import {
  Injectable,
  NotFoundException,
  ForbiddenException,
  ConflictException,
} from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';
import {
  CreateAgentProfileDto,
  UpdateAgentProfileDto,
  SearchAgentsDto,
} from './dto';
import { Prisma } from '@prisma/client';

function generateSlug(firstName: string, lastName: string): string {
  const base = `${firstName}-${lastName}`
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-|-$/g, '');
  const uniqueSuffix = Math.random().toString(36).substring(2, 8);
  return `${base}-${uniqueSuffix}`;
}

@Injectable()
export class AgentsService {
  constructor(private prisma: PrismaService) {}

  async createProfile(userId: string, dto: CreateAgentProfileDto) {
    // Check if user already has an agent profile
    const existingProfile = await this.prisma.agentProfile.findUnique({
      where: { userId },
    });

    if (existingProfile) {
      throw new ConflictException('User already has an agent profile');
    }

    const { specializationIds, ...profileData } = dto;
    const slug = generateSlug(dto.firstName, dto.lastName);

    const profile = await this.prisma.agentProfile.create({
      data: {
        ...profileData,
        userId,
        slug,
        specializations: specializationIds?.length
          ? {
              create: specializationIds.map((specId) => ({
                specializationId: specId,
              })),
            }
          : undefined,
      },
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    return profile;
  }

  async getProfile(userId: string) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { userId },
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
        verificationRequests: {
          orderBy: { createdAt: 'desc' },
          take: 5,
        },
      },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    return profile;
  }

  async getProfileById(profileId: string) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { id: profileId },
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    return profile;
  }

  async updateProfile(userId: string, dto: UpdateAgentProfileDto) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { userId },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    const { specializationIds, ...profileData } = dto;

    // If specializationIds is provided, update the specializations
    if (specializationIds !== undefined) {
      // Delete existing specializations
      await this.prisma.agentSpecialization.deleteMany({
        where: { agentProfileId: profile.id },
      });

      // Create new specializations
      if (specializationIds.length > 0) {
        await this.prisma.agentSpecialization.createMany({
          data: specializationIds.map((specId) => ({
            agentProfileId: profile.id,
            specializationId: specId,
          })),
        });
      }
    }

    const updatedProfile = await this.prisma.agentProfile.update({
      where: { userId },
      data: profileData,
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    return updatedProfile;
  }

  async searchAgents(dto: SearchAgentsDto) {
    const {
      search,
      city,
      state,
      country,
      categoryId,
      specializationIds,
      isVerified,
      page = 1,
      limit = 10,
      sortBy = 'createdAt',
      sortOrder = 'desc',
    } = dto;

    const skip = (page - 1) * limit;

    // Build where clause
    const where: Prisma.AgentProfileWhereInput = {};

    if (search) {
      where.OR = [
        { firstName: { contains: search, mode: 'insensitive' } },
        { lastName: { contains: search, mode: 'insensitive' } },
        { bio: { contains: search, mode: 'insensitive' } },
        { headline: { contains: search, mode: 'insensitive' } },
        { companyName: { contains: search, mode: 'insensitive' } },
      ];
    }

    if (city) {
      where.city = { contains: city, mode: 'insensitive' };
    }

    if (state) {
      where.state = { contains: state, mode: 'insensitive' };
    }

    if (country) {
      where.country = { contains: country, mode: 'insensitive' };
    }

    if (isVerified !== undefined) {
      where.isVerified = isVerified;
    }

    // Filter by category
    if (categoryId) {
      where.specializations = {
        some: {
          specialization: {
            categoryId,
          },
        },
      };
    }

    // Filter by specializations
    if (specializationIds?.length) {
      where.specializations = {
        some: {
          specializationId: { in: specializationIds },
        },
      };
    }

    // Build orderBy
    const orderBy: Prisma.AgentProfileOrderByWithRelationInput = {};
    if (sortBy === 'averageRating') {
      orderBy.averageRating = sortOrder;
    } else if (sortBy === 'totalReviews') {
      orderBy.totalReviews = sortOrder;
    } else if (sortBy === 'firstName') {
      orderBy.firstName = sortOrder;
    } else {
      orderBy.createdAt = sortOrder;
    }

    const [agents, total] = await Promise.all([
      this.prisma.agentProfile.findMany({
        where,
        skip,
        take: limit,
        orderBy,
        include: {
          user: {
            select: {
              id: true,
              email: true,
              avatar: true,
            },
          },
          specializations: {
            include: {
              specialization: {
                include: {
                  category: true,
                },
              },
            },
          },
        },
      }),
      this.prisma.agentProfile.count({ where }),
    ]);

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

  async getFeaturedAgents(limit = 10) {
    const agents = await this.prisma.agentProfile.findMany({
      where: {
        isVerified: true,
        isFeatured: true,
      },
      take: limit,
      orderBy: [{ averageRating: 'desc' }, { totalReviews: 'desc' }],
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    return agents;
  }

  async getTopRatedAgents(limit = 10) {
    const agents = await this.prisma.agentProfile.findMany({
      where: {
        isVerified: true,
        totalReviews: { gte: 5 },
      },
      take: limit,
      orderBy: [{ averageRating: 'desc' }, { totalReviews: 'desc' }],
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    return agents;
  }

  // Admin methods
  async adminUpdateProfile(profileId: string, dto: UpdateAgentProfileDto) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { id: profileId },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    const { specializationIds, ...profileData } = dto;

    if (specializationIds !== undefined) {
      await this.prisma.agentSpecialization.deleteMany({
        where: { agentProfileId: profileId },
      });

      if (specializationIds.length > 0) {
        await this.prisma.agentSpecialization.createMany({
          data: specializationIds.map((specId) => ({
            agentProfileId: profileId,
            specializationId: specId,
          })),
        });
      }
    }

    const updatedProfile = await this.prisma.agentProfile.update({
      where: { id: profileId },
      data: profileData,
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
        specializations: {
          include: {
            specialization: {
              include: {
                category: true,
              },
            },
          },
        },
      },
    });

    return updatedProfile;
  }

  async adminDeleteProfile(profileId: string) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { id: profileId },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    // Delete related records first
    await this.prisma.agentSpecialization.deleteMany({
      where: { agentProfileId: profileId },
    });

    await this.prisma.verificationRequest.deleteMany({
      where: { agentProfileId: profileId },
    });

    await this.prisma.agentProfile.delete({
      where: { id: profileId },
    });

    return { message: 'Agent profile deleted successfully' };
  }

  async adminVerifyAgent(profileId: string, isVerified: boolean) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { id: profileId },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    const updatedProfile = await this.prisma.agentProfile.update({
      where: { id: profileId },
      data: { isVerified },
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
      },
    });

    return updatedProfile;
  }

  async adminSetFeatured(profileId: string, isFeatured: boolean) {
    const profile = await this.prisma.agentProfile.findUnique({
      where: { id: profileId },
    });

    if (!profile) {
      throw new NotFoundException('Agent profile not found');
    }

    const updatedProfile = await this.prisma.agentProfile.update({
      where: { id: profileId },
      data: { isFeatured },
      include: {
        user: {
          select: {
            id: true,
            email: true,
            avatar: true,
          },
        },
      },
    });

    return updatedProfile;
  }

  async getAllAgentsAdmin(dto: SearchAgentsDto) {
    // Same as searchAgents but returns all data for admin
    return this.searchAgents(dto);
  }
}