package controllers

import (
	"encoding/json"
	"fmt"
	"io"
	"strconv"
	"strings"
	"time"

	"server/models"
	"server/pkg/jwtutil"

	beego "github.com/beego/beego/v2/server/web"
)

// BackendAiChatSessionController AI聊天会话控制器
type BackendAiChatSessionController struct {
	beego.Controller
}

func (c *BackendAiChatSessionController) sessionClaims() (*jwtutil.Claims, error) {
	auth := c.Ctx.Request.Header.Get("Authorization")
	if auth == "" {
		return nil, fmt.Errorf("未登录")
	}
	parts := strings.SplitN(auth, " ", 2)
	if len(parts) != 2 || parts[0] != "Bearer" {
		return nil, fmt.Errorf("认证信息格式错误")
	}
	claims, err := jwtutil.ParseToken(parts[1])
	if err != nil {
		return nil, fmt.Errorf("无效的token")
	}
	if claims.UserType != "backend" {
		return nil, fmt.Errorf("无权访问")
	}
	return claims, nil
}

func (c *BackendAiChatSessionController) sessionJsonErr(httpStatus, bizCode int, msg string) {
	c.Ctx.Output.SetStatus(httpStatus)
	c.Data["json"] = map[string]interface{}{"code": bizCode, "msg": msg}
	_ = c.ServeJSON()
}

func (c *BackendAiChatSessionController) sessionOk(data interface{}) {
	c.Data["json"] = map[string]interface{}{"code": 200, "msg": "success", "data": data}
	_ = c.ServeJSON()
}

type chatSessionPayload struct {
	Title      string `json:"title"`
	ProviderID uint64 `json:"provider_id"`
}

// List GET /backend/ai/chat/session/list
func (c *BackendAiChatSessionController) List() {
	claims, err := c.sessionClaims()
	if err != nil {
		c.sessionJsonErr(401, 401, err.Error())
		return
	}

	var list []models.BackendAiChatSession
	_, err = models.Orm.QueryTable(new(models.BackendAiChatSession)).
		Filter("tenant_id", fmt.Sprintf("%d", claims.TenantId)).
		Filter("user_id", uint64(claims.UserID)).
		Filter("delete_time__isnull", true).
		OrderBy("-update_time").
		All(&list)
	if err != nil {
		c.sessionJsonErr(500, 500, "查询失败: "+err.Error())
		return
	}

	c.sessionOk(map[string]interface{}{"list": list})
}

// Create POST /backend/ai/chat/session
func (c *BackendAiChatSessionController) Create() {
	claims, err := c.sessionClaims()
	if err != nil {
		c.sessionJsonErr(401, 401, err.Error())
		return
	}

	body, err := io.ReadAll(c.Ctx.Request.Body)
	if err != nil {
		c.sessionJsonErr(400, 400, "读取请求体失败")
		return
	}
	var p chatSessionPayload
	if err := json.Unmarshal(body, &p); err != nil {
		c.sessionJsonErr(400, 400, "参数格式错误")
		return
	}

	title := strings.TrimSpace(p.Title)
	if title == "" {
		title = "新对话"
	}

	session := models.BackendAiChatSession{
		TenantID:   fmt.Sprintf("%d", claims.TenantId),
		UserID:     uint64(claims.UserID),
		ProviderID: p.ProviderID,
		Title:      title,
		CreateTime: time.Now(),
		UpdateTime: time.Now(),
	}

	id, err := models.Orm.Insert(&session)
	if err != nil {
		c.sessionJsonErr(500, 500, "创建失败: "+err.Error())
		return
	}

	c.sessionOk(map[string]interface{}{"id": id, "title": title})
}

// Update PUT /backend/ai/chat/session/:id（重命名）
func (c *BackendAiChatSessionController) Update() {
	claims, err := c.sessionClaims()
	if err != nil {
		c.sessionJsonErr(401, 401, err.Error())
		return
	}

	idStr := c.Ctx.Input.Param(":id")
	id, err := strconv.ParseUint(idStr, 10, 64)
	if err != nil {
		c.sessionJsonErr(400, 400, "ID格式错误")
		return
	}

	session := models.BackendAiChatSession{ID: id}
	if err := models.Orm.Read(&session); err != nil {
		c.sessionJsonErr(404, 404, "会话不存在")
		return
	}
	if session.TenantID != fmt.Sprintf("%d", claims.TenantId) || session.UserID != uint64(claims.UserID) {
		c.sessionJsonErr(403, 403, "无权操作")
		return
	}

	body, err := io.ReadAll(c.Ctx.Request.Body)
	if err != nil {
		c.sessionJsonErr(400, 400, "读取请求体失败")
		return
	}
	var p chatSessionPayload
	if err := json.Unmarshal(body, &p); err != nil {
		c.sessionJsonErr(400, 400, "参数格式错误")
		return
	}

	if strings.TrimSpace(p.Title) != "" {
		session.Title = strings.TrimSpace(p.Title)
	}
	if p.ProviderID > 0 {
		session.ProviderID = p.ProviderID
	}
	session.UpdateTime = time.Now()

	_, err = models.Orm.Update(&session)
	if err != nil {
		c.sessionJsonErr(500, 500, "更新失败: "+err.Error())
		return
	}

	c.sessionOk(nil)
}

// Delete DELETE /backend/ai/chat/session/:id
func (c *BackendAiChatSessionController) Delete() {
	claims, err := c.sessionClaims()
	if err != nil {
		c.sessionJsonErr(401, 401, err.Error())
		return
	}

	idStr := c.Ctx.Input.Param(":id")
	id, err := strconv.ParseUint(idStr, 10, 64)
	if err != nil {
		c.sessionJsonErr(400, 400, "ID格式错误")
		return
	}

	session := models.BackendAiChatSession{ID: id}
	if err := models.Orm.Read(&session); err != nil {
		c.sessionJsonErr(404, 404, "会话不存在")
		return
	}
	if session.TenantID != fmt.Sprintf("%d", claims.TenantId) || session.UserID != uint64(claims.UserID) {
		c.sessionJsonErr(403, 403, "无权操作")
		return
	}

	now := time.Now()
	session.DeleteTime = &now
	_, err = models.Orm.Update(&session, "delete_time")
	if err != nil {
		c.sessionJsonErr(500, 500, "删除失败: "+err.Error())
		return
	}

	c.sessionOk(nil)
}