// Copyright (c) 2015-present, Qihoo, Inc.  All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.

#include <sstream>
#include <algorithm>
#include "slash_string.h"
#include "nemo.h"
#include "pika_geo.h"
#include "pika_server.h"
#include "pika_slot.h"
#include "pika_geohash_helper.h"

extern PikaServer *g_pika_server;

void GeoAddCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoAdd);
    return;
  }
  size_t argc = argv.size();
  if ((argc - 2) % 3 != 0) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoAdd);
    return;
  }
  key_ = argv[1];
  pos_.clear();
  size_t index = 2;
  for (; index < argc; index += 3) {
    struct GeoPoint point;
    double longitude, latitude;
    if (!slash::string2d(argv[index].data(), argv[index].size(), &longitude)) {
      res_.SetRes(CmdRes::kInvalidFloat);
      return;
    }
    if (!slash::string2d(argv[index+1].data(), argv[index+1].size(), &latitude)) {
      res_.SetRes(CmdRes::kInvalidFloat);
      return;
    }
    point.member = argv[index+2];
    point.longitude = longitude;
    point.latitude = latitude;
    pos_.push_back(point);
  }
  return;
}

void GeoAddCmd::Do() {
  nemo::Status s;
  int64_t count = 0, ret;
  const std::shared_ptr<nemo::Nemo> db = g_pika_server->db();
  std::vector<GeoPoint>::const_iterator iter = pos_.begin();
  for (; iter != pos_.end(); iter++) {
    // Convert coordinates to geohash
    GeoHashBits hash;
    geohashEncodeWGS84(iter->longitude, iter->latitude, GEO_STEP_MAX, &hash);
    GeoHashFix52Bits bits = geohashAlign52Bits(hash);
    // Convert uint64 to double
    double score;
    std::string str_bits = std::to_string(bits);
    slash::string2d(str_bits.data(), str_bits.size(), &score);
    s = db->ZAdd(key_, score, iter->member, &ret); 
    if (s.ok()) {
      count += ret;
    } else {
      res_.SetRes(CmdRes::kErrOther, s.ToString());
      return;
    }
  }
  SlotKeyAdd("z", key_);
  res_.AppendInteger(count);
  return;
}

void GeoPosCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoPos);
    return;
  }
  key_ = argv[1];
  member_.clear();
  size_t pos = 2;
  while (pos < argv.size()) {
    member_.push_back(argv[pos++]);
  }
}

void GeoPosCmd::Do() {
  double score;
  res_.AppendArrayLen(member_.size());
  for (auto v : member_) {
    nemo::Status s = g_pika_server->db()->ZScore(key_, v, &score);
    if (s.ok()) {
      double xy[2];
      GeoHashBits hash = { .bits = (uint64_t)score, .step = GEO_STEP_MAX };
      geohashDecodeToLongLatWGS84(hash, xy);

      res_.AppendArrayLen(2);
      char longitude[32];
      int64_t len = slash::d2string(longitude, sizeof(longitude), xy[0]);
      res_.AppendStringLen(len);
      res_.AppendContent(longitude);

      char latitude[32];
      len = slash::d2string(latitude, sizeof(latitude), xy[1]);
      res_.AppendStringLen(len);
      res_.AppendContent(latitude);
    
    } else if (s.IsNotFound()) {
      res_.AppendStringLen(-1);
      continue;
    } else {
      res_.SetRes(CmdRes::kErrOther, s.ToString());
      continue;	
    }
  }
}

static double length_converter(double meters, const std::string & unit) {
  if (unit == "m") {
    return meters;
  } else if (unit == "km") {
    return meters / 1000;
  } else if (unit == "ft") {
    return meters / 0.3048;
  } else if (unit == "mi") {
    return meters / 1609.34;
  } else {
    return -1;
  }
}

static bool check_unit(const std::string & unit) {
  if (unit == "m" || unit == "km" || unit == "ft" || unit == "mi") {
    return true;
  } else {
    return false;
  }
}

void GeoDistCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoDist);
    return;
  }
  if (argv.size() < 4) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoDist);
    return;
  } else if (argv.size() > 5) {
    res_.SetRes(CmdRes::kSyntaxErr);
    return;
  }
  key_ = argv[1];
  first_pos_ = argv[2];
  second_pos_ = argv[3];
  if (argv.size() == 5) {
    unit_ = argv[4];
  } else {
    unit_ = "m";
  }
  if (!check_unit(unit_)) {
    res_.SetRes(CmdRes::kErrOther, "unsupported unit provided. please use m, km, ft, mi");
    return;
  }
}

void GeoDistCmd::Do() {
  double first_score, second_score, first_xy[2], second_xy[2];
  nemo::Status s = g_pika_server->db()->ZScore(key_, first_pos_, &first_score);
  if (s.ok()) {
    GeoHashBits hash = { .bits = (uint64_t)first_score, .step = GEO_STEP_MAX };
    geohashDecodeToLongLatWGS84(hash, first_xy);
  } else if (s.IsNotFound()) {
    res_.AppendStringLen(-1);
    return;
  } else {
    res_.SetRes(CmdRes::kErrOther, s.ToString());
    return;	
  }

  s = g_pika_server->db()->ZScore(key_, second_pos_, &second_score);
  if (s.ok()) {
    GeoHashBits hash = { .bits = (uint64_t)second_score, .step = GEO_STEP_MAX };
    geohashDecodeToLongLatWGS84(hash, second_xy);
  } else if (s.IsNotFound()) {
    res_.AppendStringLen(-1);
    return;
  } else {
    res_.SetRes(CmdRes::kErrOther, s.ToString());
    return;	
  }

  double distance = geohashGetDistance(first_xy[0], first_xy[1], second_xy[0], second_xy[1]);
  distance = length_converter(distance, unit_);
  char buf[32];
  int64_t len = slash::d2string(buf, sizeof(buf), distance);
  res_.AppendStringLen(len);
  res_.AppendContent(buf);
}

void GeoHashCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoHash);
    return;
  }
  key_ = argv[1];
  member_.clear();
  size_t pos = 2;
  while (pos < argv.size()) {
    member_.push_back(argv[pos++]);
  }
}

void GeoHashCmd::Do() {
  const char * geoalphabet= "0123456789bcdefghjkmnpqrstuvwxyz";
  res_.AppendArrayLen(member_.size());
  for (auto v : member_) {
    double score;
    nemo::Status s = g_pika_server->db()->ZScore(key_, v, &score);
    if (s.ok()) {
      double xy[2];
      GeoHashBits hash = { .bits = (uint64_t)score, .step = GEO_STEP_MAX };
      geohashDecodeToLongLatWGS84(hash, xy);
      GeoHashRange r[2];
      GeoHashBits encode_hash;
      r[0].min = -180;
      r[0].max = 180;
      r[1].min = -90;
      r[1].max = 90;
      geohashEncode(&r[0], &r[1], xy[0], xy[1], 26, &encode_hash);

      char buf[12];
      int i;
      for (i = 0; i < 11; i++) {
      	int idx = (encode_hash.bits >> (52-((i+1)*5))) & 0x1f;
        buf[i] = geoalphabet[idx];
      }
      buf[11] = '\0';
      res_.AppendStringLen(11);
      res_.AppendContent(buf);
      continue;
    } else if (s.IsNotFound()) {
      res_.AppendStringLen(-1);
      continue;
    } else {
      res_.SetRes(CmdRes::kErrOther, s.ToString());
      continue;	
    }
  }
}

static bool sort_distance_asc(const NeighborPoint & pos1, const NeighborPoint & pos2) {
  return pos1.distance < pos2.distance;
}

static bool sort_distance_desc(const NeighborPoint & pos1, const NeighborPoint & pos2) {
  return pos1.distance > pos2.distance;
}

static void GetAllNeighbors(std::string & key, GeoRange & range, CmdRes & res) {
  nemo::Status s;
  double longitude = range.longitude, latitude = range.latitude, distance = range.distance;
  int count_limit = 0;
  // Convert other units to meters
  if (range.unit == "m") {
    distance = distance;
  } else if (range.unit == "km") {
    distance = distance * 1000;
  } else if (range.unit == "ft") {
    distance = distance * 0.3048;
  } else if (range.unit == "mi") {
    distance = distance * 1609.34;
  } else {
    distance = -1;
  }
  // Search the zset for all matching points
  GeoHashRadius georadius = geohashGetAreasByRadiusWGS84(longitude, latitude, distance);
  GeoHashBits neighbors[9];
  neighbors[0] = georadius.hash;
  neighbors[1] = georadius.neighbors.north;
  neighbors[2] = georadius.neighbors.south;
  neighbors[3] = georadius.neighbors.east;
  neighbors[4] = georadius.neighbors.west;
  neighbors[5] = georadius.neighbors.north_east;
  neighbors[6] = georadius.neighbors.north_west;
  neighbors[7] = georadius.neighbors.south_east;
  neighbors[8] = georadius.neighbors.south_west;

  // For each neighbor, get all the matching
  // members and add them to the potential result list.
  std::vector<NeighborPoint> result;
  for (size_t i = 0; i < sizeof(neighbors) / sizeof(*neighbors); i++) {
    GeoHashFix52Bits min, max;
    if (HASHISZERO(neighbors[i]))
      continue;
    min = geohashAlign52Bits(neighbors[i]);
    neighbors[i].bits++;
    max = geohashAlign52Bits(neighbors[i]);

    std::vector<nemo::SM> sm_v;
    s = g_pika_server->db()->ZRangebyscore(key, (double)min, (double)max, sm_v, false, false);
    if (!s.ok()) {
      res.SetRes(CmdRes::kErrOther, s.ToString());
      return;
    }
    // Insert into result only if the point is within the search area.
    for (size_t i = 0; i < sm_v.size(); ++i) {
      double xy[2], real_distance;
      GeoHashBits hash = { .bits = (uint64_t)sm_v[i].score, .step = GEO_STEP_MAX };
      geohashDecodeToLongLatWGS84(hash, xy);
      if(geohashGetDistanceIfInRadiusWGS84(longitude, latitude, xy[0], xy[1], distance, &real_distance)) {
        NeighborPoint item;
        item.member = sm_v[i].member;
        item.score = sm_v[i].score;
        item.distance = real_distance;
        result.push_back(item);
      }
    }
  }
  // If using the count opiton
  if (range.count) {
    count_limit = range.count_limit;
  } else {
    count_limit = result.size();
  }
  // If using sort option
  if (range.sort == Asc) {
    std::sort(result.begin(), result.end(), sort_distance_asc);
  } else if(range.sort == Desc) {
    std::sort(result.begin(), result.end(), sort_distance_desc);
  }
  // For each the result
  res.AppendArrayLen(count_limit);
  for (int i = 0; i < count_limit; ++i) {
    if (range.option_num != 0) {
      res.AppendArrayLen(range.option_num+1);
    }
    // Member
    res.AppendStringLen(result[i].member.size());
    res.AppendContent(result[i].member);
    
    // If using withdist option
    if (range.withdist) {  
      double xy[2];
      GeoHashBits hash = { .bits = (uint64_t)result[i].score, .step = GEO_STEP_MAX };
      geohashDecodeToLongLatWGS84(hash, xy);
      double distance = geohashGetDistance(longitude, latitude, xy[0], xy[1]);
      distance = length_converter(distance, range.unit);
      char buf[32];
      int64_t len = slash::d2string(buf, sizeof(buf), distance);
      res.AppendStringLen(len);
      res.AppendContent(buf);
    }
    // If using withcoord option
    if (range.withcoord) {
      res.AppendArrayLen(2);  
      double xy[2];
      GeoHashBits hash = { .bits = (uint64_t)result[i].score, .step = GEO_STEP_MAX };
      geohashDecodeToLongLatWGS84(hash, xy);

      char longitude[32];
      int64_t len = slash::d2string(longitude, sizeof(longitude), xy[0]);
      res.AppendStringLen(len);
      res.AppendContent(longitude);

      char latitude[32];
      len = slash::d2string(latitude, sizeof(latitude), xy[1]);
      res.AppendStringLen(len);
      res.AppendContent(latitude);
    }
    // If using withhash option
    if (range.withhash) {
      char buf[32];
      int64_t len = slash::d2string(buf, sizeof(buf), result[i].score);
      res.AppendStringLen(len);
      res.AppendContent(buf);
    }
  }
}

void GeoRadiusCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoRadius);
    return;
  }
  key_ = argv[1];
  slash::string2d(argv[2].data(), argv[2].size(), &range_.longitude);
  slash::string2d(argv[3].data(), argv[3].size(), &range_.latitude);
  slash::string2d(argv[4].data(), argv[4].size(), &range_.distance);
  range_.unit = argv[5];
  if (!check_unit(range_.unit)) {
    res_.SetRes(CmdRes::kErrOther, "unsupported unit provided. please use m, km, ft, mi");
    return;
  }
  size_t pos = 6;
  while (pos < argv.size()) {
    if (!strcasecmp(argv[pos].c_str(), "withdist")) {
      range_.withdist = true;
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "withhash")) {
      range_.withhash = true;	
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "withcoord")) {
      range_.withcoord = true;	
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "count")) {
      range_.count = true; 
      range_.count_limit = std::stoi(argv[++pos]);
    } else if (!strcasecmp(argv[pos].c_str(), "asc")) {
      range_.sort = Asc;	
    } else if (!strcasecmp(argv[pos].c_str(), "desc")) {
      range_.sort = Desc;	
    } else {
      res_.SetRes(CmdRes::kSyntaxErr);
      return;
    }
    pos++;
  }
}

void GeoRadiusCmd::Do() {
  GetAllNeighbors(key_, range_, this->res_);
}

void GeoRadiusByMemberCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  if (!ptr_info->CheckArg(argv.size())) {
    res_.SetRes(CmdRes::kWrongNum, kCmdNameGeoRadius);
    return;
  }
  key_ = argv[1];
  range_.member = argv[2];
  slash::string2d(argv[3].data(), argv[3].size(), &range_.distance);
  range_.unit = argv[4];
  if (!check_unit(range_.unit)) {
    res_.SetRes(CmdRes::kErrOther, "unsupported unit provided. please use m, km, ft, mi");
    return;
  }
  size_t pos = 5;
  while (pos < argv.size()) {
    if (!strcasecmp(argv[pos].c_str(), "withdist")) {
      range_.withdist = true;
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "withhash")) {
      range_.withhash = true; 
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "withcoord")) {
      range_.withcoord = true;  
      range_.option_num++;
    } else if (!strcasecmp(argv[pos].c_str(), "count")) {
      range_.count = true; 
      range_.count_limit = std::stoi(argv[++pos]);
    } else if (!strcasecmp(argv[pos].c_str(), "asc")) {
      range_.sort = Asc;  
    } else if (!strcasecmp(argv[pos].c_str(), "desc")) {
      range_.sort = Desc; 
    } else {
      res_.SetRes(CmdRes::kSyntaxErr);
      return;
    }
    pos++;
  }
}

void GeoRadiusByMemberCmd::Do() {
  nemo::Status s;
  double score;
  s = g_pika_server->db()->ZScore(key_, range_.member, &score);
  if (s.ok()) {
    double xy[2];
    GeoHashBits hash = { .bits = (uint64_t)score, .step = GEO_STEP_MAX };
    geohashDecodeToLongLatWGS84(hash, xy);
    range_.longitude = xy[0];
    range_.latitude = xy[1];
  }
  GetAllNeighbors(key_, range_, this->res_);
}