import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
import { ProjectionService } from "./projection.service.js";
import { WorkRosterService } from "./work-roster.service.js";

// M-9 錨定點與知識邊界：錨定點之前是角色的親身經歷、之後不存在。場景匯入時只寫入共用場景資料庫，
// 只有 storyOrder <= 錨定點的場景會被投影進角色記憶——移動錨定點（無論前進或後退）都要讓「已投影」的
// 場景集合與「storyOrder <= 錨定點」的場景集合重新同步。
@Injectable()
export class AnchorService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly projection: ProjectionService,
    private readonly roster: WorkRosterService,
  ) {}

  async setAnchor(workId: string, newStoryOrder: number): Promise<{ projected: number; unprojected: number }> {
    const work = await this.prisma.client.work.findUniqueOrThrow({ where: { id: workId } });

    const toProject = await this.prisma.client.scene.findMany({
      where: { workId, storyOrder: { lte: newStoryOrder }, projected: false },
      include: { participants: true },
    });
    for (const scene of toProject) {
      await this.projection.projectScene(scene.id);
      for (const presence of scene.participants) {
        await this.roster.checkAndPromote(presence.characterId);
      }
    }

    // 錨定點後退：她「不再知道」超出新錨定點的後段劇情——移除這些場景先前投影出的所有角色資料。
    const toUnproject = await this.prisma.client.scene.findMany({
      where: { workId, storyOrder: { gt: newStoryOrder }, projected: true },
    });
    for (const scene of toUnproject) {
      await this.prisma.client.episodicMemory.deleteMany({ where: { sourceSceneId: scene.id } });
      await this.prisma.client.semanticMemory.deleteMany({ where: { sourceSceneId: scene.id } });
      await this.prisma.client.personalityTraitSnapshot.deleteMany({ where: { sourceSceneId: scene.id } });
      await this.prisma.client.characterRelationshipEventLog.deleteMany({ where: { sceneId: scene.id } });
      await this.prisma.client.scene.update({ where: { id: scene.id }, data: { projected: false } });
    }

    await this.prisma.client.work.update({ where: { id: work.id }, data: { anchorStoryOrder: newStoryOrder } });
    return { projected: toProject.length, unprojected: toUnproject.length };
  }

  // M-9 依錨定點取用「當時的她」的性格參數：取 atStoryOrder <= 錨定點裡最新的一筆快照。
  async effectivePersonalitySnapshot(characterId: string, atStoryOrder: number) {
    return this.prisma.client.personalityTraitSnapshot.findFirst({
      where: { characterId, atStoryOrder: { lte: atStoryOrder } },
      orderBy: { atStoryOrder: "desc" },
    });
  }
}