package fileutil

import (
	"fmt"
	"os"
)

// FindDataFile locates a data file by searching up the directory tree.
// This is useful for tests that may run from different directory depths.
//
// It searches in the following order:
//  1. Current directory
//  2. One level up (../)
//  3. Two levels up (../../)
//  4. Three levels up (../../../)
//
// Example:
//
//	path, err := fileutil.FindDataFile("data/cv-en.json")
//	if err != nil {
//	    log.Fatal(err)
//	}
func FindDataFile(filename string) (string, error) {
	if filename == "" {
		return "", fmt.Errorf("filename cannot be empty")
	}

	// Try current directory first
	if _, err := os.Stat(filename); err == nil {
		return filename, nil
	}

	// Try parent directories (for tests running from subdirectories)
	paths := []string{
		filename,               // Current dir
		"../" + filename,       // One level up
		"../../" + filename,    // Two levels up (for tests in internal/handlers)
		"../../../" + filename, // Three levels up
	}

	for _, path := range paths {
		if _, err := os.Stat(path); err == nil {
			return path, nil
		}
	}

	return "", fmt.Errorf("file not found: %s (searched: current dir, ../, ../../, ../../../)", filename)
}