#include "internal.h"

flate·Writer*
flate·openwriter(io·Writer wtr, void* w, mem·Allocator mem, void* m)
{
    error      err;
    flate·Writer *zwtr;

    zwtr = mem.alloc(m, 1, sizeof(*zwtr));
    zwtr->zalloc   = (void *(*)(void *, unsigned int, unsigned int))mem.alloc;
    zwtr->zfree    = mem.free;
    zwtr->opaque   = m;
    zwtr->avail_in = 0;

    err = deflateInit(&zwtr->b.z, Z_DEFAULT_COMPRESSION);

    switch (err) {
    case Z_OK:
        return zwtr;

    case Z_MEM_ERROR:
        errorf("zlib: not enough memory");
        goto ERROR;

    case Z_VERSION_ERROR:
        errorf("zlib: incompatible version");
        goto ERROR;

    case Z_STREAM_ERROR:
        errorf("zlib: incorrect compression level");
        goto ERROR;

    default:
        errorf("zlib: unrecognized error code");
    }
ERROR:
    errorf("zlib: msg: %s", zwtr->msg);
    mem.free(m, zwtr);
    return nil;
}

error
flate·closewriter(flate·Writer *wtr)
{
    int err;
    flate·Writer zwtr;

    zwtr = *wtr;
    err = deflateEnd(&zwtr.b.z);
    if (err != Z_OK) {
        errorf("zlib: failed to cleanup");
        return err;
    }
    zwtr.zfree(zwtr.opaque, wtr);

    return 0;
}