// 生成（世界观/角色）+ 入库的纯逻辑：请求体组装、卡片归一、409 冲突收窄。
// 对齐 C3 扩（world/characters generate + characters ingest）。纯逻辑，便于 node 环境单测。

import type {
  CharacterCardView,
  CharacterGenerateRequest,
  CharacterIngestRequest,
  WorldEntityCardView,
  WorldGenerateRequest,
} from "@/lib/api/types";
import type { ReviewConflict } from "@/lib/review/sse";

// 角色数量边界（对齐后端 CharacterGenerateRequest ge=1,le=12）。
export const MIN_CHARACTER_COUNT = 1;
export const MAX_CHARACTER_COUNT = 12;

function asString(v: unknown, fallback = ""): string {
  return typeof v === "string" ? v : fallback;
}

function asStringArray(v: unknown): string[] {
  if (!Array.isArray(v)) return [];
  return v.filter((x): x is string => typeof x === "string");
}

// —— 世界观生成 ——

export function buildWorldGenerateRequest(brief: string): WorldGenerateRequest {
  return { brief: brief.trim() };
}

// —— 角色生成 ——

export function clampCharacterCount(count: number): number {
  if (!Number.isFinite(count)) return MIN_CHARACTER_COUNT;
  const n = Math.round(count);
  if (n < MIN_CHARACTER_COUNT) return MIN_CHARACTER_COUNT;
  if (n > MAX_CHARACTER_COUNT) return MAX_CHARACTER_COUNT;
  return n;
}

export function buildCharacterGenerateRequest(
  brief: string,
  count: number,
  role?: string | null,
): CharacterGenerateRequest {
  const body: CharacterGenerateRequest = {
    brief: brief.trim(),
    count: clampCharacterCount(count),
  };
  const trimmedRole = role?.trim();
  if (trimmedRole) body.role = trimmedRole;
  return body;
}

// 把作者勾选的角色卡组装成入库请求；acknowledge 用于越过 continuity gate（409 后重发）。
export function buildCharacterIngestRequest(
  cards: readonly CharacterCardView[],
  acknowledgeConflicts = false,
): CharacterIngestRequest {
  return {
    cards: cards.map((c) => ({ ...c })),
    acknowledge_conflicts: acknowledgeConflicts,
  };
}

// 入库前作者可编辑角色卡：返回新卡（不可变更新）。
export function updateCard(
  card: Readonly<CharacterCardView>,
  patch: Partial<CharacterCardView>,
): CharacterCardView {
  return { ...card, ...patch };
}

// —— 409 CONFLICT_UNRESOLVED 收窄 ——
// 后端入库 gate（C3 扩 T5.2）：details{conflicts:[{type,where,refs,suggestion}], conflict_count}。
// 复用 ReviewConflict 形（同 accept gate）。安全收窄松散 unknown。

export interface IngestConflicts {
  conflicts: ReviewConflict[];
  conflictCount: number;
}

function narrowConflict(raw: unknown): ReviewConflict {
  if (typeof raw !== "object" || raw === null) {
    return { type: "未分类", where: "", refs: [], suggestion: "" };
  }
  const c = raw as Record<string, unknown>;
  return {
    type: asString(c["type"], "未分类"),
    where: asString(c["where"]),
    refs: asStringArray(c["refs"]),
    suggestion: asString(c["suggestion"]),
  };
}

// 从错误信封提取 409 冲突详情；非冲突错误 → null。
export function extractIngestConflicts(error: unknown): IngestConflicts | null {
  if (typeof error !== "object" || error === null) return null;
  const env = error as {
    error?: {
      code?: unknown;
      details?: { conflicts?: unknown; conflict_count?: unknown } | null;
    };
  };
  if (env.error?.code !== "CONFLICT_UNRESOLVED") return null;
  const details = env.error?.details;
  if (typeof details !== "object" || details === null) return null;
  const rawConflicts = Array.isArray(details.conflicts) ? details.conflicts : [];
  const conflicts = rawConflicts.map(narrowConflict);
  const count =
    typeof details.conflict_count === "number"
      ? details.conflict_count
      : conflicts.length;
  return { conflicts, conflictCount: count };
}

// 通用错误码提取（503 LLM_UNAVAILABLE 等）。
export function errorCode(error: unknown): string | undefined {
  if (typeof error !== "object" || error === null) return undefined;
  const env = error as { error?: { code?: unknown } };
  return typeof env.error?.code === "string" ? env.error.code : undefined;
}

// 生成预览失败的统一文案（503 无凭据引导去设置）。
export function generationErrorMessage(error: unknown): string {
  return errorCode(error) === "LLM_UNAVAILABLE"
    ? "未配置提供商，请先去设置页连一家。"
    : "生成失败，请稍后重试。";
}

// 世界观实体卡展示用：rules 安全取数组。
export function worldEntityRules(entity: WorldEntityCardView): string[] {
  return entity.rules ?? [];
}

// —— 设定库 Codex 列表合并 ——
// 初始持久化列表（GET .../characters）+ 本会话新入库卡：按 name 去重（持久化优先，
// 同名以初始列表为准——避免刚入库的回显与刷新后真源重复显示）。保序：持久化在前、新卡补后。
export function mergeCharacterCards(
  persisted: readonly CharacterCardView[],
  sessionCards: readonly CharacterCardView[],
): CharacterCardView[] {
  const seen = new Set(persisted.map((c) => c.name));
  const appended = sessionCards.filter((c) => !seen.has(c.name));
  return [...persisted, ...appended];
}

// 世界观实体列表合并：同上，按 (type,name) 去重。
export function mergeWorldEntities(
  persisted: readonly WorldEntityCardView[],
  sessionEntities: readonly WorldEntityCardView[],
): WorldEntityCardView[] {
  const key = (e: WorldEntityCardView) => `${e.type} ${e.name}`;
  const seen = new Set(persisted.map(key));
  const appended = sessionEntities.filter((e) => !seen.has(key(e)));
  return [...persisted, ...appended];
}