package router

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

// buildRoutes scans the routes directory and builds the routing tree
func (r *LuaRouter) buildRoutes() error {
	r.failedRoutes = make(map[string]*RouteError)
	r.middlewareFiles = make(map[string][]string)

	// First pass: collect all middleware files
	err := filepath.Walk(r.routesDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() || !strings.HasSuffix(info.Name(), ".lua") {
			return err
		}

		if strings.TrimSuffix(info.Name(), ".lua") == "middleware" {
			relDir, err := filepath.Rel(r.routesDir, filepath.Dir(path))
			if err != nil {
				return err
			}

			fsPath := "/"
			if relDir != "." {
				fsPath = "/" + strings.ReplaceAll(relDir, "\\", "/")
			}

			// Use filesystem path for middleware (includes groups)
			r.middlewareFiles[fsPath] = append(r.middlewareFiles[fsPath], path)
		}

		return nil
	})

	if err != nil {
		return err
	}

	// Second pass: build routes with combined middleware + handler
	return filepath.Walk(r.routesDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() || !strings.HasSuffix(info.Name(), ".lua") {
			return err
		}

		fileName := strings.TrimSuffix(info.Name(), ".lua")

		// Skip middleware files (already processed)
		if fileName == "middleware" {
			return nil
		}

		relDir, err := filepath.Rel(r.routesDir, filepath.Dir(path))
		if err != nil {
			return err
		}

		fsPath := "/"
		if relDir != "." {
			fsPath = "/" + strings.ReplaceAll(relDir, "\\", "/")
		}

		pathInfo := parsePathWithGroups(fsPath)

		// Handle index.lua files
		if fileName == "index" {
			for _, method := range []string{"GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS", "HEAD"} {
				root := r.routes[method]
				node := r.findOrCreateNode(root, pathInfo.urlPath)
				node.indexFile = path
				node.modTime = info.ModTime()
				node.fsPath = pathInfo.fsPath
				r.compileWithMiddleware(node, pathInfo.fsPath, path)
			}
			return nil
		}

		// Handle method files
		method := strings.ToUpper(fileName)
		root, exists := r.routes[method]
		if !exists {
			return nil
		}

		r.addRoute(root, pathInfo, path, info.ModTime())
		return nil
	})
}