// Simplifies use of zlib for inflating data

// File_Extractor 1.0.0
#ifndef ZLIB_INFLATER_H
#define ZLIB_INFLATER_H

#include "Data_Reader.h"
#include "blargg_common.h"
#include "zlib.h"

class Zlib_Inflater
{
        public:
        // Reads at most min(*count,bytes_until_eof()) bytes into *out and set *count
        // to that number, or returns error if that many can't be read.
        typedef blargg_err_t (*callback_t)(void *user_data, void *out, int *count);

        // Begins by setting callback and filling buffer. Default buffer is 16K and
        // filled to 4K, or specify buf_size and initial_read for custom buffer size
        // and how much to read initially.
        blargg_err_t begin(callback_t, void *user_data, int buf_size = 0, int initial_read = 0);

        // Data read into buffer by begin()
        const unsigned char *data() const
        {
                return zbuf.next_in;
        }
        int filled() const
        {
                return zbuf.avail_in;
        }

        // Begins inflation using specified mode. Using mode_auto selects between
        // mode_copy and mode_ungz by examining first two bytes of buffer. Use
        // buf_offset to specify where data begins in buffer, in case there is
        // header data that should be skipped.
        enum mode_t { mode_copy, mode_ungz, mode_raw_deflate, mode_auto };
        blargg_err_t set_mode(mode_t, int buf_offset = 0);

        // True if set_mode() has been called with mode_ungz or mode_raw_deflate
        bool deflated() const
        {
                return deflated_;
        }

        // Reads/inflates at most *count_io bytes into *out and sets *count_io to actual
        // number of bytes read (less than requested if end of data was reached).
        // Buffers source data internally, even in copy mode, so input file can be
        // unbuffered without sacrificing performance.
        blargg_err_t read(void *out, int *count_io);

        // Total number of bytes read since begin()
        int tell() const
        {
                return zbuf.total_out;
        }

        // Ends inflation and frees memory
        void end();

        private:
        // noncopyable
        Zlib_Inflater(const Zlib_Inflater &);
        Zlib_Inflater &operator=(const Zlib_Inflater &);

        // Implementation
        public:
        Zlib_Inflater();
        ~Zlib_Inflater();

        private:
        z_stream_s zbuf;
        blargg_vector<unsigned char> buf;
        bool deflated_;
        callback_t callback;
        void *user_data;

        blargg_err_t fill_buf(int count);
};

#endif
