import "server-only";

import type { AgentThreadState } from "@/lib/ai/runtime/agent-thread-state";

export interface StoryboardPreferenceMemory {
  preferredGridType?: "grid_2x2" | "grid_3x2" | "grid_3x3";
  preferredShotCount?: number;
  prefersConfirmation?: boolean;
  lastUsedGridType?: "grid_2x2" | "grid_3x2" | "grid_3x3";
  lastUsedShotCount?: number;
}

function normalizeGridType(value: unknown) {
  const normalized = String(value || "").trim();
  if (normalized === "grid_2x2" || normalized === "grid_3x2" || normalized === "grid_3x3") {
    return normalized;
  }
  return undefined;
}

function normalizeShotCount(value: unknown) {
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return undefined;
  const rounded = Math.round(parsed);
  if (rounded === 4 || rounded === 6 || rounded === 9) return rounded;
  return undefined;
}

export function extractStoryboardPreferenceMemory(
  workingState?: {
    lastTurnSummary?: unknown;
  } | null,
): StoryboardPreferenceMemory | null {
  const summary = workingState?.lastTurnSummary;
  if (!summary || typeof summary !== "object") return null;
  const summaryRecord = summary as Record<string, unknown>;
  const memory = summaryRecord.storyboardMemory;
  if (!memory || typeof memory !== "object") return null;
  const memoryRecord = memory as Record<string, unknown>;

  const normalized: StoryboardPreferenceMemory = {
    preferredGridType: normalizeGridType(memoryRecord.preferredGridType),
    preferredShotCount: normalizeShotCount(memoryRecord.preferredShotCount),
    prefersConfirmation:
      typeof memoryRecord.prefersConfirmation === "boolean"
        ? memoryRecord.prefersConfirmation
        : undefined,
    lastUsedGridType: normalizeGridType(memoryRecord.lastUsedGridType),
    lastUsedShotCount: normalizeShotCount(memoryRecord.lastUsedShotCount),
  };

  if (
    !normalized.preferredGridType &&
    !normalized.preferredShotCount &&
    normalized.prefersConfirmation === undefined &&
    !normalized.lastUsedGridType &&
    !normalized.lastUsedShotCount
  ) {
    return null;
  }

  return normalized;
}

export function buildStoryboardPreferenceMemoryUpdate(params: {
  existing?: StoryboardPreferenceMemory | null;
  preferredGridType?: "grid_2x2" | "grid_3x2" | "grid_3x3";
  preferredShotCount?: number;
  prefersConfirmation?: boolean;
  lastUsedGridType?: "grid_2x2" | "grid_3x2" | "grid_3x3";
  lastUsedShotCount?: number;
}) {
  const next: StoryboardPreferenceMemory = {
    preferredGridType: params.preferredGridType ?? params.existing?.preferredGridType,
    preferredShotCount: params.preferredShotCount ?? params.existing?.preferredShotCount,
    prefersConfirmation: params.prefersConfirmation ?? params.existing?.prefersConfirmation,
    lastUsedGridType: params.lastUsedGridType ?? params.existing?.lastUsedGridType,
    lastUsedShotCount: params.lastUsedShotCount ?? params.existing?.lastUsedShotCount,
  };
  return next;
}

export function getStoryboardPreferencePlanningHints(
  threadState?: AgentThreadState | null,
): string[] {
  const metadata = threadState?.metadata;
  const memory =
    metadata && typeof metadata === "object" && !Array.isArray(metadata)
      ? ((metadata.storyboardPreferenceMemory as StoryboardPreferenceMemory | undefined) || undefined)
      : undefined;
  if (!memory) return [];

  const hints: string[] = [];
  if (memory.preferredGridType) {
    hints.push(`用户最近偏好宫格版式：${memory.preferredGridType}。`);
  }
  if (memory.preferredShotCount) {
    hints.push(`用户最近常用镜头数：${memory.preferredShotCount} 段。`);
  }
  if (memory.prefersConfirmation === true) {
    hints.push("用户偏好先确认分镜草案，再开始执行。");
  }
  if (memory.lastUsedGridType && memory.lastUsedShotCount) {
    hints.push(
      `用户最近一次分镜任务使用的是 ${memory.lastUsedGridType}（${memory.lastUsedShotCount} 段）。`
    );
  }
  return hints;
}