<?php


/**the semantics of next, related, previous, etc... is really dependent on
 * the "relation". This simple set of functions just provides
 * some helper utilities for modules
 * Each module implementing a relation type should implement it's own UI.
 */
function relation_new($left_id,$left_type, $right_id, $right_type, $relation_type) {
  $query ="INSERT INTO relations (%d,%d,%d,%d,%d)";
  db_query($query,$left_id,$left_type, $right_id, $right_type, $relation_type);
}

function relatation_get_all_right_related($id, $type) {
  $query= "SELECT right_id AS thing, rt_id AS type, relt_id AS relation 
FROM relations WHERE left_id = %d AND lt_id = %d";
  db_query($query, $id, $type);
}

function relation_get_all_right_related_by_type($id, $type) {
  $query= "SELECT right_id AS thing, rt_id AS type
WHERE left_id = %d AND lt_id = %d AND relt_id=%d";
  db_query($query, $id, $type, $rel_type);
}

function relatation_get_all_left_related($id, $type) {
  $query= "SELECT right_id AS thing, rt_id AS type, relt_id AS relation 
FROM relations WHERE right_id = %d AND rt_id = %d";
  db_query($query, $id, $type);
}

function relation_get_all_left_related_by_type($id, $type) {
  $query= "SELECT right_id AS thing, rt_id AS type
WHERE right_id = %d AND rt_id = %d AND relt_id=%d";
  db_query($query, $id, $type, $rel_type);
}

function relation_tree_index_new($id ,$sibling_right, $parent_right) {
  $query="INSERT INTO nested_set_index VALUES (%d,%d,%d,%d)";
  db_query($query, $id, $sibling_right+($parent_right-$sibling_right)/3,
           $parent_right-($parent_right-$sibling_right)/3, $thing_rel);
}

function relation_tree_get_children($id ,$sibling_right, $parent_right) {
  $query="SELECT rel.left_id,rel.lt_id FROM relations AS rel 
LEFT JOIN nested_set_index AS t ON rel.left_id=t.thing_id AND rel.lt_id=t.thing_type AND rel.relt_id=t.rel
WHERE t.left > %d AND t.right < %d
ORDER by t.left";
  db_query($query, $left,$right);
}

function relation_tree_get_parents($id ,$sibling_right, $parent_right) {
  $query="SELECT rel.left_id,rel.lt_id FROM relations AS rel 
LEFT JOIN nested_set_index AS t ON rel.left_id=t.thing_id AND rel.lt_id=t.thing_type AND rel.relt_id=t.rel
WHERE t.left < %d AND t.right > %d
ORDER by t.left";
  db_query($query, $left,$right);
}

/*
CREATE TABLE relations (
left_id INTEGER NOT NULL,
lt_id INTEGER NOT NULL,
right_id INTEGER NOT NULL,
rt_id INTEGER NOT NULL,
relt_id INTEGER NOT NULL,
KEY left  (left_id,lt_id),
KEY right (left_id,lt_id),
KEY rel (rt_id)
);

CREATE TABLE nested_set_index (
thing_id INTEGER NOT NULL,
thing_type INTEGER NOT NULL,
left INTEGER NOT NULL,
right INTEGER NOT NULL,
rel INTEGER NOT NULL,
KEY thing  (thing_id,thing_type),
KEY left (left),
KEY right (right),
KEY rel (rel)
);
*/
?>