package network

import (
	"encoding/json"
	"os"
	"path/filepath"
	"sync"
)

var defaultMetadataPath = "/etc/proxmox-router/metadata.json"

// MetadataManager manages user annotations for interfaces.
type MetadataManager struct {
	mu       sync.RWMutex
	filePath string
	store    MetadataStore
}

func NewMetadataManager(customPath string) *MetadataManager {
	p := defaultMetadataPath
	if customPath != "" {
		p = customPath
	}
	mm := &MetadataManager{
		filePath: p,
		store: MetadataStore{
			Interfaces: make(map[string]InterfaceMetadata),
		},
	}
	mm.load()
	return mm
}

func (mm *MetadataManager) load() {
	mm.mu.Lock()
	defer mm.mu.Unlock()

	data, err := os.ReadFile(mm.filePath)
	if err != nil {
		return
	}
	_ = json.Unmarshal(data, &mm.store)
	if mm.store.Interfaces == nil {
		mm.store.Interfaces = make(map[string]InterfaceMetadata)
	}
}

func (mm *MetadataManager) save() error {
	dir := filepath.Dir(mm.filePath)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return err
	}

	data, err := json.MarshalIndent(mm.store, "", "  ")
	if err != nil {
		return err
	}

	return os.WriteFile(mm.filePath, data, 0644)
}

func (mm *MetadataManager) Get(name string) InterfaceMetadata {
	mm.mu.RLock()
	defer mm.mu.RUnlock()
	return mm.store.Interfaces[name]
}

func (mm *MetadataManager) Set(name string, role, desc string) error {
	mm.mu.Lock()
	defer mm.mu.Unlock()

	mm.store.Interfaces[name] = InterfaceMetadata{
		Role:        role,
		Description: desc,
	}
	return mm.save()
}

func (mm *MetadataManager) Delete(name string) error {
	mm.mu.Lock()
	defer mm.mu.Unlock()

	delete(mm.store.Interfaces, name)
	return mm.save()
}