import { styleText } from "node:util";
import { createLogger, exec, termost } from "termost";
import package_ from "../package.json" with { type: "json" };

type ProgramContext = {
	computedFromOtherTaskValues: "big" | "small";
	execOutput: string;
	size: number;
};

const logger = createLogger({
	name: "task",
	level: "debug",
});

const program = termost<ProgramContext>({
	name: package_.name,
	description: "Example to showcase the `task` API",
	version: package_.version,
});

program
	.task({
		key: "size",
		label: "Task with returned value (persisted)",
		handler() {
			return 45;
		},
	})
	.task({
		label: "Task with side-effect only (no persisted value)",
		async handler() {
			// @note: side-effect only handler
			await wait(500);
		},
	})
	.task({
		key: "computedFromOtherTaskValues",
		label: "Task can also access other persisted task values",
		handler(context) {
			if (context.size > 2000) {
				return "big" as const;
			}

			return "small" as const;
		},
		validate({ computedFromOtherTaskValues }) {
			if (computedFromOtherTaskValues === "big") {
				return new Error("Invalid input");
			}

			return undefined;
		},
	})
	.task({
		key: "execOutput",
		label: "Or even execute external commands thanks to its provided helpers",
		async handler() {
			return exec("echo 'Hello from shell'");
		},
	})
	.task({
		label: "A task can be skipped as well",
		async handler() {
			await wait(2000);
		},
		skip(context) {
			const isNeedOptimization = context.size > 2000;

			return !isNeedOptimization;
		},
	})
	.task({
		label: (context) => {
			return `A task can have a dynamic label generated from contextual values: ${context.computedFromOtherTaskValues}`;
		},
		handler() {
			// No op
		},
	})
	.task({
		handler(context) {
			logger.info(
				'If you don\'t specify a label, the handler is executed in "live mode" (the output is not hidden by the label and is displayed gradually).',
			);

			logger.info(
				`A task with a specified "key" can be retrieved here. Size = ${context.size}. If no "key" was specified the task returned value cannot be persisted across program instructions.`,
			);
		},
	})
	.task({
		handler(context) {
			const content = "The logger helper can be used to display task content in a nice way";

			logger.debug(content);
			logger.info(content);
			logger.warn(content);
			logger.error(content);
			logger.success(content);
			logger.info("👋 You can also namespace the logger name");

			console.log(
				styleText(
					"cyan",
					`\nYou can also have a total control on the formatting through \`styleText\` from \`node:util\`.\n${JSON.stringify(context, undefined, 2)}`,
				),
			);
		},
	});

const wait = async (delay: number) => {
	return new Promise((resolve) => {
		setTimeout(resolve, delay);
	});
};