package plugin

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"sort"
	"sync"

	agentIO "gitcode.com/JianFeeeee/HomeAgent/internal/agent/io"
	"gitcode.com/JianFeeeee/HomeAgent/internal/events"
	"gitcode.com/JianFeeeee/HomeAgent/internal/knowledge"
	"gitcode.com/JianFeeeee/HomeAgent/internal/memory"
	doc "gitcode.com/JianFeeeee/HomeAgent/internal/memory/document"
	"gitcode.com/JianFeeeee/HomeAgent/internal/memory/text"
	sdk "gitcode.com/JianFeeeee/HomeAgent/internal/sdk"
	agentAPI "gitcode.com/JianFeeeee/HomeAgent/internal/agent/api"
	internalConfig "gitcode.com/JianFeeeee/HomeAgent/internal/config"
)

type NativeFactory func(name string, config map[string]interface{}) (sdk.Plugin, error)

// globalFactories 是插件通过 init() 自注册的全局工厂表。
// Registry.RegisterNative() 写入此表；Registry.Load() 从中查找。
var globalFactories sync.Map

// RegisterFactory 供插件包在 init() 中调用，实现自注册。
// plugin.RegisterFactory("timer", func(name string, cfg map[string]interface{}) (sdk.Plugin, error) { ... })
func RegisterFactory(name string, factory NativeFactory) {
	globalFactories.Store(name, factory)
}

type Registry struct {
	mu        sync.RWMutex
	plugins   map[string]sdk.Plugin
	instances []sdk.Plugin
	factories map[string]NativeFactory

	iom       *agentIO.IOManager
	evBus     *events.Bus
	memDB     *memory.GraphDB
	textMem   *text.Memory
	docStore  *doc.Store
	ks        *knowledge.Store
	mgr       *agentAPI.ProviderManager
	cfgReg    *internalConfig.ConfigRegistry
	plgDir    string

	regTool  sdk.ToolRegistrar
	regStage sdk.StageRegistrar
	regAPI   sdk.APIRegistrar
}

func NewRegistry() *Registry {
	return &Registry{
		plugins:   make(map[string]sdk.Plugin),
		factories: make(map[string]NativeFactory),
	}
}

func (r *Registry) SetIOManager(iom *agentIO.IOManager)          { r.iom = iom }
func (r *Registry) SetEventBus(evBus *events.Bus)                { r.evBus = evBus }
func (r *Registry) SetMemory(memDB *memory.GraphDB)              { r.memDB = memDB }
func (r *Registry) SetTextMemory(tm *text.Memory)                { r.textMem = tm }
func (r *Registry) SetDocStore(ds *doc.Store)                    { r.docStore = ds }
func (r *Registry) SetKnowledge(ks *knowledge.Store)             { r.ks = ks }
func (r *Registry) SetProviderManager(mgr *agentAPI.ProviderManager) { r.mgr = mgr }
func (r *Registry) SetConfigRegistry(cfgReg *internalConfig.ConfigRegistry) { r.cfgReg = cfgReg }
func (r *Registry) SetPluginDir(dir string)                      { r.plgDir = dir }
func (r *Registry) SetToolRegistrar(fn sdk.ToolRegistrar)        { r.regTool = fn }
func (r *Registry) SetStageRegistrar(fn sdk.StageRegistrar)      { r.regStage = fn }
func (r *Registry) SetAPIRegistrar(fn sdk.APIRegistrar)          { r.regAPI = fn }

func (r *Registry) RegisterNative(name string, factory NativeFactory) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.factories[name] = factory
	globalFactories.Store(name, factory)
}

func (r *Registry) buildSDK(name string) *sdk.PluginSDK {
	sett := sdk.NewSettings(name, r.cfgReg)

	regTool := r.regTool
	if regTool == nil {
		regTool = func(toolName string, def sdk.ToolDef, handler sdk.ToolHandler) error {
			return nil
		}
	}
	regStage := r.regStage
	if regStage == nil {
		regStage = func(stage sdk.Stage, handler sdk.StageHandler) {}
	}
	regAPI := r.regAPI
	if regAPI == nil {
		regAPI = func(name string) error { return nil }
	}

	return sdk.New(name,
		r.iom, r.evBus,
		sdk.NewGraphMemory(r.memDB),
		sdk.NewTextMemory(r.textMem),
		sdk.NewDocMemory(r.docStore),
		sdk.NewKnowledge(r.ks),
		sdk.NewLLM(r.mgr),
		sett,
		regTool, regStage, regAPI,
	)
}

func (r *Registry) Load(dir string) error {
	if dir == "" {
		dir = r.plgDir
	}
	os.MkdirAll(dir, 0755)

	// 1) 扫描已有目录
	loaded := map[string]bool{}
	entries, err := os.ReadDir(dir)
	if err != nil {
		if os.IsNotExist(err) {
			os.MkdirAll(dir, 0755)
			return nil
		}
		return err
	}

	for _, entry := range entries {
		if !entry.IsDir() {
			continue
		}
		name := entry.Name()
		plgDir := filepath.Join(dir, name)
		if r.loadOne(plgDir, name) {
			loaded[name] = true
		}
	}

	// 2) 对已注册但尚无目录的工厂，创建目录并加载
	r.mu.RLock()
	allFactories := make(map[string]NativeFactory)
	for name, f := range r.factories {
		allFactories[name] = f
	}
	r.mu.RUnlock()

	globalFactories.Range(func(key, val interface{}) bool {
		name := key.(string)
		if _, ok := allFactories[name]; !ok {
			allFactories[name] = val.(NativeFactory)
		}
		return true
	})

	for name, factory := range allFactories {
		if loaded[name] {
			continue
		}
		plgDir := filepath.Join(dir, name)
		os.MkdirAll(plgDir, 0755)

		cfg := r.readConfig(plgDir)
		p, err := factory(name, cfg)
		if err != nil {
			log.Printf("[plugin] factory %s: %v", name, err)
			continue
		}
		if p == nil {
			continue
		}

		plgSDK := r.buildSDK(name)
		if err := p.Start(plgSDK); err != nil {
			log.Printf("[plugin] start %s: %v", name, err)
			continue
		}

		r.mu.Lock()
		r.plugins[name] = p
		r.instances = append(r.instances, p)
		r.mu.Unlock()
		log.Printf("[plugin] loaded: %s", name)
	}

	return nil
}

func (r *Registry) loadOne(plgDir, name string) bool {
	// 1) 查找工厂（init 自注册或 RegisterNative）
	r.mu.RLock()
	factory, hasFactory := r.factories[name]
	r.mu.RUnlock()
	if !hasFactory {
		v, ok := globalFactories.Load(name)
		if ok {
			factory = v.(NativeFactory)
			hasFactory = true
		}
	}

	var plg sdk.Plugin

	if hasFactory {
		cfg := r.readConfig(plgDir)
		p, err := factory(name, cfg)
		if err != nil {
			log.Printf("[plugin] factory %s: %v", name, err)
			return false
		}
		if p == nil {
			return false
		}
		plg = p
	} else {
		// 2) 无工厂，尝试动态加载 .so / .lua
		dynCfg := r.readConfig(plgDir)
		p, err := r.tryDynamic(plgDir, name, dynCfg)
		if err != nil {
			log.Printf("[plugin] dynamic %s: %v", name, err)
		}
		if p == nil {
			return false
		}
		plg = p
	}

	plgSDK := r.buildSDK(name)
	if err := plg.Start(plgSDK); err != nil {
		log.Printf("[plugin] start %s: %v", name, err)
		return false
	}

	r.mu.Lock()
	r.plugins[name] = plg
	r.instances = append(r.instances, plg)
	r.mu.Unlock()
	log.Printf("[plugin] loaded: %s", name)
	return true
}

func (r *Registry) StopAll() {
	r.mu.Lock()
	defer r.mu.Unlock()
	for _, p := range r.instances {
		if err := p.Stop(); err != nil {
			log.Printf("[plugin] stop %s: %v", p.Name(), err)
		}
	}
	r.plugins = make(map[string]sdk.Plugin)
	r.instances = nil
}

func (r *Registry) Reload(dir string) (string, error) {
	r.StopAll()
	if err := r.Load(dir); err != nil {
		return "", err
	}
	return fmt.Sprintf("loaded %d plugins", len(r.instances)), nil
}

func (r *Registry) List() []string {
	r.mu.RLock()
	defer r.mu.RUnlock()
	list := make([]string, 0, len(r.plugins))
	for name := range r.plugins {
		list = append(list, name)
	}
	sort.Strings(list)
	return list
}

func (r *Registry) Get(name string) sdk.Plugin {
	r.mu.RLock()
	defer r.mu.RUnlock()
	return r.plugins[name]
}

func (r *Registry) tryDynamic(plgDir, name string, config map[string]interface{}) (sdk.Plugin, error) {
	// 优先尝试 .so（Go plugin），其次 .lua（Lua 脚本）
	plg, err := tryLoadSO(plgDir, name, config)
	if err != nil {
		return nil, err
	}
	if plg != nil {
		return plg, nil
	}
	return tryLoadLua(plgDir, name, config)
}

func (r *Registry) readConfig(plgDir string) map[string]interface{} {
	cfg := map[string]interface{}{}
	data, err := os.ReadFile(filepath.Join(plgDir, "skill.json"))
	if err != nil {
		return cfg
	}
	var meta map[string]interface{}
	if err := json.Unmarshal(data, &meta); err == nil {
		return meta
	}
	return cfg
}