: generated using gulpfile.js",
    "RewriteEngine On"
  ];

  let typeLines = {}; // prevent duplicates

  for(let el of flattened['@graph']) {
      try{
        let url = new URL(el['@id']);
        if(url.origin != 'https://rubenvandeven.com') {
          console.error("Invalid url in id", el['@id']);
          continue;
        }
        if(url.pathname == '' || url.pathname == '/') continue;
        let pathname = url.pathname.substr(1); // remove preceding slash ("/ruben" -> "ruben")
        contentLines.push(`RewriteRule "^${pathname}$" "index.html"`);
        let type = el['@type'].replace(/.*[#|\/]/, "");
        typeLines[type] = `RewriteRule "^@type/${type}$" "index.html"`;
      } catch(err) {
        // not an url
      }
    }

    require('fs').writeFileSync('.htaccess', contentLines.join("\n")+"\n"+Object.values(typeLines).join("\n") + "\n");
}

function createPagerankFromFlattenedJsonld(done){
  exec('ranking/venv/bin/python ranking/jsonld_ranking.py -i assets/js/rubenvandeven.jsonld -o assets/js/ranking.json', function (err, stdout, stderr) {
    if(stdout)
      console.log(stdout);
    if(stderr)
      console.error(stderr);
    done(err);
  });
}

gulp.task('flattenJsonld', function() {
  return gulp.src(paths.data.src)
    .pipe(through.obj(function (file, enc, callback) {
      let data = JSON.parse(file.contents.toString(enc));
      var transformedFile = file.clone();
      // console.log(data);
      jsonld.flatten(data, {}, (err, flattened)=> {
        if(err) {
          console.error(err);
        }
        transformedFile.contents = Buffer.from(JSON.stringify(flattened), enc);
        createHtaccessFromFlattenedJsonld(flattened);
        callback(null, transformedFile)
      });
    }))
    .pipe(gulp.dest(paths.data.dest))
});

gulp.task('jsonld', gulp.series(
  'flattenJsonld',
  createPagerankFromFlattenedJsonld
));

var watchStylesAndScripts = function() {
  gulp.watch(paths.styles.src, gulp.series('styles'));
  gulp.watch(paths.scripts.src,gulp.series('scripts', reload));
  gulp.watch(paths.scripts.d3src,gulp.series('d3', reload));
  gulp.watch([paths.data.src], gulp.series('jsonld', reload));
}

gulp.task('watch', watchStylesAndScripts);

// watch files for changes and reload
gulp.task('serve', function() {
  server.init({
    server: {
      baseDir: '.'
    }
  });

  gulp.watch(['index.html','rubenvandeven.jsonld'], reload);
  watchStylesAndScripts();
});


gulp.task('default', function() {
   gulp.parallel('styles', 'scripts');
});