package handler

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/yourname/cyrene-ai/gateway/internal/middleware"
)

// MemoryHandler 记忆查询处理器 — 代理到 AI-Core
type MemoryHandler struct {
	aiCoreURL string
	client    *http.Client
}

// NewMemoryHandler 创建记忆处理器
func NewMemoryHandler(aiCoreURL string) *MemoryHandler {
	return &MemoryHandler{
		aiCoreURL: aiCoreURL,
		client: &http.Client{
			Timeout: 15 * time.Second,
		},
	}
}

// Query 搜索用户记忆 — 代理 GET /api/v1/memory/search?user_id=...&q=...
// 管理员可通过 user_id 查询参数查询任意用户的记忆
func (h *MemoryHandler) Query(c *gin.Context) {
	authUserID := middleware.GetUserID(c)
	userID := c.Query("user_id")

	// 非管理员只能查询自己的记忆；管理员可通过查询参数指定目标用户
	if !strings.HasPrefix(authUserID, "admin_") || userID == "" {
		userID = authUserID
	}

	query := c.Query("q")
	if query == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "查询参数q不能为空"})
		return
	}

	url := fmt.Sprintf("%s/api/v1/memory/search?user_id=%s&q=%s",
		h.aiCoreURL, userID, query)

	resp, err := h.client.Get(url)
	if err != nil {
		log.Printf("[memory] AI-Core 不可达 (Query): %v", err)
		c.JSON(http.StatusBadGateway, gin.H{
			"error":     fmt.Sprintf("AI-Core 不可达: %v", err),
			"errorType": "ai_core_unreachable",
			"hint":      "AI-Core 服务未启动或不可达，请先在「服务管理」面板中启动 AI-Core",
		})
		return
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)

	var result interface{}
	json.Unmarshal(body, &result)
	c.JSON(resp.StatusCode, result)
}

// List 列出用户所有记忆 — 代理 GET /api/v1/memory?user_id=...
// 管理员可通过 user_id 查询参数查询任意用户的记忆
func (h *MemoryHandler) List(c *gin.Context) {
	authUserID := middleware.GetUserID(c)
	userID := c.Query("user_id")

	// 非管理员只能查询自己的记忆；管理员可通过查询参数指定目标用户
	if !strings.HasPrefix(authUserID, "admin_") || userID == "" {
		userID = authUserID
	}

	url := fmt.Sprintf("%s/api/v1/memory?user_id=%s", h.aiCoreURL, userID)

	resp, err := h.client.Get(url)
	if err != nil {
		log.Printf("[memory] AI-Core 不可达 (List): %v", err)
		c.JSON(http.StatusBadGateway, gin.H{
			"error":     fmt.Sprintf("AI-Core 不可达: %v", err),
			"errorType": "ai_core_unreachable",
			"hint":      "AI-Core 服务未启动或不可达，请先在「服务管理」面板中启动 AI-Core",
		})
		return
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)

	var result interface{}
	json.Unmarshal(body, &result)
	c.JSON(resp.StatusCode, result)
}

// Add 手动添加记忆 — 代理 POST /api/v1/memory
// 管理员可通过请求体中的 user_id 字段为任意用户添加记忆
func (h *MemoryHandler) Add(c *gin.Context) {
	authUserID := middleware.GetUserID(c)

	var req struct {
		UserID   string `json:"user_id"`
		Content  string `json:"content" binding:"required"`
		Category string `json:"category"`
		Priority int    `json:"priority"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}

	if req.Category == "" {
		req.Category = "other"
	}
	if req.Priority <= 0 {
		req.Priority = 1
	}

	// 管理员可通过请求体指定目标用户，否则使用认证用户
	userID := authUserID
	if strings.HasPrefix(authUserID, "admin_") && req.UserID != "" {
		userID = req.UserID
	}

	// 转发到 AI-Core
	aiReq := map[string]interface{}{
		"user_id":  userID,
		"content":  req.Content,
		"category": req.Category,
		"priority": req.Priority,
	}
	reqBody, _ := json.Marshal(aiReq)

	url := fmt.Sprintf("%s/api/v1/memory", h.aiCoreURL)
	httpReq, err := http.NewRequest("POST", url, bytes.NewReader(reqBody))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "构建请求失败"})
		return
	}
	httpReq.Header.Set("Content-Type", "application/json")

	resp, err := h.client.Do(httpReq)
	if err != nil {
		log.Printf("[memory] AI-Core 不可达 (Add): %v", err)
		c.JSON(http.StatusBadGateway, gin.H{
			"error":     fmt.Sprintf("AI-Core 不可达: %v", err),
			"errorType": "ai_core_unreachable",
			"hint":      "AI-Core 服务未启动或不可达，请先在「服务管理」面板中启动 AI-Core",
		})
		return
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)

	var result interface{}
	json.Unmarshal(body, &result)
	c.JSON(resp.StatusCode, result)
}

// Delete 删除单条记忆 — 代理 DELETE /api/v1/memory?id=...
func (h *MemoryHandler) Delete(c *gin.Context) {
	memoryID := c.Query("id")
	if memoryID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "缺少 id 参数"})
		return
	}

	url := fmt.Sprintf("%s/api/v1/memory?id=%s", h.aiCoreURL, memoryID)

	req, err := http.NewRequest("DELETE", url, nil)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "构建请求失败"})
		return
	}

	resp, err := h.client.Do(req)
	if err != nil {
		log.Printf("[memory] AI-Core 不可达 (Delete): %v", err)
		c.JSON(http.StatusBadGateway, gin.H{
			"error":     fmt.Sprintf("AI-Core 不可达: %v", err),
			"errorType": "ai_core_unreachable",
			"hint":      "AI-Core 服务未启动或不可达，请先在「服务管理」面板中启动 AI-Core",
		})
		return
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)

	var result interface{}
	json.Unmarshal(body, &result)
	c.JSON(resp.StatusCode, result)
}