import type { ExtensionAPI } from "@oh-my-pi/pi-coding-agent";

const notes = [
	{ id: "reed", habitat: "marsh", text: "Fictional reed bends beside the footbridge." },
	{ id: "fern", habitat: "woodland", text: "Fictional fern grows beneath the oak." },
] as const;

type FieldNote = (typeof notes)[number];
type FieldNotesDetails =
	| { operations: string[]; ids: FieldNote["id"][]; writes: false }
	| { matches: FieldNote[] };

export default function fieldNotes(pi: ExtensionAPI): void {
	const { Type } = pi.typebox;
	const parameters = Type.Object({
		op: Type.Union([Type.Literal("discover"), Type.Literal("inspect"), Type.Literal("query")]),
		value: Type.Optional(Type.String()),
	});
	pi.registerTool<typeof parameters, FieldNotesDetails>({
		name: "field_notes",
		label: "Field notes",
		description: "Read fictional field notes: discover operations, inspect one id, or query text. No writes.",
		parameters,
		async execute(_id, params) {
			if (params.op === "discover") {
				const details: FieldNotesDetails = { operations: ["discover", "inspect", "query"], ids: notes.map(note => note.id), writes: false };
				return { content: [{ type: "text", text: JSON.stringify(details) }], details };
			}
			const value = params.value?.trim().toLowerCase() ?? "";
			if (params.op === "inspect" && !notes.some(note => note.id === value)) {
				throw new Error("Unknown note id. Discover ids with field_notes first.");
			}
			const matches = notes.filter(note => params.op === "inspect"
				? note.id === value
				: `${note.id} ${note.habitat} ${note.text}`.toLowerCase().includes(value));
			return { content: [{ type: "text", text: JSON.stringify(matches) }], details: { matches } };
		},
	});
	pi.registerCommand("field-notes", {
		description: "Read the fictional field notebook",
		async handler(args, ctx) {
			const value = args.trim().toLowerCase();
			const matches = notes.filter(note => !value || note.id === value);
			ctx.ui.notify(matches.length ? matches.map(note => `${note.id}: ${note.text}`).join("\n") : "Unknown note. Try /field-notes reed.", matches.length ? "info" : "warning");
		},
	});
}