add basic caching

.gitignore

@@ -0,0 +1 @@
+.cache/

clear_cache.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+rm -rf .cache

main.go

@@ -2,21 +2,70 @@ package main
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
+	"os"
+	"path"
+	"time"
 
 	"github.com/karashiiro/bingode"
 	"github.com/xivapi/godestone/v2"
 )
 
+const CachePath = "./.cache"
+
+type CacheRecord struct {
+	Time time.Time `json:"time"`
+	Data string    `json:"data"`
+}
+type Cache map[uint32]CacheRecord
+
 func main() {
+	err := os.MkdirAll(CachePath, 0755)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	raw_cache, err := os.ReadFile(path.Join(CachePath, "cache.json"))
+	var cache Cache
+
+	if errors.Is(err, os.ErrNotExist) {
+		cache = make(Cache)
+	} else if err == nil {
+		err := json.Unmarshal(raw_cache, &cache)
+		if err != nil {
+			log.Fatalln(err)
+		}
+	} else {
+		log.Fatalln(err)
+	}
+
+	var id uint32 = 29932586
+	data, ok := cache[id]
+	if !ok {
+		log.Printf("Fetching fresh data for %d\n", id)
 		s := godestone.NewScraper(bingode.New(), godestone.EN)
 
-	c, err := s.FetchCharacter(29932586)
+		c, err := s.FetchCharacter(id)
 		if err != nil {
 			log.Fatalln(err)
 		}
 
-	data, _ := json.Marshal(c.ClassJobs)
-	fmt.Printf("%s\n", data)
+		raw_data, _ := json.Marshal(c.ClassJobs)
+		data = CacheRecord{Time: time.Now(), Data: string(raw_data)}
+
+		cache[id] = data
+	}
+
+	cache_as_stored, err := json.Marshal(cache)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	err = os.WriteFile(path.Join(CachePath, "cache.json"), cache_as_stored, 0755)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	fmt.Printf("%s\n", data.Data)
 }