<?php

function area_to_area($area1, $area2, $date1, $date2, $t, $c='#FF0000') {
  global $pgconn;
  $data = [];
  $q = "SELECT * FROM geofence_area WHERE id=${area1}";
  $r = pg_query($pgconn, $q);
  $area1i = pg_fetch_assoc($r);
  $boundaries = json_decode($area1i["boundaries"], true);
  $polygonCoords = [];
  
  foreach ($boundaries["polygon"] as $coord) {
    $polygonCoords[] = "$coord[0] $coord[1]";
  }
  $polygonCoordsString1 = implode(",", $polygonCoords);
  
  $q = "SELECT * FROM geofence_area WHERE id=${area2}";
  $r = pg_query($pgconn, $q);
  $area2i = pg_fetch_assoc($r);
  $boundaries = json_decode($area2i["boundaries"], true);
  $polygonCoords = [];
  foreach ($boundaries["polygon"] as $coord) {
    $polygonCoords[] = "$coord[0] $coord[1]";
  }
  $polygonCoordsString2 = implode(",", $polygonCoords);

  $q = "SELECT a.travel_date,a.cost";
  $q.= ",b.latitude AS location_start_lat,b.longitude AS location_start_lng";
  $q.= ",c.latitude AS location_end_lat,c.longitude AS location_end_lng";
  $q.= " FROM quotes a, address b, address c";
  $q.= " WHERE a.cost>0 AND a.transport_provider_id=${t}";
  $q.= " AND b.id=a.location_start_id AND c.id=a.location_end_id";
  $q.= " AND a.travel_date>'${date1} 00:00' AND a.travel_date<'${date2} 23:59'";
  $q.= " AND ST_Contains(ST_GeomFromText('POLYGON((${polygonCoordsString1}))', 4326), b.geometry::geometry)";
  $q.= " AND ST_Contains(ST_GeomFromText('POLYGON((${polygonCoordsString2}))', 4326), c.geometry::geometry)";
  $q.= " ORDER BY a.travel_date";

  $r = pg_query($pgconn, $q);
  while ($f=pg_fetch_assoc($r)) {
    $f['origin'] = $area1i['name'];
    $f['destination'] = $area2i['name'];
    $f['c'] = $c;
    $f['time'] = strtotime($f['travel_date']);
    $data[] = $f;
  }
  return [$data,$area1i["name"]." to ".$area2i["name"],$boundaries["polygon"]];
}

function trend_line($regression1, $data) {
  $i = 0;
  $pub1 = array();
  $xs1 = [];
  $ys1 = [];
  $ys2 = [];
  foreach ($data as $f) {
    $t = $f['time'];
    $pub1[$t] = array($t,$f['cost']);
    $xs1[] = [$t];
    $ys1[] = $f['cost'];
    $i++;
  }
  if ($i>0) {
        $regression1->train($xs1,$ys1);
  }
  foreach ($pub1 as $key=>$f) {
    $y = $regression1->predict( [$f[0]] );
    $f[2] = $y;
    $pub1[$key] = $f;
  }
  return [$pub1,$xs1,$ys2];
}

function variation($data, $i, $f, $t) {
  global $dMin, $dMax, $tVar, $tVar0;
  $tVar[] = $f['cost'];
  $trend = $t[$f['time']][2];
  $delta = $f['cost'] - $trend;
  $variation = stats_variance($tVar);
  if ($delta>$dMax) $dMax = $delta;
  if ($delta<$dMin) $dMin = $delta;
  $tVar0[$f['time']] = $variation;
  /* {
  "travel_date":"2020-05-10 14:54:04+00",
  "cost":"12",
  "location_start_lat":"1.319292",
  "location_start_lng":"103.9126091",
  "location_end_lat":"1.316269",
  "location_end_lng":"103.977615",
  "origin":"Central East - Eunos",
  "destination":"Far East - Changi",
  "c":"#5555ff"} */
  //if ($i<5) error_log(json_encode($t));
  return [$trend, $delta, $variation];
}