import type {
  PageDef,
  Scenario,
  ScenarioCategory,
  ScenarioPage,
  ScenarioPageRef,
  SystemScenario,
  SystemScenarioCategory,
  UserScenario,
} from "../config/types.js";
import {
  loadPagesConfig,
  loadSystemScenariosConfig,
  loadUserScenariosConfig,
} from "../config/loadConfig.js";

export type ScenarioKey = string;

export type ScenarioSource = "system" | "user";

export type ScenarioKeyParts =
  | { source: "system"; scenarioId: string }
  | { source: "user"; scenarioId: string };

export function toScenarioKey(source: ScenarioSource, scenarioId: string): ScenarioKey {
  return (source === "system" ? "s:" : "u:") + scenarioId;
}

export function parseScenarioKey(input: string): ScenarioKeyParts {
  const raw = String(input || "").trim();
  if (raw.startsWith("s:")) return { source: "system", scenarioId: raw.slice(2) };
  if (raw.startsWith("u:")) return { source: "user", scenarioId: raw.slice(2) };
  // 兼容旧链接：不带前缀的都视为 system
  return { source: "system", scenarioId: raw };
}

function pageMap(): Record<string, PageDef> {
  const cfg = loadPagesConfig();
  const map: Record<string, PageDef> = {};
  for (const p of cfg.pages) {
    map[p.id] = p;
  }
  return map;
}

function expandPages(refs: ScenarioPageRef[], pagesById: Record<string, PageDef>): ScenarioPage[] {
  return refs
    .map((r) => {
      const def = pagesById[r.pageId];
      if (!def) return null;
      return {
        id: def.id,
        title: def.title,
        boardUrl: def.boardUrl,
        staytime: r.staytime,
      } satisfies ScenarioPage;
    })
    .filter((x): x is ScenarioPage => x !== null);
}

export type HomeScenario = {
  id: ScenarioKey;
  name: string;
  image: string;
};

export type HomeCategory = {
  id: string;
  name: string;
  scenarios: HomeScenario[];
};

export function loadHomeCatalogForUser(username: string): HomeCategory[] {
  const pagesById = pageMap();
  const sys = loadSystemScenariosConfig();
  const users = loadUserScenariosConfig();
  const userScenarios = users.users[username]?.scenarios ?? [];

  const sysCats: HomeCategory[] = (sys.categories ?? []).map(
    (c: SystemScenarioCategory) => ({
    id: c.id,
    name: c.name,
    scenarios: (c.scenarios ?? []).map((s: SystemScenario) => ({
      id: toScenarioKey("system", s.id),
      name: s.name,
      image: s.image,
    })),
  }));

  const my: HomeCategory = {
    id: "my",
    name: "我的场景",
    scenarios: userScenarios.map((s: UserScenario) => ({
      id: toScenarioKey("user", s.id),
      name: s.name,
      image: s.image || (pagesById[s.pages[0]?.pageId]?.image ?? ""),
    })),
  };

  return my.scenarios.length ? [my, ...sysCats] : sysCats;
}

export function buildScenarioImageMapForUser(username: string): Record<string, string> {
  const map: Record<string, string> = {};
  const cats = loadHomeCatalogForUser(username);
  for (const c of cats) {
    for (const s of c.scenarios) {
      map[s.id] = s.image;
    }
  }
  return map;
}

export type ResolvedScenario = {
  source: ScenarioSource;
  scenario: Scenario;
};

export function resolveScenarioForUser(
  username: string,
  scenarioKey: string
): ResolvedScenario | null {
  const pagesById = pageMap();
  const key = parseScenarioKey(scenarioKey);

  if (key.source === "system") {
    const sys = loadSystemScenariosConfig();
    for (const cat of sys.categories) {
      for (const sc of cat.scenarios) {
        if (sc.id !== key.scenarioId) continue;
        const pages = expandPages(sc.pages, pagesById);
        return {
          source: "system",
          scenario: {
            id: toScenarioKey("system", sc.id),
            name: sc.name,
            image: sc.image,
            pages,
          },
        };
      }
    }
    return null;
  }

  const users = loadUserScenariosConfig();
  const mine = users.users[username]?.scenarios ?? [];
  const sc = mine.find((x) => x.id === key.scenarioId);
  if (!sc) return null;
  const pages = expandPages(sc.pages, pagesById);
  return {
    source: "user",
    scenario: {
      id: toScenarioKey("user", sc.id),
      name: sc.name,
      image: sc.image,
      pages,
    },
  };
}

/** 仅用于 view 的 slide 构建（boardUrl 在路由里再拼 dataEasePublicBase） */
export function scenarioToSlides(sc: Scenario): Array<{
  id: string;
  title: string;
  staytime: number;
  boardUrl: string;
}> {
  return sc.pages.map((p) => ({
    id: p.id,
    title: p.title,
    staytime: p.staytime,
    boardUrl: p.boardUrl,
  }));
}