Add preliminary support for parsing of command line options (#86)

* Add preliminary support for parsing of command line options

* Remove redundant options for width and height

* Add parser for command line arguments. Type validation outstanding.

* Update TODO list

* Use config for argv's default values, simplify argument management

Co-authored-by: LH <@>

5 files changed, 92 insertions, 23 deletions

diff --git a/README.md b/README.md
index f2a3fc3..a638dbe 100644
--- a/README.md
+++ b/README.md
@@ -99,11 +99,11 @@ If your terminal supports mouse events you can drag the map and use your scroll
 * MapSCII
   * [ ] GeoJSON support via [geojson-vt](https://github.com/mapbox/geojson-vt)
   * [ ] CLI support
-    * [ ] startup parameters
-      * [ ] TileSource
-      * [ ] Style
-      * [ ] center position
-      * [ ] zoom
+    * [-] startup parameters
+      * [X] TileSource
+      * [X] Style
+      * [X] center position
+      * [X] zoom
       * [ ] demo mode?
 
   * [ ] mouse control
diff --git a/main.js b/main.js
index 7498c1a..afc3337 100644
--- a/main.js
+++ b/main.js
@@ -8,9 +8,79 @@
   TODO: params parsing and so on
 #*/
 'use strict';
+const config = require('./src/config');
 const Mapscii = require('./src/Mapscii');
+const argv = require('yargs')
+  .option('latitude', {
+    alias: 'lat',
+    description: 'Latitude of initial centre',
+    default: config.initialLat,
+    type: 'number',
+  })
+  .option('longitude', {
+    alias: 'lon',
+    description: 'Longitude of initial centre',
+    default: config.initialLon,
+    type: 'number',
+  })
+  .option('zoom', {
+    alias: 'z',
+    description: 'Initial zoom',
+    default: config.initialZoom,
+    type: 'number',
+  })
+  .option('width', {
+    alias: 'w',
+    description: 'Fixed width of rendering in dot units',
+    type: 'number',
+  })
+  .option('height', {
+    alias: 'h',
+    description: 'Fixed height of rendering in dot units',
+    type: 'number',
+  })
+  .option('braille', {
+    alias: 'b',
+    description: 'Activate braille rendering',
+    default: config.useBraille,
+    type: 'boolean',
+  })
+  .option('headless', {
+    alias: 'H',
+    description: 'Activate headless mode',
+    default: config.headless,
+    type: 'boolean',
+  })
+  .option('tile_source', {
+    alias: 'tileSource',
+    description: 'URL or path to osm2vectortiles source',
+    default: config.source,
+    type: 'string',
+  })
+  .option('style_file', {
+    alias: 'style',
+    description: 'path to json style file',
+    default: config.styleFile,
+    type: 'string',
+  })
+  .strict()
+  .argv;
 
-const mapscii = new Mapscii();
+const options = {
+  initialLat: argv.latitude,
+  initialLon: argv.longitude,
+  initialZoom: argv.zoom,
+  size: {
+    width: argv.width,
+    height: argv.height
+  },
+  useBraille: argv.braille,
+  headless: argv.headless,
+  source: argv.tile_source,
+  styleFile: argv.style_file,
+}
+
+const mapscii = new Mapscii(options);
 mapscii.init().catch((err) => {
   console.error('Failed to start MapSCII.');
   console.error(err);
diff --git a/package.json b/package.json
index 8bab5b1..fa4740c 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,8 @@
     "string-width": "^4.2.0",
     "term-mouse": "^0.2.2",
     "userhome": "^1.0.0",
-    "x256": "0.0.2"
+    "x256": "0.0.2",
+    "yargs": "^15.3.1"
   },
   "devDependencies": {
     "eslint": "^7.0.0",
diff --git a/src/Mapscii.js b/src/Mapscii.js
index 541e3d2..133d756 100644
--- a/src/Mapscii.js
+++ b/src/Mapscii.js
@@ -31,17 +31,13 @@ class Mapscii {
     this.renderer = null;
 
     this.zoom = 0;
-    // sf lat: 37.787946, lon: -122.407522
-    // iceland lat: 64.124229, lon: -21.811552
-    // rgbg
-    // lat: 49.019493, lon: 12.098341
-    this.center = {
-      lat: 52.51298,
-      lon: 13.42012,
-    };
-
     this.minZoom = null;
     config = Object.assign(config, options);
+
+    this.center = {
+      lat: config.initialLat,
+      lon: config.initialLon
+    };
   }
 
   async init() {
@@ -97,13 +93,8 @@ class Mapscii {
   }
 
   _resizeRenderer() {
-    if (config.size) {
-      this.width = config.size.width;
-      this.height = config.size.height;
-    } else {
-      this.width = config.output.columns >> 1 << 2;
-      this.height = config.output.rows * 4 - 4;
-    }
+    this.width = config.size && config.size.width ? config.size.width : config.output.columns >> 1 << 2;
+    this.height = config.size && config.size.height ? config.size.height : config.output.rows * 4 - 4;
 
     this.minZoom = 4-Math.log(4096/this.width)/Math.LN2;
 
diff --git a/src/config.js b/src/config.js
index ce48ea7..1e9a4fe 100644
--- a/src/config.js
+++ b/src/config.js
@@ -13,6 +13,13 @@ module.exports = {
   maxZoom: 18,
   zoomStep: 0.2,
 
+  // sf lat: 37.787946, lon: -122.407522
+  // iceland lat: 64.124229, lon: -21.811552
+  // rgbg
+  // lat: 49.019493, lon: 12.098341
+  initialLat: 52.51298,
+  initialLon: 14.42012,
+
   simplifyPolylines: false,
 
   useBraille: true,