<template>
  <div
    :class="[
      'box ui-element rounded bg-white text-nowrap',
      { expanded: showPdfTool }
    ]"
  >
    <div style="width: 20rem">
      <h6 class="mb-0 py-2 px-3 border-bottom d-flex align-items-center">
        <font-awesome-icon icon="file-pdf" class="mr-2"></font-awesome-icon>
        <translate>Generate PDF</translate>
        <font-awesome-icon
          icon="times"
          class="ml-auto text-muted"
          @click="$store.commit('application/showPdfTool', false)"
        ></font-awesome-icon>
      </h6>
      <div class="p-3">
        <b><translate>Choose format:</translate></b>
        <select v-model="form.format" class="form-control d-block w-100">
          <option value="landscape"><translate>landscape</translate></option>
          <option value="portrait"><translate>portrait</translate></option>
        </select>
        <select v-model="form.resolution" class="form-control d-block w-100">
          <option value="80">80 dpi</option>
          <option value="120">120 dpi</option>
          <option value="200">200 dpi</option>
        </select>
        <select v-model="form.paperSize" class="form-control d-block w-100">
          <option value="a3"><translate>ISO A3</translate></option>
          <option value="a4"><translate>ISO A4</translate></option>
        </select>
        <small class="d-block my-2">
          <input
            type="radio"
            id="pdfexport-downloadtype-download"
            value="download"
            v-model="form.downloadType"
            selected
          />
          <label for="pdfexport-downloadtype-download" class="ml-1 mr-2">
            <translate>Download</translate>
          </label>
          <input
            type="radio"
            id="pdfexport-downloadtype-open"
            value="open"
            v-model="form.downloadType"
          />
          <label for="pdfexport-downloadtype-open" class="ml-1">
            <translate>Open in new window</translate>
          </label>
        </small>
        <button
          @click="download"
          type="button"
          class="btn btn-sm btn-info d-block w-100"
        >
          <translate>Generate PDF</translate>
        </button>
      </div>
    </div>
  </div>
</template>

<script>
/* This is Free Software under GNU Affero General Public License v >= 3.0
 * without warranty, see README.md and license for details.
 *
 * SPDX-License-Identifier: AGPL-3.0-or-later
 * License-Filename: LICENSES/AGPL-3.0.txt
 *
 * Copyright (C) 2018, 2019 by via donau
 *   – Österreichische Wasserstraßen-Gesellschaft mbH
 * Software engineering by Intevation GmbH
 *
 * Author(s):
 * * Markus Kottländer <markus.kottlaender@intevation.de>
 * * Bernhard E. Reiter <bernhard@intevation.de>
 * * Fadi Abbud <fadi.abbud@intevation.de>
 */
import { mapState } from "vuex";
import jsPDF from "jspdf";
import { getPointResolution } from "ol/proj.js";

var paperSizes = {
  // in millimeter, landscape [width, height]
  a3: [420, 297],
  a4: [297, 210]
};

export default {
  name: "pdftool",
  data() {
    return {
      form: {
        format: "landscape",
        paperSize: "a4",
        downloadType: "download",
        resolution: "120"
      }
    };
  },
  computed: {
    ...mapState("map", ["openLayersMap"]),
    ...mapState("application", ["showPdfTool"]),
    ...mapState("bottlenecks", ["selectedSurvey"])
  },
  methods: {
    download() {
      // FUTURE: disable button while working on it
      console.log(
        "will generate pdf with",
        this.form.paperSize,
        this.form.format,
        this.form.resolution
      );
      var width, height;

      if (this.form.format !== "portrait") {
        // landscape, default
        width = paperSizes[this.form.paperSize][0];
        height = paperSizes[this.form.paperSize][1];
      } else {
        // switch width and height
        width = paperSizes[this.form.paperSize][1];
        height = paperSizes[this.form.paperSize][0];
      }

      // FUTURE: consider margins
      console.log(width, height);

      // dots per mm = dots per inch / (25.4 mm/inch)
      var pixelsPerMapMillimeter = this.form.resolution / 25.4;
      var mapSizeForPrint = [
        // in pixel
        Math.round(width * pixelsPerMapMillimeter),
        Math.round(height * pixelsPerMapMillimeter)
      ];

      // generate PDF and open it
      // our units are milimeters; width 0 x height 0 is left upper corner

      // Step 1 prepare and save current map extend
      // Then add callback "rendercomplete" for Step 3
      //    which will generate the pdf and resets the map view
      // Step 2 which starts rendering a map with the necessary image size

      var map = this.openLayersMap;
      var mapSize = map.getSize(); // size in pixels of the map in the DOM
      // Calculate the extent for the current view state and the passed size.
      // The size is the pixel dimensions of the box into which the calculated
      // extent should fit.
      var mapExtent = map.getView().calculateExtent(mapSize);

      var pdf = new jsPDF(this.form.format, "mm", this.form.paperSize);
      var scalebarSize =
        this.form.format === "portrait" && this.form.paperSize === "a4"
          ? 10
          : 15;
      var northarrowSize = 3;
      var self = this;

      // set a callback for after the next complete rendering of the map
      map.once("rendercomplete", function(event) {
        let canvas = event.context.canvas;

        // because we are using Web Mercator, a pixel represents
        // a differently sizes spot depending on the place of the map.
        // So we use a value calculated from the center of the current view.
        let view = map.getView();
        let proj = view.getProjection();
        let metersPerPixel = // average meters (reality) per pixel (map)
          getPointResolution(proj, view.getResolution(), view.getCenter()) *
          proj.getMetersPerUnit();
        console.log("metersPerPixel = ", metersPerPixel);

        var data = canvas.toDataURL("image/jpeg");
        pdf.addImage(data, "JPEG", 0, 0, width, height);
        self.addRoundedBox(
          pdf,
          width - scalebarSize * 5.5,
          height - scalebarSize,
          scalebarSize * 5,
          scalebarSize
        );
        self.addScalebar(
          pdf,
          width - scalebarSize * 5,
          height - scalebarSize / 2,
          scalebarSize,
          scalebarSize * pixelsPerMapMillimeter * metersPerPixel
        );
        self.addText(
          pdf,
          width - scalebarSize * 5,
          height - scalebarSize * 0.6,
          10,
          "black",
          50,
          "Scale 1:" +
            Math.round(1000 * pixelsPerMapMillimeter * metersPerPixel)
        );
        //self.addText(pdf, 150, 20, 10, "black", 70, "some text");
        self.addNorthArrow(pdf, 15, 8, northarrowSize);
        pdf.save("map.pdf");
        // reset to original size
        map.setSize(mapSize);
        map.getView().fit(mapExtent, { size: mapSize });

        // FUTURE: re-enable button when done
      });

      // trigger rendering
      map.setSize(mapSizeForPrint);
      map.getView().fit(mapExtent, { size: mapSizeForPrint });

      // TODO: replace this src with an API reponse after actually generating PDFs
      /*
      let src =
        this.form.format === "landscape"
          ? "/img/PrintTemplate-Var2-Landscape.pdf"
          : "/img/PrintTemplate-Var2-Portrait.pdf";

      let a = document.createElement("a");
      a.href = src;

      if (this.form.downloadType === "download")
        a.download = src.substr(src.lastIndexOf("/") + 1);
      else a.target = "_blank";

      document.body.appendChild(a);
      a.click();
      document.body.removeChild(a);
      */
    },
    addRoundedBox(doc, x, y, w, h) {
      // draws a rounded background box at (x,y) width x height
      // using jsPDF units
      doc.setDrawColor(255, 255, 255);
      doc.setFillColor(255, 255, 255);
      doc.roundedRect(x, y, w, h, 3, 3, "FD");
    },
    addScalebar(doc, x, y, size, realLength) {
      // realLength as number in meters (reality)
      doc.setDrawColor(0, 0, 0);
      doc.setFillColor(0, 0, 0);
      doc.rect(x, y, size, 1, "FD");
      doc.setFillColor(255, 255, 255);
      doc.setDrawColor(0, 0, 0);
      doc.rect(x + size, y, size, 1, "FD");
      doc.setFillColor(0, 0, 0);
      doc.setDrawColor(0, 0, 0);
      doc.rect(x + size * 2, y, size * 2, 1, "FD");
      doc.setFontSize(5);
      doc.text(x, y + 3, "0");
      doc.text(x + size, y + 3, Math.round(realLength).toString());
      doc.text(x + size * 2, y + 3, Math.round(realLength * 2).toString());
      doc.text(
        x + size * 4,
        y + 3,
        Math.round(realLength * 4).toString() + " m"
      );
    },

    addNorthArrow(doc, x1, y1, size) {
      var y2 = y1 + size * 3;
      var x3 = x1 - size * 2;
      var y3 = y1 + size * 5;
      var x4 = x1 + size * 2;
      //white triangle
      doc.setFillColor(255, 255, 255);
      doc.setDrawColor(255, 255, 255);
      doc.triangle(x3 - 0.8, y3 + 1.2, x1, y1 - 1.2, x1, y2 + 0.6, "F");
      doc.triangle(x1, y1 - 1.2, x1, y2 + 0.6, x4 + 0.8, y3 + 1.2, "F");
      //north arrow
      doc.setDrawColor(0, 0, 0);
      doc.setFillColor(255, 255, 255);
      doc.triangle(x3, y3, x1, y1, x1, y2, "FD");
      doc.setFillColor(0, 0, 0);
      doc.triangle(x1, y1, x1, y2, x4, y3, "FD");
      doc.setFontSize(size * 3.1);
      doc.setTextColor(255, 255, 255);
      doc.setFontStyle("bold");
      doc.text(size < 3 ? x1 - 0.5 : x1 - 1.3, y3 + 1, "N");
      doc.setFontSize(size * 3);
      doc.setTextColor(0, 0, 0);
      doc.setFontStyle("normal");
      doc.text(size < 3 ? x1 - 0.5 : x1 - 1.3, y3 + 1, "N");
    },
    // add some text at specific coordinates and determine how many wrolds in single line
    addText(doc, postitionX, positionY, size, color, lineWidth, text) {
      // split the incoming string to an array, each element is a string of words in a single line
      var textLines = doc.splitTextToSize(text, lineWidth);
      // get the longest line to fit the white backround to it
      var longestString = "";
      textLines.forEach(function(element) {
        if (element.length > longestString.length) longestString = element;
      });
      var indexOfMaxString = textLines.indexOf(longestString);
      // white background (rectangular) around the text
      doc.setFillColor(255, 255, 255);
      doc.setDrawColor(255, 255, 255);
      doc.rect(
        postitionX - doc.getStringUnitWidth(textLines[indexOfMaxString]) / size,
        size > 10 ? positionY - size / 1.8 : positionY - size / 2.4,
        doc.getStringUnitWidth(textLines[indexOfMaxString]) * (size / 2.6),
        textLines.length * (size / 2),
        "FD"
      );
      //rounded rectangular
      /* doc.roundedRect(
        postitionX - doc.getStringUnitWidth(textLines[indexOfMaxString]) / size,
        size > 10 ? positionY - size / 1.8 : positionY - size / 2.6,
        doc.getStringUnitWidth(textLines[indexOfMaxString]) * (size / 2.6),
        textLines.length * (size / 2),
        3,
        3,
        "FD"
      ); */
      doc.setTextColor(color);
      doc.setFontSize(size);
      doc.text(postitionX, positionY, textLines);
    }
  }
};
</script>