import { Injectable, Logger } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { SshService } from './ssh.service';

interface AvatarCacheItem {
  expiresAt: number;
  contentType: string;
  data: Buffer;
}

@Injectable()
export class AvatarService {
  private readonly logger = new Logger(AvatarService.name);
  private readonly cache = new Map<string, AvatarCacheItem>();
  private readonly ttlMs = 5 * 60 * 1000;

  constructor(
    private readonly ssh: SshService,
    private readonly config: ConfigService,
  ) {}

  async getAvatar(sister: { name: string; ip: string; user: string }) {
    const cached = this.cache.get(sister.name);
    if (cached && cached.expiresAt > Date.now()) {
      return cached;
    }

    const sshKeyPath = this.config.get<string>('SSH_KEY_PATH');
    if (!sshKeyPath) {
      return this.getFallback(sister.name);
    }

    const files = [
      { path: '~/.hermes/avatar.png', type: 'image/png' },
      { path: '~/.hermes/avatar.jpg', type: 'image/jpeg' },
      { path: '~/.hermes/avatar.jpeg', type: 'image/jpeg' },
      { path: '~/.hermes/avatar.webp', type: 'image/webp' },
      { path: '~/.openclaw/avatar.png', type: 'image/png' },
      { path: '~/.openclaw/avatar.jpg', type: 'image/jpeg' },
      { path: '~/.openclaw/avatar.jpeg', type: 'image/jpeg' },
      { path: '~/.openclaw/avatar.webp', type: 'image/webp' },
    ];

    for (const file of files) {
      try {
        const result = await this.ssh.executeCommand(
          sister.ip,
          sister.user,
          sshKeyPath,
          `if [ -f ${file.path} ]; then base64 -w0 ${file.path}; fi`,
        );

        if (result.stdout.trim()) {
          const item = {
            contentType: file.type,
            data: Buffer.from(result.stdout.trim(), 'base64'),
            expiresAt: Date.now() + this.ttlMs,
          };
          this.cache.set(sister.name, item);
          return item;
        }
      } catch {
        this.logger.warn(`Avatar fetch failed for ${sister.name}`);
        // 실패 시 오래된 캐시 삭제 (다음 요청에서 재시도)
        this.cache.delete(sister.name);
      }
    }

    return this.getFallback(sister.name);
  }

  private getFallback(name: string) {
    const initial = name.slice(0, 1).toUpperCase();
    const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="128" height="128"><rect width="100%" height="100%" fill="#111"/><text x="50%" y="54%" dominant-baseline="middle" text-anchor="middle" font-family="Arial" font-size="56" fill="#f5f5f5">${initial}</text></svg>`;
    return {
      contentType: 'image/svg+xml',
      data: Buffer.from(svg),
      expiresAt: Date.now() + this.ttlMs,
    };
  }
}