git.scottworley.com Git - planeteer/blob - planeteer.go

   1 /* Planeteer: Give trade route advice for Planets: The Exploration of Space
   2  * Copyright (C) 2011  Scott Worley <sworley@chkno.net>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU Affero General Public License as
   6  * published by the Free Software Foundation, either version 3 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU Affero General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Affero General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package main
  19
  20 import "flag"
  21 import "json"
  22 import "os"
  23 import "fmt"
  24
  25 var datafile = flag.String("planet_data_file", "planet-data",
  26         "The file to read planet data from")
  27
  28 type Commodity struct {
  29         Name      string
  30         BasePrice int
  31         CanSell   bool
  32         Limit     int
  33 }
  34 type Planet struct {
  35         Name     string
  36         BeaconOn bool
  37         /* Use relative prices rather than absolute prices because you
  38            can get relative prices without traveling to each planet. */
  39         RelativePrices map [string] int
  40 }
  41 type planet_data struct {
  42         Commodities []Commodity
  43         Planets []Planet
  44 }
  45
  46 func ReadData() (data planet_data) {
  47         f, err := os.Open(*datafile)
  48         if err != nil {
  49                 panic(err)
  50         }
  51         defer f.Close()
  52         err = json.NewDecoder(f).Decode(&data)
  53         if err != nil {
  54                 panic(err)
  55         }
  56         return
  57 }
  58
  59 func TradeValue(from, to *Planet,
  60                 commodity *Commodity,
  61                 quantity int) int {
  62         if !commodity.CanSell {
  63                 return 0
  64         }
  65         from_relative_price, from_available := from.RelativePrices[commodity.Name]
  66         if !from_available {
  67                 return 0
  68         }
  69         to_relative_price, to_available := to.RelativePrices[commodity.Name]
  70         if !to_available {
  71                 return 0
  72         }
  73
  74         from_absolute_price := from_relative_price * commodity.BasePrice
  75         to_absolute_price := to_relative_price * commodity.BasePrice
  76         buy_price := from_absolute_price
  77         sell_price := int(float64(to_absolute_price) * 0.9)
  78         return (sell_price - buy_price) * quantity
  79
  80 }
  81
  82 func FindBestTrades(data planet_data) [][]*Commodity {
  83         best := make([][]*Commodity, len(data.Planets))
  84         for from_index := range data.Planets {
  85                 best[from_index] = make([]*Commodity, len(data.Planets))
  86                 for to_index := range data.Planets {
  87                         best_gain := 0
  88                         for commodity_index := range data.Commodities {
  89                                 gain := TradeValue(&data.Planets[from_index],
  90                                                    &data.Planets[to_index],
  91                                                    &data.Commodities[commodity_index],
  92                                                    1)
  93                                 if gain > best_gain {
  94                                         best[from_index][to_index] = &data.Commodities[commodity_index]
  95                                         gain = best_gain
  96                                 }
  97                         }
  98                 }
  99         }
 100         return best
 101 }
 102
 103 func main() {
 104         flag.Parse()
 105         data := ReadData()
 106         best_trades := FindBestTrades(data)
 107         for from_index, from_planet := range data.Planets {
 108                 for to_index, to_planet := range data.Planets {
 109                         best_trade := "(nothing)"
 110                         if best_trades[from_index][to_index] != nil {
 111                                 best_trade = best_trades[from_index][to_index].Name
 112                         }
 113                         fmt.Printf("%s to %s: %s\n", from_planet.Name, to_planet.Name, best_trade)
 114                 }
 115         }
 116 }