import { ConflictException, Injectable, NotFoundException } from '@nestjs/common';
import * as bcrypt from 'bcrypt';
import { randomBytes } from 'node:crypto';
import { PlatformPrismaService } from '../prisma/platform-prisma.service';
import { createMysqlDatabase, databaseForSlug, pushTenantSchema } from '../tenancy/provision-database';
import { publicTenantView } from '../tenancy/public-tenant';
import { TenantConnectionService } from '../tenancy/tenant-connection.service';
import { normalizeSlug } from '../tenancy/tenant-url';
import type { CreateTenantDto } from './dto/create-tenant.dto';
import { buildPlatformOverview } from './platform-overview';

@Injectable()
export class PlatformService {
  constructor(
    private readonly platform: PlatformPrismaService,
    private readonly tenants: TenantConnectionService,
  ) {}

  list() {
    return this.platform.tenant.findMany({
      orderBy: { createdAt: 'asc' },
      select: { id: true, name: true, slug: true, database: true, status: true, createdAt: true },
    });
  }

  async overview() {
    const tenants = await this.platform.tenant.findMany({
      select: { status: true, database: true },
    });
    const users = (
      await Promise.all(tenants.map((tenant) => this.tenants.getByDatabase(tenant.database).user.count()))
    ).reduce((sum, count) => sum + count, 0);
    return buildPlatformOverview(tenants, users);
  }

  async publicBySlug(raw: string) {
    let slug: string;
    try {
      slug = normalizeSlug(raw);
    } catch {
      throw new NotFoundException('Este cliente não existe.');
    }
    const tenant = await this.platform.tenant.findUnique({
      where: { slug },
      select: { name: true, slug: true, status: true },
    });
    return publicTenantView(tenant);
  }

  async create(actorId: string, dto: CreateTenantDto, ip?: string) {
    const slug = normalizeSlug(dto.slug);
    const exists = await this.platform.tenant.findUnique({ where: { slug } });
    if (exists) {
      throw new ConflictException('Já existe uma empresa com esse código.');
    }

    const database = databaseForSlug(slug);
    await createMysqlDatabase(database);
    await pushTenantSchema(database);

    const tenant = await this.platform.tenant.create({
      data: { name: dto.name.trim(), slug, database },
    });

    const adminEmail = `admin@${slug}.sinka`;
    const adminPassword = `Sinka-${randomBytes(3).toString('hex')}`;
    const db = this.tenants.getByDatabase(database);
    await db.user.create({
      data: {
        name: 'Administrador',
        email: adminEmail,
        passwordHash: await bcrypt.hash(adminPassword, 10),
        issuedPassword: adminPassword,
        role: 'ADMIN',
      },
    });

    await this.platform.platformAuditLog.create({
      data: {
        userId: actorId,
        action: 'tenant.create',
        entity: 'Tenant',
        entityId: tenant.id,
        ip,
        metadata: { slug, database },
      },
    });

    return {
      ...tenant,
      access: {
        email: adminEmail,
        password: adminPassword,
        path: `/${slug}/login`,
      },
    };
  }

  async listUsers(actorId: string, tenantId: string, ip?: string) {
    const tenant = await this.platform.tenant.findUnique({ where: { id: tenantId } });
    if (!tenant) {
      throw new NotFoundException('Cliente não encontrado.');
    }
    const db = this.tenants.getByDatabase(tenant.database);
    const users = await db.user.findMany({
      select: { id: true, name: true, email: true, role: true, issuedPassword: true },
      orderBy: { createdAt: 'asc' },
    });
    await this.platform.platformAuditLog.create({
      data: {
        userId: actorId,
        action: 'tenant.users',
        entity: 'Tenant',
        entityId: tenant.id,
        ip,
        metadata: { slug: tenant.slug, count: users.length },
      },
    });
    return {
      tenant: { id: tenant.id, name: tenant.name, slug: tenant.slug },
      users: users.map((user) => ({
        id: user.id,
        name: user.name,
        email: user.email,
        role: user.role,
        password: user.issuedPassword,
      })),
    };
  }

  async issuePassword(actorId: string, tenantId: string, userId: string, ip?: string) {
    const tenant = await this.platform.tenant.findUnique({ where: { id: tenantId } });
    if (!tenant) {
      throw new NotFoundException('Cliente não encontrado.');
    }
    const db = this.tenants.getByDatabase(tenant.database);
    const user = await db.user.findUnique({ where: { id: userId } });
    if (!user) {
      throw new NotFoundException('Usuário não encontrado.');
    }
    const password = `Sinka-${randomBytes(3).toString('hex')}`;
    await db.user.update({
      where: { id: userId },
      data: {
        passwordHash: await bcrypt.hash(password, 10),
        issuedPassword: password,
      },
    });
    await this.platform.platformAuditLog.create({
      data: {
        userId: actorId,
        action: 'tenant.user.password',
        entity: 'User',
        entityId: userId,
        ip,
        metadata: { slug: tenant.slug, email: user.email },
      },
    });
    return { id: user.id, email: user.email, password };
  }
}