Start basic CLI framework

cli/src/service/CLI.service.ts

@@ -0,0 +1,60 @@
+import AppClass from '../../../lib/src/lifecycle/AppClass.ts'
+import {Service} from '../../../di/src/decorator/Service.ts'
+import {Collection} from '../../../lib/src/collection/Collection.ts'
+import {Directive} from '../directive/Directive.ts'
+import {Logging} from '../../../lib/src/service/logging/Logging.ts'
+
+/**
+ * Error thrown when a directive registered with the same keyword as
+ * an existing directive.
+ * @extends Error
+ */
+export class DuplicateCLIDirectiveError extends Error {
+    constructor(keyword: string) {
+        super(`A CLI directive with the keyword "${keyword}" already exists.`)
+    }
+}
+
+/**
+ * Service for registering and managing CLI directives.
+ * @extends AppClass
+ */
+@Service()
+export class CLIService extends AppClass {
+    protected directives: Collection<Directive> = new Collection<Directive>()
+
+    constructor(
+        protected readonly logger: Logging,
+    ) { super() }
+
+
+    /**
+     * Find a registered directive using its keyword, if one exists.
+     * @param {string} keyword
+     * @return Directive | undefined
+     */
+    public get_directive_by_keyword(keyword: string): Directive | undefined {
+        return this.directives.firstWhere('keyword', '=', keyword)
+    }
+
+    /**
+     * Get a collection of all registered directives.
+     * @return Collection<Directive>
+     */
+    public get_directives() {
+        return this.directives.clone()
+    }
+
+    /**
+     * Register a directive with the service.
+     * @param {Directive} directive
+     */
+    public register_directive(directive: Directive) {
+        if ( this.get_directive_by_keyword(directive.keyword) ) {
+            throw new DuplicateCLIDirectiveError(directive.keyword)
+        }
+
+        this.logger.verbose(`Registering CLI directive with keyword: ${directive.keyword}`)
+        this.directives.push(directive)
+    }
+}