import * as apigateway from "@aws-cdk/aws-apigateway";
import { Stack } from '@aws-cdk/core';
import { LambdaIntegration } from "@aws-cdk/aws-apigateway";
import Function from '../function';

class APIGateway {
    readonly resource?: string;
    readonly gateway: apigateway.RestApi;

    constructor({ scope, id, name, resource }: { scope: Stack, id: string, name: string, resource?: string }) {
        const gateway = new apigateway.RestApi(
            scope,
            id,
            {
                restApiName: name,
            },
        );

        this.resource = resource;
        this.gateway = gateway;

        if (this.resource) {
            this.gateway.root.addResource(this.resource);
        }
    }

    stripPath(path: string) {
        let strippedPath = path;
        if (path.startsWith('/')) {
            strippedPath = path.substring(1, path.length);
        }

        return strippedPath;
    }

    addMethod(method: string, f: Function, path?: string) {
        const integration = new LambdaIntegration(f);

        // If a base resource is already defined, find and use that
        if (this.resource) {
            const resource = this.gateway.root.getResource(this.resource);
            if (!resource) {
                throw new Error(`Resource: ${this.resource} hasn't been correctly registered to the gateway`);
            }

            if (path) {
                resource.addResource(this.stripPath(path)).addMethod(method, integration);
                return;
            }

            resource.addMethod(method, integration);
            return;
        }

        // If we define a custom path, use that as a new resource
        if (path) {
            this.gateway.root.addResource(this.stripPath(path)).addMethod(method, integration);
            return;
        }

        // Fallback to adding the method on the root
        this.gateway.root.addMethod(method, integration);
    }
}

export default APIGateway;