<?php

/*
    What is optimum age?
    ~~~~~~~~~~~~~~~~~~~~

    Description
    ====================================================================

    An on-line serve looking at at what age females are most attractive.

    ====================================================================

    Copyright (C) 2014  Morgan Hill <morgan@pcwizzltd.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

header("content-type: application/javascript");

require_once 'config.php';

/*

Not used, but might be handy later.
-----------------------------------

function total_responses(){
    $stmt = $mysqli->prepare("select COUNT(*) from responses");
    $stmt->execute();
    $stmt->bint_result($num_rows);
    $stmt->fetch();
    return $num_rows;
}

function responses_for_age($age){
    $stmt = $mysqli->prepare("select COUNT(responses.id) from responses join images on images.id=responses.image_id where age=?");
    $stmt->bind_param("i", $age);
    $stmt->execute();
    $stmt->bind_result($num_rows);
    $stmt->fetch();
    return $num_rows;
}

function average_score(){
    $stmt = $mysqli->prepare("select AVG(score) from responses");
    $stmt->execute();
    $stmt->bind_result($avg_score);
    $stmt->fetch();
    return $avg_score;
}

function average_score_in_time_period($time_start, $time_end){
    $stmt = $mysqli->prepare("select AVG(score) from responses where datetime >= ? or datetime <= ?");
    $stmt->bind_param("ii", $time_start, $time_end);
    $stmt->execute();
    $stmt->bind_param($avg_score);
    return $avg_score;
}

function average_score_for_age_in_time_period($age, $time_start, $time_end){
    $stmt = $mysqli->prepare("select AVG(score) from responses join images on images.id=responses.image_id where age=? and (datetime >= ? or datetime <= ?)");
    $stmt->bind_param("ii", $time_start, $time_end);
    $stmt->execute();
    $stmt->bind_param($avg_score);
    return $avg_score;
}

*/

function average_score_for_age($age){
    $stmt = $mysqli->prepare("select AVG(score) from responses join images on images.id=responses.image_id where age=?");
    $stmt->bind_param("i", $age);
    $stmt->execute();
    $stmt->bind_result($avg_score);
    $stmt->fetch();
    return $avg_score;
}

function heighest_scoring_age_in_time_period($time_start, $time_end){
    $stmt = $mysqli->prepare("select age from images join responses on images.id=responses.image_id where datetime >= ? or datetime <= ? order by AVG(response.score) desc limit 1");
    $stmt->bind_param("ii", $time_start, $time_end);
    $stmt->execute();
    $stmt->bind_param($age);
    return $age;
}

function score_against_avg_age(){
    $graph = array();
    for ($a = MIN_AGE; $a <= MAX_AGE; $a++){
        array_push($graph, array(
            "age" => $a,
            "score" => average_score_for_age($a)//should rewrite as stored function, as this is a lot of mysql transactions; slow!
            ));
    }
    return $graph;
}

function highest_scoring_age_againts_time(){
    //find oldest response
    $stmt = $mysqli->prepare("select UNIX_TIMESTAMP(datetime) from images order by datetime asc limit 1");
    $stmt->execute();
    $stmt->bind_result($start_datetime);
    $stmt->fetch();
    //create time periods
    $age_diff = MAX_AGE - MIN_AGE;
    $now = time();
    $total_time_elapsed = $now - $start_datetime;
    $time_period = intval($total_time_elapsed / $age_diff);
    $graph = array();
    while ($age_diff != 0) {
        $end_time = $start_datetime + $time_period;
        $time = new DateTime($start_datetime + ($end_time - $start_datetime));
        $time->setTimestamp();
        array_push($graph, array(
            "time" => $time,
            "age" => heighest_scoring_age_in_time_period($start_datetime, $end_time)// this could also do with being an sql function.
            ));
        $start_datetime = $end_time;
        $age_diff--;
    }
    return $graph;
}

function output_graph($graph){
    echo json_encode(array("point" => $graph);
}


//inspect request and serve graph data
if($_POST['graph']){
    switch ($_POST['graph']) {
        case 'scoreAgainstAvgAge':
            output_graph(scoreAgainstAvgAge());
            break;

        case 'highestScoringAgeAgaintsTime':
            output_graph(highest_scoring_age_againts_time());
            break;
    }
}