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
  35 type planet_data struct {
  36         Commodities []Commodity
  37         Planets []struct {
  38                 Name     string
  39                 BeaconOn bool
  40                 /* Use relative prices rather than absolute prices because you
  41                    can get relative prices without traveling to each planet. */
  42                 RelativePrices map [string] int
  43         }
  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(data planet_data,
  60                 from_index, to_index, commodity_index, quantity int) int {
  61
  62         commodity := &data.Commodities[commodity_index]
  63         if !commodity.CanSell {
  64                 return 0
  65         }
  66
  67         from_planet := &data.Planets[from_index]
  68         from_relative_price, from_available := from_planet.RelativePrices[commodity.Name]
  69         if !from_available {
  70                 return 0
  71         }
  72
  73         to_planet := &data.Planets[to_index]
  74         to_relative_price, to_available := to_planet.RelativePrices[commodity.Name]
  75         if !to_available {
  76                 return 0
  77         }
  78
  79         from_absolute_price := from_relative_price * commodity.BasePrice
  80         to_absolute_price := to_relative_price * commodity.BasePrice
  81         buy_price := from_absolute_price
  82         sell_price := int(float64(to_absolute_price) * 0.9)
  83         return (sell_price - buy_price) * quantity
  84
  85 }
  86
  87 func FindBestTrades(data planet_data) [][]*Commodity {
  88         best := make([][]*Commodity, len(data.Planets))
  89         for from_index := range data.Planets {
  90                 best[from_index] = make([]*Commodity, len(data.Planets))
  91                 for to_index := range data.Planets {
  92                         best_gain := 0
  93                         for commodity_index := range data.Commodities {
  94                                 gain := TradeValue(data, from_index, to_index, commodity_index, 1)
  95                                 if gain > best_gain {
  96                                         best[from_index][to_index] = &data.Commodities[commodity_index]
  97                                         gain = best_gain
  98                                 }
  99                         }
 100                 }
 101         }
 102         return best
 103 }
 104
 105 func main() {
 106         flag.Parse()
 107         data := ReadData()
 108         best_trades := FindBestTrades(data)
 109         for from_index, from_planet := range data.Planets {
 110                 for to_index, to_planet := range data.Planets {
 111                         best_trade := "(nothing)"
 112                         if best_trades[from_index][to_index] != nil {
 113                                 best_trade = best_trades[from_index][to_index].Name
 114                         }
 115                         fmt.Printf("%s to %s: %s\n", from_planet.Name, to_planet.Name, best_trade)
 116                 }
 117         }
 118 }