import { existsSync } from "node:fs";
import { join } from "node:path";
import { pathToFileURL } from "node:url";
import { resolveTypeStrippingFlag } from "./ts-subprocess-flags.ts";

export interface SfCliEntry {
	command: string;
	args: string[];
	cwd: string;
}

/** @deprecated Use SfCliEntry instead */
export interface ResolveSfCliEntryOptions {
	packageRoot: string;
	cwd: string;
	execPath?: string;
	hostKind?: string;
	mode?: "interactive" | "rpc";
	sessionDir?: string;
	messages?: string[];
	existsSync?: (path: string) => boolean;
}

/** @deprecated Use ResolveSfCliEntryOptions instead */
function buildExtraArgs(options: ResolveSfCliEntryOptions): string[] {
	if (options.mode !== "rpc") return [];

	if (!options.sessionDir) {
		throw new Error("RPC CLI entry requires sessionDir");
	}

	return ["--mode", "rpc", "--continue", "--session-dir", options.sessionDir];
}

export function resolveSfCliEntry(
	options: ResolveSfCliEntryOptions,
): SfCliEntry {
	const checkExists = options.existsSync ?? existsSync;
	const execPath = options.execPath ?? process.execPath;
	const extraArgs = buildExtraArgs(options);
	const messageArgs =
		options.mode === "interactive" ? (options.messages ?? []) : [];

	const sourceEntry = join(options.packageRoot, "src", "loader.ts");
	const resolveTsLoader = join(
		options.packageRoot,
		"src",
		"resources",
		"extensions",
		"sf",
		"tests",
		"resolve-ts.mjs",
	);
	const builtEntry = join(options.packageRoot, "dist", "loader.js");

	const sourceCliEntry =
		checkExists(sourceEntry) && checkExists(resolveTsLoader)
			? ({
					command: execPath,
					args: [
						"--import",
						pathToFileURL(resolveTsLoader).href,
						resolveTypeStrippingFlag(options.packageRoot),
						sourceEntry,
						...extraArgs,
						...messageArgs,
					],
					cwd: options.cwd,
				} satisfies SfCliEntry)
			: null;

	const builtCliEntry = checkExists(builtEntry)
		? ({
				command: execPath,
				args: [builtEntry, ...extraArgs, ...messageArgs],
				cwd: options.cwd,
			} satisfies SfCliEntry)
		: null;

	if (options.hostKind === "packaged-standalone") {
		if (builtCliEntry) return builtCliEntry;
		if (sourceCliEntry) return sourceCliEntry;
	} else {
		if (sourceCliEntry) return sourceCliEntry;
		if (builtCliEntry) return builtCliEntry;
	}

	throw new Error(
		`SF CLI entry not found; checked=${sourceEntry},${builtEntry}`,
	);
}