#include "../include/Archive.hpp"
#include "../include/utils.hpp"
#include <cstring>
#include <archive.h>
#include <archive_entry.h>

using namespace std;

class FileHandler
{
    DISABLE_COPY(FileHandler)
public:
    FileHandler(FILE *_file) : file(_file)
    {

    }

    FileHandler(FileHandler &&other)
    {
        file = other.file;
        other.file = nullptr;
    }

    ~FileHandler()
    {
        fclose(file);
    }

    FILE *file;
};

// libarchive code is modified version of: https://github.com/libarchive/libarchive/wiki/Examples#A_Complete_Extractor
namespace sibs
{
    static int copy_data(struct archive *ar, struct archive *aw)
    {
        int r;
        const void *buff;
        size_t size;
        la_int64_t offset;

        while(true)
        {
            r = archive_read_data_block(ar, &buff, &size, &offset);
            if (r == ARCHIVE_EOF)
                return ARCHIVE_OK;
            else if (r < ARCHIVE_OK)
                return r;

            r = archive_write_data_block(aw, buff, size, offset);
            if (r < ARCHIVE_OK)
                return r;
        }
    }

    Result<bool> Archive::extract(const char *source, const char *destination)
    {
        struct archive *a;
        struct archive *ext;
        struct archive_entry *entry;
        int flags;
        int r;

        /* Select which attributes we want to restore. */
        flags = ARCHIVE_EXTRACT_TIME;
        flags |= ARCHIVE_EXTRACT_PERM;
        flags |= ARCHIVE_EXTRACT_ACL;
        flags |= ARCHIVE_EXTRACT_FFLAGS;

        string rootName;

        a = archive_read_new();
        archive_read_support_format_all(a);
        archive_read_support_compression_all(a);
        ext = archive_write_disk_new();
        archive_write_disk_set_options(ext, flags);
        archive_write_disk_set_standard_lookup(ext);


        if ((r = archive_read_open_filename(a, source, 10240)))
        {
            string errMsg = "Failed to extract archive: ";
            errMsg += source;
            return Result<bool>::Err(errMsg);
        }

        while(true)
        {
            r = archive_read_next_header(a, &entry);
            if (r == ARCHIVE_EOF)
                break;
            else if (r < ARCHIVE_OK)
            {
                string errMsg = "Failed to extract archive: ";
                errMsg += source;
                errMsg += "; reason: ";
                errMsg += archive_error_string(a);
                return Result<bool>::Err(errMsg);
            }
            else if (r < ARCHIVE_WARN)
            {
                string errMsg = "Failed to extract archive: ";
                errMsg += source;
                errMsg += "; reason: ";
                errMsg += archive_error_string(a);
                return Result<bool>::Err(errMsg);
            }

            const char* currentFile = archive_entry_pathname(entry);
            if(rootName.empty())
                rootName = currentFile;

            std::string fullOutputPath = destination;
            fullOutputPath += (currentFile + (rootName.empty() ? 0 : rootName.size() - 1));
            archive_entry_set_pathname(entry, fullOutputPath.c_str());

            r = archive_write_header(ext, entry);
            if (r < ARCHIVE_OK)
            {
                string errMsg = "Failed to extract archive: ";
                errMsg += source;
                errMsg += "; reason: ";
                errMsg += archive_error_string(ext);
                return Result<bool>::Err(errMsg);
            }
            else if (archive_entry_size(entry) > 0) {
                r = copy_data(a, ext);
                if (r < ARCHIVE_OK)
                {
                    string errMsg = "Failed to extract archive: ";
                    errMsg += source;
                    errMsg += "; reason: ";
                    errMsg += archive_error_string(ext);
                    return Result<bool>::Err(errMsg);
                }
                else if (r < ARCHIVE_WARN)
                {
                    string errMsg = "Failed to extract archive: ";
                    errMsg += source;
                    errMsg += "; reason: ";
                    errMsg += archive_error_string(ext);
                    return Result<bool>::Err(errMsg);
                }
            }

            r = archive_write_finish_entry(ext);
            if (r < ARCHIVE_OK)
            {
                string errMsg = "Failed to extract archive: ";
                errMsg += source;
                errMsg += "; reason: ";
                errMsg += archive_error_string(ext);
                return Result<bool>::Err(errMsg);
            }
            else if (r < ARCHIVE_WARN)
            {
                string errMsg = "Failed to extract archive: ";
                errMsg += source;
                errMsg += "; reason: ";
                errMsg += archive_error_string(ext);
                return Result<bool>::Err(errMsg);
            }
        }

        archive_read_close(a);
        archive_read_free(a);
        archive_write_close(ext);
        archive_write_free(ext);
        return Result<bool>::Ok(true);
    }
}