package controllers

import (
	"errors"

	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/utils"
	"go.uber.org/zap"

	"fwh-toolbox-server/config"
	"fwh-toolbox-server/middleware"
	"fwh-toolbox-server/services"
	"fwh-toolbox-server/utils/agentserver"
)

// 新 AI 助手（AgentServer）接口，见 docs/ai-assistant-agentserver/technical-design.md §3.4、§3.5

var agentService *services.AgentService

// InitAgent 初始化新 AI 助手
func InitAgent(cfg config.AgentConfig) {
	agentService = services.NewAgentService(cfg)
	zap.L().Info("[Agent] 初始化", zap.Bool("enabled", cfg.Enabled), zap.String("server", cfg.ServerURL))
}

func agentEnabled(c *fiber.Ctx) bool {
	return agentService != nil && agentService.Enabled(middleware.AuthGetRoleNameList(c))
}

// AgentGuard 未开启或角色不允许时，/agent/* 一律返回 403（/agent/config 除外）
func AgentGuard(c *fiber.Ctx) error {
	if !agentEnabled(c) {
		return Forbidden(c, "AI 助手未开启或无权使用")
	}
	return c.Next()
}

// GetAgentConfig 新助手对当前用户是否可用
// GET /agent/config
func GetAgentConfig(c *fiber.Ctx) error {
	return Success(c, fiber.Map{"enabled": agentEnabled(c)})
}

// ListAgentSessions 本人会话列表
// GET /agent/sessions
func ListAgentSessions(c *fiber.Ctx) error {
	list, err := agentService.ListSessions(c.UserContext(), middleware.AuthGetUserName(c))
	if err != nil {
		return Error(c, "获取会话列表失败: "+err.Error())
	}
	return Success(c, list)
}

// CreateAgentSession 新建会话
// POST /agent/sessions
func CreateAgentSession(c *fiber.Ctx) error {
	item, err := agentService.CreateSession(c.UserContext(), middleware.AuthGetUserName(c), middleware.AuthGetRoleNameList(c))
	if err != nil {
		zap.L().Warn("[Agent] 创建会话失败", zap.Error(err))
		return Error(c, "创建会话失败: "+err.Error())
	}
	return Success(c, fiber.Map{"sessionId": item.SessionId, "title": item.Title, "profileId": item.ProfileId})
}

// UpdateAgentSession 修改会话标题
// PATCH /agent/sessions/:id
func UpdateAgentSession(c *fiber.Ctx) error {
	sessionId := utils.CopyString(c.Params("id"))
	var req struct {
		Title string `json:"title"`
	}
	if err := c.BodyParser(&req); err != nil {
		return Fail(c, "Invalid request body")
	}
	err := agentService.RenameSession(c.UserContext(), middleware.AuthGetUserName(c), sessionId, req.Title)
	if errors.Is(err, services.ErrAgentSessionNotFound) {
		return NotFound(c, err.Error())
	}
	if err != nil {
		return Error(c, "修改标题失败: "+err.Error())
	}
	return Success[any](c, nil, "标题已更新")
}

// DeleteAgentSession 删除会话
// DELETE /agent/sessions/:id
func DeleteAgentSession(c *fiber.Ctx) error {
	sessionId := utils.CopyString(c.Params("id"))
	err := agentService.DeleteSession(c.UserContext(), middleware.AuthGetUserName(c), sessionId)
	if errors.Is(err, services.ErrAgentSessionNotFound) {
		return NotFound(c, err.Error())
	}
	if err != nil {
		return Error(c, "删除会话失败: "+err.Error())
	}
	return Success[any](c, nil, "会话已删除")
}

// ProxyAgentServer AgentServer 代理，响应原样透传（不包装 Success）
// ALL /agent/v1/*
func ProxyAgentServer(c *fiber.Ctx) error {
	if !agentEnabled(c) {
		return agentserver.WriteError(c, fiber.StatusForbidden, "forbidden", "AI 助手未开启或无权使用")
	}
	rest := utils.CopyString(c.Params("*"))
	return agentService.Proxy().Handle(c, middleware.AuthGetUserName(c), rest)
}