exo/system.go

package main

import (
	"database/sql"
	"fmt"
	"math"
	"time"
)

type System struct {
	*Shield
	id          int
	x, y, z     float64
	planets     int
	name        string
	players     map[*Connection]bool
	colonizedBy *Connection
	distances   []Ray
	money       int64
}

func (s *System) Tick(game *Game) {
	if s.colonizedBy != nil && s.money > 0 {
		s.colonizedBy.Deposit(1)
		s.money -= 1
	}
	if s.Shield != nil {
		s.Shield.Tick()
	}
}

func (s *System) Dead() bool {
	return false
}

func (s *System) Reset() {
	s.players = make(map[*Connection]bool, 32)
	s.colonizedBy = nil
}

func (s *System) Arrive(conn *Connection) {
	if s.players[conn] {
		return
	}
	log_info("player %s has arrived at system %v", conn.Name(), s)
	if s.players == nil {
		s.players = make(map[*Connection]bool, 8)
	}
	s.players[conn] = true
	if s.planets == 1 {
		conn.Printf("you are in the system %v. There is %d planet here.\n", s, s.planets)
	} else {
		conn.Printf("you are in the system %v. There are %d planets here.\n", s, s.planets)
	}
}

func (s *System) Leave(p *Connection) {
	delete(s.players, p)
}

func (s *System) NotifyInhabitants(template string, args ...interface{}) {
	s.EachConn(func(conn *Connection) {
		conn.Printf(template, args...)
	})
}

func (s *System) EachConn(fn func(*Connection)) {
	if s.players == nil {
		return
	}
	for conn, _ := range s.players {
		fn(conn)
	}
}

func (s *System) NumInhabitants() int {
	if s.players == nil {
		return 0
	}
	return len(s.players)
}

func (e System) Store(db *sql.DB) {
	_, err := db.Exec(`
    insert into planets
    (name, x, y, z, planets)
    values
    (?, ?, ?, ?, ?)
    ;`, e.name, e.x, e.y, e.z, e.planets)
	if err != nil {
		log_error("unable to store system: %v", err)
	}
}

func (s *System) DistanceTo(other *System) float64 {
	return dist3d(s.x, s.y, s.z, other.x, other.y, other.z)
}

func (s *System) LightTimeTo(other *System) time.Duration {
	return time.Duration(int64(s.DistanceTo(other) * 100000000))
}

func (s *System) BombTimeTo(other *System) time.Duration {
	return time.Duration(int64(s.DistanceTo(other) * 110000000))
}

func (s *System) TravelTimeTo(other *System) time.Duration {
	return time.Duration(int64(s.DistanceTo(other) * 125000000))
}

type Ray struct {
	s    *System
	dist float64 // distance in parsecs
}

func (s *System) Bombed(bomber *Connection, game *Game) {
	if s.Shield != nil {
		if s.Shield.Hit() {
			s.EachConn(func(conn *Connection) {
				conn.Printf("A bomb has hit %v but it was stopped by the system's shield.\n", s)
				conn.Printf("Shield remaining: %v.\n", s.energy)
				conn.Printf("Shield is recharing....\n")
			})
			return
		}
	}

	s.EachConn(func(conn *Connection) {
		conn.Die(game.frame)
		s.Leave(conn)
		bomber.MadeKill(conn)
	})
	if s.colonizedBy != nil {
		s.colonizedBy.Printf("your mining colony on %s has been destroyed!\n", s.name)
		s.colonizedBy = nil
	}

	for id, other := range game.galaxy.systems {
		if id == s.id {
			continue
		}
		delay := s.LightTimeTo(game.galaxy.systems[id])
		from := s
		to := other
		time.AfterFunc(delay, func() {
			bombNotice(to, from)
		})
	}
}

func bombNotice(to, from *System) {
	to.EachConn(func(conn *Connection) {
		conn.Printf("a bombing has been observed on %s\n", from.name)
	})
}

func (s System) String() string {
	return fmt.Sprintf("%s (id: %v)", s.name, s.id)
}

type Neighborhood []Neighbor

func (n Neighborhood) Len() int           { return len(n) }
func (n Neighborhood) Less(i, j int) bool { return n[i].distance < n[j].distance }
func (n Neighborhood) Swap(i, j int)      { n[i], n[j] = n[j], n[i] }

type Neighbor struct {
	id       int
	distance float64
}

func countSystems() (int, error) {
	row := db.QueryRow(`select count(*) from planets`)

	var n int
	err := row.Scan(&n)
	return n, err
}

func sq(x float64) float64 {
	return x * x
}

func dist3d(x1, y1, z1, x2, y2, z2 float64) float64 {
	return math.Sqrt(sq(x1-x2) + sq(y1-y2) + sq(z1-z2))
}

// func indexSystems() map[int]*System {
// 	rows, err := db.Query(`select * from planets`)
// 	if err != nil {
// 		log_error("unable to select all planets: %v", err)
// 		return nil
// 	}
// 	defer rows.Close()
// 	index = make(map[int]*System, 551)
// 	nameIndex = make(map[string]*System, 551)
// 	for rows.Next() {
// 		p := System{}
// 		if err := rows.Scan(&p.id, &p.name, &p.x, &p.y, &p.z, &p.planets); err != nil {
// 			log_info("unable to scan planet row: %v", err)
// 			continue
// 		}
// 		index[p.id] = &p
// 		nameIndex[p.name] = &p
// 		p.money = int64(rand.NormFloat64()*options.moneySigma + options.moneyMean)
// 		// log_info("seeded system %v with %v monies", p, p.money)
// 	}
// 	return index
// }