import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
import { EmotionService, dominantState } from "../emotion/emotion.service.js";
import { RomanceService } from "./romance.service.js";
import { RomanceEligibilityService } from "./romance-eligibility.service.js";
import { isOutsideSoloRoom } from "./room-context-guard.js";
import {
  CONFESSION_METER_THRESHOLD,
  AWKWARD_PERIOD_DAYS,
  REJECTION_DAMAGE_THRESHOLD,
  REJECTION_DAMAGE_METER_PENALTY,
  IMMEDIATE_RECONFESS_PENALTY,
  BAD_TIMING_DISAPPOINTMENT_WINDOW_MS,
} from "./constants.js";

const DAY_MS = 24 * 60 * 60 * 1000;

export type ConfessionOutcome = "INELIGIBLE" | "REJECTED_TOO_SOON" | "REJECTED" | "ACCEPTED";

export interface ConfessionResult {
  outcome: ConfessionOutcome;
  romanceMeter: number;
  consecutiveRejections: number;
}

function clamp(value: number, min: number, max: number): number {
  return Math.max(min, Math.min(max, value));
}

// L-2 告白事件：答覆由當時心動值與性格（透過階段/曲線間接反映）決定，可以被拒絕；
// 她的拒絕是真的拒絕——拒絕後立即再推進不是「等待被說服的關卡」，而是觸發警戒與心動值下降。
@Injectable()
export class ConfessionService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly romance: RomanceService,
    private readonly eligibility: RomanceEligibilityService,
    private readonly emotion: EmotionService,
  ) {}

  async confess(characterId: string, userId: string, now: Date = new Date(), roomId?: string): Promise<ConfessionResult> {
    // T42：房型已轉為 GROUP／LOBBY／SELF_CHAT 時，告白一律不可用——不消耗嘗試次數、不記錄拒絕。
    if (await isOutsideSoloRoom(this.prisma, roomId)) {
      return { outcome: "INELIGIBLE", romanceMeter: 0, consecutiveRejections: 0 };
    }

    const eligible = await this.eligibility.getEligibility(characterId);
    if (!eligible.romanceAxisEligible) {
      return { outcome: "INELIGIBLE", romanceMeter: 0, consecutiveRejections: 0 };
    }

    const relationship = await this.romance.getState(characterId, userId, now);

    if (relationship.awkwardUntil && now.getTime() < relationship.awkwardUntil.getTime()) {
      // 尷尬期內立即再推進：她的意願是狀態機的一部分，不是等待被說服的關卡——觸發警戒＋心動值下降。
      const penalizedMeter = clamp(relationship.romanceMeter - IMMEDIATE_RECONFESS_PENALTY, 0, 100);
      await this.emotion.processInput(characterId, "", { now, baselineSignal: { tag: "ALERT", intensity: 0.4 } });
      await this.prisma.client.relationship.update({
        where: { id: relationship.id },
        data: { romanceMeter: penalizedMeter, lastRomanceEventAt: now },
      });
      await this.prisma.client.romanceEventLog.create({
        data: { characterId, userId, eventType: "CONFESSION_REJECTED", delta: -IMMEDIATE_RECONFESS_PENALTY, occurredAt: now },
      });
      return { outcome: "REJECTED_TOO_SOON", romanceMeter: penalizedMeter, consecutiveRejections: relationship.consecutiveRejections };
    }

    const emotionState = await this.emotion.getState(characterId, now);
    const isLowEmotion = dominantState(emotionState) === "SAD";
    const recentDisappointment = await this.prisma.client.romanceEventLog.findFirst({
      where: {
        characterId,
        userId,
        eventType: "DISAPPOINTMENT",
        occurredAt: { gte: new Date(now.getTime() - BAD_TIMING_DISAPPOINTMENT_WINDOW_MS) },
      },
    });
    const badTiming = isLowEmotion || Boolean(recentDisappointment);
    const meterSufficient =
      relationship.romanceStage === "AMBIGUOUS" && relationship.romanceMeter >= CONFESSION_METER_THRESHOLD;
    const accepted = meterSufficient && !badTiming;

    if (accepted) {
      await this.prisma.client.relationship.update({
        where: { id: relationship.id },
        data: {
          romanceStage: "PARTNER",
          partnerSince: now,
          consecutiveRejections: 0,
          romanceEventsInStage: 0,
          awkwardUntil: null,
          lastRomanceEventAt: now,
        },
      });
      await this.prisma.client.romanceEventLog.create({
        data: { characterId, userId, eventType: "CONFESSION_ACCEPTED", delta: 0, occurredAt: now },
      });
      return { outcome: "ACCEPTED", romanceMeter: relationship.romanceMeter, consecutiveRejections: 0 };
    }

    const consecutiveRejections = relationship.consecutiveRejections + 1;
    // 拒絕不清空累積，但連續失敗達門檻才會真的傷關係（額外扣心動值）。
    const meterPenalty = consecutiveRejections >= REJECTION_DAMAGE_THRESHOLD ? REJECTION_DAMAGE_METER_PENALTY : 0;
    const nextMeter = clamp(relationship.romanceMeter - meterPenalty, 0, 100);
    await this.prisma.client.relationship.update({
      where: { id: relationship.id },
      data: {
        romanceMeter: nextMeter,
        consecutiveRejections,
        awkwardUntil: new Date(now.getTime() + AWKWARD_PERIOD_DAYS * DAY_MS),
        lastRomanceEventAt: now,
      },
    });
    await this.prisma.client.romanceEventLog.create({
      data: { characterId, userId, eventType: "CONFESSION_REJECTED", delta: -meterPenalty, occurredAt: now },
    });
    return { outcome: "REJECTED", romanceMeter: nextMeter, consecutiveRejections };
  }
}