import { Config } from "@systems/config";

/**
 * Parses a combat-stat value (ATK/DEF/Heal) that may use K/M shorthand,
 * case-insensitive (e.g. "500", "500k", "1.4M", "2.7m"). Comma is accepted
 * as a decimal separator too ("3,4M" parses the same as "3.4M") since
 * players naturally try it.
 *
 * A bare number with no suffix is inferred: >= 100 is assumed to already
 * be in thousands ("500" -> 500K), below 100 is assumed to be shorthand
 * millions ("1.4" -> 1.4M) — combat stats are never realistically in the
 * single-to-double-digit range.
 *
 * Also enforces a configurable plausibility ceiling (`Config.tg.maxStatValue`,
 * default 50M) — real recorded ATK/DEF values top out around 10-13M, but a
 * stray extra digit or a redundant M on an already-large number
 * ("150.0M", "124000M") silently produces a nonsense multi-billion value
 * with no upstream validation catching it otherwise. The cap is officer-
 * adjustable (`/tg-config tg set-max-stat-value`) rather than hardcoded,
 * since what counts as "impossible" can shift with game balance changes —
 * this is a sanity check, not a hard game-rule.
 *
 * Shared by the Submit Score modal, `/tg score set`, and
 * `/tg-admin score-inject` so all three entry points behave identically.
 */
export interface StatValueResult {
  value?: number;
  error?: string;
}

export function parseStatValue(raw: string | null | undefined, label: string): StatValueResult {
  if (!raw) return {};

  const normalized = raw.trim().replace(",", ".");
  const match = normalized.match(/^(\d+(?:\.\d+)?)\s*([kKmM])?$/);
  if (!match) {
    return { error: `${label} must be ${STAT_VALUE_HINT}.` };
  }

  const parsed = parseFloat(match[1]);
  const suffix = match[2]?.toLowerCase();

  let value: number;
  if (suffix === "k")      value = Math.round(parsed * 1_000);
  else if (suffix === "m") value = Math.round(parsed * 1_000_000);
  else                     value = Math.round(parsed >= 100 ? parsed * 1_000 : parsed * 1_000_000);

  const cap = Config.get({ section: "tg", key: "maxStatValue" });
  if (value > cap) {
    return {
      error: `${label} of ${value.toLocaleString()} is above the ${cap.toLocaleString()} sanity limit — ` +
             `check for a typo (e.g. an extra digit or a redundant M/K). If this is genuinely correct, ` +
             `an officer can raise the limit with \`/tg-config tg set-max-stat-value\`.`,
    };
  }

  return { value };
}

export const STAT_VALUE_HINT = "a number, optionally with a K or M suffix (e.g. `500K`, `1.4M`)";