package handlers

import (
	"encoding/json"
	"net/http"
	"strings"

	"trade/web/internal/store"
)

type llmConfigReq struct {
	BaseURL string `json:"base_url"`
	APIKey  string `json:"api_key"`
	Model   string `json:"model"`
}

type llmConfigResp struct {
	BaseURL   string `json:"base_url"`
	APIKey    string `json:"api_key"`    // 脱敏：仅显示首尾
	Model     string `json:"model"`
	HasAPIKey bool   `json:"has_api_key"` // 前端据此判断是否已配置
}

// maskKey 将 sk-abc123xyz 脱敏为 sk-a...xyz。
func maskKey(key string) string {
	if len(key) <= 8 {
		return strings.Repeat("*", len(key))
	}
	return key[:4] + "..." + key[len(key)-4:]
}

// GetLLMConfig 返回当前 LLM 配置（API Key 脱敏）。
func (d *Deps) GetLLMConfig(w http.ResponseWriter, r *http.Request) {
	cfg, err := d.Futures.GetLLMConfig()
	if err != nil {
		writeErr(w, http.StatusInternalServerError, err.Error())
		return
	}
	resp := llmConfigResp{
		BaseURL:   cfg.BaseURL,
		Model:     cfg.Model,
		HasAPIKey: cfg.APIKey != "",
	}
	if cfg.APIKey != "" {
		resp.APIKey = maskKey(cfg.APIKey)
	}
	writeJSON(w, http.StatusOK, resp)
}

// SaveLLMConfig 保存 LLM 配置。api_key 为脱敏占位时保留原值。
func (d *Deps) SaveLLMConfig(w http.ResponseWriter, r *http.Request) {
	var req llmConfigReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeErr(w, http.StatusBadRequest, "invalid json")
		return
	}
	req.BaseURL = strings.TrimSpace(req.BaseURL)
	req.Model = strings.TrimSpace(req.Model)
	if req.BaseURL == "" {
		req.BaseURL = "https://api.deepseek.com/v1"
	}
	if req.Model == "" {
		req.Model = "deepseek-chat"
	}

	// 如果前端传的是脱敏值（含 ...），说明未修改 Key，保留旧值
	if strings.Contains(req.APIKey, "...") {
		old, err := d.Futures.GetLLMConfig()
		if err != nil {
			writeErr(w, http.StatusInternalServerError, err.Error())
			return
		}
		req.APIKey = old.APIKey
	}

	cfg := &store.LLMConfig{
		BaseURL: req.BaseURL,
		APIKey:  req.APIKey,
		Model:   req.Model,
	}
	if err := d.Futures.SaveLLMConfig(cfg); err != nil {
		writeErr(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
}