From 440f0a83783a62fe7ff1f4fa464f662e4a7e1d92 Mon Sep 17 00:00:00 2001
From: Sky Johnson <skylearj@gmail.com>
Date: Wed, 5 Mar 2025 19:17:43 -0600
Subject: [PATCH] luarouter

---
 core/routers/luarouter.go      | 276 +++++++++++++++++++++++++++++++++
 core/routers/luarouter_test.go | 256 ++++++++++++++++++++++++++++++
 go.mod                         |   7 +
 moonshark.go                   |   7 +
 4 files changed, 546 insertions(+)
 create mode 100644 core/routers/luarouter.go
 create mode 100644 core/routers/luarouter_test.go
 create mode 100644 go.mod
 create mode 100644 moonshark.go

diff --git a/core/routers/luarouter.go b/core/routers/luarouter.go
new file mode 100644
index 0000000..4e7595f
--- /dev/null
+++ b/core/routers/luarouter.go
@@ -0,0 +1,276 @@
+package routers
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	luajit "git.sharkk.net/Sky/LuaJIT-to-Go"
+)
+
+// Maximum number of URL parameters per route
+const maxParams = 20
+
+// LuaRouter is a filesystem-based HTTP router for Lua files
+type LuaRouter struct {
+	routesDir string           // Root directory containing route files
+	routes    map[string]*node // Method -> route tree
+	mu        sync.RWMutex     // Lock for concurrent access to routes
+}
+
+// node represents a node in the routing trie
+type node struct {
+	handler     string           // Path to Lua file (empty if not an endpoint)
+	bytecode    []byte           // Pre-compiled Lua bytecode
+	paramName   string           // Parameter name (if this is a parameter node)
+	staticChild map[string]*node // Static children by segment name
+	paramChild  *node            // Parameter/wildcard child
+}
+
+// Params holds URL parameters with fixed-size arrays to avoid allocations
+type Params struct {
+	Keys   [maxParams]string
+	Values [maxParams]string
+	Count  int
+}
+
+// Get returns a parameter value by name
+func (p *Params) Get(name string) string {
+	for i := 0; i < p.Count; i++ {
+		if p.Keys[i] == name {
+			return p.Values[i]
+		}
+	}
+	return ""
+}
+
+// NewLuaRouter creates a new LuaRouter instance
+func NewLuaRouter(routesDir string) (*LuaRouter, error) {
+	// Verify routes directory exists
+	info, err := os.Stat(routesDir)
+	if err != nil {
+		return nil, err
+	}
+	if !info.IsDir() {
+		return nil, errors.New("routes path is not a directory")
+	}
+
+	r := &LuaRouter{
+		routesDir: routesDir,
+		routes:    make(map[string]*node),
+	}
+
+	// Initialize method trees
+	methods := []string{"GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS", "HEAD"}
+	for _, method := range methods {
+		r.routes[method] = &node{
+			staticChild: make(map[string]*node),
+		}
+	}
+
+	// Build routes
+	if err := r.buildRoutes(); err != nil {
+		return nil, err
+	}
+
+	return r, nil
+}
+
+// buildRoutes scans the routes directory and builds the routing tree
+func (r *LuaRouter) buildRoutes() error {
+	return filepath.Walk(r.routesDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Skip directories
+		if info.IsDir() {
+			return nil
+		}
+
+		// Only process .lua files
+		if !strings.HasSuffix(info.Name(), ".lua") {
+			return nil
+		}
+
+		// Extract method from filename
+		method := strings.ToUpper(strings.TrimSuffix(info.Name(), ".lua"))
+
+		// Check if valid method
+		root, exists := r.routes[method]
+		if !exists {
+			return nil // Skip invalid methods
+		}
+
+		// Get relative path for URL
+		relDir, err := filepath.Rel(r.routesDir, filepath.Dir(path))
+		if err != nil {
+			return err
+		}
+
+		// Build URL path
+		urlPath := "/"
+		if relDir != "." {
+			urlPath = "/" + strings.ReplaceAll(relDir, "\\", "/")
+		}
+
+		// Add route to tree
+		return r.addRoute(root, urlPath, path)
+	})
+}
+
+// addRoute adds a route to the routing tree and compiles the Lua file to bytecode
+func (r *LuaRouter) addRoute(root *node, urlPath, handlerPath string) error {
+	segments := strings.Split(strings.Trim(urlPath, "/"), "/")
+	current := root
+
+	for _, segment := range segments {
+		if len(segment) >= 2 && segment[0] == '[' && segment[len(segment)-1] == ']' {
+			if current.paramChild == nil {
+				current.paramChild = &node{
+					paramName:   segment[1 : len(segment)-1],
+					staticChild: make(map[string]*node),
+				}
+			}
+			current = current.paramChild
+		} else {
+			// Create or get static child
+			child, exists := current.staticChild[segment]
+			if !exists {
+				child = &node{
+					staticChild: make(map[string]*node),
+				}
+				current.staticChild[segment] = child
+			}
+			current = child
+		}
+	}
+
+	// Set handler path
+	current.handler = handlerPath
+
+	// Compile Lua file to bytecode
+	if err := r.compileHandler(current); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Match finds a handler for the given method and path
+// Uses the pre-allocated params struct to avoid allocations
+func (r *LuaRouter) Match(method, path string, params *Params) (*node, bool) {
+	// Reset params
+	params.Count = 0
+
+	// Get route tree for method
+	r.mu.RLock()
+	root, exists := r.routes[method]
+	r.mu.RUnlock()
+
+	if !exists {
+		return nil, false
+	}
+
+	// Split path
+	segments := strings.Split(strings.Trim(path, "/"), "/")
+
+	// Match path
+	return r.matchPath(root, segments, params, 0)
+}
+
+// matchPath recursively matches a path against the routing tree
+func (r *LuaRouter) matchPath(current *node, segments []string, params *Params, depth int) (*node, bool) {
+	// Base case: no more segments
+	if len(segments) == 0 {
+		if current.handler != "" {
+			return current, true
+		}
+		return nil, false
+	}
+
+	segment := segments[0]
+	remaining := segments[1:]
+
+	// Try static child first (exact match takes precedence)
+	if child, exists := current.staticChild[segment]; exists {
+		if node, found := r.matchPath(child, remaining, params, depth+1); found {
+			return node, true
+		}
+	}
+
+	// Try parameter child
+	if current.paramChild != nil {
+		// Store parameter
+		if params.Count < maxParams {
+			params.Keys[params.Count] = current.paramChild.paramName
+			params.Values[params.Count] = segment
+			params.Count++
+		}
+
+		if node, found := r.matchPath(current.paramChild, remaining, params, depth+1); found {
+			return node, true
+		}
+
+		// Backtrack: remove parameter if no match
+		params.Count--
+	}
+
+	return nil, false
+}
+
+// compileHandler compiles a Lua file to bytecode
+func (r *LuaRouter) compileHandler(n *node) error {
+	if n.handler == "" {
+		return nil
+	}
+
+	// Read the Lua file
+	content, err := os.ReadFile(n.handler)
+	if err != nil {
+		return err
+	}
+
+	// Compile to bytecode
+	state := luajit.New()
+	if state == nil {
+		return errors.New("failed to create Lua state")
+	}
+	defer state.Close()
+
+	bytecode, err := state.CompileBytecode(string(content), n.handler)
+	if err != nil {
+		return err
+	}
+
+	// Store bytecode in the node
+	n.bytecode = bytecode
+	return nil
+}
+
+// GetBytecode returns the compiled bytecode for a matched route
+func (r *LuaRouter) GetBytecode(method, path string, params *Params) ([]byte, bool) {
+	node, found := r.Match(method, path, params)
+	if !found {
+		return nil, false
+	}
+	return node.bytecode, true
+}
+
+// Refresh rebuilds the router by rescanning the routes directory
+func (r *LuaRouter) Refresh() error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	// Reset routes
+	for method := range r.routes {
+		r.routes[method] = &node{
+			staticChild: make(map[string]*node),
+		}
+	}
+
+	// Rebuild routes
+	return r.buildRoutes()
+}
diff --git a/core/routers/luarouter_test.go b/core/routers/luarouter_test.go
new file mode 100644
index 0000000..8fc336d
--- /dev/null
+++ b/core/routers/luarouter_test.go
@@ -0,0 +1,256 @@
+package routers
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func setupTestRoutes(t *testing.T) (string, func()) {
+	// Create a temporary directory for test routes
+	tempDir, err := os.MkdirTemp("", "fsrouter-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp directory: %v", err)
+	}
+
+	// Create route structure with valid Lua code
+	routes := map[string]string{
+		"get.lua":                      "return { path = '/' }",
+		"post.lua":                     "return { path = '/' }",
+		"api/get.lua":                  "return { path = '/api' }",
+		"api/users/get.lua":            "return { path = '/api/users' }",
+		"api/users/[id]/get.lua":       "return { path = '/api/users/[id]' }",
+		"api/users/[id]/posts/get.lua": "return { path = '/api/users/[id]/posts' }",
+		"api/[version]/docs/get.lua":   "return { path = '/api/[version]/docs' }",
+	}
+
+	for path, content := range routes {
+		routePath := filepath.Join(tempDir, path)
+
+		// Create directories
+		err := os.MkdirAll(filepath.Dir(routePath), 0755)
+		if err != nil {
+			t.Fatalf("Failed to create directory %s: %v", filepath.Dir(routePath), err)
+		}
+
+		// Create file
+		err = os.WriteFile(routePath, []byte(content), 0644)
+		if err != nil {
+			t.Fatalf("Failed to create file %s: %v", routePath, err)
+		}
+	}
+
+	// Return cleanup function
+	cleanup := func() {
+		os.RemoveAll(tempDir)
+	}
+
+	return tempDir, cleanup
+}
+
+func TestRouterInitialization(t *testing.T) {
+	routesDir, cleanup := setupTestRoutes(t)
+	defer cleanup()
+
+	router, err := NewLuaRouter(routesDir)
+	if err != nil {
+		t.Fatalf("Failed to create router: %v", err)
+	}
+
+	if router == nil {
+		t.Fatal("Router is nil")
+	}
+}
+
+func TestRouteMatching(t *testing.T) {
+	routesDir, cleanup := setupTestRoutes(t)
+	defer cleanup()
+
+	router, err := NewLuaRouter(routesDir)
+	if err != nil {
+		t.Fatalf("Failed to create router: %v", err)
+	}
+
+	tests := []struct {
+		method      string
+		path        string
+		wantFound   bool
+		wantParams  map[string]string
+		wantHandler string
+	}{
+		// Static routes
+		{"GET", "/", true, nil, filepath.Join(routesDir, "get.lua")},
+		{"POST", "/", true, nil, filepath.Join(routesDir, "post.lua")},
+		{"GET", "/api", true, nil, filepath.Join(routesDir, "api/get.lua")},
+		{"GET", "/api/users", true, nil, filepath.Join(routesDir, "api/users/get.lua")},
+
+		// Parameterized routes
+		{"GET", "/api/users/123", true, map[string]string{"id": "123"}, filepath.Join(routesDir, "api/users/[id]/get.lua")},
+		{"GET", "/api/users/456/posts", true, map[string]string{"id": "456"}, filepath.Join(routesDir, "api/users/[id]/posts/get.lua")},
+		{"GET", "/api/v1/docs", true, map[string]string{"version": "v1"}, filepath.Join(routesDir, "api/[version]/docs/get.lua")},
+
+		// Non-existent routes
+		{"PUT", "/", false, nil, ""},
+		{"GET", "/nonexistent", false, nil, ""},
+		{"GET", "/api/nonexistent", false, nil, ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.method+" "+tt.path, func(t *testing.T) {
+			var params Params
+			node, found := router.Match(tt.method, tt.path, &params)
+
+			if found != tt.wantFound {
+				t.Errorf("Match() found = %v, want %v", found, tt.wantFound)
+			}
+
+			if !found {
+				return
+			}
+
+			if node.handler != tt.wantHandler {
+				t.Errorf("Match() handler = %v, want %v", node.handler, tt.wantHandler)
+			}
+
+			// Verify bytecode was compiled
+			if len(node.bytecode) == 0 {
+				t.Errorf("No bytecode found for handler: %s", node.handler)
+			}
+
+			// Verify parameters
+			if tt.wantParams != nil {
+				for key, wantValue := range tt.wantParams {
+					gotValue := params.Get(key)
+					if gotValue != wantValue {
+						t.Errorf("Parameter %s = %s, want %s", key, gotValue, wantValue)
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestParamExtraction(t *testing.T) {
+	routesDir, cleanup := setupTestRoutes(t)
+	defer cleanup()
+
+	router, err := NewLuaRouter(routesDir)
+	if err != nil {
+		t.Fatalf("Failed to create router: %v", err)
+	}
+
+	var params Params
+	_, found := router.Match("GET", "/api/v2/docs", &params)
+
+	if !found {
+		t.Fatalf("Route not found")
+	}
+
+	if params.Count != 1 {
+		t.Errorf("Expected 1 parameter, got %d", params.Count)
+	}
+
+	if params.Keys[0] != "version" {
+		t.Errorf("Expected parameter key 'version', got '%s'", params.Keys[0])
+	}
+
+	if params.Values[0] != "v2" {
+		t.Errorf("Expected parameter value 'v2', got '%s'", params.Values[0])
+	}
+
+	if params.Get("version") != "v2" {
+		t.Errorf("Get(\"version\") returned '%s', expected 'v2'", params.Get("version"))
+	}
+}
+
+func TestGetBytecode(t *testing.T) {
+	routesDir, cleanup := setupTestRoutes(t)
+	defer cleanup()
+
+	router, err := NewLuaRouter(routesDir)
+	if err != nil {
+		t.Fatalf("Failed to create router: %v", err)
+	}
+
+	var params Params
+	bytecode, found := router.GetBytecode("GET", "/api/users/123", &params)
+
+	if !found {
+		t.Fatalf("Route not found")
+	}
+
+	if len(bytecode) == 0 {
+		t.Errorf("Expected non-empty bytecode")
+	}
+
+	// Check parameters were extracted
+	if params.Get("id") != "123" {
+		t.Errorf("Expected id parameter '123', got '%s'", params.Get("id"))
+	}
+}
+
+func TestRefresh(t *testing.T) {
+	routesDir, cleanup := setupTestRoutes(t)
+	defer cleanup()
+
+	router, err := NewLuaRouter(routesDir)
+	if err != nil {
+		t.Fatalf("Failed to create router: %v", err)
+	}
+
+	// Add a new route file
+	newRoutePath := filepath.Join(routesDir, "new", "get.lua")
+	err = os.MkdirAll(filepath.Dir(newRoutePath), 0755)
+	if err != nil {
+		t.Fatalf("Failed to create directory: %v", err)
+	}
+
+	err = os.WriteFile(newRoutePath, []byte("return { path = '/new' }"), 0644)
+	if err != nil {
+		t.Fatalf("Failed to create file: %v", err)
+	}
+
+	// Before refresh, route should not be found
+	var params Params
+	_, found := router.GetBytecode("GET", "/new", &params)
+	if found {
+		t.Errorf("New route should not be found before refresh")
+	}
+
+	// Refresh router
+	err = router.Refresh()
+	if err != nil {
+		t.Fatalf("Failed to refresh router: %v", err)
+	}
+
+	// After refresh, route should be found
+	bytecode, found := router.GetBytecode("GET", "/new", &params)
+	if !found {
+		t.Errorf("New route should be found after refresh")
+	}
+
+	if len(bytecode) == 0 {
+		t.Errorf("Expected non-empty bytecode for new route")
+	}
+}
+
+func TestInvalidRoutesDir(t *testing.T) {
+	// Non-existent directory
+	_, err := NewLuaRouter("/non/existent/directory")
+	if err == nil {
+		t.Error("Expected error for non-existent directory, got nil")
+	}
+
+	// Create a file instead of a directory
+	tmpFile, err := os.CreateTemp("", "fsrouter-test-file")
+	if err != nil {
+		t.Fatalf("Failed to create temp file: %v", err)
+	}
+	defer os.Remove(tmpFile.Name())
+	defer tmpFile.Close()
+
+	_, err = NewLuaRouter(tmpFile.Name())
+	if err == nil {
+		t.Error("Expected error for file as routes dir, got nil")
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..e114b05
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,7 @@
+module git.sharkk.net/Sky/Moonshark
+
+go 1.24.1
+
+require git.sharkk.net/Sky/LuaJIT-to-Go v0.0.0
+
+replace git.sharkk.net/Sky/LuaJIT-to-Go => ./luajit
diff --git a/moonshark.go b/moonshark.go
new file mode 100644
index 0000000..f7b60bd
--- /dev/null
+++ b/moonshark.go
@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello, world!")
+}