import { Argument, Flag } from "effect/unstable/cli";

import type { FlagDescriptor } from "./descriptors.js";
import { descriptors, specsDescriptor } from "./descriptors.js";

/** The description, alias and metavar every flag shares. */
const common =
	<A>(descriptor: FlagDescriptor) =>
	(flag: Flag.Flag<A>): Flag.Flag<A> => {
		let out = Flag.withDescription(flag, descriptor.description);
		if (descriptor.alias !== undefined) out = Flag.withAlias(out, descriptor.alias);
		if (descriptor.metavar !== undefined) out = Flag.withMetavar(out, descriptor.metavar);
		return out;
	};

type Descriptor<T extends FlagDescriptor["type"]["_tag"]> = FlagDescriptor & {
	readonly type: Extract<FlagDescriptor["type"], { readonly _tag: T }>;
};

// One builder per shape, not one generic builder, because the types are the
// point: `Command.make` derives the handler's argument from the exact type of
// each `Flag`, so `Flag<boolean>` and `Flag<Option<boolean>>` have to stay
// distinguishable all the way through. A single builder returning a union would
// collapse `Config` into something the handler could not read. `surface.test.ts`
// asserts the result through the real parser.
const booleanFlag = (
	descriptor: Descriptor<"Boolean"> & {
		readonly type: { readonly default: boolean };
	},
): Flag.Flag<boolean> =>
	Flag.boolean(descriptor.name).pipe(
		common(descriptor),
		Flag.withDefault(descriptor.type.default),
	);

/** A boolean whose absence is meaningful — see `--force`. */
const booleanOptionalFlag = (descriptor: Descriptor<"Boolean">) =>
	Flag.boolean(descriptor.name).pipe(common(descriptor), Flag.optional);

const integerFlag = (
	descriptor: Descriptor<"Integer"> & {
		readonly type: { readonly default: number };
	},
): Flag.Flag<number> =>
	Flag.integer(descriptor.name).pipe(
		common(descriptor),
		Flag.withDefault(descriptor.type.default),
	);

const integerOptionalFlag = (descriptor: Descriptor<"Integer">) =>
	Flag.integer(descriptor.name).pipe(common(descriptor), Flag.optional);

const textFlag = (
	descriptor: Descriptor<"Text"> & {
		readonly type: { readonly default: string };
	},
): Flag.Flag<string> =>
	Flag.string(descriptor.name).pipe(
		common(descriptor),
		Flag.withDefault(descriptor.type.default),
	);

const textOptionalFlag = (descriptor: Descriptor<"Text">) =>
	Flag.string(descriptor.name).pipe(common(descriptor), Flag.optional);

/** Repeatable; absent yields an empty list rather than nothing. */
const textListFlag = (descriptor: Descriptor<"TextList">) =>
	Flag.string(descriptor.name).pipe(common(descriptor), Flag.atLeast(0));

const choiceFlag = <const T extends ReadonlyArray<string>>(
	descriptor: Descriptor<"Choice"> & { readonly type: { readonly choices: T } },
) => Flag.choice(descriptor.name, descriptor.type.choices).pipe(common(descriptor), Flag.optional);

const fileFlag = (descriptor: Descriptor<"File">) =>
	Flag.file(descriptor.name, { mustExist: descriptor.type.mustExist }).pipe(
		common(descriptor),
		Flag.optional,
	);

const directoryFlag = (descriptor: Descriptor<"Directory">): Flag.Flag<string> =>
	Flag.directory(descriptor.name).pipe(
		common(descriptor),
		Flag.withDefault(descriptor.type.default),
	);

export const specsArgument = Argument.string(specsDescriptor.name).pipe(
	Argument.withMetavar(specsDescriptor.metavar),
	Argument.withDescription(specsDescriptor.description),
	Argument.variadic,
);

export const flags = {
	file: fileFlag(descriptors.file),
	prod: booleanFlag(descriptors.prod),
	lockfile: textFlag(descriptors.lockfile),
	out: directoryFlag(descriptors.out),
	layout: choiceFlag(descriptors.layout),
	layoutThreshold: integerOptionalFlag(descriptors.layoutThreshold),
	archiveName: textOptionalFlag(descriptors.archiveName),
	allVersions: booleanFlag(descriptors.allVersions),
	maxVersions: integerOptionalFlag(descriptors.maxVersions),
	includePrerelease: booleanFlag(descriptors.includePrerelease),
	optional: booleanFlag(descriptors.optional),
	peer: booleanFlag(descriptors.peer),
	platform: textListFlag(descriptors.platform),
	registry: textOptionalFlag(descriptors.registry),
	npmrc: fileFlag(descriptors.npmrc),
	rewriteTarballHost: booleanFlag(descriptors.rewriteTarballHost),
	timeout: integerFlag(descriptors.timeout),
	retries: integerFlag(descriptors.retries),
	concurrency: integerFlag(descriptors.concurrency),
	dryRun: booleanFlag(descriptors.dryRun),
	verify: booleanFlag(descriptors.verify),
	force: booleanOptionalFlag(descriptors.force),
	forceSpec: textListFlag(descriptors.forceSpec),
	printAbsolutePath: booleanFlag(descriptors.printAbsolutePath),
	json: booleanFlag(descriptors.json),
	quiet: booleanFlag(descriptors.quiet),
	interactive: booleanFlag(descriptors.interactive),
	yes: booleanFlag(descriptors.yes),
} satisfies Record<keyof typeof descriptors, Flag.Flag<unknown>>;