import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

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.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;

public class PullRequestFetcher {
    private static final Logger LOGGER = Logger.getLogger(PullRequestFetcher.class.getName());
    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
    private static final String GITHUB_API_URL = "https://api.github.com";
    private final String githubPersonalAccessToken;
    private final HttpClient httpClient;

    public PullRequestFetcher(String githubPersonalAccessToken) {
        this.githubPersonalAccessToken = githubPersonalAccessToken;
        this.httpClient = HttpClient.newBuilder().build();
    }

    public List<PullRequest> fetchPullRequests(String repositoryOwner, String repositoryName) {
        List<PullRequest> pullRequests = new ArrayList<>();

        String repository = repositoryOwner + "/" + repositoryName;
        String apiURL = "%s/repos/%s/pulls".formatted(GITHUB_API_URL, repository);

        LOGGER.fine("Making request to " + apiURL);

        HttpRequest httpRequest = HttpRequest.newBuilder()
                .uri(URI.create(apiURL))
                .header("Accept", "application/vnd.github+json")
                .header("X-GitHub-Api-Version", "2022-11-28")
                .header("Authorization", githubPersonalAccessToken)
                .build();
        try {
            HttpResponse<String> response = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString());
            int statusCode = response.statusCode();

            LOGGER.fine("Received http status " + statusCode);

            if(statusCode != 200) {
                LOGGER.warning("Unexpected HTTP status "
                        + statusCode
                        + " while fetching pull requests for "
                        + repository + "\nbody="
                        + response.body());
            } else {
                try {
                    pullRequests = OBJECT_MAPPER.readValue(response.body(), new TypeReference<>() {});
                } catch (JsonProcessingException jpe) {
                    LOGGER.severe("Failed to parse JSON " + jpe.getMessage());
                }
            }

        } catch (IOException | InterruptedException e) {
            LOGGER.severe("Failed to fetch pull request from discord for "
                    + repository
                    + ":"
                    + e.getMessage());
        }

        return pullRequests;
    }
}

@JsonIgnoreProperties(ignoreUnknown = true)
public record PullRequest(
        @JsonProperty("html_url") String htmlUrl,
        @JsonProperty("number") int number,
        @JsonProperty("state") String state,
        @JsonProperty("title") String title,
        @JsonProperty("user") User user,
        @JsonProperty("body") String body,
        @JsonProperty("created_at") String createdAt,
        @JsonProperty("draft") boolean draft
) {}

@JsonIgnoreProperties(ignoreUnknown = true)
public record User(
        @JsonProperty("name") String name,
        @JsonProperty("id") int id,
        @JsonProperty("avatar_url") String avatarUrl
) {}