package main

import (
	"crypto/openpgp"
	"epoint/logic"
	"fmt"
	"log"
	"net/http"
	"os"
)

const (
	port    = ":8080"
	rootdir = "teststore"
	seckey  = "./key.sec"
)

var serverkey *openpgp.Entity

// todo: http header limit: 64K, body limit: 64K

// getPubkey(db, fpr) (pk, err)
// putPubkey(db, fpr, pk) (err)
// getDraft(db, id) (draft, err)
// putDraft(db, id, draft) (err)

// getCert(db, id) (cert, err)
// putCert(db, id, cert) (err)
// getCertBySerial(db, fpr, sn) (cert, err)
// getCertByFpr(db, fpr) (cert, err)

// todo: update cert (inc serial..)

// Dummy initialization of serverkey
func initkey() (err error) {
	f, err := os.Open(seckey)
	if err != nil {
		return
	}
	keys, err := openpgp.ReadKeyRing(f)
	if err != nil {
		f.Close()
		return
	}
	err = f.Close()
	if err != nil {
		return
	}
	serverkey = keys[0]
	err = os.MkdirAll(rootdir, 0755)
	if err != nil {
		return
	}
	f, err = os.Create(rootdir + "/serverkey")
	if err != nil {
		return
	}
	err = serverkey.Serialize(f)
	if err != nil {
		return
	}
	// TODO: make sure pubkey is replicated and available
	err = f.Sync()
	if err != nil {
		return
	}
	err = f.Close()
	return
}

func defaultHandler(w http.ResponseWriter, r *http.Request) {
	log.Printf("%s %s %s\n", r.RemoteAddr, r.Method, r.URL.Raw)
	fmt.Fprintf(w, "not implemented: %s %s\n", r.Method, r.URL.Raw)
}

func submitHandler(w http.ResponseWriter, r *http.Request) {
	log.Printf("%s %s %s\n", r.RemoteAddr, r.Method, r.URL.Raw)
	draft := r.FormValue("draft")
	debit := r.FormValue("debit")
	if len(draft) > 0 {
		cert, err := logic.EvalDraft([]byte(draft), serverkey)
		if err != nil {
			log.Printf("eval draft fail: %s", err)
			fmt.Fprintf(w, "eval draft fail: %s\n", err)
		} else {
			w.Write(cert)
		}
	} else if len(debit) > 0 {
		cert, err := logic.EvalDebitCert([]byte(debit), serverkey)
		if err != nil {
			log.Printf("eval debit fail: %s", err)
			fmt.Fprintf(w, "eval debit fail: %s\n", err)
		} else {
			w.Write(cert)
		}
	} else {
		fmt.Fprintf(w, "expected draft or debit param, got: %s %s\n", r.Method, r.URL.Raw)
	}
}

func main() {
	err := initkey()
	if err != nil {
		log.Fatal(err)
	}
	err = logic.Init()
	if err != nil {
		log.Fatal(err)
	}

	http.HandleFunc("/", defaultHandler)

	// queries
	http.HandleFunc("/serverkey", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, rootdir+"/serverkey")
	})
//	http.HandleFunc("/status", defaultHandler)
//	http.HandleFunc("/pubkey", defaultHandler)
//	http.HandleFunc("/daft", defaultHandler)
//	http.HandleFunc("/cert", defaultHandler)

	// actions
	// withdraw, draw, deposit, process, clear
	http.HandleFunc("/submit", submitHandler)

	log.Printf("start service, server id: %X\n", serverkey.PrimaryKey.Fingerprint)
	log.Fatal(http.ListenAndServe(port, nil))
}