import {
  BadRequestException,
  Injectable,
  NotFoundException,
  ServiceUnavailableException,
} from '@nestjs/common';
import type {
  ApplyNoteAiSuggestionRequest,
  NoteAiPayloadDto,
  NoteAiSuggestionDto,
} from '@mento/shared';
import { PrismaService } from '../prisma/prisma.service';
import { AiService } from '../ai/ai.service';
import { MemoryService } from '../memory/memory.service';
import { type Actor, noteAccessWhere } from '../common/record-scope';

@Injectable()
export class NoteAiService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly ai: AiService,
    private readonly memory: MemoryService,
  ) {}

  async analyze(
    organizationId: string,
    noteId: string,
    actor: Actor,
  ): Promise<NoteAiSuggestionDto> {
    const note = await this.loadNote(organizationId, noteId, actor);
    if (!this.ai.isEnabled()) {
      throw new ServiceUnavailableException('هوش مصنوعی فعال نیست');
    }

    try {
      const extract = await this.ai.extractFromNote({
        body: note.body,
        title: note.title,
        noteType: note.noteType,
        personName: note.person
          ? `${note.person.firstName} ${note.person.lastName}`.trim()
          : null,
      });

      const row = await this.prisma.noteAiSuggestion.upsert({
        where: { noteId },
        create: {
          organizationId,
          noteId,
          status: 'pending',
          payload: extract,
          analyzedAt: new Date(),
        },
        update: {
          status: 'pending',
          payload: extract,
          errorMessage: null,
          analyzedAt: new Date(),
        },
      });

      return this.toDto(row);
    } catch (err) {
      const message =
        err instanceof Error ? err.message : 'تحلیل یادداشت ناموفق بود';
      await this.prisma.noteAiSuggestion.upsert({
        where: { noteId },
        create: {
          organizationId,
          noteId,
          status: 'failed',
          errorMessage: message,
          analyzedAt: new Date(),
        },
        update: {
          status: 'failed',
          errorMessage: message,
          analyzedAt: new Date(),
        },
      });
      throw err instanceof ServiceUnavailableException ||
        err instanceof BadRequestException
        ? err
        : new ServiceUnavailableException(message);
    }
  }

  async getSuggestion(
    organizationId: string,
    noteId: string,
    actor: Actor,
  ): Promise<NoteAiSuggestionDto | null> {
    await this.ensureNoteAccess(organizationId, noteId, actor);
    const row = await this.prisma.noteAiSuggestion.findUnique({
      where: { noteId },
    });
    return row ? this.toDto(row) : null;
  }

  async apply(
    organizationId: string,
    userId: string,
    noteId: string,
    actor: Actor,
    dto: ApplyNoteAiSuggestionRequest,
  ): Promise<{
    suggestion: NoteAiSuggestionDto;
    activityId?: string;
    memoryItemIds: string[];
  }> {
    const note = await this.loadNote(organizationId, noteId, actor);
    const suggestion = await this.prisma.noteAiSuggestion.findUnique({
      where: { noteId },
    });
    if (!suggestion || suggestion.status !== 'pending') {
      throw new BadRequestException('پیشنهاد فعالی برای این یادداشت وجود ندارد');
    }

    const payload = suggestion.payload as NoteAiPayloadDto | null;
    if (!payload) {
      throw new BadRequestException('داده پیشنهاد نامعتبر است');
    }

    let activityId: string | undefined;
    const memoryItemIds: string[] = [];

    if (dto.applyNextAction) {
      const next = dto.nextAction ?? payload.nextAction;
      if (!next?.title?.trim()) {
        throw new BadRequestException('عنوان کار بعدی الزامی است');
      }
      const activity = await this.prisma.activity.create({
        data: {
          organizationId,
          type: 'task',
          title: next.title.trim().slice(0, 200),
          description: next.description?.trim() || note.body,
          dueAt: next.dueAt ? new Date(next.dueAt) : note.reminderAt,
          personId: note.personId,
          companyId: note.companyId,
          dealId: note.dealId,
          assigneeId: userId,
        },
      });
      activityId = activity.id;
    }

    if (dto.memoryIndices?.length) {
      if (!note.personId) {
        throw new BadRequestException(
          'برای ذخیره حافظه، یادداشت باید به یک شخص متصل باشد',
        );
      }
      const indices = [...new Set(dto.memoryIndices)].filter(
        (i) => i >= 0 && i < payload.memoryItems.length,
      );
      for (const index of indices) {
        const edited = dto.memoryItems?.find((m) => m.index === index);
        const content =
          edited?.content?.trim() ||
          payload.memoryItems[index]?.content?.trim();
        if (!content) continue;
        const item = await this.memory.createFromNote(
          organizationId,
          userId,
          note.personId,
          noteId,
          content,
        );
        memoryItemIds.push(item.id);
      }
    }

    const updated = await this.prisma.noteAiSuggestion.update({
      where: { noteId },
      data: { status: 'applied' },
    });

    return {
      suggestion: this.toDto(updated),
      activityId,
      memoryItemIds,
    };
  }

  async dismiss(
    organizationId: string,
    noteId: string,
    actor: Actor,
  ): Promise<NoteAiSuggestionDto> {
    await this.ensureNoteAccess(organizationId, noteId, actor);
    const existing = await this.prisma.noteAiSuggestion.findUnique({
      where: { noteId },
    });
    if (!existing) {
      throw new NotFoundException('پیشنهادی برای این یادداشت وجود ندارد');
    }
    const row = await this.prisma.noteAiSuggestion.update({
      where: { noteId },
      data: { status: 'dismissed' },
    });
    return this.toDto(row);
  }

  private async loadNote(
    organizationId: string,
    noteId: string,
    actor: Actor,
  ) {
    const note = await this.prisma.note.findFirst({
      where: { id: noteId, organizationId, ...noteAccessWhere(actor) },
      include: {
        person: { select: { id: true, firstName: true, lastName: true } },
      },
    });
    if (!note) throw new NotFoundException('یادداشت پیدا نشد');
    return note;
  }

  private async ensureNoteAccess(
    organizationId: string,
    noteId: string,
    actor: Actor,
  ) {
    await this.loadNote(organizationId, noteId, actor);
  }

  private toDto(row: {
    id: string;
    noteId: string;
    status: string;
    payload: unknown;
    errorMessage: string | null;
    analyzedAt: Date | null;
    createdAt: Date;
    updatedAt: Date;
  }): NoteAiSuggestionDto {
    return {
      id: row.id,
      noteId: row.noteId,
      status: row.status as NoteAiSuggestionDto['status'],
      payload: (row.payload as NoteAiPayloadDto | null) ?? null,
      errorMessage: row.errorMessage,
      analyzedAt: row.analyzedAt?.toISOString() ?? null,
      createdAt: row.createdAt.toISOString(),
      updatedAt: row.updatedAt.toISOString(),
    };
  }
}