egonelbre · February 3, 2015 09:52 · Feb 3, 2015
diff --git a/books.go b/books.go
@@ -0,0 +1,172 @@
+package main
+
+import (
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/jmoiron/sqlx"
+)
+
+const StatusHandled = 0
+
+type Book struct {
+	BookID      string
+	CategoryID  string
+	Title       string
+	Slug        string
+	Description string
+	LikeCount   int
+	Creation    time.Time
+	LastUpdate  time.Time
+	Deleted     bool
+}
+
+type NewBook struct {
+	Title       string
+	Description string
+}
+
+type Context struct {
+	DB *sqlx.DB
+}
+
+func New(db *sql.DB) *Context {
+	return &Context{DB}
+}
+
+func readjson(r io.ReadCloser, v interface{}) error {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(data, v)
+}
+
+func (c *Context) json(rw http.ResponseWriter, r *http.Request, v interface{}) (err string, code int) {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return err.Error(), http.StatusInternalServerError
+	}
+
+	rw.Header().Set("Content-Type", "application/json")
+	rw.WriteHeader(http.StatusOK)
+	rw.Write(data)
+	return "", StatusHandled
+}
+
+func (c *Context) Books(rw http.ResponseWriter, r *http.Request) (err string, code int) {
+	vars, db := mux.Vars(r), c.DB
+
+	switch r.Method {
+	case "GET":
+		books := &Books{}
+		category := vars["category"]
+		if category == "" {
+			http.Error(rw, fmt.Sprintf("Category cannot be empty."), http.StatusBadRequest)
+			return
+		}
+
+		err := db.Select(books, "SELECT * FROM book WHERE categoryid=?", category)
+		if err != nil {
+			return fmt.Sprintf(`Error searching for books: %v`, err), http.StatusInternalServerError
+		}
+
+		return c.json(rw, r, books)
+	default:
+		return fmt.Sprintf("Invalid method: %s", r.Method), http.StatusForbidden
+	}
+}
+
+func (c *Context) ByCategory(rw http.ResponseWriter, r *http.Request) (err string, code int) {
+	vars, db := mux.Vars(r), c.DB
+
+	slug := vars["slug"]
+	category := vars["category"]
+
+	switch r.Method {
+
+	case "GET":
+		book := &Book{}
+		if slug == "" || cat == "" {
+			return fmt.Sprintf("Slug or category cannot be empty."), http.StatusBadRequest
+		}
+
+		err = db.Get(book, "SELECT * FROM book WHERE slug=? AND categoryid=?", slug, cat)
+		if err != nil {
+			return fmt.Sprintf(`Error searching for books: %v`, err), http.StatusInternalServerError
+		}
+		return c.json(rw, r, book)
+
+	case "POST":
+		book := &NewBook{}
+		err := readjson(r.Body, book)
+		if err != nil {
+			return fmt.Sprintf("Invalid book."), http.StatusBadRequest
+		}
+
+		_, err = db.Exec(`
+			INSERT INTO book 
+				(categoryid, title, slug, description, likecount, creation, lastupdate, deleted)
+			VALUES 
+				(?, ?, ?, ?, 0, NOW(), NOW(), false)`, category, book.Title, slug(book.Title), book.Description)
+		if err != nil {
+			return fmt.Sprintf("Error inserting the book: %s", err.Error()), http.StatusInternalServerError
+		}
+
+		return "", http.StatusOK
+	default:
+		return fmt.Sprintf("Invalid method: %s", r.Method), http.StatusForbidden
+	}
+}
+
+func (c *Context) BookLike(rw http.ResponseWriter, r *http.Request) (err string, code int) {
+	vars, db := mux.Vars(r), c.DB
+
+	switch r.Method {
+	case "POST":
+		id := vars["bookid"]
+		if id == "" {
+			return fmt.Sprintf("Book id cannot be empty."), http.StatusBadRequest
+		}
+
+		_, err = db.Exec(`UPDATE book SET likecount=likecount+1 WHERE bookid=?`, id)
+		if err != nil {
+			return fmt.Sprintf("Error inserting the book: %s", err.Error()), http.StatusInternalServerError
+		}
+
+		return "", http.StatusOK
+	default:
+		return fmt.Sprintf("Invalid method: %s", r.Method), http.StatusForbidden
+	}
+}
+
+var Router = mux.NewRouter()
+
+type Handler func(rw http.ResponseWriter, r *http.Request) (err string, code int)
+
+func route(path string, fn Handler) {
+	Router.HandleFunc(path, func(rw http.ResponseWriter, r *http.Request) {
+		err, code := fn(rw, r)
+		if code != StatusHandled {
+			http.Error(rw, err, code)
+		}
+	})
+}
+
+func main() {
+	db := sqlx.Open("sqlite3", "memory")
+	c := &Context{db}
+
+	route("categories/{category}/books/{slug}", c.ByCategory)
+	route("categories/{category}/books/{bookid}/like", c.BookLike)
+
+	http.Handle("/api/", Router)
+	http.ListenAndServe(":3000", nil)
+}