import {
  BadRequestException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';
import type {
  CreateNoteRequest,
  NoteAttachmentDto,
  NoteChecklistItemDto,
  NoteDto,
  NoteRevisionDto,
  NoteVisibility,
  PaginatedResponse,
  UpdateNoteRequest,
} from '@mento/shared';
import { Prisma } from '@prisma/client';
import { randomUUID } from 'node:crypto';
import * as path from 'path';
import { PrismaService } from '../prisma/prisma.service';
import { buildSearchWhere, ci } from '../common/search';
import { LocalFileStorage } from '../storage/local-file.storage';
import { GamificationService } from '../gamification/gamification.service';
import { asCustomFields, toJsonCustomFields } from '../common/custom-fields';
import {
  type Actor,
  noteAccessWhere,
  ownerWhere,
  dealAccessWhere,
} from '../common/record-scope';

type NoteActor = Pick<
  Actor,
  'userId' | 'role' | 'dataVisibility' | 'visibleUserIds'
>;

type NoteRow = {
  id: string;
  title: string | null;
  body: string;
  noteType: string;
  visibility: string;
  pinned: boolean;
  color: string | null;
  tags: string[];
  reminderAt: Date | null;
  checklist: Prisma.JsonValue | null;
  locationText: string | null;
  analyzeEnabled: boolean;
  customFields: Prisma.JsonValue;
  createdAt: Date;
  updatedAt: Date;
  person: { id: string; firstName: string; lastName: string } | null;
  company: { id: string; name: string } | null;
  deal: { id: string; title: string } | null;
  activity: { id: string; title: string } | null;
  author: { id: string; fullName: string } | null;
  attachments: Array<{
    id: string;
    fileName: string;
    mimeType: string;
    sizeBytes: number;
    createdAt: Date;
  }>;
  _count?: { revisions: number };
};

const include = {
  person: { select: { id: true, firstName: true, lastName: true } },
  company: { select: { id: true, name: true } },
  deal: { select: { id: true, title: true } },
  activity: { select: { id: true, title: true } },
  author: { select: { id: true, fullName: true } },
  attachments: {
    select: {
      id: true,
      fileName: true,
      mimeType: true,
      sizeBytes: true,
      createdAt: true,
    },
    orderBy: { createdAt: 'asc' as const },
  },
  _count: { select: { revisions: true } },
} satisfies Prisma.NoteInclude;

const MAX_ATTACHMENT_BYTES = 10 * 1024 * 1024;
const MAX_ATTACHMENTS_PER_NOTE = 8;

const ALLOWED_MIME = new Set([
  'image/jpeg',
  'image/png',
  'image/gif',
  'image/webp',
  'application/pdf',
  'text/plain',
  'text/csv',
  'application/msword',
  'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  'application/vnd.ms-excel',
  'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
  'application/zip',
  'application/x-zip-compressed',
  'audio/webm',
  'audio/wav',
  'audio/mpeg',
  'audio/mp4',
  'audio/ogg',
  'audio/x-m4a',
]);

@Injectable()
export class NotesService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly files: LocalFileStorage,
    private readonly game: GamificationService,
  ) {}

  async list(
    organizationId: string,
    actor: NoteActor,
    opts: {
      q?: string;
      pinned?: boolean;
      personId?: string;
      companyId?: string;
      dealId?: string;
      tag?: string;
      noteType?: string;
      visibility?: string;
      sort?: 'updatedAt' | 'createdAt' | 'reminderAt';
      page?: number;
      limit?: number;
    },
  ): Promise<PaginatedResponse<NoteDto>> {
    const page = opts.page ?? 1;
    const limit = opts.limit ?? 50;
    const access = noteAccessWhere(actor);
    const search = buildSearchWhere<Prisma.NoteWhereInput>(opts.q, (t) => [
      { title: ci(t) },
      { body: ci(t) },
      { tags: { has: t } },
    ]);

    const where: Prisma.NoteWhereInput = {
      organizationId,
      ...(opts.pinned != null ? { pinned: opts.pinned } : {}),
      ...(opts.personId ? { personId: opts.personId } : {}),
      ...(opts.companyId ? { companyId: opts.companyId } : {}),
      ...(opts.dealId ? { dealId: opts.dealId } : {}),
      ...(opts.noteType ? { noteType: opts.noteType } : {}),
      ...(opts.visibility === 'personal' || opts.visibility === 'team'
        ? { visibility: opts.visibility }
        : {}),
      ...(opts.tag?.trim() ? { tags: { has: opts.tag.trim() } } : {}),
      ...(search
        ? { AND: [access, search] }
        : access),
    };

    const sortField = opts.sort ?? 'updatedAt';
    const orderBy: Prisma.NoteOrderByWithRelationInput[] = [
      { pinned: 'desc' },
      { [sortField]: 'desc' },
    ];

    const [rows, total] = await this.prisma.$transaction([
      this.prisma.note.findMany({
        where,
        include,
        orderBy,
        skip: (page - 1) * limit,
        take: limit,
      }),
      this.prisma.note.count({ where }),
    ]);

    return {
      items: rows.map((row) => this.toDto(row)),
      total,
      page,
      limit,
    };
  }

  async get(
    organizationId: string,
    id: string,
    actor: NoteActor,
  ): Promise<NoteDto> {
    const row = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
      include,
    });
    if (!row) throw new NotFoundException('یادداشت پیدا نشد');
    return this.toDto(row);
  }

  async create(
    organizationId: string,
    userId: string,
    dto: CreateNoteRequest,
    actor?: NoteActor,
  ): Promise<NoteDto> {
    await this.assertLinks(
      organizationId,
      actor ?? { userId, role: 'owner' },
      dto,
    );
    const analyzeEnabled = dto.analyzeEnabled !== false;
    const checklist = parseChecklist(dto.checklist);
    const row = await this.prisma.note.create({
      data: {
        organizationId,
        authorId: userId,
        title: emptyToNull(dto.title),
        body: dto.body.trim(),
        noteType: dto.noteType?.trim() || 'general',
        visibility: normalizeVisibility(dto.visibility),
        pinned: dto.pinned ?? false,
        color: emptyToNull(dto.color) ?? 'default',
        tags: normalizeTags(dto.tags),
        reminderAt: dto.reminderAt ? new Date(dto.reminderAt) : null,
        checklist: checklist.length
          ? (checklist as unknown as Prisma.InputJsonValue)
          : Prisma.JsonNull,
        locationText: emptyToNull(dto.locationText ?? null),
        analyzeEnabled,
        customFields: toJsonCustomFields(dto.customFields),
        personId: emptyToNull(dto.personId ?? null),
        companyId: emptyToNull(dto.companyId ?? null),
        dealId: emptyToNull(dto.dealId ?? null),
        activityId: emptyToNull(dto.activityId ?? null),
      },
      include,
    });
    this.game.emit({
      organizationId,
      userId,
      event: 'NOTE_CREATED',
      entityType: 'note',
      entityId: row.id,
      entityTitle: row.title ?? row.body.slice(0, 60),
      facts: { hasDescription: row.body.trim().length >= 20 },
    });
    return this.toDto(row);
  }

  async update(
    organizationId: string,
    id: string,
    actor: NoteActor,
    dto: UpdateNoteRequest,
  ): Promise<NoteDto> {
    const existing = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
    });
    if (!existing) throw new NotFoundException('یادداشت پیدا نشد');
    await this.assertLinks(organizationId, actor, dto);

    const data: Prisma.NoteUncheckedUpdateInput = {};
    if ('title' in dto) data.title = emptyToNull(dto.title);
    if (dto.body !== undefined) data.body = dto.body.trim();
    if (dto.noteType !== undefined) data.noteType = dto.noteType.trim() || 'general';
    if (dto.visibility !== undefined) {
      data.visibility = normalizeVisibility(dto.visibility);
    }
    if (dto.pinned !== undefined) data.pinned = dto.pinned;
    if ('color' in dto) data.color = emptyToNull(dto.color) ?? 'default';
    if (dto.tags !== undefined) data.tags = normalizeTags(dto.tags);
    if ('reminderAt' in dto) {
      data.reminderAt = dto.reminderAt ? new Date(dto.reminderAt) : null;
    }
    if (dto.checklist !== undefined) {
      const checklist = parseChecklist(dto.checklist);
      data.checklist = checklist.length
        ? (checklist as unknown as Prisma.InputJsonValue)
        : Prisma.JsonNull;
    }
    if ('locationText' in dto) {
      data.locationText = emptyToNull(dto.locationText ?? null);
    }
    if (dto.analyzeEnabled !== undefined) {
      data.analyzeEnabled = dto.analyzeEnabled;
    }
    if ('customFields' in dto) {
      data.customFields = toJsonCustomFields(dto.customFields);
    }
    if ('personId' in dto) data.personId = emptyToNull(dto.personId ?? null);
    if ('companyId' in dto) data.companyId = emptyToNull(dto.companyId ?? null);
    if ('dealId' in dto) data.dealId = emptyToNull(dto.dealId ?? null);
    if ('activityId' in dto) {
      data.activityId = emptyToNull(dto.activityId ?? null);
    }

    const nextTitle =
      'title' in dto ? emptyToNull(dto.title) : existing.title;
    const nextBody = dto.body !== undefined ? dto.body.trim() : existing.body;
    const nextType =
      dto.noteType !== undefined
        ? dto.noteType.trim() || 'general'
        : existing.noteType;
    const nextVisibility =
      dto.visibility !== undefined
        ? normalizeVisibility(dto.visibility)
        : normalizeVisibility(existing.visibility);
    const nextTags =
      dto.tags !== undefined ? normalizeTags(dto.tags) : existing.tags;
    const nextChecklist =
      dto.checklist !== undefined
        ? parseChecklist(dto.checklist)
        : parseChecklist(existing.checklist);

    const contentChanged =
      (nextTitle ?? '') !== (existing.title ?? '') ||
      nextBody !== existing.body ||
      nextType !== existing.noteType ||
      nextVisibility !== normalizeVisibility(existing.visibility) ||
      JSON.stringify(nextTags) !== JSON.stringify(existing.tags) ||
      JSON.stringify(nextChecklist) !==
        JSON.stringify(parseChecklist(existing.checklist));

    if (contentChanged) {
      await this.prisma.noteRevision.create({
        data: {
          organizationId,
          noteId: id,
          editorId: actor.userId,
          title: existing.title,
          body: existing.body,
          noteType: existing.noteType,
          visibility: normalizeVisibility(existing.visibility),
          tags: existing.tags,
          checklist: existing.checklist ?? Prisma.JsonNull,
        },
      });
    }

    const row = await this.prisma.note.update({
      where: { id },
      data,
      include,
    });
    return this.toDto(row);
  }

  async listRevisions(
    organizationId: string,
    noteId: string,
    actor: NoteActor,
  ): Promise<NoteRevisionDto[]> {
    await this.ensureExists(organizationId, noteId, actor);
    const rows = await this.prisma.noteRevision.findMany({
      where: { noteId, organizationId },
      include: { editor: { select: { id: true, fullName: true } } },
      orderBy: { createdAt: 'desc' },
      take: 50,
    });
    return rows.map((row) => ({
      id: row.id,
      title: row.title,
      body: row.body,
      noteType: row.noteType,
      visibility: normalizeVisibility(row.visibility),
      tags: row.tags,
      checklist: parseChecklist(row.checklist),
      editor: row.editor,
      createdAt: row.createdAt.toISOString(),
    }));
  }

  async restoreRevision(
    organizationId: string,
    noteId: string,
    revisionId: string,
    actor: NoteActor,
  ): Promise<NoteDto> {
    await this.ensureExists(organizationId, noteId, actor);
    const revision = await this.prisma.noteRevision.findFirst({
      where: { id: revisionId, noteId, organizationId },
    });
    if (!revision) throw new NotFoundException('نسخه پیدا نشد');
    return this.update(organizationId, noteId, actor, {
      title: revision.title,
      body: revision.body,
      noteType: revision.noteType,
      visibility: normalizeVisibility(revision.visibility),
      tags: revision.tags,
      checklist: parseChecklist(revision.checklist),
    });
  }

  async togglePin(
    organizationId: string,
    id: string,
    actor: NoteActor,
  ): Promise<NoteDto> {
    const existing = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
      select: { pinned: true },
    });
    if (!existing) throw new NotFoundException('یادداشت پیدا نشد');
    const row = await this.prisma.note.update({
      where: { id },
      data: { pinned: !existing.pinned },
      include,
    });
    return this.toDto(row);
  }

  async convertToTask(
    organizationId: string,
    userId: string,
    id: string,
    actor: NoteActor,
  ): Promise<{ note: NoteDto; activityId: string }> {
    const note = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
      include,
    });
    if (!note) throw new NotFoundException('یادداشت پیدا نشد');

    const activity = await this.prisma.activity.create({
      data: {
        organizationId,
        type: 'task',
        title: (note.title?.trim() || note.body.trim()).slice(0, 200),
        description: note.body,
        dueAt: note.reminderAt,
        personId: note.personId,
        companyId: note.companyId,
        dealId: note.dealId,
        assigneeId: userId,
      },
    });

    return { note: this.toDto(note), activityId: activity.id };
  }

  async remove(
    organizationId: string,
    id: string,
    actor: NoteActor,
  ): Promise<void> {
    const note = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
      include: { attachments: { select: { storageKey: true } } },
    });
    if (!note) throw new NotFoundException('یادداشت پیدا نشد');

    for (const att of note.attachments) {
      await this.files.remove(att.storageKey);
    }
    await this.prisma.note.delete({ where: { id } });
  }

  async addAttachment(
    organizationId: string,
    userId: string,
    noteId: string,
    file: Express.Multer.File,
    actor: NoteActor,
  ): Promise<NoteAttachmentDto> {
    await this.ensureExists(organizationId, noteId, actor);

    if (!file?.buffer?.length) {
      throw new BadRequestException('فایلی ارسال نشده است');
    }
    if (file.size > MAX_ATTACHMENT_BYTES) {
      throw new BadRequestException('حداکثر حجم فایل ۱۰ مگابایت است');
    }

    const mimeType = (file.mimetype || '').toLowerCase();
    if (!ALLOWED_MIME.has(mimeType)) {
      throw new BadRequestException(
        'نوع فایل مجاز نیست. تصویر، PDF، Word، Excel، متن، ZIP یا صوت بفرستید.',
      );
    }

    const count = await this.prisma.noteAttachment.count({ where: { noteId } });
    if (count >= MAX_ATTACHMENTS_PER_NOTE) {
      throw new BadRequestException(
        `حداکثر ${MAX_ATTACHMENTS_PER_NOTE} پیوست برای هر یادداشت مجاز است`,
      );
    }

    const fileName = sanitizeFileName(file.originalname);
    const ext = path.extname(fileName).slice(0, 12);
    const attachmentId = randomUUID().replace(/-/g, '').slice(0, 24);
    const storageKey = path
      .join(organizationId, 'notes', noteId, `${attachmentId}${ext}`)
      .replace(/\\/g, '/');

    await this.files.save(storageKey, file.buffer);

    try {
      const row = await this.prisma.noteAttachment.create({
        data: {
          id: attachmentId,
          organizationId,
          noteId,
          fileName,
          mimeType,
          sizeBytes: file.size,
          storageKey,
          uploadedById: userId,
        },
      });
      return this.toAttachmentDto(row);
    } catch (err) {
      await this.files.remove(storageKey);
      throw err;
    }
  }

  async removeAttachment(
    organizationId: string,
    noteId: string,
    attachmentId: string,
    actor: NoteActor,
  ): Promise<void> {
    await this.ensureExists(organizationId, noteId, actor);
    const row = await this.prisma.noteAttachment.findFirst({
      where: { id: attachmentId, noteId, organizationId },
    });
    if (!row) throw new NotFoundException('پیوست پیدا نشد');
    await this.files.remove(row.storageKey);
    await this.prisma.noteAttachment.delete({ where: { id: row.id } });
  }

  async openAttachmentDownload(
    organizationId: string,
    noteId: string,
    attachmentId: string,
    actor: NoteActor,
  ): Promise<{
    stream: ReturnType<LocalFileStorage['openReadStream']>;
    fileName: string;
    mimeType: string;
  }> {
    await this.ensureExists(organizationId, noteId, actor);
    const row = await this.prisma.noteAttachment.findFirst({
      where: { id: attachmentId, noteId, organizationId },
    });
    if (!row) throw new NotFoundException('پیوست پیدا نشد');
    return {
      stream: this.files.openReadStream(row.storageKey),
      fileName: row.fileName,
      mimeType: row.mimeType,
    };
  }

  private async ensureExists(
    organizationId: string,
    id: string,
    actor: NoteActor,
  ) {
    const found = await this.prisma.note.findFirst({
      where: { id, organizationId, ...noteAccessWhere(actor) },
      select: { id: true },
    });
    if (!found) throw new NotFoundException('یادداشت پیدا نشد');
  }

  private async assertLinks(
    organizationId: string,
    actor: NoteActor,
    dto: {
      personId?: string | null;
      companyId?: string | null;
      dealId?: string | null;
      activityId?: string | null;
    },
  ) {
    const personId = emptyToNull(dto.personId ?? null);
    const companyId = emptyToNull(dto.companyId ?? null);
    const dealId = emptyToNull(dto.dealId ?? null);
    const activityId = emptyToNull(dto.activityId ?? null);
    const scope = ownerWhere(actor);

    if (personId) {
      const person = await this.prisma.person.findFirst({
        where: { id: personId, organizationId, ...scope },
        select: { id: true },
      });
      if (!person) throw new BadRequestException('شخص انتخاب‌شده معتبر نیست');
    }
    if (companyId) {
      const company = await this.prisma.company.findFirst({
        where: { id: companyId, organizationId, ...scope },
        select: { id: true },
      });
      if (!company) throw new BadRequestException('شرکت انتخاب‌شده معتبر نیست');
    }
    if (dealId) {
      const deal = await this.prisma.deal.findFirst({
        where: { id: dealId, organizationId, ...dealAccessWhere(actor) },
        select: { id: true },
      });
      if (!deal) throw new BadRequestException('معامله انتخاب‌شده معتبر نیست');
    }
    if (activityId) {
      const activity = await this.prisma.activity.findFirst({
        where: { id: activityId, organizationId },
        select: { id: true },
      });
      if (!activity) throw new BadRequestException('فعالیت انتخاب‌شده معتبر نیست');
    }
  }

  private toDto(row: NoteRow): NoteDto {
    return {
      id: row.id,
      title: row.title,
      body: row.body,
      noteType: row.noteType,
      visibility: normalizeVisibility(row.visibility),
      pinned: row.pinned,
      color: row.color,
      tags: row.tags,
      reminderAt: row.reminderAt?.toISOString() ?? null,
      checklist: parseChecklist(row.checklist),
      locationText: row.locationText ?? null,
      analyzeEnabled: row.analyzeEnabled ?? true,
      customFields: asCustomFields(row.customFields),
      person: row.person
        ? {
            id: row.person.id,
            fullName: `${row.person.firstName} ${row.person.lastName}`.trim(),
          }
        : null,
      company: row.company,
      deal: row.deal,
      activity: row.activity,
      author: row.author,
      attachments: (row.attachments ?? []).map((a) => this.toAttachmentDto(a)),
      revisionCount: row._count?.revisions ?? 0,
      createdAt: row.createdAt.toISOString(),
      updatedAt: row.updatedAt.toISOString(),
    };
  }

  private toAttachmentDto(row: {
    id: string;
    fileName: string;
    mimeType: string;
    sizeBytes: number;
    createdAt: Date;
  }): NoteAttachmentDto {
    return {
      id: row.id,
      fileName: row.fileName,
      mimeType: row.mimeType,
      sizeBytes: row.sizeBytes,
      createdAt: row.createdAt.toISOString(),
    };
  }
}

function emptyToNull(value?: string | null): string | null {
  if (value == null) return null;
  const trimmed = value.trim();
  return trimmed.length ? trimmed : null;
}

function normalizeVisibility(value?: string | null): NoteVisibility {
  return value === 'personal' ? 'personal' : 'team';
}

function normalizeTags(tags?: string[]): string[] {
  if (!tags?.length) return [];
  const seen = new Set<string>();
  const result: string[] = [];
  for (const tag of tags) {
    const cleaned = tag.trim().replace(/^#/, '');
    if (!cleaned || seen.has(cleaned)) continue;
    seen.add(cleaned);
    result.push(cleaned.slice(0, 40));
  }
  return result.slice(0, 12);
}

function sanitizeFileName(raw: string): string {
  const base = path.basename(raw || 'file').replace(/[<>:"/\\|?*\x00-\x1f]/g, '_');
  const trimmed = base.trim() || 'file';
  return trimmed.slice(0, 180);
}

function parseChecklist(raw: unknown): NoteChecklistItemDto[] {
  if (!Array.isArray(raw)) return [];
  const items: NoteChecklistItemDto[] = [];
  for (const entry of raw) {
    if (!entry || typeof entry !== 'object') continue;
    const rec = entry as Record<string, unknown>;
    const id = typeof rec.id === 'string' ? rec.id.trim() : '';
    const text = typeof rec.text === 'string' ? rec.text.trim() : '';
    if (!id && !text) continue;
    items.push({
      id: id || randomUUID(),
      text: text.slice(0, 500),
      done: Boolean(rec.done),
    });
  }
  return items.slice(0, 50);
}