#ifndef VIENNA_RNA_PACKAGE_INTERIOR_LOOPS_H
#define VIENNA_RNA_PACKAGE_INTERIOR_LOOPS_H

#include <ViennaRNA/utils.h>
#include "ViennaRNA/energy_par.h"
#include <ViennaRNA/data_structures.h>
#include <ViennaRNA/params.h>
#include <ViennaRNA/constraints.h>

#ifdef __GNUC__
# define INLINE inline
#else
# define INLINE
#endif

#ifdef ON_SAME_STRAND
#undef ON_SAME_STRAND
#endif

#define ON_SAME_STRAND(I, J, C)  (((I) >= (C)) || ((J) < (C)))

/**
 *  @file     interior_loops.h
 *  @ingroup  loops
 *  @brief    Energy evaluation of interior loops for MFE and partition function calculations
 */

/**
 *  @addtogroup   loops
 *  @{
 */

/**
 *  <H2>Compute the Energy of an interior-loop</H2>
 *  This function computes the free energy @f$\Delta G@f$ of an interior-loop with the
 *  following structure: <BR>
 *  <PRE>
 *        3'  5'
 *        |   |
 *        U - V
 *    a_n       b_1
 *     .        .
 *     .        .
 *     .        .
 *    a_1       b_m
 *        X - Y
 *        |   |
 *        5'  3'
 *  </PRE>
 *  This general structure depicts an interior-loop that is closed by the base pair (X,Y).
 *  The enclosed base pair is (V,U) which leaves the unpaired bases a_1-a_n and b_1-b_n
 *  that constitute the loop. In this example, the length of the interior-loop is @f$(n+m)@f$
 *  where n or m may be 0 resulting in a bulge-loop or base pair stack.
 *  The mismatching nucleotides for the closing pair (X,Y) are:<BR>
 *  5'-mismatch: a_1<BR>
 *  3'-mismatch: b_m<BR>
 *  and for the enclosed base pair (V,U):<BR>
 *  5'-mismatch: b_1<BR>
 *  3'-mismatch: a_n<BR>
 *  @note Base pairs are always denoted in 5'->3' direction. Thus the enclosed base pair
 *  must be 'turned arround' when evaluating the free energy of the interior-loop
 *  @see scale_parameters()
 *  @see vrna_param_t
 *  @note This function is threadsafe
 *
 *  @param  n1      The size of the 'left'-loop (number of unpaired nucleotides)
 *  @param  n2      The size of the 'right'-loop (number of unpaired nucleotides)
 *  @param  type    The pair type of the base pair closing the interior loop
 *  @param  type_2  The pair type of the enclosed base pair
 *  @param  si1     The 5'-mismatching nucleotide of the closing pair
 *  @param  sj1     The 3'-mismatching nucleotide of the closing pair
 *  @param  sp1     The 3'-mismatching nucleotide of the enclosed pair
 *  @param  sq1     The 5'-mismatching nucleotide of the enclosed pair
 *  @param  P       The datastructure containing scaled energy parameters
 *  @return The Free energy of the Interior-loop in dcal/mol
 */
PRIVATE INLINE int E_IntLoop(int          n1,
                             int          n2,
                             int          type,
                             int          type_2,
                             int          si1,
                             int          sj1,
                             int          sp1,
                             int          sq1,
                             vrna_param_t *P);


/**
 *  <H2>Compute Boltzmann weight @f$e^{-\Delta G/kT} @f$ of interior loop</H2>
 *  multiply by scale[u1+u2+2] for scaling
 *  @see get_scaled_pf_parameters()
 *  @see vrna_exp_param_t
 *  @see E_IntLoop()
 *  @note This function is threadsafe
 *
 *  @param  u1      The size of the 'left'-loop (number of unpaired nucleotides)
 *  @param  u2      The size of the 'right'-loop (number of unpaired nucleotides)
 *  @param  type    The pair type of the base pair closing the interior loop
 *  @param  type2   The pair type of the enclosed base pair
 *  @param  si1     The 5'-mismatching nucleotide of the closing pair
 *  @param  sj1     The 3'-mismatching nucleotide of the closing pair
 *  @param  sp1     The 3'-mismatching nucleotide of the enclosed pair
 *  @param  sq1     The 5'-mismatching nucleotide of the enclosed pair
 *  @param  P       The datastructure containing scaled Boltzmann weights of the energy parameters
 *  @return The Boltzmann weight of the Interior-loop
 */
PRIVATE INLINE FLT_OR_DBL exp_E_IntLoop(int               u1,
                                        int               u2,
                                        int               type,
                                        int               type2,
                                        short             si1,
                                        short             sj1,
                                        short             sp1,
                                        short             sq1,
                                        vrna_exp_param_t  *P);


PRIVATE INLINE int E_IntLoop_Co(int           type,
                                int           type_2,
                                int           i,
                                int           j,
                                int           p,
                                int           q,
                                int           cutpoint,
                                short         si1,
                                short         sj1,
                                short         sp1,
                                short         sq1,
                                int           dangles,
                                vrna_param_t  *P);


/*
 #################################
 # BEGIN OF FUNCTION DEFINITIONS #
 #################################
 */

/*
 *  ugly but fast interior loop evaluation
 *
 *  Avoid including this function in your own code. It only serves
 *  as a fast inline block internally re-used throughout the RNAlib. It
 *  evalutes the free energy of interior loops in single sequences or sequence
 *  hybrids. Soft constraints are also applied if available.
 *
 *  NOTE: do not include into doxygen reference manual!
 */
PRIVATE INLINE int
ubf_eval_int_loop(int           i,
                  int           j,
                  int           p,
                  int           q,
                  int           i1,
                  int           j1,
                  int           p1,
                  int           q1,
                  short         si,
                  short         sj,
                  short         sp,
                  short         sq,
                  unsigned char type,
                  unsigned char type_2,
                  int           *rtype,
                  int           ij,
                  int           cp,
                  vrna_param_t  *P,
                  vrna_sc_t     *sc)
{
  int energy, u1, u2;

  u1  = p1 - i;
  u2  = j1 - q;

  if ((cp < 0) || (ON_SAME_STRAND(i, p, cp) && ON_SAME_STRAND(q, j, cp))) {
    /* regular interior loop */
    energy = E_IntLoop(u1, u2, type, type_2, si, sj, sp, sq, P);
  } else {
    /* interior loop like cofold structure */
    short Si, Sj;
    Si      = ON_SAME_STRAND(i, i1, cp) ? si : -1;
    Sj      = ON_SAME_STRAND(j1, j, cp) ? sj : -1;
    energy  = E_IntLoop_Co(rtype[type], rtype[type_2],
                           i, j, p, q,
                           cp,
                           Si, Sj,
                           sp, sq,
                           P->model_details.dangles,
                           P);
  }

  /* add soft constraints */
  if (sc) {
    if (sc->energy_up)
      energy += sc->energy_up[i1][u1]
                + sc->energy_up[q1][u2];

    if (sc->energy_bp)
      energy += sc->energy_bp[ij];

    if (sc->energy_stack)
      if (u1 + u2 == 0) {
        int a = sc->energy_stack[i]
                + sc->energy_stack[p]
                + sc->energy_stack[q]
                + sc->energy_stack[j];
        energy += a;
      }

    if (sc->f)
      energy += sc->f(i, j, p, q, VRNA_DECOMP_PAIR_IL, sc->data);
  }

  return energy;
}


PRIVATE INLINE int
ubf_eval_int_loop2(int            i,
                   int            j,
                   int            p,
                   int            q,
                   int            i1,
                   int            j1,
                   int            p1,
                   int            q1,
                   short          si,
                   short          sj,
                   short          sp,
                   short          sq,
                   unsigned char  type,
                   unsigned char  type_2,
                   int            *rtype,
                   int            ij,
                   unsigned int   *sn,
                   unsigned int   *ss,
                   vrna_param_t   *P,
                   vrna_sc_t      *sc)
{
  int energy, u1, u2;

  u1  = p1 - i;
  u2  = j1 - q;

  if ((sn[i] == sn[p]) && (sn[q] == sn[j])) {
    /* regular interior loop */
    energy = E_IntLoop(u1, u2, type, type_2, si, sj, sp, sq, P);
  } else {
    /* interior loop like cofold structure */
    short Si, Sj;
    Si      = (sn[i1] == sn[i]) ? si : -1;
    Sj      = (sn[j] == sn[j1]) ? sj : -1;
    energy  = E_IntLoop_Co(rtype[type], rtype[type_2],
                           i, j, p, q,
                           ss[1],
                           Si, Sj,
                           sp, sq,
                           P->model_details.dangles,
                           P);
  }

  /* add soft constraints */
  if (sc) {
    if (sc->energy_up)
      energy += sc->energy_up[i1][u1]
                + sc->energy_up[q1][u2];

    if (sc->energy_bp)
      energy += sc->energy_bp[ij];

    if (sc->energy_stack)
      if (u1 + u2 == 0) {
        int a = sc->energy_stack[i]
                + sc->energy_stack[p]
                + sc->energy_stack[q]
                + sc->energy_stack[j];
        energy += a;
      }

    if (sc->f)
      energy += sc->f(i, j, p, q, VRNA_DECOMP_PAIR_IL, sc->data);
  }

  return energy;
}


/*
 *  ugly but fast exterior interior loop evaluation
 *
 *  Avoid including this function in your own code. It only serves
 *  as a fast inline block internally re-used throughout the RNAlib. It
 *  evalutes the free energy of interior loops in single sequences or sequence
 *  hybrids. Soft constraints are also applied if available.
 *
 *  NOTE: do not include into doxygen reference manual!
 */
PRIVATE INLINE int
ubf_eval_ext_int_loop(int           i,
                      int           j,
                      int           p,
                      int           q,
                      int           i1,
                      int           j1,
                      int           p1,
                      int           q1,
                      short         si,
                      short         sj,
                      short         sp,
                      short         sq,
                      unsigned char type,
                      unsigned char type_2,
                      int           length,
                      vrna_param_t  *P,
                      vrna_sc_t     *sc)
{
  int energy, u1, u2, u3;

  u1  = i1;
  u2  = p1 - j;
  u3  = length - q;

  energy = E_IntLoop(u2, u1 + u3, type, type_2, si, sj, sp, sq, P);

  /* add soft constraints */
  if (sc) {
    if (sc->energy_up) {
      energy += sc->energy_up[j1][u2]
                + ((u3 > 0) ? sc->energy_up[q1][u3] : 0)
                + ((u1 > 0) ? sc->energy_up[1][u1] : 0);
    }

    if (sc->energy_stack)
      if (u1 + u2 + u3 == 0)
        energy += sc->energy_stack[i]
                  + sc->energy_stack[p]
                  + sc->energy_stack[q]
                  + sc->energy_stack[j];

    if (sc->f)
      energy += sc->f(i, j, p, q, VRNA_DECOMP_PAIR_IL, sc->data);
  }

  return energy;
}


PRIVATE INLINE int
E_IntLoop(int           n1,
          int           n2,
          int           type,
          int           type_2,
          int           si1,
          int           sj1,
          int           sp1,
          int           sq1,
          vrna_param_t  *P)
{
  /* compute energy of degree 2 loop (stack bulge or interior) */
  int nl, ns, u, energy;

  energy = INF;

  if (n1 > n2) {
    nl  = n1;
    ns  = n2;
  } else {
    nl  = n2;
    ns  = n1;
  }

  if (nl == 0)
    return P->stack[type][type_2];  /* stack */

  if (ns == 0) {
    /* bulge */
    energy = (nl <= MAXLOOP) ? P->bulge[nl] :
             (P->bulge[30] + (int)(P->lxc * log(nl / 30.)));
    if (nl == 1) {
      energy += P->stack[type][type_2];
    } else {
      if (type > 2)
        energy += P->TerminalAU;

      if (type_2 > 2)
        energy += P->TerminalAU;
    }

    return energy;
  } else {
    /* interior loop */
    if (ns == 1) {
      if (nl == 1)                    /* 1x1 loop */
        return P->int11[type][type_2][si1][sj1];

      if (nl == 2) {
        /* 2x1 loop */
        if (n1 == 1)
          energy = P->int21[type][type_2][si1][sq1][sj1];
        else
          energy = P->int21[type_2][type][sq1][si1][sp1];

        return energy;
      } else {
        /* 1xn loop */
        energy =
          (nl + 1 <=
           MAXLOOP) ? (P->internal_loop[nl + 1]) : (P->internal_loop[30] +
                                                    (int)(P->lxc * log((nl + 1) / 30.)));
        energy  += MIN2(MAX_NINIO, (nl - ns) * P->ninio[2]);
        energy  += P->mismatch1nI[type][si1][sj1] + P->mismatch1nI[type_2][sq1][sp1];
        return energy;
      }
    } else if (ns == 2) {
      if (nl == 2) {
        /* 2x2 loop */
        return P->int22[type][type_2][si1][sp1][sq1][sj1];
      } else if (nl == 3) {
        /* 2x3 loop */
        energy  = P->internal_loop[5] + P->ninio[2];
        energy  += P->mismatch23I[type][si1][sj1] + P->mismatch23I[type_2][sq1][sp1];
        return energy;
      }
    }

    {
      /* generic interior loop (no else here!)*/
      u       = nl + ns;
      energy  =
        (u <=
         MAXLOOP) ? (P->internal_loop[u]) : (P->internal_loop[30] + (int)(P->lxc * log((u) / 30.)));

      energy += MIN2(MAX_NINIO, (nl - ns) * P->ninio[2]);

      energy += P->mismatchI[type][si1][sj1] + P->mismatchI[type_2][sq1][sp1];
    }
  }

  return energy;
}


PRIVATE INLINE FLT_OR_DBL
exp_E_IntLoop(int               u1,
              int               u2,
              int               type,
              int               type2,
              short             si1,
              short             sj1,
              short             sp1,
              short             sq1,
              vrna_exp_param_t  *P)
{
  int     ul, us, no_close = 0;
  double  z           = 0.;
  int     noGUclosure = P->model_details.noGUclosure;

  if ((noGUclosure) && ((type2 == 3) || (type2 == 4) || (type == 3) || (type == 4)))
    no_close = 1;

  if (u1 > u2) {
    ul  = u1;
    us  = u2;
  } else {
    ul  = u2;
    us  = u1;
  }

  if (ul == 0) {
    /* stack */
    z = P->expstack[type][type2];
  } else if (!no_close) {
    if (us == 0) {
      /* bulge */
      z = P->expbulge[ul];
      if (ul == 1) {
        z *= P->expstack[type][type2];
      } else {
        if (type > 2)
          z *= P->expTermAU;

        if (type2 > 2)
          z *= P->expTermAU;
      }

      return (FLT_OR_DBL)z;
    } else if (us == 1) {
      if (ul == 1)                     /* 1x1 loop */
        return (FLT_OR_DBL)(P->expint11[type][type2][si1][sj1]);

      if (ul == 2) {
        /* 2x1 loop */
        if (u1 == 1)
          return (FLT_OR_DBL)(P->expint21[type][type2][si1][sq1][sj1]);
        else
          return (FLT_OR_DBL)(P->expint21[type2][type][sq1][si1][sp1]);
      } else {
        /* 1xn loop */
        z = P->expinternal[ul + us] * P->expmismatch1nI[type][si1][sj1] *
            P->expmismatch1nI[type2][sq1][sp1];
        return (FLT_OR_DBL)(z * P->expninio[2][ul - us]);
      }
    } else if (us == 2) {
      if (ul == 2) {
        /* 2x2 loop */
        return (FLT_OR_DBL)(P->expint22[type][type2][si1][sp1][sq1][sj1]);
      } else if (ul == 3) {
        /* 2x3 loop */
        z = P->expinternal[5] * P->expmismatch23I[type][si1][sj1] *
            P->expmismatch23I[type2][sq1][sp1];
        return (FLT_OR_DBL)(z * P->expninio[2][1]);
      }
    }

    /* generic interior loop (no else here!)*/
    z = P->expinternal[ul + us] * P->expmismatchI[type][si1][sj1] *
        P->expmismatchI[type2][sq1][sp1];
    return (FLT_OR_DBL)(z * P->expninio[2][ul - us]);
  }

  return (FLT_OR_DBL)z;
}


PRIVATE INLINE int
E_IntLoop_Co(int          type,
             int          type_2,
             int          i,
             int          j,
             int          p,
             int          q,
             int          cutpoint,
             short        si1,
             short        sj1,
             short        sp1,
             short        sq1,
             int          dangles,
             vrna_param_t *P)
{
  int energy, ci, cj, cp, cq, d3, d5, d5_2, d3_2, tmm, tmm_2;

  energy = 0;
  if (type > 2)
    energy += P->TerminalAU;

  if (type_2 > 2)
    energy += P->TerminalAU;

  if (!dangles)
    return energy;

  ci  = ON_SAME_STRAND(i, i + 1, cutpoint);
  cj  = ON_SAME_STRAND(j - 1, j, cutpoint);
  cp  = ON_SAME_STRAND(p - 1, p, cutpoint);
  cq  = ON_SAME_STRAND(q, q + 1, cutpoint);

  d3    = ci  ? P->dangle3[type][si1]   : 0;
  d5    = cj  ? P->dangle5[type][sj1]   : 0;
  d5_2  = cp  ? P->dangle5[type_2][sp1] : 0;
  d3_2  = cq  ? P->dangle3[type_2][sq1] : 0;

  tmm   = (cj && ci) ? P->mismatchExt[type][sj1][si1]   : d5 + d3;
  tmm_2 = (cp && cq) ? P->mismatchExt[type_2][sp1][sq1] : d5_2 + d3_2;

  if (dangles == 2)
    return energy + tmm + tmm_2;

  /* now we may have non-double dangles only */
  if (i + 2 < p) {
    if (q + 2 < j)
      energy += tmm + tmm_2;
    else if (q + 2 == j)
      energy += (cj && cq) ? MIN2(tmm + d5_2, tmm_2 + d3) : tmm + tmm_2;
    else
      energy += d3 + d5_2;
  } else if (i + 2 == p) {
    if (q + 2 < j)
      energy += (ci && cp) ? MIN2(tmm + d3_2, tmm_2 + d5) : tmm + tmm_2;
    else if (q + 2 == j)
      energy += MIN2(tmm, MIN2(tmm_2, MIN2(d5 + d5_2, d3 + d3_2)));
    else
      energy += MIN2(d3, d5_2);
  } else {
    if (q + 2 < j)
      energy += d5 + d3_2;
    else if (q + 2 == j)
      energy += MIN2(d5, d3_2);
  }

  return energy;
}


int
vrna_E_int_loop(vrna_fold_compound_t  *vc,
                int                   i,
                int                   j);


/**
 *  @brief Evaluate the free energy contribution of an interior loop with delimiting
 *  base pairs @f$(i,j)@f$ and @f$(k,l)@f$
 *
 *  @note This function is polymorphic, i.e. it accepts #vrna_fold_compound_t of type
 *        #VRNA_FC_TYPE_SINGLE as well as #VRNA_FC_TYPE_COMPARATIVE
 */
int
vrna_eval_int_loop(vrna_fold_compound_t *vc,
                   int                  i,
                   int                  j,
                   int                  k,
                   int                  l);


/* j < i indicates circular folding, i.e. collect contributions for exterior int loops */
FLT_OR_DBL
vrna_exp_E_int_loop(vrna_fold_compound_t  *vc,
                    int                   i,
                    int                   j);


FLT_OR_DBL
vrna_exp_E_interior_loop(vrna_fold_compound_t *vc,
                         int                  i,
                         int                  j,
                         int                  k,
                         int                  l);


int
vrna_E_ext_int_loop(vrna_fold_compound_t  *vc,
                    int                   i,
                    int                   j,
                    int                   *ip,
                    int                   *iq);


int
vrna_E_stack(vrna_fold_compound_t *vc,
             int                  i,
             int                  j);


/**
 *  @brief Backtrack a stacked pair closed by @f$ (i,j) @f$
 *
 */
int
vrna_BT_stack(vrna_fold_compound_t  *vc,
              int                   *i,
              int                   *j,
              int                   *en,
              vrna_bp_stack_t       *bp_stack,
              int                   *stack_count);


/**
 *  @brief Backtrack an interior loop closed by @f$ (i,j) @f$
 *
 */
int
vrna_BT_int_loop(vrna_fold_compound_t *vc,
                 int                  *i,
                 int                  *j,
                 int                  en,
                 vrna_bp_stack_t      *bp_stack,
                 int                  *stack_count);


/**
 * @}
 */


#endif
