/**
 * Xiaomi MiMo search provider.
 *
 * Uses the `web_search` tool type in the Chat Completions API to perform
 * web searches. This is NOT standard OpenAI protocol — MiMo adds a
 * `tools: [{ type: 'web_search' }]` entry that other providers don't support.
 *
 * Supported models: mimo-v2.5, mimo-v2.5-pro, mimo-v2.5-pro-ultraspeed.
 *
 * @module @kamitobi/dsh-multi-search/providers/mimo
 */

import type {
  WebSearchProvider,
  WebSearchRequest,
  WebSearchResult,
  WebSearchSource,
} from '@deepseek-ai/dsh-web'
import type { BaseProviderConfig } from '../types.js'
import { callChatCompletions, type ChatCompletionResponse } from '../api.js'

// ─── Config ────────────────────────────────────────────────────────────────

/** MiMo-specific configuration options. */
export interface MiMoProviderConfig extends BaseProviderConfig {
  /** Force web search even if the model thinks it's unnecessary. */
  forceSearch?: boolean
  /** Maximum keywords per search round. */
  maxKeyword?: number
  /** Maximum number of search results to return. */
  maxResults?: number
}

const DEFAULTS: Required<Omit<MiMoProviderConfig, 'apiKey' | 'apiKeyEnv' | 'baseURL'>> = {
  model: 'mimo-v2.5',
  forceSearch: true,
  maxKeyword: 3,
  maxResults: 5,
}

const DEFAULT_BASE_URL = 'https://api.xiaomimimo.com/v1'

// ─── Provider ──────────────────────────────────────────────────────────────

/** Response annotation shape from MiMo. */
interface MiMoAnnotation {
  type?: string
  url?: string
  title?: string
  summary?: string
  site_name?: string
  publish_time?: string
}

export class MiMoSearchProvider implements WebSearchProvider {
  readonly id = 'multi-search'

  private readonly apiKey: string
  private readonly baseURL: string
  private readonly model: string
  private readonly forceSearch: boolean
  private readonly maxKeyword: number
  private readonly maxResults: number

  constructor(config: MiMoProviderConfig) {
    this.apiKey = config.apiKey || ''
    this.baseURL = config.baseURL || DEFAULT_BASE_URL
    this.model = config.model || DEFAULTS.model
    this.forceSearch = config.forceSearch ?? DEFAULTS.forceSearch
    this.maxKeyword = config.maxKeyword ?? DEFAULTS.maxKeyword
    this.maxResults = config.maxResults ?? DEFAULTS.maxResults
  }

  available(): boolean {
    return Boolean(this.apiKey)
  }

  async search(request: WebSearchRequest, signal?: AbortSignal): Promise<WebSearchResult> {
    const maxResults = request.maxResults ?? this.maxResults

    const body: Record<string, unknown> = {
      model: this.model,
      messages: [
        {
          role: 'system',
          content: 'You are a helpful search assistant. Use web search to find information.',
        },
        { role: 'user', content: request.query },
      ],
      max_completion_tokens: 1024,
      stream: false,
      tools: [
        {
          type: 'web_search',
          max_keyword: this.maxKeyword,
          force_search: this.forceSearch,
          limit: maxResults,
        },
      ],
      tool_choice: 'auto',
    }

    const data = await callChatCompletions(this.baseURL, this.apiKey, body, signal)
    const sources = extractAnnotations(data)
    const content = data.choices?.[0]?.message?.content

    return {
      content,
      sources,
      truncated: sources.length > maxResults,
    }
  }
}

// ─── Annotation extraction ─────────────────────────────────────────────────

function extractAnnotations(data: ChatCompletionResponse): WebSearchSource[] {
  const sources: WebSearchSource[] = []
  const seen = new Set<string>()

  const annotations = data.choices?.[0]?.message?.annotations as MiMoAnnotation[] | undefined
  if (annotations) {
    for (const a of annotations) {
      if (a.url && !seen.has(a.url)) {
        seen.add(a.url)
        sources.push({
          url: a.url,
          title: a.title || a.site_name,
          snippet: a.summary,
          publishedAt: a.publish_time,
        })
      }
    }
  }

  return sources
}