primeiro commit

internal/vn/script.go

@@ -0,0 +1,144 @@
+package vn
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v3"
+)
+
+// MaxImportNesting defines the maximum recursive import depth.
+const MaxImportNesting = 8
+
+// Script is the root structure for a visual novel script file.
+type Script struct {
+	Title       string   `yaml:"title"`
+	Start       string   `yaml:"start"`
+	Imports     []string `yaml:"imports"`
+	Scenes      []Scene  `yaml:"scenes"`
+	BaseDir     string   `yaml:"-"`
+	LoadedFiles []string `yaml:"-"`
+}
+
+// Scene is a labeled sequence of commands.
+type Scene struct {
+	ID       string    `yaml:"id"`
+	Commands []Command `yaml:"commands"`
+}
+
+// Command is a single script instruction.
+type Command struct {
+	Type            string     `yaml:"type"`
+	Speaker         string     `yaml:"speaker,omitempty"`
+	Text            string     `yaml:"text,omitempty"`
+	Background      string     `yaml:"background,omitempty"`
+	BackgroundImage string     `yaml:"background_image,omitempty"`
+	Character       string     `yaml:"character,omitempty"`
+	Emotion         string     `yaml:"emotion,omitempty"`
+	Sprite          string     `yaml:"sprite,omitempty"`
+	Key             string     `yaml:"key,omitempty"`
+	Value           any        `yaml:"value,omitempty"`
+	Target          string     `yaml:"target,omitempty"`
+	If              string     `yaml:"if,omitempty"`
+	Then            []Command  `yaml:"then,omitempty"`
+	Else            []Command  `yaml:"else,omitempty"`
+	Choices         []Choice   `yaml:"choices,omitempty"`
+	MenuItems       []MenuItem `yaml:"menu_items,omitempty"`
+}
+
+// Choice is a branching option shown to the player.
+type Choice struct {
+	Text   string `yaml:"text"`
+	Target string `yaml:"target"`
+	If     string `yaml:"if,omitempty"`
+}
+
+// MenuItem is a positioned interactive sprite option for a menu command.
+type MenuItem struct {
+	ID         string    `yaml:"id,omitempty"`
+	Sprite     string    `yaml:"sprite"`
+	X          float64   `yaml:"x"`
+	Y          float64   `yaml:"y"`
+	If         string    `yaml:"if,omitempty"`
+	Selectable *bool     `yaml:"selectable,omitempty"`
+	Commands   []Command `yaml:"commands"`
+}
+
+func LoadScript(path string) (*Script, error) {
+	rootPath, err := filepath.Abs(path)
+	if err != nil {
+		return nil, fmt.Errorf("resolve script path: %w", err)
+	}
+
+	visited := map[string]bool{}
+	stack := map[string]bool{}
+	loaded := []string{}
+	root, err := loadScriptRecursive(rootPath, 0, visited, stack, &loaded)
+	if err != nil {
+		return nil, err
+	}
+
+	if root.Start == "" {
+		return nil, fmt.Errorf("script missing start scene")
+	}
+	if len(root.Scenes) == 0 {
+		return nil, fmt.Errorf("script has no scenes")
+	}
+	root.BaseDir = filepath.Dir(rootPath)
+	root.LoadedFiles = loaded
+	return root, nil
+}
+
+func loadScriptRecursive(path string, depth int, visited, stack map[string]bool, loaded *[]string) (*Script, error) {
+	if depth > MaxImportNesting {
+		return nil, fmt.Errorf("import depth exceeded max (%d) at %s", MaxImportNesting, path)
+	}
+
+	if stack[path] {
+		return nil, fmt.Errorf("cyclic import detected at %s", path)
+	}
+
+	if visited[path] {
+		return &Script{}, nil
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("read script %s: %w", path, err)
+	}
+
+	var current Script
+	if err := yaml.Unmarshal(data, &current); err != nil {
+		return nil, fmt.Errorf("parse yaml %s: %w", path, err)
+	}
+
+	visited[path] = true
+	stack[path] = true
+	*loaded = append(*loaded, path)
+
+	mergedScenes := make([]Scene, 0, len(current.Scenes))
+	for _, imp := range current.Imports {
+		resolved := imp
+		if !filepath.IsAbs(resolved) {
+			resolved = filepath.Join(filepath.Dir(path), imp)
+		}
+		resolved, err = filepath.Abs(resolved)
+		if err != nil {
+			delete(stack, path)
+			return nil, fmt.Errorf("resolve import %s from %s: %w", imp, path, err)
+		}
+
+		child, err := loadScriptRecursive(resolved, depth+1, visited, stack, loaded)
+		if err != nil {
+			delete(stack, path)
+			return nil, err
+		}
+		mergedScenes = append(mergedScenes, child.Scenes...)
+	}
+
+	delete(stack, path)
+	mergedScenes = append(mergedScenes, current.Scenes...)
+	current.Scenes = mergedScenes
+	return &current, nil
+}