#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "ss.h"
#include "parse.h"

/* allocate new node, exit if malloc fails */

static Node *new_node( void)
{
  Node *e = malloc( sizeof( Node) );

  if( e == NULL)
  {
    yyerror( "new_node: malloc failed");
    exit(1);
  }

  e->next = NULL; /* next only used in expr_list */

  return e;
}

static void lval_type_error( int type)
{
  char msg[100];
  sprintf( msg, "lval type %d is not a cell or symbol", type);
  yyerror( msg);
}

/* adding new nodes */

Node *add_func( int op, Expr_list *r, Expr_list *e)
{
  int acount, rcount;
  Node *n = new_node();

  n->type = op;

  if( e) /* set arg count */
  {
    acount = e->count;
    Right(n) = e->head;
    free(e);
  }
  else
  {
    acount = 0;
    Right(n) = NULL;
  }
    
  if( r) /* set result count */
  {
    if( op == RF_STATS) listify_ranges( r); // stats is a special case

    rcount = r->count;
    Left(n) = r->head;
    free(r);
  }
  else
  {
    rcount = 0;
    Left(n) = NULL;
  }

  if( func[op]->nargs >= 0 && func[op]->nargs != acount)
  {
    char msg[100];
    sprintf( msg, "%s takes %d argument%s", func[op]->name, func[op]->nargs,
      (func[op]->nargs != 1) ? "s" : "");
    yyerror( msg);
    n->type = 0;
  }

  if( func[op]->rcount >= 0 && func[op]->rcount < rcount)
  {
    char msg[100];
    sprintf( msg, "%s returns %d value%s", func[op]->name, func[op]->rcount,
      (func[op]->rcount != 1) ? "s" : "");
    yyerror( msg);
    n->type = 0;
  }

  if( rcount == 0) // function call is NOT of the form: { results... } = func...
    return n;

// function call IS of the form: { results... } = func...
//
// first let install_tree() fix result types RCCELL, RCRANGE, RCA0RANGE, etc.
//
  Node *lval = Left(n);

  install_tree( lval, &cell_00, 1);

// special case, install symbol or cell
//
  if( rcount == 1 && lval->type != RANGE)
  {
    Left(n) = NULL;

    switch( lval->type)
    {
      case ID:
	install_symbol( lval->u.s, n);
	break;

      case CELL:
	install_cell( lval, n, 1, 1);
	break;

      default: /* should not happen */
        lval_type_error( lval->type);
	break;
    }
    return n;
  }

// rcount > 1 or lval is a RANGE, install formula in symbol table
//
  Symbol *s = lookup_symbol("");

  install_symbol( s, n);

 // set indirect dependencies
 //
  while( lval)
  {
    switch( lval->type)
    {
      case CELL:
	if( !check_cell( &lval->u.c))
	{
	  SS *cp = &ss[lval->u.c.row][lval->u.c.col];
	  if( cp->n || cp->depend)
	  {
	    yyerror( "cell already has formula or dependency");
	    fprintf( out, "add_func: cell ");
	    print_cell( &lval->u.c, &cell_00); putc( '\n', out);
	  }
	  cp->depend = s;
	  cp->used = 1;
	}
	break;

      case ID:
	if( lval->u.s->n || lval->u.s->depend)
	{
	    yyerror( "symbol already has formula or dependency");
	    fprintf( out, "add_func: symbol %s\n", lval->u.s->name);
	}
	lval->u.s->depend = s;
	break;

      case RANGE:
	add_range_depend( lval, s);
	break;

      default: // should not happen
	lval_type_error( lval->type);
	break;
    }
    lval = lval->next;
  }

  return n;
}

Node *add_op( int op, Node *left, Node *right)
{
  Node *e = NULL;

  switch( op)
  {
    case X_MM:
    case X_PP: e = left; break;

    case MM_X:
    case PP_X: e = right; break;
  }

  if( e && e->type != CELL && e->type != RCCELL && e->type != ID)
  {
    yyerror( "can only increment/decrement cell or symbol");
    return e;
  }

  if( e && e->type == ID && e->u.s->constant)
  {
    yyerror( "can not change constant");
    return e;
  }

  e = new_node();

  e->type = op;
  Left(e) = left;
  Right(e) = right;

  return e;
}

/* ?: node, left contains condition,
 * right is additional node for middle/right choices
 */
Node *add_cond( Node *left, Node *middle, Node *right)
{
  Node *e = new_node();
  Node *f = new_node();

  e->type = '?';
  Left(e) = left;
  Right(e) = f;

  f->type = ':';  /* this type doesn't matter, it is not used */

  Left(f) = middle;
  Right(f) = right;

  return e;
}

Node *add_string( const char *str)
{
  Node *e = new_node();

  e->type = STRING;
  e->u.str = str;

  return e;
}

Node *add_number( double val)
{
  Node *e = new_node();

  e->type = NUMBER;
  e->u.val = val;

  return e;
}

Node *add_empty( void)
{
  Node *e = new_node();

  e->type = EMPTY;

  return e;
}

Node *add_cell( const Cell *c, int type)
{
  Node *e = new_node();

  e->type = type;
  e->u.c = *c;

  return e;
}

Node *add_range( const Range *r, int type)
{
  Node *e = new_node();

  e->type = type;
  e->u.r = *r;

  return e;
}

Node *add_symbol( Symbol *s)
{
  Node *e = new_node();

  e->type = ID;
  e->u.s = s;

  return e;
}

Expr_list *new_expr_list( Node *n)
{
  Expr_list *e = malloc( sizeof( Expr_list) );

  if( e == NULL)
  {
    yyerror( "new_expr_list: malloc failed");
    exit(1);
  }

  e->head = e->tail = n;
  e->count = 1;

  return e;
}

void append_expr_list( Expr_list *e, Node *n)
{
  e->tail->next = n;
  e->tail = n;
  ++e->count;
}

/* print the parse tree fully parenthesized */

void print_tree( const Node *t, const Cell *ref_cell, int level)
{
  char *lparen = (level > 0) ? "(" : "";
  char *rparen = (level > 0) ? ")" : "";

  if( t == NULL)
    return;

  switch( t->type)
  {
    case STRING:
	fprintf( out, "\"%s\"", t->u.str);
	break;

    case NUMBER:
	fprintf( out, "%g", t->u.val);
	break;

    case CELL:
	switch( print_Format)
	{
	  case RC: print_cell_RC( &t->u.c); break;
	  case CR: print_cell_CR( &t->u.c); break;
	  default: print_cell( &t->u.c, ref_cell); break;
	}
	break;

    case RANGE:
	switch( print_Format)
	{
	  case RC: print_range_RC( &t->u.r); break;
	  case CR: print_range_CR( &t->u.r); break;
	  default: print_range( &t->u.r, ref_cell); break;
	}
	break;

    case ID:
	fprintf( out, "%s", t->u.s->name);
	break;

    /* '?' is a special case */

    case '?':
	fprintf( out, "%s", lparen);
	print_tree( Left(t), ref_cell, level+1);
	fprintf( out, " ? ");
	print_tree( Left(Right(t)), ref_cell, level+1);
	fprintf( out, " : (");
	print_tree( Right(Right(t)), ref_cell, level+1);
	fprintf( out, ")%s", rparen);
	break;

    case EMPTY: /* should not happen */
	fprintf( out, "EMPTY");
	break;

    default: /* function */
      {
	int type = func[t->type]->type;

	if( type & SS_OP) /* operator function */
	{
	  fprintf( out, "%s", lparen);
	  if( !(type & SS_ASGN) )
	    print_tree( Left(t), ref_cell, level+1);
	  fprintf( out, (type & SS_WORD) ? " %s " : "%s", func[t->type]->name);
	  print_tree( Right(t), ref_cell, level+1);
	  fprintf( out, "%s", rparen);
	}
	else /* numeric or range function */
	{
	  if( Left(t))
	  {
	    fprintf( out, "{");
	    print_tree( Left(t), ref_cell, 0);
	    fprintf( out, "} = ");
	  }
	  fprintf( out, "%s(", func[t->type]->name);
	  print_tree( Right(t), ref_cell, level+1);
	  fprintf( out, ")");
	}
	break;
      }
  }

  if( t->next) /* expr list */
  {
    putc( ',', out);
    print_tree( t->next, ref_cell, level+1);
  }

}

/* make cell reference relative */

static void mkrel_cell( Cell *c, const Cell *r)
{
  if( !c->row_fixed) c->row -= r->row;
  if( !c->col_fixed) c->col -= r->col;
}

/* traverse tree and make cell references relative
 *
 * When invoked from install_range() for:  range = { expr_list }
 * install_list will be 0 to prevent traversal of the expression list,
 * but subsequent recursive calls below set install_list = 1 so that
 * function argument lists will be processed.
 */
void install_tree( Node *t, const Cell *ref_cell, int install_list)
{
  if( t == NULL)
    return;

  switch( t->type)
  {
    case STRING:
    case NUMBER:
    case ID:
	break;

    case RCCELL: /* already relative */
	t->type = CELL;
	break;

    case CELL:
	check_cell( &t->u.c);
	mkrel_cell( &t->u.c, ref_cell);
	break;

    case RCRANGE: /* already relative */
	t->type = RANGE;
	break;

    case A0RCRANGE: /* end is already relative */
	t->type = RANGE;
	check_cell( &t->u.r.start);
	mkrel_cell( &t->u.r.start, ref_cell);
	break;

    case RCA0RANGE: /* start is already relative */
	t->type = RANGE;
	check_cell( &t->u.r.end);
	mkrel_cell( &t->u.r.end, ref_cell);
	break;

    case RANGE:
	check_cell( &t->u.r.start);
	mkrel_cell( &t->u.r.start, ref_cell);
	check_cell( &t->u.r.end);
	mkrel_cell( &t->u.r.end, ref_cell);
	break;

    /* '?' is a special case */

    case '?':
	install_tree( Left(t), ref_cell, 1);
	install_tree( Left(Right(t)), ref_cell, 1);
	install_tree( Right(Right(t)), ref_cell, 1);
	break;

    default: /* function */

	if( func[t->type]->type & SS_OP) /* operator function */
	{
	  install_tree( Left(t), ref_cell, 1);
	  install_tree( Right(t), ref_cell, 1);
	}
	else /* numeric or range function */
	{
	  install_tree( Right(t), ref_cell, 1);
	}
	break;
  }

  if( install_list)
    install_tree( t->next, ref_cell, 1);
}

/* dependency evaluation of a symbol */

double eval_symbol( Symbol *e)
{
  double r = 0;

  if( debug)
    fprintf( out, "eval_symbol: %s", e->name);

  if( !depend)
  {
    if( debug) fprintf( out, " using current value\n");
    r = e->val;
  }
  else if( e->state == EVALUATED)
  {
    if( debug) fprintf( out, " is EVALUATED\n");
    r = e->val;
  }
  else if( e->state == INPROGRESS)
  {
    if( debug) fprintf( out, " is INPROGRESS\n");
    fprintf( out, "eval_symbol: %s has a cyclic dependency\n", e->name);
  }
  else // UNEVALUATED
  {
    if( debug) fprintf( out, " is UNEVALUATED\n");
    e->state = INPROGRESS;
    if( e->depend)
    {
       eval_symbol( e->depend); // indirectly sets e->val
       r = e->val;
    }
    else
    {
      r = e->val = eval_tree( e->n, &cell_00);
    }
    e->state = evaluated; // EVALUATED, or UNEVALUATED if called from rf/search.c
  }

  return r;
}

/* dependency evaluation of a cell */

double eval_cell( SS *cp, const Cell *c)
{
  double r = 0;

  if( debug)
  {
    fprintf( out, "eval_cell: ");
    print_cell( c, &cell_00);
  }

  if( !depend)
  {
    if( debug) fprintf( out, " using current value\n");
    r = cp->val;
  }
  else if( cp->state == EVALUATED)
  {
    if( debug) fprintf( out, " is EVALUATED\n");
    r = cp->val;
  }
  else if( cp->state == INPROGRESS)
  {
    if( debug) fprintf( out, " is INPROGRESS\n");
    fprintf( out, "eval_cell: ");
    print_cell( c, &cell_00);
    fprintf( out, " has a cyclic dependency\n");
  }
  else // UNEVALUATED
  {
    if( debug) fprintf( out, " is UNEVALUATED\n");
    cp->state = INPROGRESS;
    if( cp->depend)
    {
       eval_symbol( cp->depend); // indirectly sets cp->val
       r = cp->val;
    }
    else
    {
       r = cp->val = eval_tree( cp->n, c);
    }
    cp->state = evaluated; // EVALUATED, or UNEVALUATED if called from rf/search.c
  }

  return r;
}

/* evaluate tree */

double eval_tree( const Node *t, const Cell *ref_cell)
{
  Cell c;
  double r = 0;

  if( t == NULL)
    return r;

  switch( t->type)
  {
    case STRING:
	break;

    case NUMBER:
	r = t->u.val;
	break;

    case ID:
	r = eval_symbol( t->u.s);
	break;

    case CELL:
	c = t->u.c;

	adjust_cell( &c, ref_cell);

	if( !check_cell( &c) )
	{
	  SS *cp = &ss[c.row][c.col];

	  r = eval_cell( cp, &c);
	}
	break;

    case RANGE: /* should not happen */
	fprintf( out, "eval_tree: got RANGE! ");
	print_range( &t->u.r, ref_cell); putc( '\n', out);
	break;

    default: /* function */

	r = func[t->type]->f( t, ref_cell);
	break;
  }

  return r;
}