HW-03-oop-and-api/src/main/java/movie/apis/MovieService.java

package movie.apis;

import com.google.gson.*;
import com.google.gson.reflect.TypeToken;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

public class MovieService {

    private final static String GENRES_URL = "https://api.meshcomp.ir/api/v1/genres";
    private final static String MOVIE_BY_ID_URL = "https://api.meshcomp.ir/api/v1/movies/";
    private final static HttpClient client = HttpClient.newHttpClient();

    private String getGenresList() {
        try {
            HttpRequest request = HttpRequest.newBuilder()
                    .uri(URI.create(GENRES_URL))
                    .build();

            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

            if (response.statusCode() == 200) {
                System.out.println("Genres List received successfully");
                return response.body();
            } else {
                throw new IOException("HTTP error code: " + response.statusCode());
            }
        } catch (Exception e) {
            System.out.println("!!Exception : " + e.getMessage());
        }
        return null;
    }

    private String getMoviesByGenreList(Long genreId, Long page) {
        try {
            String url = "https://api.meshcomp.ir/api/v1/genres/" + genreId + "/movies?page=" + page;

            HttpRequest request = HttpRequest.newBuilder()
                    .uri(URI.create(url))
                    .build();

            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

            if (response.statusCode() == 200) {
                return response.body();
            } else {
                System.out.println("HTTP error code: " + response.statusCode());
                return null;
            }
        } catch (Exception e) {
            System.out.println("!!Exception : " + e.getMessage());
        }
        return null;
    }



    public void displayGenres() {
        String jsonResponse = getGenresList();

        if (jsonResponse == null) {
            System.out.println("Failed to get genres");
            return;
        }

        try {
            JsonObject rootObject = JsonParser.parseString(jsonResponse).getAsJsonObject();
            JsonArray genresArray = rootObject.getAsJsonArray("genres");
            Type genreListType = new TypeToken<ArrayList<Genre>>(){}.getType();
            Gson gson = new Gson();
            List<Genre> genres = gson.fromJson(genresArray, genreListType);

            System.out.println("\nALL GENRES:");
            for (Genre genre : genres) {
                System.out.println(genre.getId() + ". " + genre.getName());
            }
            System.out.println();
        } catch (Exception e) {
            System.err.println("ERROR parsing genres: " + e.getMessage());
        }
    }

    /**
     * TODO 1: Display movies for a specific genre and page
     *
     * JSON format: { "movies": [ { "id": 1, "title": "Movie", "year": "1994" } ], "total": 177, "total_pages": 18 }
     *
     * Steps:
     * - Call getMoviesByGenreList(genreId, page) to get JSON
     * - Parse JSON to JsonObject
     * - Get "movies" array (NOT "data")
     * - Loop through array and print: "ID: {id} | {title} ({year})"
     * - Also print total and total_pages
     *
     * PUT ALL PARSING CODE INSIDE try-catch
     */
    public void displayMoviesByGenre(Long genreId, Long page) {
        try {
            String jsonResponse = getMoviesByGenreList(genreId , page);
            if(jsonResponse == null){
                System.out.println("Failed to get movies for this gener");
                return;
            }

            JsonObject root = JsonParser.parseString(jsonResponse).getAsJsonObject();

            JsonArray moviesArray = root.getAsJsonArray("movies");

            if(moviesArray == null || moviesArray.isEmpty()){
                System.out.println("No Movie found");
                return;
            }

            System.out.println("\nMOVIES LIST (Gener ID :" + genreId + ", Page :" + page + "):");
            for(JsonElement movieElement : moviesArray){

                JsonObject movieObj = movieElement.getAsJsonObject();
                long id = movieObj.get("id").getAsLong();
                String title = movieObj.get("title").getAsString();
                String year = movieObj.get("year").getAsString();

                System.out.println("ID:" + id + " | " + title + "(" + year + ")");
            }

            int total = root.get("total").getAsInt();
            int totalPage = root.get("total_pages").getAsInt();

            System.out.println("Total Movies : " + total);
            System.out.println("Total Pages : " + totalPage);

        } catch (Exception e) {
            System.err.println("ERROR: " + e.getMessage());
        }
    }


    /**
     * BONUS: Fetch movie details from API using movie ID
     * URL format: https://api.meshcomp.ir/api/v1/movies/{movieId}
     */
    private String getMovieById(Long movieId) {
        try {
            // TODO: Complete this method
             String url = MOVIE_BY_ID_URL + movieId;
             HttpRequest request = HttpRequest.newBuilder().uri(URI.create(url)).build();
             HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
             if (response.statusCode() == 200) return response.body();
             else {
                 System.out.println("HTTP error code :" + response.statusCode());
                 return null;
             }
        } catch (Exception e) {
            System.out.println("!!Exception : " + e.getMessage());
        }
        return null;
    }
    
    /**
     * BONUS TODO: Display complete movie details for a given movie ID
     *
     * Expected JSON format from getMovieById():
     * {
     *   "id": 1,
     *   "title": "The Shawshank Redemption",
     *   "year": "1994",
     *   "genres": ["Crime", "Drama"],
     *   "poster": "https://moviesapi.ir/images/tt0111161_poster.jpg",
     *   "country": "USA",
     *   "imdb_rating": "9.3"
     * }
     *
     * INSTRUCTIONS:
     * 1. Call getMovieById(movieId) to get the JSON response
     * 2. Check if response is null (if yes, print error and return)
     * 3. Parse the JSON string to JsonObject (inside try-catch)
     * 4. Extract all fields: id, title, year, genres array, poster, country, imdb_rating
     * 5. Convert genres array to comma-separated string
     * 6. Print all movie details in a readable format
     *
     * PUT ALL PARSING CODE INSIDE THE EXISTING try-catch
     *
     * @param movieId The ID of the movie to display
     */
    public void displayMovieDetails(Long movieId) {
        // Step 1: Get JSON response from API
        String jsonResponse = getMovieById(movieId);

        // Step 2: Check if we got valid data
        if (jsonResponse == null) {
            System.out.println("Failed to get movie details for ID: " + movieId);
            return;
        }

        // Step 3-6: Parse JSON and display details (PUT YOUR CODE INSIDE try-catch)
        try {
            // TODO: Parse jsonResponse to JsonObject
            // TODO: Extract id, title, year, genres array, poster, country, imdb_rating
            // TODO: Convert genres array to a readable string
            // TODO: Print all movie details
            // HINT: Use JsonParser.parseString(jsonResponse).getAsJsonObject()
            // HINT: Use getAsJsonArray("genres") to get genres
            // HINT: For each genre, use getAsString()

            // Your code here:
            JsonObject movieObj = JsonParser.parseString(jsonResponse).getAsJsonObject();

            if(movieObj == null){
                System.out.println("Movie not foud!");
                return;
            }

            long id = movieObj.get("id").getAsLong();
            String title = movieObj.get("title").getAsString();
            String year = movieObj.get("year").getAsString();
            String poster = movieObj.get("poster").getAsString();
            String country = movieObj.get("country").getAsString();
            String imdb_rating = movieObj.get("imdb_rating").getAsString();
            JsonArray genresArray =  movieObj.get("genres").getAsJsonArray();
            List<String> genreList = new ArrayList<>();
            for(JsonElement g : genresArray){
                genreList.add(g.getAsString());
            }

            System.out.println("\nMOVIE DETAILS: ");
            System.out.println("ID: "+  id);
            System.out.println("Title: "+ title);
            System.out.println("Year: " + year);
            System.out.println("Country: " + country);
            System.out.println("imdb_rating: " + imdb_rating);
            System.out.println("Genres: " + genreList);
            System.out.println("Poster: " + poster);
        } catch (Exception e) {
            System.err.println("ERROR parsing movie details: " + e.getMessage());
        }
    }
}