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#include "rewriter/version_rewriter.h"

#include <algorithm>
#include <map>
#include <string>
#include <vector>

#include "base/const.h"
#include "base/logging.h"
#include "base/singleton.h"
#include "base/version.h"
#include "converter/conversion_request.h"
#include "converter/segments.h"
#include "session/commands.pb.h"

namespace mozc {
namespace {

class VersionDataImpl {
 public:
  struct VersionEntry {
    string base_candidate_;
    string output_;
    size_t rank_;
    VersionEntry(const string& base_candidate,
                 const string& output,
                 size_t rank)
        : base_candidate_(base_candidate),
          output_(output), rank_(rank) {}
  };

  const VersionEntry *Lookup(const string &key) const {
    map<string, VersionEntry *>::const_iterator it = entries_.find(key);
    if (it == entries_.end()) {
      return NULL;
    }
    return it->second;
  }

  VersionDataImpl() {
    static const struct {
      const char *key;
      const char *base_candidate;
    } kKeyCandList[] = {
      {
        // "う゛ぁーじょん"
        "\xe3\x81\x86\xe3\x82\x9b\xe3\x81\x81\xe3\x83\xbc"
        "\xe3\x81\x98\xe3\x82\x87\xe3\x82\x93",
        // "ヴァージョン"
        "\xe3\x83\xb4\xe3\x82\xa1\xe3\x83\xbc"
        "\xe3\x82\xb8\xe3\x83\xa7\xe3\x83\xb3",
      }, {
        // "ゔぁーじょん"
        "\xe3\x82\x94\xe3\x81\x81\xe3\x83\xbc"
        "\xe3\x81\x98\xe3\x82\x87\xe3\x82\x93",
        // "ヴァージョン"
        "\xe3\x83\xb4\xe3\x82\xa1\xe3\x83\xbc"
        "\xe3\x82\xb8\xe3\x83\xa7\xe3\x83\xb3",
      }, {
        // "ばーじょん"
        "\xe3\x81\xb0\xe3\x83\xbc\xe3\x81\x98"
        "\xe3\x82\x87\xe3\x82\x93",
        // "バージョン"
        "\xe3\x83\x90\xe3\x83\xbc\xe3\x82\xb8"
        "\xe3\x83\xa7\xe3\x83\xb3",
      },
    };

    const string &version_string =
        kVersionRewriterVersionPrefix + Version::GetMozcVersion();
    for (int i = 0; i < arraysize(kKeyCandList); ++i) {
      entries_[kKeyCandList[i].key] =
          new VersionEntry(kKeyCandList[i].base_candidate,
                           version_string, 9);
    }
  }

  ~VersionDataImpl() {
    for (map<string, VersionEntry *>::iterator it = entries_.begin();
         it != entries_.end();
         ++it) {
      delete it->second;
    }
    entries_.clear();
  }

 private:
  map<string, VersionEntry *> entries_;
};
}  // namespace

VersionRewriter::VersionRewriter() {}

VersionRewriter::~VersionRewriter() {}

int VersionRewriter::capability(const ConversionRequest &request) const {
  if (request.request().mixed_conversion()) {
    return RewriterInterface::ALL;
  }
  return RewriterInterface::CONVERSION;
}

bool VersionRewriter::Rewrite(const ConversionRequest &request,
                              Segments *segments) const {
  bool result = false;
  for (size_t i = segments->history_segments_size();
       i < segments->segments_size(); ++i) {
    Segment* seg = segments->mutable_segment(i);
    DCHECK(seg);
    const VersionDataImpl::VersionEntry *ent
        = Singleton<VersionDataImpl>::get()->Lookup(seg->key());
    if (ent != NULL) {
      for (size_t j = 0; j < seg->candidates_size(); ++j) {
        const Segment::Candidate& c = seg->candidate(static_cast<int>(j));
        if (c.value == ent->base_candidate_) {
          Segment::Candidate* new_cand =
              seg->insert_candidate(static_cast<int>(
                  min(seg->candidates_size(),
                      ent->rank_)));
          if (new_cand != NULL) {
            new_cand->lid = c.lid;
            new_cand->rid = c.rid;
            new_cand->cost = c.cost;
            new_cand->value = ent->output_;
            new_cand->content_value = ent->output_;
            new_cand->key = seg->key();
            new_cand->content_key = seg->key();
            // we don't learn version
            new_cand->attributes |= Segment::Candidate::NO_LEARNING;
            result = true;
          }
          break;
        }
      }
    }
  }
  return result;
}
}  // namespace mozc