package scanner

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

// IncludePatterns are patterns for env files to include
var IncludePatterns = []string{
	".env",
	".env.*",
	"*.env",
}

// ExcludeFiles are specific filenames to exclude
var ExcludeFiles = []string{
	".env.example",
	".env.sample",
	".env.template",
}

// ExcludeDirs are directories to skip when scanning
var ExcludeDirs = []string{
	"node_modules",
	".git",
	"vendor",
	"venv",
	".venv",
	"__pycache__",
	".idea",
	".vscode",
	"dist",
	"build",
}

// Scan recursively scans the directory for env files
func Scan(rootDir string) ([]string, error) {
	var envFiles []string

	err := filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		// Skip excluded directories
		if info.IsDir() {
			for _, excludeDir := range ExcludeDirs {
				if info.Name() == excludeDir {
					return filepath.SkipDir
				}
			}
			return nil
		}

		// Check if file should be excluded
		for _, excludeFile := range ExcludeFiles {
			if info.Name() == excludeFile {
				return nil
			}
		}

		// Check if file matches include patterns
		if matchesPattern(info.Name()) {
			// Get relative path from rootDir
			relPath, err := filepath.Rel(rootDir, path)
			if err != nil {
				return err
			}
			envFiles = append(envFiles, relPath)
		}

		return nil
	})

	if err != nil {
		return nil, err
	}

	return envFiles, nil
}

// matchesPattern checks if filename matches any include pattern
func matchesPattern(filename string) bool {
	// Pattern: .env (exact match)
	if filename == ".env" {
		return true
	}

	// Pattern: .env.* (e.g., .env.production, .env.local)
	if strings.HasPrefix(filename, ".env.") {
		return true
	}

	// Pattern: *.env (e.g., docker.env, app.env)
	if strings.HasSuffix(filename, ".env") && filename != ".env" {
		return true
	}

	return false
}