import type { CampaignInventory } from "./campaign-types.ts";
import { dirname, resolve } from "@std/path";

function isCampaignInventory(raw: unknown): raw is CampaignInventory {
  const r = raw as CampaignInventory | null;
  if (!r || r.version !== 1) return false;
  if (typeof r.outputFolderName !== "string" || !r.outputFolderName.trim()) {
    return false;
  }
  if (!r.info || typeof r.info !== "object") return false;
  if (typeof r.info.name !== "string") return false;
  if (!Array.isArray(r.mapPositions) || !Array.isArray(r.missions)) {
    return false;
  }
  return true;
}

export function parseCampaignInventory(json: unknown): CampaignInventory {
  if (!isCampaignInventory(json)) {
    throw new Error(
      "Invalid campaign.inventory.json: expected version 1 with info, mapPositions, missions",
    );
  }
  return json;
}

export async function readCampaignInventory(
  path: string,
): Promise<CampaignInventory> {
  const text = await Deno.readTextFile(path);
  const data = JSON.parse(text) as unknown;
  return parseCampaignInventory(data);
}

export async function writeCampaignInventory(
  path: string,
  inv: CampaignInventory,
): Promise<void> {
  const dir = dirname(resolve(path));
  await Deno.mkdir(dir, { recursive: true });
  await Deno.writeTextFile(path, JSON.stringify(inv, null, 2) + "\n");
}

export function nextMissionIndex(inv: CampaignInventory): number {
  if (inv.missions.length === 0) return 0;
  return Math.max(...inv.missions.map((m) => m.index)) + 1;
}

export function defaultInventoryTemplate(): CampaignInventory {
  return {
    version: 1,
    outputFolderName: "OurCampaign",
    info: {
      name: "New Campaign",
      desc: "Subtitle",
      bigDesc: "Long description for the campaign detail panel.",
      allUnlocked: false,
      mapHeight: 500,
      backgroundAlpha: 1,
    },
    mapPositions: [],
    missions: [],
  };
}