#pragma once

#include <mutex>
#include <memory>
#include <string>
#include <vector>
#include <string_view>
#include <filesystem>
#include <optional>
#include <exception>

#include <curl/curl.h>
#include <nlohmann/json.hpp>
#include <archive.h>
#include <archive_entry.h>

#include "atomicmutex.h"
#include "loggable.h"

class Collection;

class Download : protected Loggable {
    struct RepoInfo;
    struct CurlDeleter {
        void operator() (CURL* curl) const;
    };
    struct FileDeleter {
        void operator() (FILE* file) const;
    };
    class CurlError;
    class FileError;

public:
    explicit Download(
        const std::string& url,
        const std::filesystem::path& destination,
        const std::shared_ptr<Logger>& logger
    );
    ~Download();

    void proceed();
    std::optional<std::filesystem::path> getLocation() const;

private:
    std::optional<RepoInfo> testRepo() const;

    std::optional<std::filesystem::path> downloadAsRepo(const RepoInfo& repo);

    std::optional<nlohmann::json> repoInfoGiteaApi1(const RepoInfo& repo);
    std::optional<std::filesystem::path> downloadRepoGiteaApi1(const RepoInfo& repo, const std::string& branch);

    bool extract(const std::filesystem::path& source, const std::filesystem::path& destination) const;
    int copy(struct archive *ar, struct archive *aw) const;

    CURLcode httpGet(const std::string& url, std::string& result, const std::vector<std::string_view>& headers = {});
    CURLcode httpDownload(const std::string& url, const std::filesystem::path& path, const std::vector<std::string_view>& headers = {});
    void setHeaders (const std::vector<std::string_view>& headers);

    static size_t writeString(void* data, size_t size, size_t nmemb, void* mem);
    static int trace(CURL *handle, curl_infotype type, char *data, size_t size, void *clientp);
    void createCurl();

private:
    static AtomicMutex amx;
    static unsigned int instances;
    std::unique_ptr<CURL, CurlDeleter> curl;
    std::string url;
    std::filesystem::path destination;
    std::optional<std::filesystem::path> location;
};

struct Download::RepoInfo {
    std::string protocol;
    std::string host;
    std::string owner;
    std::string name;

    std::string origin() const;
    std::string project() const;
};

class Download::CurlError : public std::runtime_error {
public:
    explicit CurlError(const std::string& message);
};

class Download::FileError : public std::runtime_error {
public:
    explicit FileError(const std::string& message);
};