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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
18package main
19
20import "flag"
21import "json"
22import "os"
23import "fmt"
24
25var datafile = flag.String("planet_data_file", "planet-data",
26 "The file to read planet data from")
27
28type Commodity struct {
29 Name string
30 BasePrice int
31 CanSell bool
32 Limit int
33}
34type 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}
41type planet_data struct {
42 Commodities []Commodity
43 Planets []Planet
44}
45
46func 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
59func 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
82func 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
103func 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}