add find by capital

2 files changed, 27 insertions, 3 deletions

diff --git a/src/app.ts b/src/app.ts
index 09db256..10129e1 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -1,3 +1,4 @@
+import { green, cyan } from "https://deno.land/x/[email protected]/mod.ts";
 import { Countries } from "./countries.ts";
 import { Cache } from "./util/cache.ts";
 import { help } from "./util/help.ts";
@@ -11,14 +12,22 @@ export async function app() {
     case undefined:
       help();
       break;
+    case "help":
+      help();
+      break;
     case "sync":
       await countries.sync({ force: true });
       break;
     case "random":
       countries.print(countries.random());
       break;
-    case "help":
-      help();
+    case "capital":
+      const [, ...args] = Deno.args;
+      const capital = args.join(" ");
+      const country = countries.findByCapital(capital);
+      console.log(
+        green(capital) + " is the capital of " + cyan(country.name.common)
+      );
       break;
     default:
       countries.print(Deno.args.join(" "));
diff --git a/src/countries.ts b/src/countries.ts
index dba4d1a..05d6a17 100644
--- a/src/countries.ts
+++ b/src/countries.ts
@@ -47,7 +47,7 @@ export class Countries {
     return this.list;
   }
 
-  find(name: string): Country {
+  find(name: string) {
     name = name.toLowerCase();
     // Find exact match first, then fall back to fuzzy match
     const country = this.list.find((c) => {
@@ -62,6 +62,21 @@ export class Countries {
     return country;
   }
 
+  findByCapital(capital: string) {
+    const country = this.list.find((c) => {
+      const capitalsLowercase = c.capital.map((capital) =>
+        capital.toLowerCase()
+      );
+      return capitalsLowercase.includes(capital);
+    });
+
+    if (!country) {
+      throw Error(`Could not find the country of capital: ${capital}`);
+    }
+
+    return country;
+  }
+
   print(name: string) {
     const country = this.find(name);
     let currencies = [];