package config

import (
	"fmt"
	"os"
	"path/filepath"
)

// RootDir checks the current working directory and its parent directories for
// a given filename and returns the absolute path to the directory. If the file
// is not found within the specified depth or any other error occurs, it will
// panic. If depth is zero or negative, RootDir checks the current directory only.
func RootDir(searchName string, depth ...int) string {
	// Get the current working directory
	cwd, err := os.Getwd()
	if err != nil {
		panic(err)
	}

	// Apply default depth if not provided
	depthVal := 0
	if len(depth) > 0 {
		depthVal = depth[0]
	}

	// Walk directories up to the specified depth to find the file
	path := walkRootDir(searchName, cwd, depthVal)
	if path == "" {
		panic(fmt.Errorf("RootDir checked %d directories, no '%s' file found", depthVal+1, searchName))
	}

	// Try to get the absolute path of the found directory
	abs, err := filepath.Abs(path)
	if err != nil || abs == "" {
		panic(fmt.Errorf("RootDir failed to get absolute path: %v", err))
	}

	return abs
}

// walkRootDir recursively checks directories up to the specified reverseDepth.
func walkRootDir(searchName, path string, reverseDepth int) string {
	if _, err := os.Stat(filepath.Join(path, searchName)); err == nil {
		return path
	}

	if reverseDepth > 0 {
		return walkRootDir(searchName, path+"/..", reverseDepth-1)
	}

	return ""
}