import type { BestiaryIndex, BestiaryIndexEntry } from "@initiative/domain";

import rawIndex from "../../../../data/bestiary/index.json";

interface CompactCreature {
	readonly n: string;
	readonly s: string;
	readonly ac: number;
	readonly hp: number;
	readonly dx: number;
	readonly cr: string;
	readonly ip: number;
	readonly sz: string;
	readonly tp: string;
}

interface CompactIndex {
	readonly sources: Record<string, string>;
	readonly creatures: readonly CompactCreature[];
}

function mapCreature(c: CompactCreature): BestiaryIndexEntry {
	return {
		name: c.n,
		source: c.s,
		ac: c.ac,
		hp: c.hp,
		dex: c.dx,
		cr: c.cr,
		initiativeProficiency: c.ip,
		size: c.sz,
		type: c.tp,
	};
}

// Source codes whose filename on the remote differs from a simple lowercase.
// Plane Shift sources use a hyphen: PSA -> ps-a, etc.
const FILENAME_OVERRIDES: Record<string, string> = {
	PSA: "ps-a",
	PSD: "ps-d",
	PSI: "ps-i",
	PSK: "ps-k",
	PSX: "ps-x",
	PSZ: "ps-z",
};

// Source codes with no corresponding remote bestiary file.
// Excluded from the index entirely so creatures aren't searchable
// without a fetchable source.
const EXCLUDED_SOURCES = new Set<string>([]);

let cachedIndex: BestiaryIndex | undefined;

export function loadBestiaryIndex(): BestiaryIndex {
	if (cachedIndex) return cachedIndex;

	const compact = rawIndex as unknown as CompactIndex;
	const sources = Object.fromEntries(
		Object.entries(compact.sources).filter(
			([code]) => !EXCLUDED_SOURCES.has(code),
		),
	);
	cachedIndex = {
		sources,
		creatures: compact.creatures
			.filter((c) => !EXCLUDED_SOURCES.has(c.s))
			.map(mapCreature),
	};
	return cachedIndex;
}

export function getAllSourceCodes(): string[] {
	const index = loadBestiaryIndex();
	return Object.keys(index.sources).filter((c) => !EXCLUDED_SOURCES.has(c));
}

function sourceCodeToFilename(sourceCode: string): string {
	return FILENAME_OVERRIDES[sourceCode] ?? sourceCode.toLowerCase();
}

export function getDefaultFetchUrl(
	sourceCode: string,
	baseUrl?: string,
): string {
	const filename = `bestiary-${sourceCodeToFilename(sourceCode)}.json`;
	if (baseUrl !== undefined) {
		const normalized = baseUrl.endsWith("/") ? baseUrl : `${baseUrl}/`;
		return `${normalized}${filename}`;
	}
	return `https://raw.githubusercontent.com/5etools-mirror-3/5etools-src/main/data/bestiary/${filename}`;
}

export function getSourceDisplayName(sourceCode: string): string {
	const index = loadBestiaryIndex();
	return index.sources[sourceCode] ?? sourceCode;
}