simple android todo app in php

php-android-todo.php

<?php

// droid is coming from testnow.php

// all this app can do. corresponding functions are
// named do_XXX where XXX is the action
$actions = array('create', 'list', 'done', 'exit');

// database as array. read when started, saved on exit.
$data = null;

// where the database-file is stored
if (is_phone()) {
    $filename = '/sdcard/todo.db';
} else {
    $filename = '/tmp/todo.db';   
}

init_app();

main_loop();

function init_app() {
    global $filename;
    global $data;
    if (file_exists($filename)) {
        $contents = file_get_contents($filename);    
        $lines = explode("\n", $contents);
        $data = array_map(function ($line) { return explode(';', $line); }, $lines);
    } else {
        // file is created on save if inexistent
        $data = array();
    }
}

function main_loop() {
    global $actions;
    do  {
        $action = input('What do you want to do?', format_actions($actions));
        $continue = run_action($action);
    } while ($continue);
}

function format_actions(array $actions) {
    return implode("\n", array_map('ucfirst', $actions));
}

function output($title, $msg) {
    if (is_phone()) {
        global $droid;
        $droid->makeToast($title, $msg);
    }
    echo "$title\n\n$msg\n";
}

function input($title, $msg) {
    if (is_phone()) {
        global $droid;
        $res = $droid->dialogGetInput($title, $msg);
        return $res['result'] == null ? 'exit' : $res['result'];
    } else {
        return readline("$title\n\n$msg\n");
    }
}

function run_action($input) {
    global $actions;
    $input = trim($input);
    $input = strtolower($input);
    if (!in_array($input, $actions)) {
        output('Error', 'Unknown action \''.$input.'\'');
        return true;
    } else {
        $action = 'do_'.$input;
        return $action();
    }
}

function do_create(){
    global $data;
    $title = input('Create', 'Enter a title');
    $data[] = array($title, 'F');
    return true;
}

function do_list(){
    global $data;
    if (empty($data)) {
        output('List', 'Nothing here..');
    } else {
        output('List', data_to_string($data));
    }
    return true;
}

function do_done(){
    global $data;
    $title = input('Done', 'Which one shall be marked done?');
    foreach ($data as $key => $item) {
        if ($item[0] == $title) {
            $data[$key][1] = 'T';
        }
    }
    return true;
}

function do_exit(){
    global $data;
    global $filename;

    if (!empty($data)) {
        $handle = fopen($filename, 'w+');
        if (!$handle) die ("failed to save database\n");
        $ret = fwrite($handle, data_to_string($data));
        if (!$ret) die ("failed to save database\n");
    }

    output('Exit', 'Saved. Farewell!');
    return false;
}

function data_to_string($data) {
    $lines = array_map(function ($line) { return implode(';', $line); }, $data);
    return implode("\n", $lines);
}

function is_phone() {
    return file_exists('/sdcard');
}

//$n = $droid->dialogGetInput('Fuck!', 'How many times have I told you to stay away?');
//echo "after\n";
//$droid->makeToast('Fuck! You\'re right! ' . $n['result'] . ' times!');
//echo "after dem after\n";