extern crate libc;
use self::libc::{c_char, c_int, c_void, size_t};

#[repr(C)]
pub struct RocksdbOptions(pub *const c_void);
#[repr(C)]
pub struct RocksdbInstance(pub *const c_void);
#[repr(C)]
pub struct RocksdbWriteOptions(pub *const c_void);
#[repr(C)]
pub struct RocksdbReadOptions(pub *const c_void);
#[repr(C)]
pub struct RocksdbCompactionFilter(pub *const c_void);
#[repr(C)]
pub struct RocksdbMergeOperator(pub *const c_void);
#[repr(C)]
pub struct RocksdbFilterPolicy(pub *const c_void);

#[repr(C)]
pub enum RocksdbCompressionType {
  RocksdbNoCompression   = 0,
  RocksdbSnappyCompression = 1,
  RocksdbZlibCompression   = 2,
  RocksdbBz2Compression  = 3,
  RocksdbLz4Compression  = 4,
  RocksdbLz4hcCompression  = 5
}

#[repr(C)]
pub enum RocksdbCompactionStyle {
  RocksdbLevelCompaction   = 0,
  RocksdbUniversalCompaction = 1,
  RocksdbFifoCompaction    = 2
}

#[repr(C)]
pub enum RocksdbUniversalCompactionStyle {
  rocksdb_similar_size_compaction_stop_style = 0,
  rocksdb_total_size_compaction_stop_style   = 1
}

#[link(name = "rocksdb")]
extern {
  pub fn rocksdb_options_create() -> RocksdbOptions;
  pub fn rocksdb_options_increase_parallelism(
    options: RocksdbOptions, threads: c_int);
  pub fn rocksdb_options_optimize_level_style_compaction(
    options: RocksdbOptions, memtable_memory_budget: c_int);
  pub fn rocksdb_options_set_create_if_missing(
    options: RocksdbOptions, v: c_int);
  pub fn rocksdb_options_set_max_open_files(
    options: RocksdbOptions, files: c_int);
  pub fn rocksdb_options_set_use_fsync(
    options: RocksdbOptions, v: c_int);
  pub fn rocksdb_options_set_bytes_per_sync(
    options: RocksdbOptions, bytes: u64);
  pub fn rocksdb_options_set_disable_data_sync(
    options: RocksdbOptions, v: c_int);
  pub fn rocksdb_options_optimize_for_point_lookup(
    options: RocksdbOptions, block_cache_size_mb: u64);
  pub fn rocksdb_options_set_table_cache_numshardbits(
    options: RocksdbOptions, bits: u64);
  pub fn rocksdb_options_set_max_write_buffer_number(
    options: RocksdbOptions, bufno: c_int);
  pub fn rocksdb_options_set_min_write_buffer_number_to_merge(
    options: RocksdbOptions, bufno: c_int);
  pub fn rocksdb_options_set_level0_file_num_compaction_trigger(
    options: RocksdbOptions, no: c_int);
  pub fn rocksdb_options_set_level0_slowdown_writes_trigger(
    options: RocksdbOptions, no: c_int);
  pub fn rocksdb_options_set_level0_stop_writes_trigger(
    options: RocksdbOptions, no: c_int);
  pub fn rocksdb_options_set_write_buffer_size(
    options: RocksdbOptions, bytes: u64);
  pub fn rocksdb_options_set_target_file_size_base(
    options: RocksdbOptions, bytes: u64);
  pub fn rocksdb_options_set_target_file_size_multiplier(
    options: RocksdbOptions, mul: c_int);
  pub fn rocksdb_options_set_max_log_file_size(
    options: RocksdbOptions, bytes: u64);
  pub fn rocksdb_options_set_max_manifest_file_size(
    options: RocksdbOptions, bytes: u64);
  pub fn rocksdb_options_set_hash_skip_list_rep(
    options: RocksdbOptions, bytes: u64, a1: i32, a2: i32);
  pub fn rocksdb_options_set_compaction_style(
    options: RocksdbOptions, cs: RocksdbCompactionStyle);
  pub fn rocksdb_options_set_compression(
    options: RocksdbOptions, compression_style_no: c_int);
  pub fn rocksdb_options_set_max_background_compactions(
    options: RocksdbOptions, max_bg_compactions: c_int);
  pub fn rocksdb_options_set_max_background_flushes(
    options: RocksdbOptions, max_bg_flushes: c_int);
  pub fn rocksdb_options_set_filter_deletes(
    options: RocksdbOptions, v: u8);
  //pub fn rocksdb_compactionfilter_create() -> RocksdbCompactionFilter;
  pub fn rocksdb_filterpolicy_create_bloom(
    bits_per_key: c_int) -> RocksdbFilterPolicy;
  pub fn rocksdb_open(options: RocksdbOptions,
    path: *const i8, err: *mut i8) -> RocksdbInstance;
  pub fn rocksdb_writeoptions_create() -> RocksdbWriteOptions;
  pub fn rocksdb_put(db: RocksdbInstance, writeopts: RocksdbWriteOptions,
    k: *const u8, kLen: size_t, v: *const u8,
    vLen: size_t, err: *mut i8);
  pub fn rocksdb_readoptions_create() -> RocksdbReadOptions;
  pub fn rocksdb_get(db: RocksdbInstance, readopts: RocksdbReadOptions,
    k: *const u8, kLen: size_t,
    valLen: *const size_t, err: *mut i8) -> *mut c_void;
  pub fn rocksdb_delete(db: RocksdbInstance, writeopts: RocksdbWriteOptions,
    k: *const u8, kLen: size_t, err: *mut i8) -> *mut c_void;
  pub fn rocksdb_close(db: RocksdbInstance);
  pub fn rocksdb_destroy_db(
    options: RocksdbOptions, path: *const i8, err: *mut i8);
  pub fn rocksdb_repair_db(
    options: RocksdbOptions, path: *const i8, err: *mut i8);

  // Merge Operator
  pub fn rocksdb_mergeoperator_create(
    state: *mut c_void,
    destroy: extern fn(*mut c_void) -> (),
    full_merge: extern fn (
      arg: *mut c_void, key: *const c_char, key_len: *mut size_t,
      existing_value: *const c_char, existing_value_len: *mut size_t,
      operands_list: &[*const c_char], operands_list_len: *const size_t,
      num_operands: c_int,
      success: *mut u8, new_value_length: *mut size_t
    ) -> *const c_char,
    partial_merge: extern fn(
      *mut c_void, key: *const c_char, key_len: *mut size_t,
      operands_list: &[*const c_char], operands_list_len: *const size_t,
      num_operands: c_int,
      success: *mut u8, new_value_length: *mut size_t
    ) -> *const c_char,
    delete_value: extern fn(*mut c_void, value: *const c_char, value_len: *mut size_t) -> (),
    name_fn: extern fn(*mut c_void) -> *const c_char,
  ) -> RocksdbMergeOperator;
  pub fn rocksdb_mergeoperator_destroy(mo: RocksdbMergeOperator);
  pub fn rocksdb_options_set_merge_operator(
    options: RocksdbOptions,
    mo: RocksdbMergeOperator);
}

#[allow(dead_code)]
#[test]
fn internal() {
  unsafe {
    let opts = rocksdb_options_create();
    let RocksdbOptions(opt_ptr) = opts;
    assert!(opt_ptr.is_not_null());

    rocksdb_options_increase_parallelism(opts, 0);
    rocksdb_options_optimize_level_style_compaction(opts, 0);
    rocksdb_options_set_create_if_missing(opts, 1);

    let rustpath = "internaltest";
    let cpath = rustpath.to_c_str();
    let cpath_ptr = cpath.as_ptr();

    let err = 0 as *mut i8;
    let db = rocksdb_open(opts, cpath_ptr, err);
    assert!(err.is_null());
    libc::free(err as *mut c_void);

    let writeopts = rocksdb_writeoptions_create();
    let RocksdbWriteOptions(write_opt_ptr) = writeopts;
    assert!(write_opt_ptr.is_not_null());

    let key = b"name\x00";
    let val = b"spacejam\x00";

    rocksdb_put(db, writeopts, key.as_ptr(), 4, val.as_ptr(), 8, err);
    assert!(err.is_null());
    libc::free(err as *mut c_void);

    let readopts = rocksdb_readoptions_create();
    let RocksdbReadOptions(read_opts_ptr) = readopts;
    assert!(read_opts_ptr.is_not_null());
    libc::free(err as *mut c_void);

    let val_len: size_t = 0;
    let val_len_ptr = &val_len as *const size_t;
    rocksdb_get(db, readopts, key.as_ptr(), 4, val_len_ptr, err);
    assert!(err.is_null());
    libc::free(err as *mut c_void);
    rocksdb_close(db);
  }
}