96 lines
2 KiB
Go
96 lines
2 KiB
Go
package game
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import (
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"encoding/json"
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"fmt"
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"io/ioutil"
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"os"
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"path"
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"github.com/google/uuid"
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)
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// World describes a self contained universe and everything in it
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type World struct {
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Instances map[uuid.UUID]Instance `json:"instances"`
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// dataPath is the location for the data to be stored
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dataPath string
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}
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// Instance describes a single entity or instance of an entity in the world
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type Instance struct {
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// id is a unique ID for this instance
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id uuid.UUID
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// pos represents where this instance is in the world
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pos Position
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}
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const kWorldFileName = "rove-world.json"
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// NewWorld creates a new world object
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func NewWorld(data string) *World {
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return &World{
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Instances: make(map[uuid.UUID]Instance),
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dataPath: data,
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}
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}
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// path returns the full path to the data file
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func (w *World) path() string {
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return path.Join(w.dataPath, kWorldFileName)
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}
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// Load will load the accountant from data
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func (w *World) Load() error {
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// Don't load anything if the file doesn't exist
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_, err := os.Stat(w.path())
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if os.IsNotExist(err) {
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fmt.Printf("File %s didn't exist, loading with fresh world data\n", w.path())
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return nil
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}
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if b, err := ioutil.ReadFile(w.path()); err != nil {
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return err
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} else if err := json.Unmarshal(b, &w); err != nil {
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return err
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}
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return nil
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}
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// Save will save the accountant data out
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func (w *World) Save() error {
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if b, err := json.MarshalIndent(w, "", "\t"); err != nil {
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return err
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} else {
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if err := ioutil.WriteFile(w.path(), b, os.ModePerm); err != nil {
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return err
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}
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}
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return nil
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}
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// Adds an instance to the game
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func (w *World) CreateInstance() uuid.UUID {
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id := uuid.New()
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// Initialise the instance
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instance := Instance{
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id: id,
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}
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// Append the instance to the list
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w.Instances[id] = instance
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return id
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}
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// GetPosition returns the position of a given instance
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func (w World) GetPosition(id uuid.UUID) (Position, error) {
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if i, ok := w.Instances[id]; ok {
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return i.pos, nil
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} else {
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return Position{}, fmt.Errorf("no instance matching id")
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}
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}
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