// The plugin's configuration model (design §9) — the single source of truth for the sync engine,
// editable by hand (headless boxes) or by the web UI. Everything the engine needs is derivable from
// this file plus a directory scan; the `resolveConfig` helper fills defaults so the rest of the code
// works against a fully-populated shape.

import type { EmulatorDef } from "./emulators.js";
import type { Platform } from "./platforms.js";

/** A ROM root: a directory paired with the platform its files belong to (design §5). */
export interface RomRoot {
	/** Absolute directory to scan. */
	dir: string;
	/** Platform id (a key into the resolved platform registry). */
	platform: string;
	/** Per-root glob ignore patterns (`*.sav`, `bios/**`). */
	excludes?: string[];
}

/** A per-platform launch override — replaces the platform's built-in default emulator/core. */
export interface PlatformLaunch {
	emulator: string;
	core?: string;
	extraArgs?: string;
}

/** A per-game override, keyed by `external_id` (`snes/Chrono Trigger (USA).sfc`). */
export interface GameOverride {
	/** Skip this ROM entirely. */
	exclude?: boolean;
	/** Override the resolved emulator/core/args for just this title. */
	emulator?: string;
	core?: string;
	extraArgs?: string;
	/** Override the displayed title. */
	title?: string;
	/** Override the box-art portrait URL. */
	art?: string;
}

export interface SyncOptions {
	/** Interval poll in minutes (watchers are unreliable on SMB/NFS — poll is the primary trigger). */
	pollMinutes: number;
	/** Enable fs watching (an accelerator on top of the poll). */
	watch: boolean;
	/** Debounce window for coalescing watch/poll-triggered rescans (ms). */
	debounceMs: number;
	/** Platform ids to region-dedupe ("one entry per title", design §5) — default none. */
	dedupeRegions: string[];
	/** Region preference order for dedupe (best first). */
	regionPriority: string[];
	/** Warn in the UI above this entry count (design §8 scale guard). */
	warnEntries: number;
	/** Hard cap — truncate with a loud report above this many entries. */
	maxEntries: number;
	/** Attach `prep`/`undo` that kills the emulator at session end ("close emulator when stream ends"). */
	closeOnEnd: boolean;
}

/** Which art source to use (design §7, revised): SteamGridDB (like Steam ROM Manager) or the keyless
 *  libretro-thumbnails fallback. `auto` = SteamGridDB when a key is set, else libretro. */
export type ArtProviderChoice = "auto" | "steamgriddb" | "libretro";

export interface ArtOptions {
	/** Fetch box art at all. */
	enabled: boolean;
	/** Art source selection (default `auto`). */
	provider: ArtProviderChoice;
	/**
	 * SteamGridDB API key (free, from steamgriddb.com profile preferences). Unlocks full portrait +
	 * hero + logo + header art with fuzzy title matching. Absent → the keyless libretro fallback.
	 */
	steamGridDbKey?: string;
}

export interface UiOptions {
	/**
	 * Fallback standalone mode (design §9): serve the UI on a fixed, possibly non-loopback port behind
	 * a password instead of via the console proxy. For host-only installs without the console.
	 */
	standalone: boolean;
	/** Standalone bind port. */
	port: number;
	/** Standalone bind address (defaults to loopback; a non-loopback bind REQUIRES a password). */
	bind: string;
	/** scrypt password hash (`scrypt$<saltB64>$<hashB64>`), required for a non-loopback standalone bind. */
	passwordHash?: string;
}

/** The on-disk config as authored (all optional — `resolveConfig` fills the rest). */
export interface RawConfig {
	roots?: RomRoot[];
	/** Per-platform launch overrides, keyed by platform id. */
	platformLaunch?: Record<string, PlatformLaunch>;
	/** Per-game overrides, keyed by `external_id`. */
	gameOverrides?: Record<string, GameOverride>;
	/** Operator-added / overriding platform defs (merged over the built-ins by id). */
	platforms?: Platform[];
	/** Operator-added / overriding emulator defs (merged over the built-ins by id). */
	emulators?: EmulatorDef[];
	sync?: Partial<SyncOptions>;
	art?: Partial<ArtOptions>;
	ui?: Partial<UiOptions>;
	/** Dev/M0 acceptance flag: reconcile one hardcoded entry so the round-trip is observable. */
	devEntry?: boolean;
}

/** The fully-resolved config the engine consumes. */
export interface Config {
	roots: RomRoot[];
	platformLaunch: Record<string, PlatformLaunch>;
	gameOverrides: Record<string, GameOverride>;
	platforms?: Platform[];
	emulators?: EmulatorDef[];
	sync: SyncOptions;
	art: ArtOptions;
	ui: UiOptions;
	devEntry: boolean;
}

export const DEFAULT_SYNC: SyncOptions = {
	pollMinutes: 15,
	watch: true,
	debounceMs: 2000,
	dedupeRegions: [],
	regionPriority: ["USA", "World", "Europe", "Japan"],
	warnEntries: 2000,
	maxEntries: 5000,
	closeOnEnd: false,
};

export const DEFAULT_UI: UiOptions = {
	standalone: false,
	port: 47993,
	bind: "127.0.0.1",
};

/** Fill defaults over an authored config so the rest of the engine sees a total shape. */
export const resolveConfig = (raw: RawConfig): Config => ({
	roots: raw.roots ?? [],
	platformLaunch: raw.platformLaunch ?? {},
	gameOverrides: raw.gameOverrides ?? {},
	platforms: raw.platforms,
	emulators: raw.emulators,
	sync: { ...DEFAULT_SYNC, ...raw.sync },
	art: { enabled: true, provider: "auto", ...raw.art },
	ui: { ...DEFAULT_UI, ...raw.ui },
	devEntry: raw.devEntry ?? false,
});

/** The empty starting config for a fresh install (no roots yet). */
export const emptyConfig = (): Config => resolveConfig({});