cache.go

package main

import (
	"encoding/gob"
	"net/http"
	"net/http/cookiejar"
	"os"

	"golang.org/x/net/publicsuffix"
)

var (
	dataPath         = os.Getenv("HOME") + "/.local/share/uva-cli/"
	pdfPath          = dataPath + "pdf/"
	testDataPath     = dataPath + "test-data/"
	loginInfoFile    = dataPath + "login-info.gob"
	problemsInfoFile = dataPath + "problems-info.gob"
)

func getProblemInfo(pid int) problemInfo {
	var problems map[int]problemInfo
	if exists(problemsInfoFile) {
		f, err := os.Open(problemsInfoFile)
		if err != nil {
			panic(err)
		}
		defer f.Close()
		if err := gob.NewDecoder(f).Decode(&problems); err != nil {
			panic(err)
		}
	} else {
		problems = crawlProblemsInfo()
		f, err := os.Create(problemsInfoFile)
		if err != nil {
			panic(err)
		}
		defer f.Close()
		if err := gob.NewEncoder(f).Encode(problems); err != nil {
			panic(err)
		}
	}
	r, ok := problems[pid]
	if !ok {
		panic("problem not found")
	}
	return r
}

func getTestData(pid int) (input string, output string) {
	testDataFile := testDataPath + getProblemInfo(pid).getFileName("gob")
	if exists(testDataFile) {
		f, err := os.Open(testDataFile)
		if err != nil {
			panic(err)
		}
		defer f.Close()
		dec := gob.NewDecoder(f)
		if err = dec.Decode(&input); err != nil {
			panic(err)
		}
		if err = dec.Decode(&output); err != nil {
			panic(err)
		}
	} else {
		input, output = crawlTestData(pid)
		f, err := os.Create(testDataFile)
		if err != nil {
			panic(err)
		}
		defer f.Close()
		enc := gob.NewEncoder(f)
		if err = enc.Encode(input); err != nil {
			panic(err)
		}
		if err = enc.Encode(output); err != nil {
			panic(err)
		}
	}
	return
}

func loadLoginInfo() loginInfo {
	if !exists(loginInfoFile) {
		panic("you are not logged in yet")
	}

	f, err := os.Open(loginInfoFile)
	if err != nil {
		panic(err)
	}
	defer f.Close()
	var info loginInfo
	if err := gob.NewDecoder(f).Decode(&info); err != nil {
		panic(err)
	}
	jar, err := cookiejar.New(&cookiejar.Options{PublicSuffixList: publicsuffix.List})
	if err != nil {
		panic(err)
	}
	jar.SetCookies(uvaURL, info.Cookies)
	http.DefaultClient.Jar = jar
	return info
}