/*
 * alignment.h
 *
 *  Created on: May 23, 2013
 *      Author: lijunhui
 */

#ifndef ALIGNMENT_H_
#define ALIGNMENT_H_

#include <string>
#include <assert.h>
#include <stdio.h>
#include <string.h>

#include "stringlib.h"

/*
 * Note:
 *      m_vec_s_align.size() may not be equal to the length of source side
 *sentence
 *                           due to the last words may not be aligned
 *
 */
struct SAlignment {
  typedef std::vector<int> SingleAlign;
  SAlignment(const char* pszAlign) { fnInitializeAlignment(pszAlign); }
  ~SAlignment() {}

  bool fnIsAligned(int i, bool s) const {
    const std::vector<SingleAlign>* palign;
    if (s == true)
      palign = &m_vec_s_align;
    else
      palign = &m_vec_t_align;
    if ((*palign)[i].size() == 0) return false;
    return true;
  }

  /*
   * return true if [b, e] is aligned phrases on source side (if s==true) or on
   * the target side (if s==false);
   * return false, otherwise.
   */
  bool fnIsAlignedPhrase(int b, int e, bool s, int* pob, int* poe) const {
    int ob, oe;  //[b, e] on the other side
    if (s == true)
      fnGetLeftRightMost(b, e, m_vec_s_align, ob, oe);
    else
      fnGetLeftRightMost(b, e, m_vec_t_align, ob, oe);

    if (ob == -1) {
      if (pob != NULL) (*pob) = -1;
      if (poe != NULL) (*poe) = -1;
      return false;  // no aligned word among [b, e]
    }
    if (pob != NULL) (*pob) = ob;
    if (poe != NULL) (*poe) = oe;

    int bb, be;  //[b, e] back given [ob, oe] on the other side
    if (s == true)
      fnGetLeftRightMost(ob, oe, m_vec_t_align, bb, be);
    else
      fnGetLeftRightMost(ob, oe, m_vec_s_align, bb, be);

    if (bb < b || be > e) return false;
    return true;
  }

  bool fnIsAlignedTightPhrase(int b, int e, bool s, int* pob, int* poe) const {
    const std::vector<SingleAlign>* palign;
    if (s == true)
      palign = &m_vec_s_align;
    else
      palign = &m_vec_t_align;

    if ((*palign).size() <= e || (*palign)[b].size() == 0 ||
        (*palign)[e].size() == 0)
      return false;

    return fnIsAlignedPhrase(b, e, s, pob, poe);
  }

  void fnGetLeftRightMost(int b, int e, bool s, int& ob, int& oe) const {
    if (s == true)
      fnGetLeftRightMost(b, e, m_vec_s_align, ob, oe);
    else
      fnGetLeftRightMost(b, e, m_vec_t_align, ob, oe);
  }

  /*
   * look the translation of source[b, e] is continuous or not
   * 1) return "Unaligned": if the source[b, e] is translated silently;
   * 2) return "Con't": if none of target words in target[.., ..] is exclusively
   * aligned to any word outside source[b, e]
   * 3) return "Discon't": otherwise;
   */
  std::string fnIsContinuous(int b, int e) const {
    int ob, oe;
    fnGetLeftRightMost(b, e, true, ob, oe);
    if (ob == -1) return "Unaligned";

    for (int i = ob; i <= oe; i++) {
      if (!fnIsAligned(i, false)) continue;
      const SingleAlign& a = m_vec_t_align[i];
      int j;
      for (j = 0; j < a.size(); j++)
        if (a[j] >= b && a[j] <= e) break;
      if (j == a.size()) return "Discon't";
    }
    return "Con't";
  }

  const SingleAlign* fnGetSingleWordAlign(int i, bool s) const {
    if (s == true) {
      if (i >= m_vec_s_align.size()) return NULL;
      return &(m_vec_s_align[i]);
    } else {
      if (i >= m_vec_t_align.size()) return NULL;
      return &(m_vec_t_align[i]);
    }
  }

 private:
  void fnGetLeftRightMost(int b, int e, const std::vector<SingleAlign>& align,
                          int& ob, int& oe) const {
    ob = oe = -1;
    for (int i = b; i <= e && i < align.size(); i++) {
      if (align[i].size() > 0) {
        if (align[i][0] < ob || ob == -1) ob = align[i][0];
        if (oe < align[i][align[i].size() - 1])
          oe = align[i][align[i].size() - 1];
      }
    }
  }
  void fnInitializeAlignment(const char* pszAlign) {
    m_vec_s_align.clear();
    m_vec_t_align.clear();

    std::vector<std::string> terms = SplitOnWhitespace(std::string(pszAlign));
    int si, ti;
    for (size_t i = 0; i < terms.size(); i++) {
      sscanf(terms[i].c_str(), "%d-%d", &si, &ti);

      while (m_vec_s_align.size() <= si) {
        SingleAlign sa;
        m_vec_s_align.push_back(sa);
      }
      while (m_vec_t_align.size() <= ti) {
        SingleAlign sa;
        m_vec_t_align.push_back(sa);
      }

      m_vec_s_align[si].push_back(ti);
      m_vec_t_align[ti].push_back(si);
    }

    // sort
    for (size_t i = 0; i < m_vec_s_align.size(); i++) {
      std::sort(m_vec_s_align[i].begin(), m_vec_s_align[i].end());
    }
    for (size_t i = 0; i < m_vec_t_align.size(); i++) {
      std::sort(m_vec_t_align[i].begin(), m_vec_t_align[i].end());
    }
  }

 private:
  std::vector<SingleAlign> m_vec_s_align;  // source side words' alignment
  std::vector<SingleAlign> m_vec_t_align;  // target side words' alignment
};

struct SAlignmentReader {
  SAlignmentReader(const char* pszFname) {
    m_fpIn = fopen(pszFname, "r");
    assert(m_fpIn != NULL);
  }
  ~SAlignmentReader() {
    if (m_fpIn != NULL) fclose(m_fpIn);
  }
  SAlignment* fnReadNextAlignment() {
    if (feof(m_fpIn) == true) return NULL;
    char* pszLine = new char[100001];
    pszLine[0] = '\0';
    fgets(pszLine, 10001, m_fpIn);
    int iLen = strlen(pszLine);
    if (iLen == 0) return NULL;
    while (iLen > 0 && pszLine[iLen - 1] > 0 && pszLine[iLen - 1] < 33) {
      pszLine[iLen - 1] = '\0';
      iLen--;
    }
    SAlignment* pAlign = new SAlignment(pszLine);
    delete[] pszLine;
    return pAlign;
  }

 private:
  FILE* m_fpIn;
};

#endif /* ALIGNMENT_H_ */