import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
import { SentimentLedgerService } from "../relationship/sentiment-ledger.service.js";
import { TaskSchedulerService } from "./task-scheduler.service.js";
import { parseReminderRequest } from "./task-parser.js";
import { acceptanceLine } from "./task-performance.js";
import { TASK_LEDGER_EVENT, TASK_LEDGER_WEIGHT, RAPPORT_THRESHOLD } from "./constants.js";

export interface CreateTaskResult {
  task: Awaited<ReturnType<PrismaService["client"]["task"]["create"]>>;
  performanceLine: string;
  rapport: boolean;
}

// J-1/J-2/J-5 委託子系統核心：解析自然語句、實際建立任務（引擎責任），並附上接案演出（角色責任）。
@Injectable()
export class TaskService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly sentimentLedger: SentimentLedgerService,
    private readonly scheduler: TaskSchedulerService,
  ) {}

  // 嘗試把使用者輸入解析為單次提醒委託；無法辨識時回傳 null（呼叫端應視為一般對話）。
  async tryCreateFromText(
    characterId: string,
    userId: string,
    text: string,
    now: Date = new Date(),
  ): Promise<CreateTaskResult | null> {
    const parsed = parseReminderRequest(text, now);
    if (!parsed) {
      return null;
    }
    return this.create(
      characterId,
      userId,
      { type: "ONE_TIME", content: parsed.content, rawText: text, triggerAt: parsed.triggerAt },
      now,
    );
  }

  async create(
    characterId: string,
    userId: string,
    input: {
      type: "ONE_TIME" | "RECURRING" | "CONDITIONAL" | "QUERY_ORGANIZE" | "TODO_TRACKING";
      content: string;
      rawText: string;
      triggerAt?: Date;
      cronExpression?: string;
      condition?: string;
      sourceRoomId?: string; // T7：房內自走委託的來源房間，供追溯到來源房間與該則發言
    },
    now: Date = new Date(),
  ): Promise<CreateTaskResult> {
    const character = await this.prisma.client.character.findUniqueOrThrow({ where: { id: characterId } });

    // J-5 默契旗標：同角色/同使用者/同類型/同內容的委託，這是第幾次了。
    const priorCount = await this.prisma.client.task.count({
      where: { characterId, userId, type: input.type, content: input.content },
    });
    const rapport = priorCount + 1 >= RAPPORT_THRESHOLD;

    const task = await this.prisma.client.task.create({
      data: {
        characterId,
        userId,
        type: input.type,
        content: input.content,
        rawText: input.rawText,
        triggerAt: input.triggerAt,
        cronExpression: input.cronExpression,
        condition: input.condition,
        sourceRoomId: input.sourceRoomId,
      },
    });

    if (task.triggerAt) {
      this.scheduler.scheduleTask(task.id, task.triggerAt);
    }

    // J-5 任務與關係的迴路：委託本身（接案）就寫入正向關係帳本事件，不必等到完成。
    await this.sentimentLedger.recordEvent(
      characterId,
      userId,
      TASK_LEDGER_EVENT.ACCEPTED,
      TASK_LEDGER_WEIGHT.ACCEPTED,
      { now },
    );

    const performanceLine = acceptanceLine(character.personalityArchetype, priorCount);
    return { task, performanceLine, rapport };
  }

  async get(taskId: string) {
    return this.prisma.client.task.findUnique({ where: { id: taskId } });
  }

  async listForUser(characterId: string, userId: string) {
    return this.prisma.client.task.findMany({
      where: { characterId, userId },
      orderBy: { createdAt: "desc" },
    });
  }

  async cancel(taskId: string) {
    return this.prisma.client.task.update({ where: { id: taskId }, data: { status: "CANCELLED" } });
  }
}