import type OpenAI from "openai";
import { type PolyModel, modelKey } from "@/lib/ai/core/types";
import { createOpenAICompatAdapter, listOpenAIModels } from "../shared/openai-compat/factory";
import { DEEPSEEK_CATALOG } from "./catalog";

/**
 * DeepSeek — OpenAI-compatible at https://api.deepseek.com. `GET /models` exposes ids only, so the
 * catalog (docs/provider-research/deepseek.md) provides limits, pricing and thinking controls.
 * Reasoning arrives as `delta.reasoning_content`; cache hits as `prompt_cache_hit_tokens`.
 */
export function normalizeDeepSeekModel(m: { id: string }): PolyModel | null {
  if (!m.id.startsWith("deepseek")) return null;
  const cat = DEEPSEEK_CATALOG.get(m.id);
  const vision = m.id.includes("vision");
  return {
    key: modelKey("deepseek", m.id),
    id: m.id,
    provider: "deepseek",
    displayName: cat?.displayName ?? prettify(m.id),
    family: cat?.family ?? "DeepSeek V4",
    capabilities: cat?.capabilities ?? { text: true, vision, audioInput: false, audioOutput: false, imageGeneration: false, video: false, reasoning: true, tools: true, structuredOutput: true, streaming: true, files: false, webSearch: false },
    limits: cat?.limits ?? {},
    parameters: cat?.parameters ?? { temperature: true, topP: true, maxTokens: true, stop: true, frequencyPenalty: true, presencePenalty: true, seed: false, topK: false, reasoningEffort: true, reasoningEffortLevels: ["none", "medium"], temperatureRange: { min: 0, max: 2 } },
    status: cat?.status ?? (m.id.includes("exp") ? "preview" : "active"),
    pricing: cat?.pricing ?? null,
    metadata: { ...(cat?.metadata ?? {}), sortWeight: cat?.sortWeight ?? (m.id.includes("pro") ? 100 : m.id.includes("vision") ? 80 : 90) },
  };
}

function prettify(id: string) {
  return id.replace(/^deepseek-/, "DeepSeek ").replace(/-/g, " ").replace(/\bv(\d)/i, "V$1").replace(/\b(\w)/g, (c) => c.toUpperCase()).replace(/Exp$/, "(experimental)");
}

async function list(client: OpenAI, _k: string, signal?: AbortSignal): Promise<PolyModel[]> {
  return (await listOpenAIModels(client, signal)).map(normalizeDeepSeekModel).filter((m): m is PolyModel => Boolean(m));
}

export const deepseekAdapter = createOpenAICompatAdapter({
  id: "deepseek",
  name: "DeepSeek",
  baseURL: "https://api.deepseek.com/v1",
  keyDocsUrl: "https://platform.deepseek.com/api_keys",
  keyPrefixHint: "sk-",
  listModels: list,
  useMaxTokens: true,
  messageOptions: { inlineFiles: true, replayReasoningContent: true },
  tweakParams: (params, settings, req) => {
    const p = params as unknown as Record<string, unknown>;
    const meta = (req.modelInfo?.metadata ?? {}) as Record<string, unknown>;
    if (req.modelInfo?.capabilities.reasoning) {
      const effort = settings.reasoningEffort;
      if (effort === "none") p.thinking = { type: "disabled" };
      else if (effort) {
        p.thinking = { type: "enabled" };
        // DeepSeek accepts low | high | max (medium/xhigh are treated as high).
        p.reasoning_effort = effort === "minimal" || effort === "low" ? "low" : effort === "max" ? "max" : "high";
      }
      // Reasoning consumes `max_tokens`; a tiny cap yields an empty answer with finish_reason "length".
      if (effort !== "none" && typeof params.max_tokens === "number" && params.max_tokens < Number(meta.minOutputForReasoning ?? 2000)) params.max_tokens = Number(meta.minOutputForReasoning ?? 2000);
    }
    delete p.seed; // silently ignored — never pretend determinism
  },
  refineError: (status, code, message) => {
    if (status === 401) return "INVALID_API_KEY";
    if (status === 402) return "INSUFFICIENT_CREDITS";
    if (status === 422) return "INVALID_PARAMETER";
    if (status === 503) return "PROVIDER_UNAVAILABLE";
    if (status === 400 && /supported API model names|model/i.test(message) && /model/i.test(message)) return "MODEL_NOT_FOUND";
    void code;
    return undefined;
  },
});