import { Injectable, NotFoundException, NotImplementedException } from '@nestjs/common';
import { randomUUID } from 'crypto';
import { PrismaService } from '../../prisma/prisma.service';
import { CreateTemplateDto } from './dto/create-template.dto';
import { CreateTemplateMakeTaskDto } from './dto/create-template-make-task.dto';
import { TemplateAssetsDto } from './dto/get-template-assets.dto';
import { ListTemplatesQueryDto } from './dto/list-templates-query.dto';
import { TemplateBasicInfoDto } from './dto/template-basic-info.dto';
import { UpdateTemplateBasicInfoDto } from './dto/update-template-basic-info.dto';
import { TemplateAiClient } from './template-ai.client';
import { TemplateTaskRunner } from './template-task-runner';

type TemplateListQuery = ListTemplatesQueryDto & {
  stylistId: bigint;
};

const TEMPLATE_CATEGORIES = ['LONG', 'MEDIUM', 'SHORT', 'DYE'] as const;
const TEMPLATE_STATUSES = ['DRAFT', 'PUBLIC'] as const;

@Injectable()
export class TemplatesService {
  private get systemConfigDelegate(): {
    findMany: (args: Record<string, unknown>) => Promise<
      Array<{
        id: bigint;
        configKey: string;
        configName: string;
        configGroup: string;
        configValue: string | null;
      }>
    >;
  } {
    return (
      this.prisma as PrismaService & {
        systemConfig: {
          findMany: (args: Record<string, unknown>) => Promise<
            Array<{
              id: bigint;
              configKey: string;
              configName: string;
              configGroup: string;
              configValue: string | null;
            }>
          >;
        };
      }
    ).systemConfig;
  }

  constructor(
    private readonly prisma: PrismaService,
    private readonly templateAiClient: TemplateAiClient,
    private readonly templateTaskRunner: TemplateTaskRunner,
  ) {}

  private async getOwnedTemplate(stylistId: bigint, templateId: string) {
    const template = await this.prisma.hairTemplate.findFirst({
      where: {
        id: BigInt(templateId),
        hairstylistId: stylistId,
        isDeleted: 0,
      },
    });

    if (!template) {
      throw new NotFoundException('模板不存在');
    }

    return template;
  }

  private toBasicInfoDto(template: {
    id: bigint;
    templateName: string;
    status: 'DRAFT' | 'PUBLIC';
    category: 'LONG' | 'MEDIUM' | 'SHORT' | 'DYE';
    tags: string;
    description: string | null;
    coverUrl: string;
    templateUrl: string;
  }): TemplateBasicInfoDto {
    return {
      id: template.id.toString(),
      templateName: template.templateName,
      status: template.status,
      category: template.category,
      tags: template.tags
        ? template.tags
            .split(',')
            .map((tag) => tag.trim())
            .filter(Boolean)
        : [],
      description: template.description ?? '',
      coverUrl: template.coverUrl,
      templateUrl: template.templateUrl,
    };
  }

  private toTemplateListItem(
    template: {
      id: bigint;
      templateName: string;
      category: 'LONG' | 'MEDIUM' | 'SHORT' | 'DYE';
      status: 'DRAFT' | 'PUBLIC';
      description: string | null;
      tags: string;
      coverUrl: string;
      usedCount: number;
    },
    taskMap: Map<string, { id: bigint; taskStatus: string }>,
  ) {
    const task = taskMap.get(template.id.toString());

    return {
      id: template.id.toString(),
      name: template.templateName,
      category: template.category,
      status: template.status,
      description: template.description ?? '',
      tags: template.tags
        ? template.tags
            .split(',')
            .map((tag) => tag.trim())
            .filter(Boolean)
        : [],
      image: template.coverUrl,
      makeTaskId: task?.id.toString(),
      makeTaskStatus: task?.taskStatus,
      usedCount: template.usedCount ?? 0,
    };
  }

  async getTemplateAssets(): Promise<TemplateAssetsDto> {
    type AssetConfigRow = {
      id: bigint;
      configKey: string;
      configName: string;
      configGroup: string;
      configValue: string | null;
    };

    const rows = await this.systemConfigDelegate.findMany({
      where: {
        isDeleted: 0,
        configGroup: {
          in: ['ai-model', 'clothing', 'background'],
        },
      },
      orderBy: [{ sort: 'asc' }, { id: 'asc' }],
    });

    const mapRow = (row: AssetConfigRow) => ({
      id: row.id.toString(),
      name: row.configName,
      url: row.configValue ?? '',
      configKey: row.configKey,
    });

    return {
      models: rows.filter((row: AssetConfigRow) => row.configGroup === 'ai-model').map(mapRow),
      clothes: rows.filter((row: AssetConfigRow) => row.configGroup === 'clothing').map(mapRow),
      backgrounds: rows
        .filter((row: AssetConfigRow) => row.configGroup === 'background')
        .map(mapRow),
    };
  }

  private async getRequiredStep1TemplateUrl(): Promise<string> {
    const rows = await this.systemConfigDelegate.findMany({
      where: {
        isDeleted: 0,
        configGroup: 'template-step1',
      },
      orderBy: [{ sort: 'asc' }, { id: 'asc' }],
      take: 1,
    });

    const templateUrl = rows[0]?.configValue?.trim() ?? '';
    if (!templateUrl) {
      throw new NotFoundException('缺少 template-step1 配置');
    }

    return templateUrl;
  }

  async createTemplateMakeTask(
    stylistId: bigint,
    dto: CreateTemplateMakeTaskDto,
  ): Promise<{
    templateId: string;
    taskId: string;
    totalTaskId: string;
    taskStatus: 'PROCESSING';
  }> {
    const step1TemplateUrl = await this.getRequiredStep1TemplateUrl();
    const totalTaskId = `tmpl_${Date.now()}_${randomUUID()}`;

    const created = await this.prisma.$transaction(async (tx) => {
      const template = await tx.hairTemplate.create({
        data: {
          templateName: dto.templateName,
          coverUrl: '',
          status: dto.status,
          category: dto.category,
          tags: (dto.tags ?? []).join(','),
          description: dto.description ?? null,
          modelUrl: dto.modelUrl,
          clothesUrl: dto.clothesUrl,
          backgroundUrl: dto.backgroundUrl,
          refHairUrl: dto.refHairUrl,
          hairstylistId: stylistId,
          templateUrl: '',
          isSystemTemplate: 'NO',
        },
      });

      const task = await tx.hairTemplateMakeTask.create({
        data: {
          totalTaskId,
          step1TaskId: '',
          step2TaskId: '',
          taskStatus: 'WAIT',
          templateId: template.id,
          step1Resource: JSON.stringify({
            templateUrl: step1TemplateUrl,
            lastError: null,
          }),
          step2Resource: JSON.stringify({
            uploadedZipUrl: null,
            lastError: null,
          }),
          refHairUrl: dto.refHairUrl,
          modelUrl: dto.modelUrl,
          clothesUrl: dto.clothesUrl,
          backgroundUrl: dto.backgroundUrl,
        },
      });

      return { template, task };
    });

    const step1 = await this.templateAiClient.executeTemplate(step1TemplateUrl, {
      images: [dto.refHairUrl],
    });

    await this.prisma.hairTemplateMakeTask.update({
      where: { id: created.task.id },
      data: {
        step1TaskId: step1.taskId,
        taskStatus: 'PROCESSING',
        step1Resource: JSON.stringify({
          templateUrl: step1TemplateUrl,
          lastError: null,
        }),
      },
    });

    return {
      templateId: created.template.id.toString(),
      taskId: created.task.id.toString(),
      totalTaskId,
      taskStatus: 'PROCESSING',
    };
  }

  async getTemplateMakeTaskDetail(
    hairstylistId: bigint,
    taskId: string,
  ) {
    return this.templateTaskRunner.refreshTask(hairstylistId, taskId);
  }

  async getBasicInfo(
    stylistId: bigint,
    templateId: string,
  ): Promise<TemplateBasicInfoDto> {
    const template = await this.getOwnedTemplate(stylistId, templateId);
    return this.toBasicInfoDto(template);
  }

  async updateBasicInfo(
    stylistId: bigint,
    templateId: string,
    dto: UpdateTemplateBasicInfoDto,
  ): Promise<TemplateBasicInfoDto> {
    const template = await this.getOwnedTemplate(stylistId, templateId);
    const updated = await this.prisma.hairTemplate.update({
      where: { id: template.id },
      data: {
        templateName: dto.templateName,
        status: dto.status,
        category: dto.category,
        tags: (dto.tags ?? []).join(','),
        description: dto.description ?? '',
      },
    });

    return this.toBasicInfoDto(updated);
  }

  async deleteTemplate(
    stylistId: bigint,
    templateId: string,
  ): Promise<{ success: true }> {
    const template = await this.getOwnedTemplate(stylistId, templateId);

    await this.prisma.hairTemplate.updateMany({
      where: {
        id: template.id,
        hairstylistId: stylistId,
        isDeleted: 0,
      },
      data: {
        isDeleted: 1,
      },
    });

    await this.prisma.hairTemplateMakeTask.updateMany({
      where: {
        templateId: template.id,
        isDeleted: 0,
      },
      data: {
        isDeleted: 1,
      },
    });

    return { success: true };
  }

  async deleteTemplates(
    stylistId: bigint,
    templateIds: string[],
  ): Promise<{ deletedCount: number }> {
    const parsedIds = Array.from(
      new Set(
        templateIds
          .map((id) => id.trim())
          .filter(Boolean)
          .map((id) => BigInt(id)),
      ),
    );

    if (parsedIds.length === 0) {
      return { deletedCount: 0 };
    }

    const ownedTemplates = await this.prisma.hairTemplate.findMany({
      where: {
        id: {
          in: parsedIds,
        },
        hairstylistId: stylistId,
        isDeleted: 0,
      },
      select: {
        id: true,
      },
    });

    const ownedIds = ownedTemplates.map((item) => item.id);

    if (ownedIds.length === 0) {
      return { deletedCount: 0 };
    }

    const { count } = await this.prisma.hairTemplate.updateMany({
      where: {
        id: {
          in: ownedIds,
        },
        hairstylistId: stylistId,
        isDeleted: 0,
      },
      data: {
        isDeleted: 1,
      },
    });

    await this.prisma.hairTemplateMakeTask.updateMany({
      where: {
        templateId: {
          in: ownedIds,
        },
        isDeleted: 0,
      },
      data: {
        isDeleted: 1,
      },
    });

    return {
      deletedCount: count,
    };
  }

  async getSummary(stylistId: bigint): Promise<{
    total: number;
    published: number;
    weeklyUsed: number;
    draft: number;
  }> {
    const now = new Date();
    const utcDay = now.getUTCDay();
    const diffToMonday = utcDay === 0 ? 6 : utcDay - 1;
    const startOfWeek = new Date(
      Date.UTC(
        now.getUTCFullYear(),
        now.getUTCMonth(),
        now.getUTCDate() - diffToMonday,
      ),
    );
    const endOfWeek = new Date(
      Date.UTC(
        now.getUTCFullYear(),
        now.getUTCMonth(),
        now.getUTCDate() - diffToMonday + 7,
      ),
    );

    const [total, published, draft, templates] = await Promise.all([
      this.prisma.hairTemplate.count({
        where: {
          hairstylistId: stylistId,
          isDeleted: 0,
        },
      }),
      this.prisma.hairTemplate.count({
        where: {
          hairstylistId: stylistId,
          isDeleted: 0,
          status: 'PUBLIC',
        },
      }),
      this.prisma.hairTemplate.count({
        where: {
          hairstylistId: stylistId,
          isDeleted: 0,
          status: 'DRAFT',
        },
      }),
      this.prisma.hairTemplate.findMany({
        where: {
          hairstylistId: stylistId,
          isDeleted: 0,
        },
        select: {
          id: true,
        },
      }),
    ]);

    const templateIds = templates.map((item) => item.id.toString());
    const weeklyUsed = templateIds.length
      ? await this.prisma.aiHairSimulationTask.count({
          where: {
            taskStatus: 'SUCCESSES',
            isDeleted: 0,
            templateId: {
              in: templateIds,
            },
            taskFinishTime: {
              gte: startOfWeek,
              lt: endOfWeek,
            },
          },
        })
      : 0;

    return {
      total,
      published,
      weeklyUsed,
      draft,
    };
  }

  async list(query: TemplateListQuery): Promise<{
    items: Array<{
      id: string;
      name: string;
      category: 'LONG' | 'MEDIUM' | 'SHORT' | 'DYE';
      status: 'DRAFT' | 'PUBLIC';
      description: string;
      tags: string[];
      image: string;
      makeTaskId?: string;
      makeTaskStatus?: string;
      usedCount: number;
    }>;
    total: number;
    page: number;
    pageSize: number;
  }> {
    const page = query.page && query.page > 0 ? query.page : 1;
    const pageSize = query.pageSize && query.pageSize > 0 ? query.pageSize : 8;
    const keyword = query.q?.trim();
    const category = TEMPLATE_CATEGORIES.find((item) => item === query.category);
    const status = TEMPLATE_STATUSES.find((item) => item === query.status);

    const where = {
      hairstylistId: query.stylistId,
      isDeleted: 0,
      ...(category ? { category } : {}),
      ...(status ? { status } : {}),
      ...(keyword
        ? {
            OR: [
              { templateName: { contains: keyword } },
              { tags: { contains: keyword } },
              { description: { contains: keyword } },
            ],
          }
        : {}),
    };

    const [total, templates] = await Promise.all([
      this.prisma.hairTemplate.count({ where }),
      this.prisma.hairTemplate.findMany({
        where,
        orderBy: [{ id: 'desc' }],
        skip: (page - 1) * pageSize,
        take: pageSize,
        select: {
          id: true,
          templateName: true,
          category: true,
          status: true,
          description: true,
          tags: true,
          coverUrl: true,
          usedCount: true,
        },
      }),
    ]);

    const templateIds = templates.map((item) => item.id);
    const tasks = templateIds.length
      ? await this.prisma.hairTemplateMakeTask.findMany({
          where: {
            isDeleted: 0,
            templateId: { in: templateIds },
          },
          orderBy: [{ id: 'desc' }],
        })
      : [];

    const taskMap = new Map<string, { id: bigint; taskStatus: string }>();
    for (const task of tasks) {
      if (!task.templateId) {
        continue;
      }
      const key = task.templateId.toString();
      if (!taskMap.has(key)) {
        taskMap.set(key, { id: task.id, taskStatus: task.taskStatus });
      }
    }

    return {
      items: templates.map((template) => this.toTemplateListItem(template, taskMap)),
      total,
      page,
      pageSize,
    };
  }

  async create(_body: CreateTemplateDto): Promise<never> {
    throw new NotImplementedException('Template creation is not implemented yet');
  }
}