//
// Copyright 2015, Google Inc.
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//

#include "src/core/lib/transport/method_config.h"

#include <string.h>

#include <grpc/impl/codegen/grpc_types.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/time.h>

#include "src/core/lib/slice/slice_hash_table.h"
#include "src/core/lib/slice/slice_internal.h"
#include "src/core/lib/transport/metadata.h"
#include "src/core/lib/transport/static_metadata.h"

//
// grpc_method_config
//

// bool vtable

static void *bool_copy(void *valuep) {
  bool value = *(bool *)valuep;
  bool *new_value = gpr_malloc(sizeof(bool));
  *new_value = value;
  return new_value;
}

static int bool_cmp(void *v1, void *v2) {
  bool b1 = *(bool *)v1;
  bool b2 = *(bool *)v2;
  if (!b1 && b2) return -1;
  if (b1 && !b2) return 1;
  return 0;
}

static void free_mem(grpc_exec_ctx *exec_ctx, void *p) { gpr_free(p); }

static grpc_slice_hash_table_vtable bool_vtable = {free_mem, bool_copy,
                                                   bool_cmp};

// timespec vtable

static void *timespec_copy(void *valuep) {
  gpr_timespec value = *(gpr_timespec *)valuep;
  gpr_timespec *new_value = gpr_malloc(sizeof(gpr_timespec));
  *new_value = value;
  return new_value;
}

static int timespec_cmp(void *v1, void *v2) {
  return gpr_time_cmp(*(gpr_timespec *)v1, *(gpr_timespec *)v2);
}

static grpc_slice_hash_table_vtable timespec_vtable = {free_mem, timespec_copy,
                                                       timespec_cmp};

// int32 vtable

static void *int32_copy(void *valuep) {
  int32_t value = *(int32_t *)valuep;
  int32_t *new_value = gpr_malloc(sizeof(int32_t));
  *new_value = value;
  return new_value;
}

static int int32_cmp(void *v1, void *v2) {
  int32_t i1 = *(int32_t *)v1;
  int32_t i2 = *(int32_t *)v2;
  if (i1 < i2) return -1;
  if (i1 > i2) return 1;
  return 0;
}

static grpc_slice_hash_table_vtable int32_vtable = {free_mem, int32_copy,
                                                    int32_cmp};

struct grpc_method_config {
  grpc_slice_hash_table *table;
};

grpc_method_config *grpc_method_config_create(
    bool *wait_for_ready, gpr_timespec *timeout,
    int32_t *max_request_message_bytes, int32_t *max_response_message_bytes) {
  grpc_method_config *method_config = gpr_malloc(sizeof(grpc_method_config));
  memset(method_config, 0, sizeof(grpc_method_config));
  grpc_slice_hash_table_entry entries[4];
  size_t num_entries = 0;
  if (wait_for_ready != NULL) {
    entries[num_entries].key = GRPC_MDSTR_GRPC_DOT_WAIT_FOR_READY;
    entries[num_entries].value = wait_for_ready;
    entries[num_entries].vtable = &bool_vtable;
    ++num_entries;
  }
  if (timeout != NULL) {
    entries[num_entries].key = GRPC_MDSTR_GRPC_DOT_TIMEOUT;
    entries[num_entries].value = timeout;
    entries[num_entries].vtable = &timespec_vtable;
    ++num_entries;
  }
  if (max_request_message_bytes != NULL) {
    entries[num_entries].key = GRPC_MDSTR_GRPC_DOT_MAX_REQUEST_MESSAGE_BYTES;
    entries[num_entries].value = max_request_message_bytes;
    entries[num_entries].vtable = &int32_vtable;
    ++num_entries;
  }
  if (max_response_message_bytes != NULL) {
    entries[num_entries].key = GRPC_MDSTR_GRPC_DOT_MAX_RESPONSE_MESSAGE_BYTES;
    entries[num_entries].value = max_response_message_bytes;
    entries[num_entries].vtable = &int32_vtable;
    ++num_entries;
  }
  method_config->table = grpc_slice_hash_table_create(num_entries, entries);
  return method_config;
}

grpc_method_config *grpc_method_config_ref(grpc_method_config *method_config) {
  grpc_slice_hash_table_ref(method_config->table);
  return method_config;
}

void grpc_method_config_unref(grpc_exec_ctx *exec_ctx,
                              grpc_method_config *method_config) {
  if (grpc_slice_hash_table_unref(exec_ctx, method_config->table)) {
    gpr_free(method_config);
  }
}

int grpc_method_config_cmp(const grpc_method_config *method_config1,
                           const grpc_method_config *method_config2) {
  return grpc_slice_hash_table_cmp(method_config1->table,
                                   method_config2->table);
}

const bool *grpc_method_config_get_wait_for_ready(
    const grpc_method_config *method_config) {
  return grpc_slice_hash_table_get(method_config->table,
                                   GRPC_MDSTR_GRPC_DOT_WAIT_FOR_READY);
}

const gpr_timespec *grpc_method_config_get_timeout(
    const grpc_method_config *method_config) {
  return grpc_slice_hash_table_get(method_config->table,
                                   GRPC_MDSTR_GRPC_DOT_TIMEOUT);
}

const int32_t *grpc_method_config_get_max_request_message_bytes(
    const grpc_method_config *method_config) {
  return grpc_slice_hash_table_get(
      method_config->table, GRPC_MDSTR_GRPC_DOT_MAX_REQUEST_MESSAGE_BYTES);
}

const int32_t *grpc_method_config_get_max_response_message_bytes(
    const grpc_method_config *method_config) {
  return grpc_slice_hash_table_get(
      method_config->table, GRPC_MDSTR_GRPC_DOT_MAX_RESPONSE_MESSAGE_BYTES);
}

//
// grpc_method_config_table
//

static void method_config_unref(grpc_exec_ctx *exec_ctx, void *valuep) {
  grpc_method_config_unref(exec_ctx, valuep);
}

static void *method_config_ref(void *valuep) {
  return grpc_method_config_ref(valuep);
}

static int method_config_cmp(void *valuep1, void *valuep2) {
  return grpc_method_config_cmp(valuep1, valuep2);
}

static const grpc_slice_hash_table_vtable method_config_table_vtable = {
    method_config_unref, method_config_ref, method_config_cmp};

grpc_method_config_table *grpc_method_config_table_create(
    size_t num_entries, grpc_method_config_table_entry *entries) {
  grpc_slice_hash_table_entry *hash_table_entries =
      gpr_malloc(sizeof(grpc_slice_hash_table_entry) * num_entries);
  for (size_t i = 0; i < num_entries; ++i) {
    hash_table_entries[i].key = entries[i].method_name;
    hash_table_entries[i].value = entries[i].method_config;
    hash_table_entries[i].vtable = &method_config_table_vtable;
  }
  grpc_method_config_table *method_config_table =
      grpc_slice_hash_table_create(num_entries, hash_table_entries);
  gpr_free(hash_table_entries);
  return method_config_table;
}

grpc_method_config_table *grpc_method_config_table_ref(
    grpc_method_config_table *table) {
  return grpc_slice_hash_table_ref(table);
}

void grpc_method_config_table_unref(grpc_exec_ctx *exec_ctx,
                                    grpc_method_config_table *table) {
  grpc_slice_hash_table_unref(exec_ctx, table);
}

int grpc_method_config_table_cmp(const grpc_method_config_table *table1,
                                 const grpc_method_config_table *table2) {
  return grpc_slice_hash_table_cmp(table1, table2);
}

void *grpc_method_config_table_get(grpc_exec_ctx *exec_ctx,
                                   const grpc_slice_hash_table *table,
                                   const grpc_slice path) {
  void *value = grpc_slice_hash_table_get(table, path);
  // If we didn't find a match for the path, try looking for a wildcard
  // entry (i.e., change "/service/method" to "/service/*").
  if (value == NULL) {
    int sep_pos = grpc_slice_rchr(path, '/') + 1;
    grpc_slice search = grpc_slice_malloc((size_t)(sep_pos + 1));
    memcpy(GRPC_SLICE_START_PTR(search), GRPC_SLICE_START_PTR(path),
           (size_t)sep_pos);
    GRPC_SLICE_START_PTR(search)[sep_pos] = '*';
    value = grpc_slice_hash_table_get(table, search);
    grpc_slice_unref_internal(exec_ctx, search);
  }
  return value;
}

static void *copy_arg(void *p) { return grpc_method_config_table_ref(p); }

static void destroy_arg(grpc_exec_ctx *exec_ctx, void *p) {
  grpc_method_config_table_unref(exec_ctx, p);
}

static int cmp_arg(void *p1, void *p2) {
  return grpc_method_config_table_cmp(p1, p2);
}

static grpc_arg_pointer_vtable arg_vtable = {copy_arg, destroy_arg, cmp_arg};

grpc_arg grpc_method_config_table_create_channel_arg(
    grpc_method_config_table *table) {
  grpc_arg arg;
  arg.type = GRPC_ARG_POINTER;
  arg.key = GRPC_ARG_SERVICE_CONFIG;
  arg.value.pointer.p = table;
  arg.value.pointer.vtable = &arg_vtable;
  return arg;
}

// State used by convert_entry() below.
typedef struct conversion_state {
  void *(*convert_value)(const grpc_method_config *method_config);
  const grpc_slice_hash_table_vtable *vtable;
  size_t num_entries;
  grpc_slice_hash_table_entry *entries;
} conversion_state;

// A function to be passed to grpc_slice_hash_table_iterate() to create
// a copy of the entries.
static void convert_entry(const grpc_slice_hash_table_entry *entry,
                          void *user_data) {
  conversion_state *state = user_data;
  state->entries[state->num_entries].key = grpc_slice_ref_internal(entry->key);
  state->entries[state->num_entries].value = state->convert_value(entry->value);
  state->entries[state->num_entries].vtable = state->vtable;
  ++state->num_entries;
}

grpc_slice_hash_table *grpc_method_config_table_convert(
    grpc_exec_ctx *exec_ctx, const grpc_method_config_table *table,
    void *(*convert_value)(const grpc_method_config *method_config),
    const grpc_slice_hash_table_vtable *vtable) {
  // Create an array of the entries in the table with converted values.
  conversion_state state;
  state.convert_value = convert_value;
  state.vtable = vtable;
  state.num_entries = 0;
  state.entries = gpr_malloc(sizeof(grpc_slice_hash_table_entry) *
                             grpc_slice_hash_table_num_entries(table));
  grpc_slice_hash_table_iterate(table, convert_entry, &state);
  // Create a new table based on the array we just constructed.
  grpc_slice_hash_table *new_table =
      grpc_slice_hash_table_create(state.num_entries, state.entries);
  // Clean up the array.
  for (size_t i = 0; i < state.num_entries; ++i) {
    grpc_slice_unref_internal(exec_ctx, state.entries[i].key);
    vtable->destroy_value(exec_ctx, state.entries[i].value);
  }
  gpr_free(state.entries);
  // Return the new table.
  return new_table;
}