package controllers

import (
	"bufio"
	"encoding/json"
	"fmt"
	"fwh-toolbox-server/middleware"
	"fwh-toolbox-server/services"

	"github.com/gofiber/fiber/v2"
)

var acpManager *services.ACPManager

// InitAIChat 初始化 AI Chat 模块
func InitAIChat(serviceDir string) {
	acpManager = services.NewACPManager(serviceDir, []string{"HOME=/home/jerry-remote"})
}

// AiChat 发送消息（SSE 流式响应）
// POST /ai/chat
func AiChat(c *fiber.Ctx) error {
	var req struct {
		Message   string `json:"message"`
		SessionId string `json:"sessionId"`
	}
	if err := c.BodyParser(&req); err != nil {
		return Fail(c, "Invalid request body")
	}
	if req.Message == "" {
		return Fail(c, "message 不能为空")
	}

	userId := middleware.AuthGetUserName(c)

	sess, err := acpManager.GetOrCreateSession(userId)
	if err != nil {
		return Error(c, fmt.Sprintf("AI 会话创建失败: %v", err))
	}

	// SSE 流式响应
	c.Set("Content-Type", "text/event-stream")
	c.Set("Cache-Control", "no-cache")
	c.Set("Connection", "keep-alive")
	c.Set("X-Accel-Buffering", "no")

	c.Context().SetBodyStreamWriter(func(w *bufio.Writer) {
		// 如果有欢迎消息且是新会话，先发送 welcome 事件
		if sess.WelcomeMessage != "" {
			welcomeEvent, _ := json.Marshal(services.AIChatEvent{Type: "welcome", Content: sess.WelcomeMessage})
			fmt.Fprintf(w, "event: welcome\ndata: %s\n\n", string(welcomeEvent))
			w.Flush()
		}

		eventCh := make(chan services.AIChatEvent, 50)

		go acpManager.Prompt(sess, req.Message, eventCh)

		for event := range eventCh {
			data, _ := json.Marshal(event)
			fmt.Fprintf(w, "event: %s\ndata: %s\n\n", event.Type, string(data))
			w.Flush()
		}
	})
	return nil
}

// GetAiSessions 获取当前用户的会话信息
// GET /ai/sessions
func GetAiSessions(c *fiber.Ctx) error {
	userId := middleware.AuthGetUserName(c)
	sess, err := acpManager.GetOrCreateSession(userId)
	if err != nil {
		return Error(c, fmt.Sprintf("AI 会话创建失败: %v", err))
	}

	if sess == nil {
		return Success(c, fiber.Map{
			"active":    false,
			"sessionId": "",
		})
	}

	return Success(c, fiber.Map{
		"active":         true,
		"sessionId":      sess.SessionId,
		"title":          sess.Title,
		"welcomeMessage": sess.WelcomeMessage,
		"lastActive":     sess.LastActive,
	})
}

// GetAiSessionList 获取用户的会话历史列表
// GET /ai/sessions/list
func GetAiSessionList(c *fiber.Ctx) error {
	userId := middleware.AuthGetUserName(c)
	list := acpManager.GetSessionList(userId)
	return Success(c, list)
}

// CreateAiSession 创建新的 AI 会话（保留旧会话到历史）
// POST /ai/sessions/new
func CreateAiSession(c *fiber.Ctx) error {
	userId := middleware.AuthGetUserName(c)

	// 创建新会话（旧会话自动归档到历史）
	sess, err := acpManager.CreateNewSession(userId)
	if err != nil {
		return Error(c, fmt.Sprintf("创建会话失败: %v", err))
	}

	return Success(c, fiber.Map{
		"sessionId": sess.SessionId,
	})
}

// LoadAiSession 加载历史会话（恢复 AI 上下文）
// POST /ai/sessions/:id/load
func LoadAiSession(c *fiber.Ctx) error {
	sessionId := c.Params("id")
	if sessionId == "" {
		return Fail(c, "sessionId 不能为空")
	}

	userId := middleware.AuthGetUserName(c)
	sess, err := acpManager.LoadSession(userId, sessionId)
	if err != nil {
		return Error(c, fmt.Sprintf("加载会话失败: %v", err))
	}

	return Success(c, fiber.Map{
		"sessionId":      sess.SessionId,
		"title":          sess.Title,
		"replayMessages": sess.ReplayMessages,
	})
}

// UpdateAiSessionTitle 更新会话标题
// PATCH /ai/sessions/:id
func UpdateAiSessionTitle(c *fiber.Ctx) error {
	sessionId := c.Params("id")
	if sessionId == "" {
		return Fail(c, "sessionId 不能为空")
	}

	var req struct {
		Title string `json:"title"`
	}
	if err := c.BodyParser(&req); err != nil {
		return Fail(c, "Invalid request body")
	}

	userId := middleware.AuthGetUserName(c)
	acpManager.UpdateSessionTitle(userId, sessionId, req.Title)
	return Success[any](c, nil, "标题已更新")
}

// DeleteAiSession 删除 AI 会话
// DELETE /ai/sessions/:id
func DeleteAiSession(c *fiber.Ctx) error {
	sessionId := c.Params("id")
	userId := middleware.AuthGetUserName(c)

	if sessionId == "" {
		// 无 id 参数，删除当前活跃会话
		acpManager.DeleteSession(userId)
	} else {
		// 删除指定会话
		acpManager.DeleteSessionFromHistory(userId, sessionId)
	}

	return Success[any](c, nil, "会话已删除")
}

// CancelAiChat 取消当前 AI 操作
// POST /ai/cancel
func CancelAiChat(c *fiber.Ctx) error {
	userId := middleware.AuthGetUserName(c)
	sess := acpManager.GetSessionInfo(userId)
	if sess == nil {
		return Fail(c, "没有活跃的会话")
	}
	acpManager.Cancel(sess)
	return Success[any](c, nil, "已取消")
}

// ResolvePermission 前端回传写权限选择
// POST /ai/permission
func ResolvePermission(c *fiber.Ctx) error {
	var req struct {
		OptionId string `json:"optionId"`
	}
	if err := c.BodyParser(&req); err != nil {
		return Fail(c, "Invalid request body")
	}
	if req.OptionId == "" {
		return Fail(c, "optionId 不能为空")
	}

	userId := middleware.AuthGetUserName(c)
	if err := acpManager.ResolvePermission(userId, req.OptionId); err != nil {
		return Fail(c, err.Error())
	}

	return Success[any](c, nil, "已回复")
}

// DownloadAiFile 下载 AI 生成的文件
// GET /ai/files/download?key=xxx
func DownloadAiFile(c *fiber.Ctx) error {
	key := c.Query("key")
	if key == "" {
		return Fail(c, "key 不能为空")
	}

	userId := middleware.AuthGetUserName(c)
	sess := acpManager.GetSessionInfo(userId)
	if sess == nil {
		return Fail(c, "没有活跃的会话")
	}

	// 从 FileStore 查找文件记录
	record := sess.Client.FileStore.GetFileByKey(key)
	if record == nil {
		return Fail(c, "文件不存在")
	}

	// 从 MinIO 读取文件内容
	content, err := sess.Client.FileStore.ReadFile(record.Path)
	if err != nil {
		return Error(c, err.Error())
	}

	// 设置下载头（文件名为原始名，不含 uuid 前缀）
	c.Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, record.FileName))
	c.Set("Content-Type", "application/octet-stream")
	return c.SendString(content)
}