// The config model. ONE schema: the Encoded side IS the authored file shape (RawConfig),
// the Type side is the fully-resolved shape the engine consumes (Config). Defaults live
// ONLY here (`withDecodingDefaultKey` + encodingStrategy "omit") — the kit's ConfigService
// persists the raw shape verbatim, so a UI save never bakes defaults into the file.
//
// Dropped vs 0.2.x: `ui.*` (the standalone password server is gone — console surface +
// CLI only) and `devEntry` (dev flag out of the prod shape; use `preview` instead).
// Stale keys in existing files are tolerated on decode and dropped by the next save.
import { Effect, Schema } from "effect";
import { EmulatorDef, Platform } from "./domain.js";

const withDefault = <S extends Schema.Top>(
	schema: S,
	value: S["Encoded"],
) =>
	schema.pipe(
		Schema.withDecodingDefaultKey(Effect.succeed(value), {
			encodingStrategy: "omit",
		}),
	);

/** A ROM root: a directory paired with the platform its files belong to (design §5). */
export const RomRoot = Schema.Struct({
	dir: Schema.String,
	platform: Schema.String,
	excludes: Schema.optionalKey(Schema.Array(Schema.String)),
});
export type RomRoot = typeof RomRoot.Type;

/** A per-platform launch override — replaces the platform's built-in default. */
export const PlatformLaunch = Schema.Struct({
	emulator: Schema.String,
	core: Schema.optionalKey(Schema.String),
	extraArgs: Schema.optionalKey(Schema.String),
});
export type PlatformLaunch = typeof PlatformLaunch.Type;

/** A per-game override, keyed by `external_id` (`snes/Chrono Trigger (USA).sfc`). */
export const GameOverride = Schema.Struct({
	exclude: Schema.optionalKey(Schema.Boolean),
	emulator: Schema.optionalKey(Schema.String),
	core: Schema.optionalKey(Schema.String),
	extraArgs: Schema.optionalKey(Schema.String),
	title: Schema.optionalKey(Schema.String),
	art: Schema.optionalKey(Schema.String),
});
export type GameOverride = typeof GameOverride.Type;

export const ArtProviderChoice = Schema.Literals([
	"auto",
	"steamgriddb",
	"libretro",
]);
export type ArtProviderChoice = typeof ArtProviderChoice.Type;

export const SyncOptions = Schema.Struct({
	/** Interval poll in minutes (watchers are unreliable on SMB/NFS — poll is primary). */
	pollMinutes: withDefault(Schema.Number, 15),
	watch: withDefault(Schema.Boolean, true),
	debounceMs: withDefault(Schema.Number, 2000),
	/** Platform ids to region-dedupe ("one entry per title", design §5). */
	dedupeRegions: withDefault(Schema.Array(Schema.String), []),
	regionPriority: withDefault(Schema.Array(Schema.String), [
		"USA",
		"World",
		"Europe",
		"Japan",
	]),
	warnEntries: withDefault(Schema.Number, 2000),
	maxEntries: withDefault(Schema.Number, 5000),
	closeOnEnd: withDefault(Schema.Boolean, false),
});
export type SyncOptions = typeof SyncOptions.Type;

export const ArtOptions = Schema.Struct({
	enabled: withDefault(Schema.Boolean, true),
	provider: withDefault(ArtProviderChoice, "auto"),
	steamGridDbKey: Schema.optionalKey(Schema.String),
});
export type ArtOptions = typeof ArtOptions.Type;

export const RomConfigSchema = Schema.Struct({
	roots: withDefault(Schema.Array(RomRoot), []),
	platformLaunch: withDefault(Schema.Record(Schema.String, PlatformLaunch), {}),
	gameOverrides: withDefault(Schema.Record(Schema.String, GameOverride), {}),
	/** Operator-added / overriding platform defs (merged over built-ins by id). */
	platforms: Schema.optionalKey(Schema.Array(Platform)),
	/** Operator-added / overriding emulator defs (merged over built-ins by id). */
	emulators: Schema.optionalKey(Schema.Array(EmulatorDef)),
	sync: withDefault(SyncOptions, {}),
	art: withDefault(ArtOptions, {}),
});

/** The fully-resolved config the engine consumes. */
export type Config = typeof RomConfigSchema.Type;
/** The on-disk config as authored (all optional). */
export type RawConfig = typeof RomConfigSchema.Encoded;

/**
 * Resolve an authored raw config to the total shape (defaults filled). Throws on an
 * invalid shape — the sync path for tests and the UI; the server side uses the kit's
 * ConfigService (Effect + typed errors) instead.
 */
export const resolveConfig = (raw: unknown): Config =>
	Schema.decodeUnknownSync(RomConfigSchema)(raw);