import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import type { Prisma } from '@prisma/client';
import { PrismaService } from '../../prisma/prisma.service';
import { WorkActivityService } from '../work-activity/work-activity.service';
import { CreateTestCaseDto } from './dto/create-test-case.dto';
import { UpdateTestCaseDto } from './dto/update-test-case.dto';

@Injectable()
export class TestCaseService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly workActivity: WorkActivityService,
  ) {}

  async create(versionId: string, dto: CreateTestCaseDto) {
    const version = await this.ensureVersion(versionId);
    const item = await this.prisma.testCase.create({
      data: {
        ...this.toTestCaseData(dto),
        versionId,
        productId: version.productId,
        projectId: version.projectId,
        code: dto.code?.trim() || dto.caseNo?.trim() || createFallbackCode('TC'),
        title: dto.title,
        status: dto.status ?? 'pending',
      },
    });
    const activity = await this.recordTestCaseActivity(item, 'test_case_created', 'creation', `新建测试用例：${item.title}`);
    return { item, activities: [activity] };
  }

  async createMany(versionId: string, dtos: CreateTestCaseDto[]) {
    if (dtos.length === 0) return { items: [], activities: [] };
    const version = await this.ensureVersion(versionId);
    const rows = dtos.map((dto) => ({
      ...this.toTestCaseData(dto),
      versionId,
      productId: version.productId,
      projectId: version.projectId,
      code: dto.code?.trim() || dto.caseNo?.trim() || createFallbackCode('TC'),
      title: dto.title,
      status: dto.status ?? 'pending',
    }));
    await this.prisma.testCase.createMany({ data: rows, skipDuplicates: true });
    const items = await this.prisma.testCase.findMany({
      where: { versionId, code: { in: rows.map((row) => row.code) } },
    });
    const activities = await Promise.all(items.map((item) => (
      this.recordTestCaseActivity(item, 'test_case_created', 'creation', `新建测试用例：${item.title}`)
    )));
    return { items, activities };
  }

  findAll(versionId: string) {
    return this.prisma.testCase.findMany({
      where: { versionId },
      orderBy: [{ roundNo: 'asc' }, { code: 'asc' }],
    });
  }

  async update(versionId: string, id: string, dto: UpdateTestCaseDto) {
    await this.ensureTestCaseInVersion(versionId, id);
    const item = await this.prisma.testCase.update({
      where: { id_versionId: { id, versionId } },
      data: this.toTestCaseData(dto),
    });
    return { item, activities: [] };
  }

  async updateStatus(versionId: string, id: string, status: string) {
    const current = await this.ensureTestCaseInVersion(versionId, id);
    const data: Record<string, unknown> = { status };
    if (status === 'running' && !current.startedAt) data.startedAt = new Date();
    if ((status === 'passed' || status === 'failed' || status === 'blocked') && !current.completedAt) {
      data.completedAt = new Date();
    }
    const item = await this.prisma.testCase.update({
      where: { id_versionId: { id, versionId } },
      data,
    });
    const activity = await this.recordStatusActivity(item, current.status, status);
    return { item, activities: activity ? [activity] : [] };
  }

  async remove(versionId: string, id: string) {
    await this.ensureTestCaseInVersion(versionId, id);
    return this.prisma.testCase.delete({ where: { id_versionId: { id, versionId } } });
  }

  private toTestCaseData(dto: Partial<CreateTestCaseDto>) {
    return {
      ...(dto.requirementId !== undefined && { requirementId: emptyToNull(dto.requirementId) }),
      ...(dto.requirementProductId !== undefined && { requirementProductId: emptyToNull(dto.requirementProductId) }),
      ...(dto.categoryId !== undefined && { categoryId: emptyToNull(dto.categoryId) }),
      ...(dto.code !== undefined || dto.caseNo !== undefined ? { code: dto.code?.trim() || dto.caseNo?.trim() } : {}),
      ...(dto.title !== undefined && { title: dto.title }),
      ...(dto.description !== undefined && { description: dto.description ?? '' }),
      ...(dto.status !== undefined && { status: dto.status }),
      ...(dto.roundNo !== undefined && { roundNo: normalizeRoundNo(dto.roundNo) }),
      ...(dto.priority !== undefined && { priority: parsePriority(dto.priority) ?? 0 }),
      ...(dto.assigneeId !== undefined && { assigneeId: emptyToNull(dto.assigneeId) }),
      ...(dto.creatorId !== undefined || dto.createdBy !== undefined ? { creatorId: emptyToNull(dto.creatorId ?? dto.createdBy) } : {}),
      ...(dto.plannedTestAt !== undefined && { plannedTestAt: parseOptionalDate(dto.plannedTestAt) }),
      ...(dto.plannedEndAt !== undefined && { plannedEndAt: parseOptionalDate(dto.plannedEndAt) }),
      ...(dto.startedAt !== undefined && { startedAt: parseOptionalDate(dto.startedAt) }),
      ...(dto.completedAt !== undefined && { completedAt: parseOptionalDate(dto.completedAt) }),
      ...(dto.estimateHours !== undefined && { estimateHours: dto.estimateHours }),
      ...(dto.aiEstimateHours !== undefined && { aiEstimateHours: dto.aiEstimateHours }),
      ...(dto.references !== undefined && { references: toJsonInput(dto.references) }),
      ...(dto.aiDraft !== undefined && { aiDraft: dto.aiDraft }),
      ...(dto.aiDraftAt !== undefined && { aiDraftAt: parseOptionalDate(dto.aiDraftAt) }),
    };
  }

  private async ensureVersion(versionId: string) {
    const version = await this.prisma.version.findUnique({ where: { id: versionId } });
    if (!version) throw new NotFoundException('版本不存在');
    if (!version.projectId) throw new BadRequestException('测试用例所属版本必须归属于项目');
    return { ...version, projectId: version.projectId };
  }

  private async ensureTestCaseInVersion(versionId: string, id: string) {
    const testCase = await this.prisma.testCase.findFirst({ where: { id, versionId } });
    if (!testCase) throw new NotFoundException('测试用例不存在');
    return testCase;
  }

  private recordStatusActivity(testCase: any, fromStatus: string, toStatus: string) {
    if (toStatus === 'running') {
      return this.recordTestCaseActivity(testCase, 'test_case_started', 'progress', `开始测试：${testCase.title}`, { fromStatus, toStatus });
    }
    if (toStatus === 'passed') {
      return this.recordTestCaseActivity(testCase, 'test_case_passed', 'delivery', `测试通过：${testCase.title}`, { fromStatus, toStatus });
    }
    if (toStatus === 'failed') {
      return this.recordTestCaseActivity(testCase, 'test_case_failed', 'risk', `测试不通过：${testCase.title}`, { fromStatus, toStatus });
    }
    if (toStatus === 'blocked') {
      return this.recordTestCaseActivity(testCase, 'test_case_blocked', 'risk', `测试阻塞：${testCase.title}`, { fromStatus, toStatus });
    }
    return undefined;
  }

  private recordTestCaseActivity(testCase: any, action: string, category: string, summary: string, metadata: Record<string, unknown> = {}) {
    return this.workActivity.record({
      versionId: testCase.versionId,
      productId: testCase.productId,
      projectId: testCase.projectId,
      actorId: testCase.assigneeId ?? testCase.creatorId,
      sourceType: 'test_case',
      sourceId: testCase.id,
      action,
      category,
      title: testCase.title,
      summary,
      metadata,
    });
  }
}

function createFallbackCode(prefix: string) {
  return `${prefix}-${Date.now().toString(36).toUpperCase()}`;
}

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

function parseOptionalDate(value: string | null | undefined): Date | null {
  if (!value) return null;
  const date = new Date(value);
  return Number.isFinite(date.getTime()) ? date : null;
}

function normalizeRoundNo(value: number | null | undefined): number {
  if (typeof value !== 'number' || !Number.isFinite(value) || value < 1) return 1;
  return Math.floor(value);
}

function parsePriority(value: string | number | null | undefined): number | undefined {
  if (value === null || value === undefined || value === '') return undefined;
  if (typeof value === 'number') return Number.isFinite(value) ? Math.max(0, Math.min(4, Math.floor(value))) : undefined;
  const match = /^P([0-4])$/i.exec(value.trim());
  if (match) return Number(match[1]);
  const parsed = Number(value);
  return Number.isFinite(parsed) ? Math.max(0, Math.min(4, Math.floor(parsed))) : undefined;
}

function toJsonInput(value: unknown): Prisma.InputJsonValue {
  return value as Prisma.InputJsonValue;
}