import { Injectable, NotFoundException } from "@nestjs/common";
import { Prisma } from "@prisma/client";
import { PrismaService } from "../prisma/prisma.service";
import { ActivityService } from "../activity/activity.service";
import { ProjectStatus } from "@prisma/client";
import type { CreateProjectDto, UpdateProjectDto, QueryProjectsDto } from "./dto";

/**
 * Service for managing projects
 */
@Injectable()
export class ProjectsService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly activityService: ActivityService
  ) {}

  /**
   * Create a new project
   */
  async create(
    workspaceId: string,
    userId: string,
    createProjectDto: CreateProjectDto
  ) {
    const data: any = {
      ...createProjectDto,
      workspaceId,
      creatorId: userId,
      status: createProjectDto.status || ProjectStatus.PLANNING,
      metadata: createProjectDto.metadata || {},
    };

    const project = await this.prisma.project.create({
      data,
      include: {
        creator: {
          select: { id: true, name: true, email: true },
        },
        _count: {
          select: { tasks: true, events: true },
        },
      },
    });

    // Log activity
    await this.activityService.logProjectCreated(workspaceId, userId, project.id, {
      name: project.name,
    });

    return project;
  }

  /**
   * Get paginated projects with filters
   */
  async findAll(query: QueryProjectsDto) {
    const page = query.page || 1;
    const limit = query.limit || 50;
    const skip = (page - 1) * limit;

    // Build where clause
    const where: any = {
      workspaceId: query.workspaceId,
    };

    if (query.status) {
      where.status = query.status;
    }

    if (query.startDateFrom || query.startDateTo) {
      where.startDate = {};
      if (query.startDateFrom) {
        where.startDate.gte = query.startDateFrom;
      }
      if (query.startDateTo) {
        where.startDate.lte = query.startDateTo;
      }
    }

    // Execute queries in parallel
    const [data, total] = await Promise.all([
      this.prisma.project.findMany({
        where,
        include: {
          creator: {
            select: { id: true, name: true, email: true },
          },
          _count: {
            select: { tasks: true, events: true },
          },
        },
        orderBy: {
          createdAt: "desc",
        },
        skip,
        take: limit,
      }),
      this.prisma.project.count({ where }),
    ]);

    return {
      data,
      meta: {
        total,
        page,
        limit,
        totalPages: Math.ceil(total / limit),
      },
    };
  }

  /**
   * Get a single project by ID
   */
  async findOne(id: string, workspaceId: string) {
    const project = await this.prisma.project.findUnique({
      where: {
        id,
        workspaceId,
      },
      include: {
        creator: {
          select: { id: true, name: true, email: true },
        },
        tasks: {
          select: {
            id: true,
            title: true,
            status: true,
            priority: true,
            dueDate: true,
          },
          orderBy: { sortOrder: "asc" },
        },
        events: {
          select: {
            id: true,
            title: true,
            startTime: true,
            endTime: true,
          },
          orderBy: { startTime: "asc" },
        },
        _count: {
          select: { tasks: true, events: true },
        },
      },
    });

    if (!project) {
      throw new NotFoundException(`Project with ID ${id} not found`);
    }

    return project;
  }

  /**
   * Update a project
   */
  async update(
    id: string,
    workspaceId: string,
    userId: string,
    updateProjectDto: UpdateProjectDto
  ) {
    // Verify project exists
    const existingProject = await this.prisma.project.findUnique({
      where: { id, workspaceId },
    });

    if (!existingProject) {
      throw new NotFoundException(`Project with ID ${id} not found`);
    }

    const project = await this.prisma.project.update({
      where: {
        id,
        workspaceId,
      },
      data: updateProjectDto as any,
      include: {
        creator: {
          select: { id: true, name: true, email: true },
        },
        _count: {
          select: { tasks: true, events: true },
        },
      },
    });

    // Log activity
    await this.activityService.logProjectUpdated(workspaceId, userId, id, {
      changes: updateProjectDto as Prisma.JsonValue,
    });

    return project;
  }

  /**
   * Delete a project
   */
  async remove(id: string, workspaceId: string, userId: string) {
    // Verify project exists
    const project = await this.prisma.project.findUnique({
      where: { id, workspaceId },
    });

    if (!project) {
      throw new NotFoundException(`Project with ID ${id} not found`);
    }

    await this.prisma.project.delete({
      where: {
        id,
        workspaceId,
      },
    });

    // Log activity
    await this.activityService.logProjectDeleted(workspaceId, userId, id, {
      name: project.name,
    });
  }
}