// SPDX-FileCopyrightText: Amolith <amolith@secluded.site>
//
// SPDX-License-Identifier: MIT

import {
	type ExtensionAPI,
	type ExtensionContext,
	ModelSelectorComponent,
	SettingsManager,
} from "@earendil-works/pi-coding-agent";

export type SetModelResult =
	| { ok: true }
	| { ok: false; reason: "invalid-format" | "unknown-model" | "set-failed"; detail: string };

/**
 * Parse a "provider/modelId" string, look it up in the model registry, and
 * set it as the active model. Returns a result describing what happened.
 */
export async function parseAndSetModel(spec: string, ctx: ExtensionContext, pi: ExtensionAPI): Promise<SetModelResult> {
	const slashIdx = spec.indexOf("/");
	if (slashIdx <= 0 || slashIdx === spec.length - 1) {
		return { ok: false, reason: "invalid-format", detail: `Invalid model format "${spec}", expected provider/modelId` };
	}

	const provider = spec.slice(0, slashIdx);
	const modelId = spec.slice(slashIdx + 1);
	const model = ctx.modelRegistry.find(provider, modelId);

	if (!model) {
		return { ok: false, reason: "unknown-model", detail: `Unknown model: ${spec}` };
	}

	try {
		await pi.setModel(model);
	} catch (err) {
		const msg = err instanceof Error ? err.message : String(err);
		return { ok: false, reason: "set-failed", detail: `Failed to set model ${spec}: ${msg}` };
	}

	return { ok: true };
}

/**
 * Convenience wrapper: parse and set the model, notifying the user on failure.
 */
export async function parseAndSetModelWithNotify(
	spec: string,
	ctx: ExtensionContext,
	pi: ExtensionAPI,
): Promise<SetModelResult> {
	const result = await parseAndSetModel(spec, ctx, pi);
	if (!result.ok) {
		ctx.ui.notify(result.detail, "warning");
	}
	return result;
}

/**
 * Show Pi's built-in model picker and return the user's selection without
 * changing Pi's active model or default model setting.
 */
export async function pickModel(
	ctx: ExtensionContext,
	currentModel: ExtensionContext["model"] = ctx.model,
	initialSearchInput?: string,
): Promise<ExtensionContext["model"]> {
	return ctx.ui.custom<ExtensionContext["model"]>((tui, _theme, _keybindings, done) => {
		const selector = new ModelSelectorComponent(
			tui,
			currentModel,
			SettingsManager.inMemory(),
			ctx.modelRegistry,
			[],
			(model) => done(model),
			() => done(undefined),
			initialSearchInput,
		);

		return selector;
	});
}