-- down the graph: eg from  chromosome to contig
CREATE OR REPLACE FUNCTION project_point_up(int,int,int,int)
 RETURNS int AS
'SELECT
  CASE WHEN $4<0
   THEN $3-$1             -- rev strand
   ELSE $1-$2             -- fwd strand
  END AS p'
LANGUAGE 'sql'; 

-- down the graph: eg from contig to chromosome
CREATE OR REPLACE FUNCTION project_point_down(int,int,int,int)
 RETURNS int AS
'SELECT
  CASE WHEN $4<0
   THEN $3-$1
   ELSE $1+$2
  END AS p'
LANGUAGE 'sql'; 

CREATE OR REPLACE FUNCTION project_featureloc_up(int,int)
 RETURNS featureloc AS
'
DECLARE
    in_featureloc_id alias for $1;
    up_srcfeature_id alias for $2;
    in_featureloc featureloc%ROWTYPE;
    up_featureloc featureloc%ROWTYPE;
    nu_featureloc featureloc%ROWTYPE;
    nu_fmin INT;
    nu_fmax INT;
    nu_strand INT;
BEGIN
 SELECT INTO in_featureloc
   featureloc.*
  FROM featureloc
  WHERE featureloc_id = in_featureloc_id;

 SELECT INTO up_featureloc
   up_fl.*
  FROM featureloc AS in_fl
  INNER JOIN featureloc AS up_fl
    ON (in_fl.srcfeature_id = up_fl.feature_id)
  WHERE
   in_fl.featureloc_id = in_featureloc_id AND
   up_fl.srcfeature_id = up_srcfeature_id;

  IF up_featureloc.strand IS NULL
   THEN RETURN NULL;
  END IF;
  
  IF up_featureloc.strand < 0
  THEN
   nu_fmin = project_point_up(in_featureloc.fmax,
                              up_featureloc.fmin,up_featureloc.fmax,-1);
   nu_fmax = project_point_up(in_featureloc.fmin,
                              up_featureloc.fmin,up_featureloc.fmax,-1);
   nu_strand = -in_featureloc.strand;
  ELSE
   nu_fmin = project_point_up(in_featureloc.fmin,
                              up_featureloc.fmin,up_featureloc.fmax,1);
   nu_fmax = project_point_up(in_featureloc.fmax,
                              up_featureloc.fmin,up_featureloc.fmax,1);
   nu_strand = in_featureloc.strand;
  END IF;
  in_featureloc.fmin = nu_fmin;
  in_featureloc.fmax = nu_fmax;
  in_featureloc.strand = nu_strand;
  in_featureloc.srcfeature_id = up_featureloc.srcfeature_id;
  RETURN in_featureloc;
END
'   
LANGUAGE 'plpgsql';

CREATE OR REPLACE FUNCTION project_point_g2t(int,int,int)
 RETURNS INT AS '
 DECLARE
    in_p             alias for $1;
    srcf_id          alias for $2;
    t_id             alias for $3;
    e_floc           featureloc%ROWTYPE;
    out_p            INT;
    exon_cvterm_id   INT;
BEGIN
 SELECT INTO exon_cvterm_id get_feature_type_id(''exon'');
 SELECT INTO out_p
  CASE 
   WHEN strand<0 THEN fmax-p
   ELSE p-fmin
   END AS p
  FROM featureloc
   INNER JOIN feature USING (feature_id)
   INNER JOIN feature_relationship ON (feature.feature_id=subject_id)
  WHERE
   object_id = t_id                     AND
   feature.type_id = exon_cvterm_id     AND
   featureloc.srcfeature_id = srcf_id   AND
   in_p >= fmin                         AND
   in_p <= fmax;
  RETURN in_featureloc;
END
'   
LANGUAGE 'plpgsql';

