package server

import (
	"errors"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"code.littlelan.cn/CarrotAssistant/backend/internal/security"
	"code.littlelan.cn/CarrotAssistant/backend/internal/store"
)

type modelConfigReq struct {
	Name          string `json:"name" binding:"required"`
	BaseURL       string `json:"base_url" binding:"required"`
	APIKey        string `json:"api_key"`
	DefaultModel  string `json:"default_model" binding:"required"`
	SupportsTools *bool  `json:"supports_tools"`
	MaxTokens     int    `json:"max_tokens"`
}

// GET /admin/model-configs
func (d Deps) handleListModels(c *gin.Context) {
	var list []store.ModelConfig
	d.DB.Order("id DESC").Find(&list)
	c.JSON(http.StatusOK, list)
}

// POST /admin/model-configs
func (d Deps) handleCreateModel(c *gin.Context) {
	var req modelConfigReq
	if !bind(c, &req) {
		return
	}
	req.BaseURL = strings.TrimRight(strings.TrimSpace(req.BaseURL), "/")
	enc, err := d.Crypto.Encrypt(req.APIKey)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "加密失败"})
		return
	}
	m := store.ModelConfig{
		Name:            req.Name,
		BaseURL:         req.BaseURL,
		APIKeyEncrypted: enc,
		APIKeyPreview:   security.GenerateAPIKeyPreview(req.APIKey),
		DefaultModel:    req.DefaultModel,
		SupportsTools:   req.SupportsTools == nil || *req.SupportsTools,
		MaxTokens:       req.MaxTokens,
	}
	if err := d.DB.Create(&m).Error; err != nil {
		if errors.Is(err, gorm.ErrDuplicatedKey) {
			c.JSON(http.StatusConflict, gin.H{"error": "名称已存在"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建失败"})
		return
	}
	d.audit(c, nil, nil, "model_config.create", map[string]any{"id": m.ID, "name": m.Name})
	c.JSON(http.StatusOK, m)
}

// PUT /admin/model-configs/:id — api_key is optional on update; an empty
// value keeps the existing key, a non-empty value replaces it.
func (d Deps) handleUpdateModel(c *gin.Context) {
	id := c.Param("id")
	var m store.ModelConfig
	if err := d.DB.First(&m, "id = ?", id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "未找到"})
		return
	}
	var req modelConfigReq
	if !bind(c, &req) {
		return
	}
	req.BaseURL = strings.TrimRight(strings.TrimSpace(req.BaseURL), "/")
	m.Name = req.Name
	m.BaseURL = req.BaseURL
	m.DefaultModel = req.DefaultModel
	m.MaxTokens = req.MaxTokens
	if req.SupportsTools != nil {
		m.SupportsTools = *req.SupportsTools
	}
	if strings.TrimSpace(req.APIKey) != "" {
		enc, err := d.Crypto.Encrypt(req.APIKey)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "加密失败"})
			return
		}
		m.APIKeyEncrypted = enc
		m.APIKeyPreview = security.GenerateAPIKeyPreview(req.APIKey)
	}
	if err := d.DB.Save(&m).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "保存失败"})
		return
	}
	d.audit(c, nil, nil, "model_config.update", map[string]any{"id": m.ID})
	c.JSON(http.StatusOK, m)
}

// DELETE /admin/model-configs/:id
func (d Deps) handleDeleteModel(c *gin.Context) {
	id := c.Param("id")
	res := d.DB.Delete(&store.ModelConfig{}, "id = ?", id)
	if res.Error != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "删除失败"})
		return
	}
	if res.RowsAffected == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "未找到"})
		return
	}
	d.audit(c, nil, nil, "model_config.delete", map[string]any{"id": id})
	c.JSON(http.StatusOK, gin.H{"ok": true})
}