Upload New File

oblig1/endpoints/bookcount.go

+package endpoints
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// BookCountResponse represents the structure of the response for book count endpoint.
+type BookCountResponse struct {
+	Language string  `json:"language"`
+	Books    int     `json:"books"`
+	Authors  int     `json:"authors"`
+	Fraction float64 `json:"fraction"`
+}
+
+type Books struct {
+	Count    int      `json:"count"`
+	Next     string   `json:"next"`
+	Previous string   `json:"previous"`
+	Results  []Result `json:"results"`
+}
+type Result struct {
+	Authors []Author `json:"authors"`
+}
+type Author struct {
+	Name string `json:"name"`
+}
+
+// BookCountHandler handles requests to the /librarystats/v1/bookcount/ endpoint.
+func BookCountHandler(w http.ResponseWriter, r *http.Request) {
+	languages := r.URL.Query().Get("language")
+
+	// Split the language codes into a slice.
+	languageCodes := strings.Split(languages, ",")
+
+	// Placeholder values for books, authors, and total books.
+	var totalBooks int
+	var uniqueAuthors = make(map[string]struct{}) // Use a map as a set for unique authors
+	var allBooks int
+
+	// Create a slice to store results for each language.
+	var response []BookCountResponse
+
+	// Iterate through each language code.
+	for _, language := range languageCodes {
+		// Placeholder for the URL of the first page of results.
+		gutendexAPIURL := fmt.Sprintf("http://129.241.150.113:8000/books/?languages=%v", language)
+
+		// Fetch all pages of results.
+		for gutendexAPIURL != "" {
+			req, err := http.NewRequest("GET", gutendexAPIURL, nil)
+			if err != nil {
+				http.Error(w, "Failed to create a new request", http.StatusInternalServerError)
+				return
+			}
+			req.Header.Add("Content-Type", "application/json")
+
+			client := &http.Client{}
+
+			res, err := client.Do(req)
+			if err != nil {
+				http.Error(w, "Failed to send a request to Gutendex API", http.StatusInternalServerError)
+				return
+			}
+			defer res.Body.Close()
+
+			// Decode the response.
+			body, err := io.ReadAll(res.Body)
+			if err != nil {
+				http.Error(w, "Failed to read Gutendex API response", http.StatusInternalServerError)
+				return
+			}
+
+			var books Books
+			err = json.Unmarshal(body, &books)
+			if err != nil {
+				http.Error(w, "Failed to decode Gutendex API response", http.StatusInternalServerError)
+				return
+			}
+
+			// Increment total books and unique authors for each language.
+			totalBooks = books.Count
+			for _, book := range books.Results {
+				for _, author := range book.Authors {
+					uniqueAuthors[author.Name] = struct{}{}
+				}
+			}
+
+			// Update total books for the first page only.
+			if allBooks == 0 {
+				allBooks = getBooksCount(w)
+			}
+
+			// Update the URL to the next page of results.
+			gutendexAPIURL = books.Next
+		}
+		// Calculate fraction.
+		var fraction float64
+		if allBooks > 0 {
+			fraction = float64(totalBooks) / float64(allBooks)
+		}
+		// Append results for the current language to the response slice.
+		response = append(response, BookCountResponse{
+			Language: language,
+			Books:    totalBooks,
+			Authors:  len(uniqueAuthors),
+			Fraction: fraction,
+		})
+		// Clear the set of unique authors for the next language.
+		uniqueAuthors = make(map[string]struct{})
+	}
+
+	// Send the response.
+	sendJSONResponse(w, response)
+}
+
+func getBooksCount(w http.ResponseWriter) int {
+	gutendexCount := "http://129.241.150.113:8000/books/"
+
+	req, err := http.NewRequest("GET", gutendexCount, nil)
+	if err != nil {
+		http.Error(w, "Failed to create a new request", http.StatusInternalServerError)
+		return 1
+	}
+	req.Header.Add("Content-Type", "application/json")
+
+	client := &http.Client{}
+
+	res, err := client.Do(req)
+	if err != nil {
+		http.Error(w, "Failed to send a request to Gutendex API", http.StatusInternalServerError)
+		return 1
+	}
+	defer res.Body.Close()
+
+	// Decode the response.
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		http.Error(w, "Failed to read Gutendex API response", http.StatusInternalServerError)
+		return 1
+	}
+
+	var books Books
+	err = json.Unmarshal(body, &books)
+	if err != nil {
+		http.Error(w, "Failed to decode Gutendex API response", http.StatusInternalServerError)
+		return 1
+	}
+	return books.Count
+}