import { Inject, Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
import { WorkingMemoryService } from "../memory/working-memory.service.js";
import { EmotionService, dominantState } from "../emotion/emotion.service.js";
import { RelationshipService } from "../relationship/relationship.service.js";
import { ScheduleService } from "../schedule/schedule.service.js";
import { ScheduleExceptionService } from "../schedule/schedule-exception.service.js";
import { ScheduleEmotionBaselineService } from "../schedule/schedule-emotion-baseline.service.js";
import { OfflineEventService } from "../schedule/offline-event.service.js";
import { availabilityForStatus, type AvailabilityMode, type ExceptionType } from "../schedule/constants.js";
import { LLM_PROVIDER, type LLMProvider } from "./llm-provider.js";
import { ContextAssemblerService } from "./context-assembler.service.js";
import { OutputFilterService } from "./output-filter.service.js";
import { FastChannelDetector, DEFAULT_FAST_REPLIES } from "./fast-channel.service.js";
import { extractActions } from "./action-markup.js";
import { getForbiddenWords, applySpeechQuirks } from "../personality/language-style.js";
import type { GenerationContext } from "./types.js";

export interface HandleMessageOptions {
  seed?: number;
  now?: Date;
}

export interface HandleMessageResult {
  text: string;
  actions: string[];
  isFastChannel: boolean;
  availability: AvailabilityMode;
  exceptionType: ExceptionType | null;
  context: GenerationContext | null;
}

function fastChannelSituation(reason: string): string {
  return `fast-channel:${reason}`;
}

const DELAYED_ACKNOWLEDGEMENT = "抱歉剛剛在忙，現在才看到——";

// F 群組整合入口：串起雙速通道判斷、上下文組裝、Provider 生成、輸出過濾與工作記憶寫入。
// I 群組擴充：作息可用度／破例規則／作息情緒基線／離線事件生成（見 todo.md 實作記錄）。
@Injectable()
export class DialogueService {
  constructor(
    @Inject(LLM_PROVIDER) private readonly llmProvider: LLMProvider,
    private readonly fastChannel: FastChannelDetector,
    private readonly contextAssembler: ContextAssemblerService,
    private readonly outputFilter: OutputFilterService,
    private readonly workingMemory: WorkingMemoryService,
    private readonly emotion: EmotionService,
    private readonly relationship: RelationshipService,
    private readonly schedule: ScheduleService,
    private readonly scheduleException: ScheduleExceptionService,
    private readonly scheduleBaseline: ScheduleEmotionBaselineService,
    private readonly offlineEvent: OfflineEventService,
    private readonly prisma: PrismaService,
  ) {}

  async handleMessage(
    characterId: string,
    userId: string,
    sessionId: string,
    userInput: string,
    options: HandleMessageOptions = {},
  ): Promise<HandleMessageResult> {
    const now = options.now ?? new Date();
    await this.workingMemory.append(sessionId, { role: "user", content: userInput, timestamp: now });

    // I-6：按需生成離線事件（今天只生成一次），成為話題來源。
    await this.offlineEvent.maybeGenerate(characterId, now);

    // I-5：作息驅動的情緒基線，只在本輪沒有明確情緒訊號時才介入。
    const baselineSignal = await this.scheduleBaseline.computeBaseline(characterId, now);
    const emotionResult = await this.emotion.processInput(characterId, userInput, {
      now,
      baselineSignal: baselineSignal ?? undefined,
    });
    await this.relationship.recordInteraction(characterId, userId, now);

    // I-2：目前時段狀態 → 回應可用度；I-4：條件符合且未在冷卻期時才破例。
    const scheduleInfo = await this.schedule.getInfo(characterId, now);
    const availability = availabilityForStatus(scheduleInfo.slot?.status ?? null);

    let exceptionType: ExceptionType | null = null;
    let effectiveAvailability = availability;
    if (availability !== "NORMAL") {
      const { relationship } = await this.relationship.getState(characterId, userId, now);
      exceptionType = await this.scheduleException.tryApply(
        characterId,
        userId,
        availability,
        { intimacy: relationship.intimacy, dominantEmotion: dominantState(emotionResult.state), userInput },
        now,
      );
      if (exceptionType) {
        effectiveAvailability = "NORMAL";
      }
    }

    if (effectiveAvailability === "NO_REPLY") {
      return { text: "", actions: [], isFastChannel: false, availability: effectiveAvailability, exceptionType, context: null };
    }

    const { isFastChannel, reason } = this.fastChannel.detect(userInput);
    const skipMemoryRetrieval = isFastChannel || effectiveAvailability === "BRIEF";

    const context = await this.contextAssembler.assemble(characterId, userId, sessionId, userInput, {
      skipMemoryRetrieval,
      seed: options.seed,
      now,
    });

    let text: string;
    let actions: string[];

    if (effectiveAvailability === "DELAYED" && !exceptionType) {
      text = DELAYED_ACKNOWLEDGEMENT;
      actions = [];
    } else if (isFastChannel && reason) {
      const rule = await this.prisma.client.proceduralRule.findFirst({
        where: { characterId, situation: fastChannelSituation(reason) },
        orderBy: { weight: "desc" },
      });
      text = rule?.responsePattern ?? DEFAULT_FAST_REPLIES[reason];
      actions = extractActions(text);
    } else {
      const generated = await this.llmProvider.generate(context);
      text = generated.text;
      actions = generated.actions;
    }

    // I-2 剛醒／睡前：以拖長語尾的簡單標記呈現迷糊演出（完整口吻交由模板庫日後擴充）。
    if (scheduleInfo.isWaking || scheduleInfo.isPreSleep) {
      text = `……${text}`;
    }

    const forbiddenWords = getForbiddenWords(context.character.personalityArchetype);
    const filteredText = applySpeechQuirks(
      this.outputFilter.filter(text, forbiddenWords),
      context.character.personalityArchetype,
    );
    await this.workingMemory.append(sessionId, { role: "character", content: filteredText, timestamp: now });

    return { text: filteredText, actions, isFastChannel, availability: effectiveAvailability, exceptionType, context };
  }
}