package service

import (
	"context"
	"fmt"
	"sync"
	"time"

	"market-data-service/adapter"
	"market-data-service/adapter/tushare"
	"market-data-service/api"
)

// AdapterService 适配器管理服务接口
type AdapterService interface {
	// GetAdapterList 获取适配器列表
	GetAdapterList(ctx context.Context) (*api.AdapterListData, error)
	
	// ToggleAdapter 启用/禁用适配器
	ToggleAdapter(ctx context.Context, req *api.AdapterToggleRequest) error
	
	// UpdateAdapterConfig 更新适配器配置
	UpdateAdapterConfig(ctx context.Context, req *api.AdapterConfigUpdateRequest) error
	
	// GetActiveAdapter 获取当前激活的适配器
	GetActiveAdapter(assetClass string) (adapter.DataSourceAdapter, error)
	
	// GetAvailableAdapters 获取所有可用的适配器名称
	GetAvailableAdapters() []string
	
	// RegisterAdapter 注册适配器
	RegisterAdapter(name string, factory AdapterFactory)
}

// AdapterFactory 适配器工厂函数
type AdapterFactory func() adapter.DataSourceAdapter

// AdapterServiceImpl 适配器服务实现
type AdapterServiceImpl struct {
	mu sync.RWMutex
	
	// 已注册的适配器工厂
	factories map[string]AdapterFactory
	
	// 适配器配置
	configs map[string]*adapterConfig
	
	// 当前激活的适配器实例
	activeAdapters map[string]adapter.DataSourceAdapter
	
	// 适配器元数据
	metadata map[string]*adapterMetadata
}

// adapterConfig 适配器配置
type adapterConfig struct {
	Enabled bool              `json:"enabled"`
	Config  map[string]string `json:"config"`
}

// adapterMetadata 适配器元数据
type adapterMetadata struct {
	Name        string    `json:"name"`
	Type        string    `json:"type"`
	Version     string    `json:"version"`
	Description string    `json:"description"`
	UpdatedAt   time.Time `json:"updated_at"`
}

// NewAdapterService 创建适配器服务
func NewAdapterService() AdapterService {
	service := &AdapterServiceImpl{
		factories:      make(map[string]AdapterFactory),
		configs:        make(map[string]*adapterConfig),
		activeAdapters: make(map[string]adapter.DataSourceAdapter),
		metadata:       make(map[string]*adapterMetadata),
	}
	
	// 注册内置适配器
	service.registerBuiltinAdapters()
	
	return service
}

// registerBuiltinAdapters 注册内置适配器
func (s *AdapterServiceImpl) registerBuiltinAdapters() {
	// 注册Tushare适配器
	s.RegisterAdapter("tushare", func() adapter.DataSourceAdapter {
		return tushare.NewAdapter()
	})
	
	// 设置Tushare元数据
	s.metadata["tushare"] = &adapterMetadata{
		Name:        "tushare",
		Type:        "http",
		Version:     "1.0.0",
		Description: "Tushare Pro 金融数据接口",
		UpdatedAt:   time.Now(),
	}
	
	// 默认配置
	s.configs["tushare"] = &adapterConfig{
		Enabled: true,
		Config: map[string]string{
			"token":    "",
			"base_url": "https://api.tushare.pro",
		},
	}
	
	// 预留Wind适配器
	s.metadata["wind"] = &adapterMetadata{
		Name:        "wind",
		Type:        "ws",
		Version:     "1.0.0",
		Description: "Wind 金融终端接口（预留）",
		UpdatedAt:   time.Now(),
	}
	
	s.configs["wind"] = &adapterConfig{
		Enabled: false,
		Config: map[string]string{
			"host": "localhost",
			"port": "8081",
		},
	}
}

// GetAdapterList 获取适配器列表
func (s *AdapterServiceImpl) GetAdapterList(ctx context.Context) (*api.AdapterListData, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()
	
	adapters := make([]api.AdapterInfo, 0, len(s.metadata))
	
	for name, meta := range s.metadata {
		cfg, ok := s.configs[name]
		if !ok {
			cfg = &adapterConfig{Enabled: false, Config: make(map[string]string)}
		}
		
		status := api.AdapterStatusDisabled
		if cfg.Enabled {
			status = api.AdapterStatusStandby
			// 检查是否是激活状态
			if _, active := s.activeAdapters[name]; active {
				status = api.AdapterStatusActive
			}
		}
		
		adapters = append(adapters, api.AdapterInfo{
			Name:        meta.Name,
			Type:        meta.Type,
			Version:     meta.Version,
			Description: meta.Description,
			Status:      status,
			Config:      cfg.Config,
			UpdatedAt:   meta.UpdatedAt,
		})
	}
	
	return &api.AdapterListData{
		Adapters: adapters,
	}, nil
}

// ToggleAdapter 启用/禁用适配器
func (s *AdapterServiceImpl) ToggleAdapter(ctx context.Context, req *api.AdapterToggleRequest) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	
	cfg, ok := s.configs[req.Name]
	if !ok {
		return fmt.Errorf("adapter not found: %s", req.Name)
	}
	
	cfg.Enabled = req.Enable
	
	// 如果禁用，关闭适配器连接
	if !req.Enable {
		if adapter, ok := s.activeAdapters[req.Name]; ok {
			adapter.Close()
			delete(s.activeAdapters, req.Name)
		}
	}
	
	// 更新元数据
	if meta, ok := s.metadata[req.Name]; ok {
		meta.UpdatedAt = time.Now()
	}
	
	return nil
}

// UpdateAdapterConfig 更新适配器配置
func (s *AdapterServiceImpl) UpdateAdapterConfig(ctx context.Context, req *api.AdapterConfigUpdateRequest) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	
	cfg, ok := s.configs[req.Name]
	if !ok {
		return fmt.Errorf("adapter not found: %s", req.Name)
	}
	
	// 更新配置
	for k, v := range req.Config {
		cfg.Config[k] = v
	}
	
	// 如果适配器已激活，重新连接
	if adapter, ok := s.activeAdapters[req.Name]; ok {
		adapter.Close()
		delete(s.activeAdapters, req.Name)
		
		// 如果启用状态，重新连接
		if cfg.Enabled {
			if err := s.connectAdapter(req.Name); err != nil {
				return fmt.Errorf("failed to reconnect adapter: %w", err)
			}
		}
	}
	
	// 更新元数据
	if meta, ok := s.metadata[req.Name]; ok {
		meta.UpdatedAt = time.Now()
	}
	
	return nil
}

// GetActiveAdapter 获取当前激活的适配器
func (s *AdapterServiceImpl) GetActiveAdapter(assetClass string) (adapter.DataSourceAdapter, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()
	
	// 根据资产类别获取配置
	// 这里简化处理，实际应该从配置服务获取
	adapterName := "tushare"
	if assetClass == "futures" {
		adapterName = "tushare"
	}
	
	// 检查是否已有激活的实例
	if adapter, ok := s.activeAdapters[adapterName]; ok {
		return adapter, nil
	}
	
	return nil, fmt.Errorf("no active adapter for %s", assetClass)
}

// GetAvailableAdapters 获取所有可用的适配器名称
func (s *AdapterServiceImpl) GetAvailableAdapters() []string {
	s.mu.RLock()
	defer s.mu.RUnlock()
	
	names := make([]string, 0, len(s.metadata))
	for name, meta := range s.metadata {
		// 只返回有工厂的适配器（已实现的）
		if _, ok := s.factories[name]; ok {
			names = append(names, fmt.Sprintf("%s|%s", name, meta.Description))
		}
	}
	return names
}

// RegisterAdapter 注册适配器
func (s *AdapterServiceImpl) RegisterAdapter(name string, factory AdapterFactory) {
	s.mu.Lock()
	defer s.mu.Unlock()
	
	s.factories[name] = factory
}

// connectAdapter 连接适配器
func (s *AdapterServiceImpl) connectAdapter(name string) error {
	factory, ok := s.factories[name]
	if !ok {
		return fmt.Errorf("adapter factory not found: %s", name)
	}
	
	cfg, ok := s.configs[name]
	if !ok {
		return fmt.Errorf("adapter config not found: %s", name)
	}
	
	adapter := factory()
	if err := adapter.Connect(cfg.Config); err != nil {
		return err
	}
	
	s.activeAdapters[name] = adapter
	return nil
}

// HealthCheck 适配器健康检查
func (s *AdapterServiceImpl) HealthCheck(name string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()
	
	adapter, ok := s.activeAdapters[name]
	if !ok {
		return fmt.Errorf("adapter not active: %s", name)
	}
	
	return adapter.HealthCheck()
}