import { ConflictException, Injectable, NotFoundException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import bcrypt from 'bcryptjs';
import { randomBytes } from 'crypto';
import { GuildNode } from '../entities/guild-node.entity.js';
import { AuditService } from '../audit/audit.service.js';

@Injectable()
export class NodeAdminService {
  constructor(
    @InjectRepository(GuildNode)
    private readonly nodeRepo: Repository<GuildNode>,
    private readonly audit: AuditService,
  ) {}

  async registerNode(input: { nodeId: string; name: string; endpoint: string }) {
    const existedByNodeId = await this.nodeRepo.findOne({ where: { nodeId: input.nodeId } });
    if (existedByNodeId) {
      throw new ConflictException('nodeId already exists');
    }

    const existedByEndpoint = await this.nodeRepo.findOne({ where: { endpoint: input.endpoint } });
    if (existedByEndpoint) {
      throw new ConflictException('endpoint already exists');
    }

    const node = this.nodeRepo.create({
      nodeId: input.nodeId,
      name: input.name,
      endpoint: input.endpoint,
      status: 'active',
      apiKeyHash: null,
    });

    const rawApiKey = `gk_${randomBytes(24).toString('hex')}`;
    node.apiKeyHash = await bcrypt.hash(rawApiKey, 10);
    const saved = await this.nodeRepo.save(node);

    await this.audit.write({
      action: 'node.register',
      targetType: 'node',
      targetId: saved.nodeId,
      detail: JSON.stringify({ endpoint: saved.endpoint, via: 'cli' }),
    });

    return {
      node: {
        id: saved.id,
        nodeId: saved.nodeId,
        name: saved.name,
        endpoint: saved.endpoint,
        status: saved.status,
      },
      apiKey: rawApiKey,
    };
  }

  // Admin-only via cli (never HTTP): set the free-form purpose string on
  // a guild node. Pass an empty string to clear it (null).
  async setPurpose(nodeId: string, purpose: string) {
    const node = await this.nodeRepo.findOne({ where: { nodeId } });
    if (!node) throw new NotFoundException(`node ${nodeId} not found`);
    const trimmed = String(purpose ?? '').trim();
    node.purpose = trimmed === '' ? null : trimmed;
    const saved = await this.nodeRepo.save(node);
    await this.audit.write({
      action: 'node.set_purpose',
      targetType: 'node',
      targetId: saved.nodeId,
      detail: JSON.stringify({ purpose: saved.purpose, via: 'cli' }),
    });
    return {
      nodeId: saved.nodeId,
      name: saved.name,
      purpose: saved.purpose,
    };
  }
}