package storage

import (
	"context"
	"fmt"
	"io"
	"os"
	"path/filepath"

	"git.nakama.town/fmartingr/hako/internal/model"
	"github.com/google/uuid"
)

// LocalStorage implements Storage interface using local filesystem
type LocalStorage struct {
	basePath string
}

// NewLocalStorage creates a new LocalStorage instance
func NewLocalStorage(basePath string) *LocalStorage {
	return &LocalStorage{
		basePath: basePath,
	}
}

// Save stores a file at basePath/linkID/filename
// Returns the relative storage path
func (s *LocalStorage) Save(ctx context.Context, linkID string, filename string, reader io.Reader) (string, error) {
	// Get relative path for link directory
	linkDirRelPath := model.GetPathForLink(linkID)
	linkDir := filepath.Join(s.basePath, linkDirRelPath)
	if err := os.MkdirAll(linkDir, 0755); err != nil {
		return "", fmt.Errorf("failed to create directory: %w", err)
	}

	// Generate a unique filename to avoid collisions
	ext := filepath.Ext(filename)
	randomName := uuid.New().String() + ext

	// Get relative path for the file
	relPath := model.GetPathForLinkFile(linkID, randomName)
	fullPath := filepath.Join(s.basePath, relPath)

	// Create the file
	file, err := os.Create(fullPath)
	if err != nil {
		return "", fmt.Errorf("failed to create file: %w", err)
	}
	defer func() { _ = file.Close() }()

	// Copy data from reader to file
	if _, err := io.Copy(file, reader); err != nil {
		return "", fmt.Errorf("failed to write file: %w", err)
	}

	return relPath, nil
}

// Get retrieves a file from storage
func (s *LocalStorage) Get(ctx context.Context, path string) (io.ReadCloser, error) {
	fullPath := filepath.Join(s.basePath, path)

	file, err := os.Open(fullPath)
	if err != nil {
		return nil, fmt.Errorf("failed to open file: %w", err)
	}

	return file, nil
}

// Delete removes a file from storage
func (s *LocalStorage) Delete(ctx context.Context, path string) error {
	fullPath := filepath.Join(s.basePath, path)

	if err := os.Remove(fullPath); err != nil {
		return fmt.Errorf("failed to delete file: %w", err)
	}

	return nil
}

// Exists checks if a file exists in storage
func (s *LocalStorage) Exists(ctx context.Context, path string) (bool, error) {
	fullPath := filepath.Join(s.basePath, path)

	_, err := os.Stat(fullPath)
	if err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, fmt.Errorf("failed to check file existence: %w", err)
	}

	return true, nil
}

// DeleteDirectory removes an entire link directory and all its contents
func (s *LocalStorage) DeleteDirectory(ctx context.Context, linkID string) error {
	linkDirRelPath := model.GetPathForLink(linkID)
	linkDir := filepath.Join(s.basePath, linkDirRelPath)

	if err := os.RemoveAll(linkDir); err != nil {
		return fmt.Errorf("failed to delete link directory: %w", err)
	}

	return nil
}