feat: add google maps mcp source (#125)

packages/freya-source-google-maps/src/google-maps-source.ts

@@ -0,0 +1,151 @@
+import {
+	McpSource,
+	type McpActionMapping,
+	type McpClient,
+	type McpHttpHeaders,
+	type McpSourceOptions,
+} from "@freya/source-mcp"
+
+import {
+	ComputeRoutesInput,
+	LookupWeatherInput,
+	ResolveMapsUrlsInput,
+	ResolveNamesInput,
+	SearchPlacesInput,
+} from "./schemas"
+
+export type GoogleMapsApiKey = string | (() => Promise<string>)
+
+export interface GoogleMapsSourceOptions {
+	readonly endpoint?: string | URL
+	readonly apiKey?: GoogleMapsApiKey
+	readonly timeoutMs?: number
+	readonly headers?: McpHttpHeaders | (() => Promise<McpHttpHeaders>)
+	readonly requestInit?: RequestInit
+	readonly transportOptions?: McpSourceOptions["transportOptions"]
+	readonly client?: McpClient
+	readonly clientFactory?: McpSourceOptions["clientFactory"]
+}
+
+export const GoogleMapsSourceId = "freya.google-maps"
+
+export const GoogleMapsMcpEndpoint = "https://mapstools.googleapis.com/mcp"
+
+export const GoogleMapsAction = {
+	SearchPlaces: "search-places",
+	LookupWeather: "lookup-weather",
+	ComputeRoutes: "compute-routes",
+	ResolveNames: "resolve-names",
+	ResolveMapsUrls: "resolve-maps-urls",
+} as const
+
+export type GoogleMapsAction = (typeof GoogleMapsAction)[keyof typeof GoogleMapsAction]
+
+export const GoogleMapsTool = {
+	SearchPlaces: "search_places",
+	LookupWeather: "lookup_weather",
+	ComputeRoutes: "compute_routes",
+	ResolveNames: "resolve_names",
+	ResolveMapsUrls: "resolve_maps_urls",
+} as const
+
+export type GoogleMapsTool = (typeof GoogleMapsTool)[keyof typeof GoogleMapsTool]
+
+const GoogleMapsActions = {
+	[GoogleMapsAction.SearchPlaces]: {
+		tool: GoogleMapsTool.SearchPlaces,
+		description:
+			"Find places, businesses, addresses, locations, and points of interest with Google Maps.",
+		input: SearchPlacesInput,
+	},
+	[GoogleMapsAction.LookupWeather]: {
+		tool: GoogleMapsTool.LookupWeather,
+		description: "Retrieve current conditions and weather forecasts through Google Maps.",
+		input: LookupWeatherInput,
+	},
+	[GoogleMapsAction.ComputeRoutes]: {
+		tool: GoogleMapsTool.ComputeRoutes,
+		description: "Compute a Google Maps route between an origin and destination.",
+		input: ComputeRoutesInput,
+	},
+	[GoogleMapsAction.ResolveNames]: {
+		tool: GoogleMapsTool.ResolveNames,
+		description: "Resolve specific place names or addresses into Google Maps Place IDs.",
+		input: ResolveNamesInput,
+	},
+	[GoogleMapsAction.ResolveMapsUrls]: {
+		tool: GoogleMapsTool.ResolveMapsUrls,
+		description: "Resolve Google Maps URLs into canonical Google Maps Place IDs.",
+		input: ResolveMapsUrlsInput,
+	},
+} as const satisfies Record<GoogleMapsAction, McpActionMapping>
+
+export class GoogleMapsSource extends McpSource {
+	constructor(options: GoogleMapsSourceOptions = {}) {
+		super({
+			id: GoogleMapsSourceId,
+			url: options.endpoint ?? GoogleMapsMcpEndpoint,
+			clientName: "freya-source-google-maps",
+			clientVersion: "0.0.0",
+			timeoutMs: options.timeoutMs,
+			headers: createGoogleMapsHeaders({
+				headers: options.headers,
+				apiKey: options.apiKey,
+			}),
+			requestInit: options.requestInit,
+			transportOptions: options.transportOptions,
+			client: options.client,
+			clientFactory: options.clientFactory,
+			actions: GoogleMapsActions,
+		})
+	}
+}
+
+interface GoogleMapsHeaderOptions {
+	readonly headers: McpHttpHeaders | (() => Promise<McpHttpHeaders>) | undefined
+	readonly apiKey: GoogleMapsApiKey | undefined
+}
+
+function createGoogleMapsHeaders({
+	headers,
+	apiKey,
+}: GoogleMapsHeaderOptions): McpHttpHeaders | (() => Promise<McpHttpHeaders>) | undefined {
+	if (!apiKey) {
+		return headers
+	}
+
+	return async () => {
+		const merged = new Headers()
+		const resolvedHeaders = typeof headers === "function" ? await headers() : headers
+		if (resolvedHeaders) {
+			applyHeaders(merged, resolvedHeaders)
+		}
+
+		if (apiKey) {
+			const resolvedApiKey = typeof apiKey === "function" ? await apiKey() : apiKey
+			merged.set("x-goog-api-key", resolvedApiKey)
+		}
+
+		return merged
+	}
+}
+
+function applyHeaders(target: Headers, headers: McpHttpHeaders): void {
+	if (headers instanceof Headers) {
+		headers.forEach((value, key) => {
+			target.set(key, value)
+		})
+		return
+	}
+
+	if (Array.isArray(headers)) {
+		for (const [key, value] of headers) {
+			target.set(key, value)
+		}
+		return
+	}
+
+	for (const [key, value] of Object.entries(headers)) {
+		target.set(key, value)
+	}
+}