import { HttpStatus, Inject, Injectable } from '@nestjs/common';
import { randomUUID } from 'node:crypto';
import sanitizeHtml from 'sanitize-html';
import {
  API_ERROR_CODES,
  type FinancialDisclosureDetail,
  type FinancialDisclosureDetailResponse,
  type PaginatedFinancialDisclosuresResponse,
} from '@lehuo/contracts';
import { AuditService } from '../audit/audit.service';
import { ApplicationError } from '../common/application-error';
import type { AuthContext, RequestContext } from '../common/request-context';
import { PrismaService } from '../database/prisma.service';
import type { FinancialDisclosure, Prisma } from '../generated/prisma/client';
import { SensitiveDataService } from '../security/sensitive-data.service';
import type {
  CreateFinancialDisclosureDto,
  FinancialDisclosureQueryDto,
  TransitionFinancialDisclosureDto,
  UpdateFinancialDisclosureDto,
} from './dto/financial-disclosure.dto';

const clean = (html: string) =>
  sanitizeHtml(html, {
    allowedTags: [
      'p',
      'br',
      'h1',
      'h2',
      'h3',
      'h4',
      'strong',
      'b',
      'em',
      'i',
      'u',
      's',
      'blockquote',
      'ul',
      'ol',
      'li',
      'table',
      'thead',
      'tbody',
      'tr',
      'th',
      'td',
      'a',
      'img',
      'hr',
      'span',
    ],
    allowedAttributes: {
      a: ['href', 'title'],
      img: ['src', 'alt', 'title'],
      th: ['colspan', 'rowspan'],
      td: ['colspan', 'rowspan'],
      span: ['style'],
      p: ['style'],
      h1: ['style'],
      h2: ['style'],
      h3: ['style'],
    },
    allowedStyles: {
      '*': {
        'text-align': [/^(left|right|center|justify)$/],
        color: [/^#[0-9a-f]{3,6}$/i],
        'background-color': [/^#[0-9a-f]{3,6}$/i],
      },
    },
    allowedSchemes: ['https'],
    allowedSchemesByTag: { img: ['https'] },
    enforceHtmlBoundary: true,
  });

@Injectable()
export class FinancialDisclosuresService {
  constructor(
    @Inject(PrismaService) private readonly prisma: PrismaService,
    @Inject(SensitiveDataService) private readonly sensitive: SensitiveDataService,
    @Inject(AuditService) private readonly audit: AuditService,
  ) {}
  listAdmin(q: FinancialDisclosureQueryDto) {
    return this.list(q.status ? { status: q.status as never } : {}, q.page, q.pageSize);
  }
  listPublic(q: FinancialDisclosureQueryDto) {
    return this.list({ status: 'PUBLISHED' }, q.page, q.pageSize);
  }
  async getAdmin(id: string): Promise<FinancialDisclosureDetailResponse> {
    return { disclosure: this.detail(await this.find(id)) };
  }
  async getPublic(id: string): Promise<FinancialDisclosureDetailResponse> {
    const item = await this.find(id);
    if (item.status !== 'PUBLISHED') throw this.notFound();
    return { disclosure: this.detail(item) };
  }

  async create(
    input: CreateFinancialDisclosureDto,
    actor: AuthContext,
    req: RequestContext,
  ): Promise<FinancialDisclosureDetailResponse & { idempotentReplay: boolean }> {
    const richText = this.sanitize(input.richText),
      fp = this.fingerprint('financial-disclosure-create', { ...input, richText });
    const replay = await this.prisma.financialDisclosure.findUnique({
      where: {
        createdById_clientRequestId: {
          createdById: actor.userId,
          clientRequestId: input.clientRequestId,
        },
      },
    });
    if (replay) {
      if (replay.requestFingerprint !== fp) throw this.duplicate();
      return { disclosure: this.detail(replay), idempotentReplay: true };
    }
    const item = await this.prisma.$transaction(async (tx) => {
      const created = await tx.financialDisclosure.create({
        data: {
          publicId: randomUUID(),
          clientRequestId: input.clientRequestId,
          requestFingerprint: fp,
          title: input.title.trim(),
          summary: input.summary?.trim() || null,
          richText,
          isPinned: input.isPinned ?? false,
          sortOrder: input.sortOrder ?? 0,
          createdById: actor.userId,
          updatedById: actor.userId,
        },
      });
      await tx.financialDisclosureStatusHistory.create({
        data: {
          financialDisclosureId: created.id,
          requestId: input.clientRequestId,
          requestFingerprint: fp,
          toStatus: 'DRAFT',
          operatorUserId: actor.userId,
        },
      });
      await this.audit.record(
        req,
        {
          action: 'FINANCIAL_DISCLOSURE_CREATED',
          result: 'SUCCESS',
          actor,
          resourceType: 'FINANCIAL_DISCLOSURE',
          resourcePublicId: created.publicId,
        },
        tx,
      );
      return created;
    });
    return { disclosure: this.detail(item), idempotentReplay: false };
  }

  async update(
    id: string,
    input: UpdateFinancialDisclosureDto,
    actor: AuthContext,
    req: RequestContext,
  ): Promise<FinancialDisclosureDetailResponse> {
    const current = await this.find(id);
    if (current.status !== 'DRAFT') throw this.invalid();
    if (current.revision !== input.expectedRevision) throw this.conflict();
    const richText = this.sanitize(input.richText);
    const updated = await this.prisma.$transaction(async (tx) => {
      const result = await tx.financialDisclosure.updateMany({
        where: { id: current.id, revision: input.expectedRevision, status: 'DRAFT' },
        data: {
          title: input.title.trim(),
          summary: input.summary?.trim() || null,
          richText,
          isPinned: input.isPinned ?? false,
          sortOrder: input.sortOrder ?? 0,
          updatedById: actor.userId,
          revision: { increment: 1 },
        },
      });
      if (result.count !== 1) throw this.conflict();
      await this.audit.record(
        req,
        {
          action: 'FINANCIAL_DISCLOSURE_UPDATED',
          result: 'SUCCESS',
          actor,
          resourceType: 'FINANCIAL_DISCLOSURE',
          resourcePublicId: id,
        },
        tx,
      );
      return tx.financialDisclosure.findUniqueOrThrow({ where: { id: current.id } });
    });
    return { disclosure: this.detail(updated) };
  }

  async transition(
    id: string,
    input: TransitionFinancialDisclosureDto,
    actor: AuthContext,
    req: RequestContext,
  ) {
    const current = await this.find(id),
      fp = this.fingerprint('financial-disclosure-transition', {
        id,
        targetStatus: input.targetStatus,
      });
    const replay = await this.prisma.financialDisclosureStatusHistory.findUnique({
      where: { requestId: input.clientRequestId },
      include: { financialDisclosure: true },
    });
    if (replay) {
      if (replay.requestFingerprint !== fp) throw this.duplicate();
      return { disclosure: this.detail(replay.financialDisclosure), idempotentReplay: true };
    }
    const allowed =
      (current.status === 'DRAFT' && input.targetStatus === 'PUBLISHED') ||
      (current.status === 'PUBLISHED' && input.targetStatus === 'ARCHIVED');
    if (!allowed) throw this.invalid();
    const updated = await this.prisma.$transaction(async (tx) => {
      const result = await tx.financialDisclosure.updateMany({
        where: { id: current.id, status: current.status },
        data: {
          status: input.targetStatus,
          updatedById: actor.userId,
          revision: { increment: 1 },
          ...(input.targetStatus === 'PUBLISHED' ? { publishedAt: new Date() } : {}),
        },
      });
      if (result.count !== 1) throw this.conflict();
      await tx.financialDisclosureStatusHistory.create({
        data: {
          financialDisclosureId: current.id,
          requestId: input.clientRequestId,
          requestFingerprint: fp,
          fromStatus: current.status,
          toStatus: input.targetStatus,
          operatorUserId: actor.userId,
        },
      });
      await this.audit.record(
        req,
        {
          action: 'FINANCIAL_DISCLOSURE_STATUS_CHANGED',
          result: 'SUCCESS',
          actor,
          resourceType: 'FINANCIAL_DISCLOSURE',
          resourcePublicId: id,
          metadata: { fromStatus: current.status, toStatus: input.targetStatus },
        },
        tx,
      );
      return tx.financialDisclosure.findUniqueOrThrow({ where: { id: current.id } });
    });
    return { disclosure: this.detail(updated), idempotentReplay: false };
  }

  private async list(
    where: Prisma.FinancialDisclosureWhereInput,
    page: number,
    pageSize: number,
  ): Promise<PaginatedFinancialDisclosuresResponse> {
    const [total, items] = await this.prisma.$transaction([
      this.prisma.financialDisclosure.count({ where }),
      this.prisma.financialDisclosure.findMany({
        where,
        orderBy: [
          { isPinned: 'desc' },
          { sortOrder: 'desc' },
          { publishedAt: 'desc' },
          { updatedAt: 'desc' },
        ],
        skip: (page - 1) * pageSize,
        take: pageSize,
      }),
    ]);
    return { items: items.map((i) => this.item(i)), page, pageSize, total };
  }
  private async find(publicId: string) {
    const item = await this.prisma.financialDisclosure.findUnique({ where: { publicId } });
    if (!item) throw this.notFound();
    return item;
  }
  private item(i: FinancialDisclosure) {
    return {
      publicId: i.publicId,
      title: i.title,
      summary: i.summary,
      status: i.status,
      isPinned: i.isPinned,
      sortOrder: i.sortOrder,
      revision: i.revision,
      publishedAt: i.publishedAt?.toISOString() ?? null,
      updatedAt: i.updatedAt.toISOString(),
    };
  }
  private detail(i: FinancialDisclosure): FinancialDisclosureDetail {
    return { ...this.item(i), richText: i.richText };
  }
  private sanitize(value: string) {
    const result = clean(value).trim();
    if (!result || !sanitizeHtml(result, { allowedTags: [], allowedAttributes: {} }).trim())
      throw new ApplicationError(
        API_ERROR_CODES.VALIDATION_ERROR,
        '财务公开正文不能为空',
        HttpStatus.BAD_REQUEST,
      );
    return result;
  }
  private fingerprint(domain: string, value: object) {
    return this.sensitive.lookupHash(domain, JSON.stringify(value));
  }
  private notFound() {
    return new ApplicationError(
      API_ERROR_CODES.RESOURCE_NOT_FOUND,
      '未找到该财务公开文档',
      HttpStatus.NOT_FOUND,
    );
  }
  private invalid() {
    return new ApplicationError(
      API_ERROR_CODES.INVALID_STATE_TRANSITION,
      '当前文档状态不能执行该操作',
      HttpStatus.CONFLICT,
    );
  }
  private conflict() {
    return new ApplicationError(
      API_ERROR_CODES.RESOURCE_CONFLICT,
      '文档已更新，请刷新后重试',
      HttpStatus.CONFLICT,
    );
  }
  private duplicate() {
    return new ApplicationError(
      API_ERROR_CODES.DUPLICATE_REQUEST,
      '请求标识已用于其他操作',
      HttpStatus.CONFLICT,
    );
  }
}