<?php
# Reporting functions

/**
 * Retrieves the name of a report
 *
 * @param array $report The report array containing at least a 'name' key.
 * @return string The translated report name.
 */
function get_report_name($report)
{
    # Translates or customizes the report name.
    $customName = hook('customreportname', '', array($report));
    if ($customName) {
        return $customName;
    }

    return lang_or_i18n_get_translated($report["name"], "report-");
}

/**
 * Retrieves an array of reports from the database.
 *
 * This function queries the database for all reports and processes them by:
 * 1. Translating the report names using the `get_report_name` function.
 * 2. Checking if the reports contain date fields using `report_has_date`.
 * 3. Verifying if the reports have associated thumbnails using `report_has_thumbnail`.
 *
 * The reports are always listed in the same order, regardless of the language used.
 *
 * @return array An array of processed reports, each containing 'ref', 'name',
 *               'contains_date', and 'has_thumbnail' keys.
 */
function get_reports()
{
    # Executes query.
    $r = ps_query("SELECT ref, `name`, `query`, support_non_correlated_sql FROM report ORDER BY name");

    # Translates report names in the newly created array.
    $return = array();
    for ($n = 0; $n < count($r); $n++) {
        if (!hook('ignorereport', '', array($r[$n]))) {
            $r[$n]["name"] = get_report_name($r[$n]);
            $r[$n]["contains_date"] = report_has_date((string) $r[$n]["query"]);
            $r[$n]['has_thumbnail'] = report_has_thumbnail((string) $r[$n]["query"]);
            $return[] = $r[$n];
        }
    }
    return $return;
}

/**
 * do_report   - Runs the specified report. This is used in a number of ways:-
 *               1) Outputs an HTML table to screen ($download = false)
 *               2) Produces a CSV
 *                  - for direct download from team_report.php
 *                  - captured and saved as a CSV file if called by send_periodic_report_emails() and over 100 rows are returned
 *
 *
 * @param  int $ref                 Report ID
 * @param  mixed $from_y            Start year (used for reprts with date placholders)
 * @param  mixed $from_m            Start month
 * @param  mixed $from_d            Start day
 * @param  mixed $to_y              End year
 * @param  mixed $to_m              To month
 * @param  mixed $to_d              To day
 * @param  mixed $download          Output as CSV attachment (default)/output directly to client
 * @param  mixed $add_border        Optional table border (not for download)
 * @param  mixed $foremail          Sending as email?
 * @param  array $search_params     Search parameters - {@see get_search_params()} - will run the report on the search
 *                                  results and replace the '[non_correlated_sql]' placeholder with the search query.
 *
 * @return void | string | array    Outputs CSV file, returns HTML table or returns an array with path to the CSV file, rows and filename
 */
function do_report($ref, $from_y, $from_m, $from_d, $to_y, $to_m, $to_d, $download = true, $add_border = false, $foremail = false, array $search_params = array())
{
    # Run report with id $ref for the date range specified. Returns a result array.
    global $lang, $baseurl, $report_rows_attachment_limit;

    $report = ps_query("SELECT ref, `name`, `query`, support_non_correlated_sql FROM report WHERE ref = ?", array("i",$ref));

    if (count($report) < 1) {
        return $lang['error_generic'];
    }

    $has_date_range = report_has_date($report[0]["query"]);
    $report = $report[0];
    $report['name'] = get_report_name($report);

    if ($download || $foremail) {
        if ($has_date_range) {
            $filename = str_replace(array(" ","(",")","-","/",","), "_", $report["name"]) . "_" . $from_y . "_" . $from_m . "_" . $from_d . "_" . $lang["to"] . "_" . $to_y . "_" . $to_m . "_" . $to_d . ".csv";
        } else {
            $filename = str_replace(array(" ","(",")","-","/",","), "_", $report["name"]) . ".csv";
        }
    }

    if ($results = hook("customreport", "", array($ref,$from_y,$from_m,$from_d,$to_y,$to_m,$to_d,$download,$add_border, $report))) {
        // Hook has created the $results array
    } else {
        // Generate report results normally
        $sql_parameters = array();
        $report_placeholders = [
            '[from-y]' => $from_y,
            '[from-m]' => $from_m,
            '[from-d]' => $from_d,
            '[to-y]' => $to_y,
            '[to-m]' => $to_m,
            '[to-d]' => $to_d,
        ];
        if ((bool)$report['support_non_correlated_sql'] === true && !empty($search_params)) {
            // If report supports being run on search results, embed the non correlated sql necessary to feed the report
            $returned_search = do_search(
                $search_params['search'],
                $search_params['restypes'],
                $search_params['order_by'],
                $search_params['archive'],
                -1, # fetchrows
                $search_params['sort'],
                false, # access_override
                DEPRECATED_STARSEARCH,
                false, # ignore_filters
                false, # return_disk_usage
                $search_params['recentdaylimit'],
                false, # go
                false, # stats_logging
                true, # return_refs_only
                false, # editable_only
                true # returnsql
            );

            if (!is_a($returned_search, "PreparedStatementQuery") || !is_string($returned_search->sql)) {
                debug("Invalid SQL returned by do_search(). Report cannot be generated");
                return "";
            }
            $sql_parameters = array_merge($sql_parameters, $returned_search->parameters);
            $report_placeholders[REPORT_PLACEHOLDER_NON_CORRELATED_SQL] = "(SELECT ncsql.ref FROM ({$returned_search->sql}) AS ncsql)";
        }

        $sql = report_process_query_placeholders($report['query'], $report_placeholders);

        db_set_connection_mode("read_only");
        $results = ps_query($sql, $sql_parameters);
        db_clear_connection_mode();
    }

    $resultcount = count($results);
    if ($resultcount == 0) {
        // No point downloading as the resultant file will be empty
        $download = false;
    }

    foreach ($results as &$result) {
        foreach ($result as $key => &$value) {
            # Merge translation strings if multiple in a single column
            if (substr($key, 0, 4) == "i18n") {
                $delimiter = substr($key, 4, strpos($key, "_") - 4);
                $value = implode("", i18n_merge_translations(explode($delimiter, (string)$value)));
            }
        }
        unset($value);
    }
    unset($result);

    if ($download) {
        header("Content-type: application/octet-stream");
        header("Content-disposition: attachment; filename=\"" . $filename . "\"");
    }

    if ($download || ($foremail && $resultcount > $report_rows_attachment_limit)) {
        if ($foremail) {
            ob_clean();
            ob_start();
        }
        for ($n = 0; $n < $resultcount; $n++) {
            $result = $results[$n];
            if ($n == 0) {
                $f = 0;
                foreach ($result as $key => $value) {
                    $f++;
                    if ($f > 1) {
                        echo ",";
                    }
                    if (substr($key, 0, 4) == "i18n") {
                        $key = substr($key, strpos($key, "_") + 1);
                    }
                    if ($key != "thumbnail") {
                        echo "\"" . lang_or_i18n_get_translated($key, "columnheader-") . "\"";
                    }
                }
                echo "\n";
            }
            $f = 0;
            foreach ($result as $key => $value) {
                $f++;
                if ($f > 1) {
                    echo ",";
                }
                $custom = hook('customreportfield', '', array($result, $key, $value, $download));
                if ($custom !== false) {
                    echo $custom;
                } elseif ($key != "thumbnail") {
                    $value = lang_or_i18n_get_translated($value, "usergroup-");
                    $value = str_replace('"', '""', $value); # escape double quotes
                    if (substr($value, 0, 1) == ",") {
                        $value = substr($value, 1);
                    } # Remove comma prefix on dropdown / checkbox values
                    echo "\"" . $value  . "\"";
                }
            }
            echo "\n";
        }

        if ($foremail) {
            $output = ob_get_contents();
            ob_end_clean();
            $unique_id = uniqid();
            $reportfile = get_temp_dir(false, "Reports") . "/Report_" . $unique_id . ".csv";
            file_put_contents($reportfile, $output);
            return array("file" => $reportfile,"filename" => $filename, "rows" => $resultcount);
        }
    } else {
        # Not downloading - output a table

        // If report results are too big, display the first rows and notify user they should download it instead
        $output = '';
        if ($resultcount > $report_rows_attachment_limit) {
            $results = array_slice($results, 0, $report_rows_attachment_limit);

            // Catch the error now and place it above the table in the output
            render_top_page_error_style($lang['team_report__err_report_too_long']);
            $output = ob_get_contents();
            ob_clean();
            ob_start();
        }

        // Pre-render process: Process nodes search syntax (e.g @@228 or @@!223) and add a new column that contains the node list and their names
        if (isset($results[0]['search_string'])) {
            $results = process_node_search_syntax_to_names($results, 'search_string');
        }
        $border = "";
        if ($add_border) {
            $border = "border=\"1\"";
        }
        $output .= "<br /><h2>" . $report['name'] . "</h2><style>.InfoTable td {padding:5px;}</style><table $border class=\"InfoTable\">";
        for ($n = 0; $n < count($results); $n++) {
            $result = $results[$n];
            if ($n == 0) {
                $f = 0;
                $output .= "<tr>\r\n";
                foreach ($result as $key => $value) {
                    $f++;
                    if ($key == "thumbnail") {
                        $output .= "<td><strong>Link</strong></td>\r\n";
                    } else {
                        if (substr($key, 0, 4) == "i18n") {
                            $key = substr($key, strpos($key, "_") + 1);
                        }
                        $output .= "<td><strong>" . lang_or_i18n_get_translated($key, "columnheader-") . "</strong></td>\r\n";
                    }
                }
                $output .= "</tr>\r\n";
            }
            $f = 0;
            $output .= "<tr>\r\n";
            foreach ($result as $key => $value) {
                $f++;
                if ($key == "thumbnail") {
                    $thm_path = get_resource_path($value, true, "thm", false, "", -1, 1, false);
                    if (!file_exists($thm_path)) {
                        $thm_path = dirname(__DIR__) . "/gfx/no_preview/default_thm.png";
                    } else {
                        $thm_path = get_resource_path($value, true, "col", false, "", -1, 1, false);
                    }

                    $output .= sprintf(
                        "<td><a href=\"%s/?r=%s\" target=\"_blank\"><img src=\"data:image/%s;base64,%s\"></a></td>\r\n",
                        $baseurl,
                        $value,
                        pathinfo($thm_path, PATHINFO_EXTENSION),
                        base64_encode(file_get_contents($thm_path))
                    );
                } else {
                    $custom = hook('customreportfield', '', array($result, $key, $value, $download));
                    if ($custom !== false) {
                        $output .= $custom;
                    } else {
                        $output .= "<td>" . strip_tags_and_attributes(lang_or_i18n_get_translated($value, "usergroup-"), array("a"), ['href', 'target', 'rel', 'title']) . "</td>\r\n";
                    }
                }
            }
            $output .= "</tr>\r\n";
        }
        $output .= "</table>\r\n";
        if (count($results) == 0) {
            $output .= $lang["reportempty"];
        }
        return $output;
    }

    exit();
}

/**
* Creates a new automatic periodic e-mail report
*
*/
function create_periodic_email($user, $report, $period, $email_days, array $user_groups, array $search_params)
{
    if ($email_days < 1) {
        $email_days = 1; # Minimum email frequency is daily.
    }
    # Delete any matching rows for this report/period.
    $query = "DELETE FROM report_periodic_emails
              WHERE user = ?
              AND report = ?
              AND period = ?";
    $parameters = array("i",$user, "i",$report, "i",$period);
    ps_query($query, $parameters);

    # Insert a new row.
    $query = "INSERT INTO report_periodic_emails 
                        (user, report, period, email_days, search_params)
                 VALUES (?,?,?,?,?)";
    $parameters = array("i",$user, "i",$report, "i",$period, "i",$email_days,
                      "s",json_encode($search_params, JSON_UNESCAPED_UNICODE | JSON_NUMERIC_CHECK));
    ps_query($query, $parameters);

    $ref = sql_insert_id();

    # Send to all users?
    if (
        checkperm('m')
        && !empty($user_groups)
    ) {
            $ugstring = implode(",", $user_groups);
            ps_query("UPDATE report_periodic_emails SET user_groups = ? WHERE ref = ?", array("s",$ugstring, "i",$ref));
    }

    # Return
    return true;
}

/**
 * Sends periodic report emails to users based on configured schedules.
 *
 * This function checks for any scheduled reports that need to be sent, either because they are
 * pending or overdue. It gathers the necessary user email addresses, generates the reports,
 * and sends them as emails with attachments if applicable.
 *
 * @param bool $echo_out Determines whether to output progress messages during processing.
 * @param bool $toemail Determines whether to send the reports via email.
 *
 * @return void
 */
function send_periodic_report_emails($echo_out = true, $toemail = true)
{
    # For all configured periodic reports, send a mail if necessary.
    global $lang,$baseurl, $report_rows_zip_limit, $email_notify_usergroups, $userref;

    if (is_process_lock("periodic_report_emails")) {
        echo " - periodic_report_emails process lock is in place. Skipping.\n";
        return;
    }

    set_process_lock("periodic_report_emails");

    // Keep record of temporary CSV/ZIP files to delete after emails have been sent
    $deletefiles = array();
    $users = [];

    # Query to return all 'pending' report e-mails, i.e. where we haven't sent one before OR one is now overdue.
    $query = "
        SELECT pe.ref,
               pe.user,
               pe.send_all_users,
               pe.user_groups,
               pe.report,
               pe.period,
               pe.email_days,
               pe.last_sent,
               pe.search_params,
               u.email,
               r.name
          FROM report_periodic_emails pe
          JOIN user u ON pe.user = u.ref
          JOIN report r ON pe.report = r.ref
         WHERE pe.last_sent IS NULL
            OR (date_add(date(pe.last_sent), INTERVAL pe.email_days DAY) <= date(now()) AND pe.email_days > 0);
    ";
    $reports = ps_query($query);

    foreach ($reports as $report) {
        $start = time() - (60 * 60 * 24 * $report["period"]);

        $from_y = date("Y", $start);
        $from_m = date("m", $start);
        $from_d = date("d", $start);

        $to_y = date("Y");
        $to_m = date("m");
        $to_d = date("d");

        // Send e-mail reports to users belonging to the specific user groups
        if (empty($report['user_groups'])) {
            if ($report['send_all_users']) {
                // Send to all users is deprecated. Send to $email_notify_usergroups or Super Admin if not set
                if (!empty($email_notify_usergroups)) {
                    foreach ($email_notify_usergroups as $usergroup) {
                        if (get_usergroup($usergroup) !== false) {
                            $addusers = get_users($usergroup, "", "u.username", false, -1, 1);
                            $users = array_merge($users, $addusers);
                        }
                    }
                } else {
                    $users = get_notification_users("SYSTEM_ADMIN");
                }
            }
        } else {
            $users = get_users($report['user_groups'], "", "u.username", false, -1, 1);
        }

        // Always add original report creator
        $creator = get_user($report['user']);
        $users[] = $creator;
        $sentousers  = [];
        if (isset($userref)) {
            // Store current user before emulating each to get report
            $saveduserref = $userref;
        }

        // Get unsubscribed users
        $unsubscribed = ps_array(
            'SELECT user_id as `value` 
                FROM report_periodic_emails_unsubscribe 
                WHERE periodic_email_id = ?',
            ["i",$report['ref']]
        );

        $reportcache = null;
        foreach ($users as $user) {
            if (in_array($user["ref"], $unsubscribed) || in_array($user["ref"], $sentousers)) {
                // User has unsubscribed from this report or already been sent it
                continue;
            }

            // Check valid email
            $email = $user['email'];
            if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
                continue;
            }

            // Construct and run the report
            // Emulate the receiving user so language text strings are translated and search results take into account any permissions and filters
            emulate_user($user["ref"]);
            $userref = $user["ref"];

            // Translates the report name.
            $report["name"] = lang_or_i18n_get_translated($report["name"], "report-");

            $search_params = (trim($report['search_params'] ?? "") !== '' ? json_decode($report['search_params'], true) : []);

            $static_report = true; // If no dynamic search results are included then the same report results can be used for all  recipients

            if (!empty($search_params)) {
                $static_report = false; // Report may vary so cannot be cached
            }

            # Generate report (table or CSV)
            if ($static_report && isset($reportcache)) {
                $output = $reportcache["output"];
                $reportfiles = $reportcache["reportfiles"];
            } else {
                $output = do_report($report["report"], $from_y, $from_m, $from_d, $to_y, $to_m, $to_d, false, true, $toemail, $search_params);

                if (empty($output)) {
                    // No data, maybe no access to search results
                    $output = "<br/>" . $lang["reportempty"] . "<br/>";
                }
                $reportfiles = [];
                // If report is large, make it an attachment (requires $use_phpmailer=true)
                if (is_array($output) && isset($output["file"])) {
                    $deletefiles[] = $output["file"];
                    // Include the file as an attachment
                    if ($output["rows"] > $report_rows_zip_limit) {
                        // Convert to  zip file
                        $unique_id = uniqid();
                        $zipfile = get_temp_dir(false, "Reports") . "/Report_" . $unique_id . ".zip";
                        $zip = new ZipArchive();
                        $zip->open($zipfile, ZIPARCHIVE::CREATE);
                        $zip->addFile($output["file"], $output["filename"]);

                        $zip->close();
                        $deletefiles[] = $zipfile;
                        $zipname = str_replace(".csv", ".zip", $output["filename"]);
                        $reportfiles[$zipname] = $zipfile;
                    } else {
                        $reportfiles[$output["filename"]] = $output["file"];
                    }
                }
                if ($static_report) {
                    $reportcache["output"] = $output;
                    $reportcache["reportfiles"] = $reportfiles;
                }
            }

            // Formulate a title
            $title = $report["name"] . ": " . str_replace("?", $report["period"], $lang["lastndays"]);
            if (!empty($reportfiles)) {
                $output = str_replace("[report_title]", $title, $lang["report_periodic_email_report_attached"]);
            }

            $unsubscribe_url = generateURL($baseurl, ["ur" => $report["ref"],"u" => $user["ref"]]);
            $unsubscribe_link = sprintf(
                "<br />%s<br /><a href=\"%s\" target=\"_blank\">%s</a>",
                $lang["unsubscribereport"],
                $unsubscribe_url,
                $unsubscribe_url
            );

            if ($echo_out) {
                echo escape($lang["sendingreportto"]) . " " . $email . "<br />" . $output . $unsubscribe_link . "<br />";
            }

            $delete_link = "";
            if ((int)$user['ref'] == (int)$report["user"]) {
                // Add a delete link to the report
                $delete_link = "<br />" . $lang["report_delete_periodic_email_link"] . "<br /><a href=\"" . $baseurl . "/?dr=" . $report["ref"] . "\" target=\"_blank\">" . $baseurl . "/?dr=" . $report["ref"] . "</a>";
            }
            send_mail($email, $title, $output . $delete_link  . $unsubscribe_link, "", "", "", "", "", "", "", $reportfiles);
            $sentousers[] =  $user['ref'];
        }

        if (isset($saveduserref)) {
            $userref = $saveduserref;
            emulate_user($userref);
        }

        # Mark as done.
        ps_query('UPDATE report_periodic_emails set last_sent = now() where ref = ?', array("i",$report['ref']));
    }

    $GLOBALS["use_error_exception"] = true;
    foreach ($deletefiles as $deletefile) {
        try {
            unlink($deletefile);
        } catch (Exception $e) {
            debug("Unable to delete - file not found: " . $deletefile);
        }
    }
    unset($GLOBALS["use_error_exception"]);

    clear_process_lock("periodic_report_emails");
}

/**
 * Deletes a periodic report for the current user.
 *
 * This function removes the specified periodic report from the database for the user
 * and also clears any associated unsubscribe (opt out) records.
 *
 * @param int $ref The reference ID of the periodic report to delete.
 * @return bool Returns true upon successful deletion.
 */
function delete_periodic_report($ref)
{
    global $userref;
    ps_query('DELETE FROM report_periodic_emails WHERE user = ? AND ref = ?', array("i",$userref, "i",$ref));
    ps_query('DELETE FROM report_periodic_emails_unsubscribe WHERE periodic_email_id = ?', array("i", $ref));

    return true;
}

/**
 * Unsubscribes a user from a specified periodic report.
 *
 * This function inserts a record into the unsubscribe table, preventing the specified user
 * from receiving future emails related to the given periodic report.
 *
 * @param int $user_id The ID of the user to unsubscribe.
 * @param int $periodic_email_id The ID of the periodic email report to unsubscribe from.
 * @return bool Returns true upon successful unsubscription.
 */
function unsubscribe_user_from_periodic_report($user_id, $periodic_email_id)
{
    $query = 'INSERT INTO report_periodic_emails_unsubscribe 
                  (user_id, periodic_email_id)
                 VALUES (?, ?)';
    ps_query($query, array("i",$user_id, "i",$periodic_email_id));

    return true;
}

/**
 * Retrieves the translated version of an activity type.
 *
 * This function takes an activity type string, checks if a corresponding
 * translation exists in the global language array, and returns the
 * translated string if available. If no translation is found, it returns
 * the original activity type.
 *
 * @param string $activity_type The activity type in plain text English.
 * @return string The translated activity type if available; otherwise, the original activity type.
 */
function get_translated_activity_type($activity_type)
{
    # Activity types are stored in plain text english in daily_stat. This function will use language strings to resolve a translated value where one is set.
    global $lang;
    $key = "stat-" . strtolower(str_replace(" ", "", $activity_type));
    if (!isset($lang[$key])) {
        return $activity_type;
    } else {
        return $lang[$key];
    }
}

/**
 * Checks for the presence of date placeholders in a report's SQL query.
 *
 * @param  string   $query   The report's SQL query.
 *
 * @return boolean  Returns true if a date placeholder was found else false.
 */
function report_has_date(string $query)
{
    $date_placeholders = array('[from-y]','[from-m]','[from-d]','[to-y]','[to-m]','[to-d]');
    $date_present = false;

    foreach ($date_placeholders as $placeholder) {
        $position = strpos($query, $placeholder);
        if ($position !== false) {
            $date_present = true;
            break;
        }
    }

    return $date_present;
}

/**
 * Checks for the presence of date placeholders in a report's sql query using the report's id.
 *
 * @param  int   $report   Report id of the report to retrieve the query data from the report table.
 *
 * @return boolean  Returns true if a date placeholder was found else false.
 */
function report_has_date_by_id(int $report)
{
    $query = ps_value("SELECT `query` as value FROM report WHERE ref = ?", array("i",$report), 0);
    return report_has_date($query);
}

/**
 * Check if report has a "thumbnail" column in its SQL query.
 *
 * @param ?string $query The reports' SQL query.
*/
function report_has_thumbnail(?string $query): bool
{
    return preg_match('/(AS )*\'thumbnail\'/mi', (string) $query);
}

/**
 * Get report date range based on user input
 *
 * @param array $info Information about the period selection. See unit test for example input
 */
function report_process_period(array $info): array
{
    $available_periods = array_merge($GLOBALS['reporting_periods_default'], [0, -1]);
    $period = isset($info['period']) && in_array($info['period'], $available_periods) ? $info['period'] : $available_periods[0];

    // Specific number of days specified.
    if ($period == 0) {
        $period = (int) $info['period_days'] ?? 0;
        if ($period < 1) {
            $period = 1;
        }
    }

    // Specific date range specified.
    if ($period == -1) {
        $from_y = $info['from-y'] ?? '';
        $from_m = $info['from-m'] ?? '';
        $from_d = $info['from-d'] ?? '';

        $to_y = $info['to-y'] ?? '';
        $to_m = $info['to-m'] ?? '';
        $to_d = $info['to-d'] ?? '';
    }
    // Work out the FROM and TO range based on the provided period in days.
    else {
        $start = time() - (60 * 60 * 24 * $period);

        $from_y = date('Y', $start);
        $from_m = date('m', $start);
        $from_d = date('d', $start);

        $to_y = date('Y');
        $to_m = date('m');
        $to_d = date('d');
    }

    return [
        'from_year' => $from_y,
        'from_month' => $from_m,
        'from_day' => $from_d,
        'to_year' => $to_y,
        'to_month' => $to_m,
        'to_day' => $to_d,
    ];
}

/**
 * Find and replace a reports' query placeholders with their values.
 *
 * @param string $query Reports' SQL query
 * @param array $placeholders Map between a placeholder and its actual value
 */
function report_process_query_placeholders(string $query, array $placeholders): string
{
    $default_placeholders = [
        '[title_field]' => $GLOBALS['view_title_field'],
    ];
    $all_placeholders = array_merge($default_placeholders, $placeholders);

    $sql = $query;
    foreach ($all_placeholders as $placeholder => $value) {
        $sql = str_replace($placeholder, $value, $sql);
    }

    return $sql;
}

/**
 * Output the Javascript to build a pie chart in the canvas denoted by $id
 * $data must be in the following format
 * $data = array(
 *     "slice_a label" => "slice_a value",
 *     "slice_b label" => "slice_b value",
 * );
 *
 * @param  string       $id     identifier for the canvas to render the chart in
 * @param  array        $data   data to be rendered in the chart
 * @param  string|null  $total  null will mean that the data is complete and an extra field is not required
 *                              a string can be used to denote the total value to pad the data to
 * @return void
 */
function render_pie_graph($id, $data, $total = null)
{
    global $home_colour_style_override,$header_link_style_override;

    $rt = 0;
    $labels = [];
    $values = [];
    foreach ($data as $row) {
        $rt += $row["c"];
        $values[ ] = $row["c"];
        $labels[] = $row["name"];
    }

    if (!is_null($total) && $total > $rt) {
        # The total doesn't match, some rows were truncated, add an "Other".
        $values[] = $total - $rt;
        $labels[] = "Other";
    }

    $labels = array_map(fn($v) => substr(json_encode($v), 1, -1), $labels);
    ?>
    <script type="text/javascript">
    // Setup Styling
    new Chart(document.getElementById('<?php echo escape($id) ?>'), {
        type: 'pie',
        data: {
            labels: ['<?php echo implode("', '", $labels) ?>'],
                datasets: [
                        {
                    data: [<?php echo escape(implode(", ", $values)) ?>]
                }
            ]
        },
        options: chartstyling<?php echo escape($id)?>,
    });
    </script>
    <?php
}

/**
 * Output the Javascript to build a bar chart in the canvas denoted by $id
 * $data must be in the following format
 * $data = array(
 *     "point_a x value" => "point_a y value",
 *     "point_b x value" => "point_b y value",
 *
 * @param  string   $id     identifier for the canvas to render the chart in
 * @param  array    $data   data to be rendered in the chart
 * @return void
 */
function render_bar_graph(string $id, array $data)
{
    $values = "";
    foreach ($data as $t => $c) {
        $values .= "{x: $t, y: $c },\n";
    }
    ?>
    <script type="text/javascript">
        new Chart(
            document.getElementById('<?php echo escape($id) ?>'),
            {
            type: 'line',
            data: {
                datasets: [
                    {
                        data: [<?php echo escape($values) ?>]
                    }
                ]
            },
            options: chartstyling<?php echo escape($id)?>,
        }
        );
    </script>
    <?php
}