server/game.go

package main

import (
	// "encoding/json"
	"errors"
	"log"
	"sort"
	"sync"
	"time"
)

const maxPlayer = 128

type BotHealth struct {
	RobotId string `json:"robot_id"`
	Health  int    `json:"health"`
}

type Boardstate struct {
	MyRobots    []Robot      `json:"my_robots"`
	OtherRobots []OtherRobot `json:"robots"`
	Projectiles []Projectile `json:"projectiles"`
	Splosions   []Splosion   `json:"splosions"`
	Obstacles   []Obstacle   `json:"obj"`
	Reset       bool         `json:"reset"`
	Type        string       `json:"type"`
	Turn        int          `json:"turn"`
	AllBots     []BotHealth  `json:"all_bots"`
}

func NewBoardstate() *Boardstate {
	return &Boardstate{
		MyRobots:    []Robot{},
		OtherRobots: []OtherRobot{},
		Projectiles: []Projectile{},
		Splosions:   []Splosion{},
		AllBots:     []BotHealth{},
		Type:        "boardstate",
	}
}

type Scanner struct {
	Id   string `json:"id"`
	Type string `json:"type"`
}

type MapLock struct {
	m map[string]*game
	sync.RWMutex
}

// get is a function that returns a game if found, and creates one if
// not found and force is true. In order to get a hash (rather than use
// the string you pass) send "" for id.
func (ml *MapLock) get(id string, force bool) (*game, error) {
	ml.Lock()
	g, ok := games.m[id]
	ml.Unlock()

	if ok {
		return g, nil
	}

	if !force {
		return nil, errors.New("game not found")
	}

	if id == "" {
		id = idg.Hash()
	}

	_g := NewGame(id, float32(*width), float32(*height))
	go _g.run()

	ml.Lock()
	ml.m[id] = _g
	ml.Unlock()

	return _g, nil
}

type game struct {
	id            string
	players       map[*player]bool
	projectiles   map[*Projectile]bool
	splosions     map[*Splosion]bool
	obstacles     []Obstacle
	register      chan *player
	unregister    chan *player
	turn          int
	width, height float32
	spectators    map[*Spectator]bool
	sregister     chan *Spectator
	sunregister   chan *Spectator
	kill          chan bool
}

func NewGame(id string, width, height float32) *game {
	g := &game{
		id:          id,
		register:    make(chan *player),
		unregister:  make(chan *player, maxPlayer),
		projectiles: make(map[*Projectile]bool),
		splosions:   make(map[*Splosion]bool),
		obstacles:   GenerateObstacles(5, width, height),
		players:     make(map[*player]bool),
		turn:        0,
		width:       width,
		height:      height,
		spectators:  make(map[*Spectator]bool),
		sregister:   make(chan *Spectator),
		sunregister: make(chan *Spectator),
		kill:        make(chan bool, maxPlayer),
	}
	return g
}

func (g *game) tick(payload *Boardstate) int {
	robots_remaining := 0

	payload.Obstacles = g.obstacles

	// Update Players
	for p := range g.players {
		if p.Robot.Health > 0 {
			robots_remaining++
			p.Tick(g)
		}
		payload.OtherRobots = append(
			payload.OtherRobots,
			p.Robot.GetTruncatedDetails())

		payload.AllBots = append(
			payload.AllBots,
			BotHealth{RobotId: p.Robot.Id, Health: p.Robot.Health})
	}

	// Update Projectiles
	for pr := range g.projectiles {
		pr.Tick(g)
	}

	// We do this here, because the tick calls can alter g.projectiles
	for pr := range g.projectiles {
		payload.Projectiles = append(payload.Projectiles, *pr)
	}

	// Update Splosions
	for s := range g.splosions {
		s.Tick()
		if !s.Alive() {
			delete(g.splosions, s)
		}
		payload.Splosions = append(payload.Splosions, *s)
	}

	return robots_remaining
}

func (g *game) send_update(payload *Boardstate) {
	// Ensure that the robots are always sent in a consistent order
	sort.Sort(RobotSorter{Robots: payload.OtherRobots})

	for p := range g.players {
		// Copy the payload but only add the robots in scanner range
		player_payload := NewBoardstate()
		player_payload.Projectiles = payload.Projectiles
		player_payload.Splosions = payload.Splosions
		player_payload.Obstacles = payload.Obstacles
		player_payload.AllBots = payload.AllBots
		player_payload.Turn = payload.Turn
		player_payload.Reset = payload.Reset
		player_payload.MyRobots = append(player_payload.MyRobots, p.Robot)
		player_payload.OtherRobots = append(
			player_payload.OtherRobots,
			p.Robot.GetTruncatedDetails())

		if p.Robot.Health > 0 {
			for player := range g.players {
				for _, scan_entry := range p.Robot.Scanners {
					if player.Robot.Id == scan_entry.Id {
						player_payload.OtherRobots = append(
							player_payload.OtherRobots,
							player.Robot.GetTruncatedDetails())
					}
				}
			}
		} else {
			player_payload.OtherRobots = payload.OtherRobots
		}

		// x, _ := json.Marshal(player_payload)
		// log.Printf("%v", string(x))
		p.send <- player_payload
	}
	for s := range g.spectators {
		s.send <- payload
	}

}

func (g *game) run() {
	var t0, t1 time.Time
	ticker := time.NewTicker(time.Duration(*tick) * time.Millisecond)
	for {
		select {
		case <-g.kill:
			log.Printf("game %s: received kill signal, dying gracefully", g.id)
			games.Lock()
			for player := range g.players {
				close(player.send)
			}
			delete(games.m, g.id)
			games.Unlock()
			return
		case p := <-g.register:
			g.players[p] = true
		case p := <-g.unregister:
			delete(g.players, p)
			close(p.send)
		case s := <-g.sregister:
			g.spectators[s] = true
		case s := <-g.sunregister:
			delete(g.spectators, s)
			close(s.send)
		case <-ticker.C:
			t0 = time.Now()
			payload := NewBoardstate()

			g.turn++
			payload.Turn = g.turn
			if *verbose {
				log.Printf("\033[2JTurn: %v", g.turn)
				log.Printf("Players: %v", len(g.players))
				log.Printf("Projectiles: %v", len(g.projectiles))
				log.Printf("Explosions: %v", len(g.splosions))
			}

			// UPDATE GAME STATE
			robots_remaining := g.tick(payload)

			// Determine end game?
			if robots_remaining <= 1 && len(g.players) > 1 {
				for p := range g.players {
					if p.Robot.Health > 0 {
						log.Printf("Robot %v Wins", p.Robot.Id)
						log.Printf("game %s: game over", g.id)
					}
					p.reset(g)
					g.obstacles = GenerateObstacles(5, g.width, g.height)
				}
				payload.Reset = true
			} else {
				payload.Reset = false
			}

			t1 = time.Now()
			if *verbose {
				log.Printf("Turn Processes %v\n", t1.Sub(t0))
			}

			// SEND THE UPDATE TO EACH PLAYER
			g.send_update(payload)

			t1 = time.Now()
			if *verbose {
				log.Printf("Sent Payload %v\n", t1.Sub(t0))
			}
		}
	}
}