handlerの構造体を実装

handler.go

@@ -0,0 +1,208 @@
+package main
+
+import (
+	"net/http"
+	"encoding/json"
+	"strconv"
+	"fmt"
+	"database/sql"
+)
+
+// Handlers HTTPハンドラを集めた型
+type Handlers struct {
+	DB *sql.DB
+}
+
+// AvailableListHandler 公開されている宝くじ情報の一覧を取得
+func (hs *Handlers) AvailableListHandler(w http.ResponseWriter, r *http.Request) {
+	resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/available_lotteries")
+		if err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+		defer resp.Body.Close()
+
+		var lotteries []*Lottery
+		if err := json.NewDecoder(resp.Body).Decode(&lotteries); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+
+		if err := listTmpl.Execute(w, lotteries); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+} 
+
+// GetHandler IDを指定して宝くじ情報を取得する
+func (hs *Handlers) GetHandler(w http.ResponseWriter, r *http.Request) {
+	resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/lottery?id=" + r.FormValue("id"))
+		if err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+		defer resp.Body.Close()
+
+		var l Lottery
+		if err := json.NewDecoder(resp.Body).Decode(&l); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+
+		data := struct {
+			Lottery
+			Remain int64
+		}{
+			Lottery: l,
+			Remain:  l.Num, // TODO: 残りを計算する
+		}
+		if err := purchasePageTmpl.Execute(w, data); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+}
+
+// PurchaseHandler 宝くじの購入
+func (hs *Handlers) PurchaseHandler (w http.ResponseWriter, r *http.Request) {
+
+	db := hs.DB
+
+	id := r.FormValue("id")
+	num, err := strconv.Atoi(r.FormValue("num"))
+	if err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+	// TODO: パラメタのバリデーション
+
+	resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/lottery?id=" + id)
+	if err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+	defer resp.Body.Close()
+
+	var l Lottery
+	if err := json.NewDecoder(resp.Body).Decode(&l); err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+
+	var count int
+	if err := db.QueryRow("SELECT COUNT(*) FROM purchased WHERE lottery_id = ?", l.ID).Scan(&count); err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+
+	for i := 1; i <= num; i++ {
+		const sql = "INSERT INTO purchased(lottery_id, number) values (?,?)"
+		format := fmt.Sprintf(`%%0%dd`, len(strconv.FormatInt(l.Num-1, 10)))
+		n := fmt.Sprintf(format, count+i)
+		if _, err := db.Exec(sql, id, n); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+	}
+
+	http.Redirect(w, r, "/purchase_page?id="+l.ID, http.StatusFound)
+}
+
+
+// ResultHandler 結果を取得
+func (hs *Handlers) ResultHandler(w http.ResponseWriter, r *http.Request) {
+
+	db := hs.DB
+
+	resp1, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/result?id=" + r.FormValue("id"))
+	if err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+	defer resp1.Body.Close()
+
+	var result Result
+	if err := json.NewDecoder(resp1.Body).Decode(&result); err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+
+	resp2, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/lottery?id=" + r.FormValue("id"))
+	if err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+	defer resp2.Body.Close()
+
+	var l Lottery
+	if err := json.NewDecoder(resp2.Body).Decode(&l); err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+
+	type winner struct {
+		Prize   *Prize
+		Numbers []string
+	}
+
+	data := struct {
+		Lottery
+		Winners map[string]*winner
+	}{
+		Lottery: l,
+		Winners: map[string]*winner{},
+	}
+
+	rows, err := db.Query("SELECT number FROM purchased WHERE lottery_id = ?", l.ID)
+	if err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+	for rows.Next() {
+		var number string
+		if err := rows.Scan(&number); err != nil {
+			const status = http.StatusInternalServerError
+			http.Error(w, http.StatusText(status), status)
+			return
+		}
+
+		for i := range result.Winners {
+			for _, n := range result.Winners[i].Numbers {
+				if number == n {
+					prizeID := result.Winners[i].PrizeID
+					if data.Winners[prizeID] == nil {
+						for _, p := range l.Prizes {
+							if p.ID == prizeID {
+								data.Winners[prizeID] = &winner{
+									Prize: p,
+								}
+							}
+						}
+					}
+					data.Winners[prizeID].Numbers = append(data.Winners[prizeID].Numbers, n)
+				}
+			}
+		}
+	}
+
+	if err := resultTmpl.Execute(w, data); err != nil {
+		const status = http.StatusInternalServerError
+		http.Error(w, http.StatusText(status), status)
+		return
+	}
+}