/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016-2017 Dan "Ducky" Little
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import React from "react";
import USNG from "usng-tools-js";
import proj4 from "proj4";

import { addProjDef } from "../util";

import * as proj from "ol/proj";

/**
 * Ensure the coordinates look pretty before output.
 * TODO: Localize the number formatting.
 *
 * @param {Object} projection - Output projection definition.
 * @param {number[]} coordinates - Coordinates to format.
 *
 * @return {string} Formatted coordinates.
 */
export function formatCoordinates(projection, coords, defaultPrecision = 4) {
  const precision = projection.precision !== undefined ? projection.precision : defaultPrecision;
  return coords.map((x) => x.toFixed(precision)).join(", ");
}

/**
 * Convert the zoom level to a number of digits for lat/lon
 * formatting.
 *
 * @param {Number} zoom - The map's zoom level.
 *
 * @returns {Number} the number of digits.
 */
const zoomToPrecision = (zoom) => {
  if (zoom > 18) {
    return 6;
  } else if (zoom > 9) {
    return 4;
  }
  return 2;
};

/**
 * CoordinateDisplay options
 * - These options can be passed when adding the coordinate display to the app
 *
 * @param {Object[]} projections - an array of projections
 * @param {string} projections[].label - The label appearing next to displayed coordinates
 * @param {string} projections[].ref - an ID referring to the projection being used
 * @param {number} projections[].precision - integer referring to the number of decimal places
 *     to display for this projection
 *
 * Named Projections (do not need to be defined by the user):
 *     - USNG
 *        ref: 'usng'
 *     - XY
 *        ref: 'xy'
 *
 * Predefined Projections
 *     - Lat/Lng
 *        ref: 'EPSG:4326'
 *     - Web Mercator
 *        ref: 'EPSG:3857'
 *
 * Default Projections - displayed when user fails to configure component
 *     - XY, Lat/Lng, USNG
 */
export default class CoordinateDisplay extends React.Component {
  constructor(props) {
    super(props);
    this.u = new USNG();
    this.defaultProjections = [
      {
        label: "X,Y",
        ref: "xy",
      },
      {
        label: "Lat,Lng",
        ref: "EPSG:4326",
      },
      {
        label: "USNG",
        ref: "usng",
      },
    ];
    this.namedProjections = ["xy", "usng", "latlon"];
    this.getProjectionCoords = this.getProjectionCoords.bind(this);

    /**
     * Validate specified projections
     *     - Register undefined projections with Proj4 if <projDef> property is specified
     *     - Add special-case projections ('xy', 'usng')
     *     - If not a special case, add if Proj definition exists
     */

    if (this.props.projections) {
      this.projections = [];
      for (const projection of this.props.projections) {
        if (typeof projection.projDef !== "undefined") {
          addProjDef(proj4, projection.ref, projection.projDef);
        }
        const isNamedProjection = this.namedProjections.indexOf(projection.ref) !== -1;
        let isDefinedProjection = false;
        if (!isNamedProjection) {
          // This is not the cleanest test for definition,
          // but prevents the error during render.
          try {
            proj4(projection.ref, [0, 0]);
            isDefinedProjection = true;
          } catch (err) {
            // swallow the error of the undefined projection.
            console.error("Undefined projection", err);
          }
        }
        if (isNamedProjection || isDefinedProjection) {
          this.projections.push(projection);
        }
      }
    } else {
      this.projections = this.defaultProjections;
    }
  }

  mapXY() {
    const coords = this.props.coords;
    return coords[0].toFixed(1) + ", " + coords[1].toFixed(1);
  }

  usng() {
    const coords = this.getLatLonCoords();
    try {
      // TODO: This assumes resolution is in meters per pixel
      const resolution = this.props.resolution;
      const digits = Math.max(Math.min(Math.ceil(Math.log10(100000 / resolution)), 5), 0);
      return this.u.fromLonLat({ lon: coords[0], lat: coords[1] }, digits);
    } catch (e) {
      console.error("Bug with USNG coordinate", e);
      return "--";
    }
  }

  /** Transform the map coordinate in to a lat-lon
   *  set of coordinates.
   */
  getLatLonCoords() {
    // TODO: The projection should be stored in the store,
    //       and defined by the user.
    const mapProj = new proj.get("EPSG:3857");
    const latlonProj = new proj.get("EPSG:4326");

    // transform the point
    return proj.transform(this.props.coords, mapProj, latlonProj);
  }

  latlon(projection, autoPrecision = true) {
    const coords = this.getLatLonCoords();
    const digits = autoPrecision ? zoomToPrecision(this.props.zoom) : 4;
    return formatCoordinates(projection, [coords[1], coords[0]], digits);
  }

  getProjectionCoords(projection) {
    // TODO: The projection should be stored in the store,
    //       and defined by the user.
    const mapProj = "EPSG:3857";
    // transform the point, slice is used to ensure only 2D coordinates.
    const coords = proj4(mapProj, projection.ref, this.props.coords.slice(0, 2));
    return formatCoordinates(projection, coords);
  }

  getData(projection) {
    switch (projection.ref) {
      case "usng":
        return {
          label: projection.label,
          point: this.usng(),
        };
      case "latlon":
        return {
          label: projection.label,
          point: this.latlon(projection),
        };
      case "xy":
        return {
          label: projection.label,
          point: formatCoordinates(projection, this.props.coords, 1),
        };
      default:
        return {
          label: projection.label,
          point: this.getProjectionCoords(projection),
        };
    }
  }

  render() {
    if (this.props.asTable) {
      return (
        <div className="gm-grid">
          <table>
            {this.props.children}
            <tbody>
              {this.projections.map((projection) => {
                const data = this.getData(projection);
                return (
                  <tr key={projection.ref}>
                    <th>{data.label}</th>
                    <td>{data.point}</td>
                  </tr>
                );
              })}
            </tbody>
          </table>
        </div>
      );
    }
    return (
      <span className="coordinate-display">
        {this.projections.map((projection) => {
          const className = "coordinates map-" + projection.ref.replace(/:/g, "-");
          const data = this.getData(projection);
          return (
            <span className={className} key={projection.ref}>
              <label>{data.label}</label>
              {data.point}
            </span>
          );
        })}
      </span>
    );
  }
}
