<?php

/**
 * Matomo - free/libre analytics platform
 *
 * @link    https://matomo.org
 * @license https://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 */

namespace Piwik\DataTable\Renderer;

use Piwik\Common;
use Piwik\DataTable\Renderer;
use Piwik\DataTable\Simple;
use Piwik\DataTable;
use Piwik\Filesystem;
use Piwik\Period;
use Piwik\Period\Range;
use Piwik\Piwik;
use Piwik\ProxyHttp;

/**
 * CSV export
 *
 * When rendered using the default settings, a CSV report has the following characteristics:
 * The first record contains headers for all the columns in the report.
 * All rows have the same number of columns.
 * The default field delimiter string is a comma (,).
 * Formatting and layout are ignored.
 *
 */
class Csv extends Renderer
{
    /**
     * Column separator
     *
     * @var string
     */
    public $separator = ",";

    /**
     * Line end
     *
     * @var string
     */
    public $lineEnd = "\n";

    /**
     * Converts the content to unicode so that UTF8 characters (eg. chinese) can be imported in Excel
     *
     * @var bool
     */
    public $convertToUnicode = true;

    /**
     * This string is also hardcoded in archive,sh
     */
    public const NO_DATA_AVAILABLE = 'No data available';

    private $unsupportedColumns = [];

    /**
     * Computes the dataTable output and returns the string/binary
     *
     * @return string
     */
    public function render(): string
    {
        $str = $this->renderTable($this->table);
        if (empty($str)) {
            return self::NO_DATA_AVAILABLE;
        }

        $this->renderHeader();

        return $this->convertToUnicode($str);
    }

    /**
     * Enables / Disables unicode converting
     *
     * @param $bool
     */
    public function setConvertToUnicode(bool $convertToUnicode): void
    {
        $this->convertToUnicode = $convertToUnicode;
    }

    /**
     * Sets the column separator
     *
     * @param string $separator
     */
    public function setSeparator(string $separator): void
    {
        $this->separator = $separator;
    }

    /**
     * Computes the output of the given data table
     *
     * @param DataTable|array $table
     * @param array $allColumns
     * @return string
     */
    protected function renderTable($table, array &$allColumns = []): string
    {
        if (is_array($table)) {
            // convert array to DataTable
            $table = DataTable::makeFromSimpleArray($table);
        }

        if ($table instanceof DataTable\Map) {
            $str = $this->renderDataTableMap($table, $allColumns);
        } else {
            $str = $this->renderDataTable($table, $allColumns);
        }
        return $str;
    }

    /**
     * Computes the output of the given data table array
     *
     * @param DataTable\Map $table
     * @param array $allColumns
     * @return string
     */
    protected function renderDataTableMap(DataTable\Map $table, array &$allColumns = []): string
    {
        $str = '';
        foreach ($table->getDataTables() as $currentLinePrefix => $dataTable) {
            $returned = explode("\n", $this->renderTable($dataTable, $allColumns));

            // get rid of the columns names
            $returned = array_slice($returned, 1);

            // case empty datatable we don't print anything in the CSV export
            // when in xml we would output <result date="2008-01-15" />
            if (!empty($returned)) {
                foreach ($returned as &$row) {
                    $row = $this->formatValue($currentLinePrefix) . $this->separator . $row;
                }
                $str .= "\n" . implode("\n", $returned);
            }
        }

        // prepend table key to column list
        $allColumns = array_merge(array($table->getKeyName() => true), $allColumns);

        // add header to output string
        return $this->getHeaderLine(array_keys($allColumns)) . $str;
    }

    /**
     * Converts the output of the given simple data table
     *
     * @param DataTable|Simple $table
     * @param array $allColumns
     * @return string
     */
    protected function renderDataTable($table, array &$allColumns = []): string
    {
        if ($table instanceof Simple) {
            $row = $table->getFirstRow();
            if ($row !== false) {
                $columnNameToValue = $row->getColumns();
                if (count($columnNameToValue) === 1) {
                    // simple tables should only have one column, the value
                    $allColumns['value'] = true;

                    $value = array_values($columnNameToValue);
                    return 'value' . $this->lineEnd . $this->formatValue($value[0]);
                }
            }
        }

        $csv = $this->makeArrayFromDataTable($table, $allColumns);

        return $this->buildCsvString($allColumns, $csv);
    }

    /**
     * Returns the CSV header line for a set of metrics. Will translate columns if desired.
     *
     * @param array $columnMetrics
     * @return string
     */
    private function getHeaderLine(array $columnMetrics): string
    {
        foreach ($columnMetrics as $index => $value) {
            if (in_array($value, $this->unsupportedColumns)) {
                unset($columnMetrics[$index]);
            }
        }

        if ($this->translateColumnNames) {
            $columnMetrics = $this->translateColumnNames($columnMetrics);
        }

        foreach ($columnMetrics as &$value) {
            $value = $this->formatValue($value);
        }

        return implode($this->separator, $columnMetrics);
    }

    /**
     * Formats/Escapes the given value
     *
     * @param mixed $value
     * @return string
     */
    public function formatValue($value)
    {
        if (
            is_string($value)
            && !is_numeric($value)
        ) {
            $value = html_entity_decode($value, ENT_QUOTES, 'UTF-8');
        } elseif ($value === false) {
            $value = 0;
        }

        $value = $this->formatFormulas($value);

        if (is_string($value)) {
            $value = str_replace(["\t"], ' ', $value);

            // surround value with double quotes if it contains a double quote or a commonly used separator
            if (
                strpos($value, '"') !== false
                || strpos($value, $this->separator) !== false
                || strpos($value, $this->lineEnd) !== false
                || strpos($value, ',') !== false
                || strpos($value, ';') !== false
            ) {
                $value = '"' . str_replace('"', '""', $value) . '"';
            }
        }

        // in some number formats (e.g. German), the decimal separator is a comma
        // we need to catch and replace this
        if (is_numeric($value)) {
            $value = (string)$value;
            $value = str_replace(',', '.', $value);
        }

        return $value;
    }

    protected function formatFormulas($value)
    {
        // Excel / Libreoffice formulas may start with one of these characters
        $formulaStartsWith = array('=', '+', '-', '@');

        // remove first % sign and if string is still a number, return it as is
        $valueWithoutFirstPercentSign = $this->removeFirstPercentSign((string)$value);

        if (
            empty($valueWithoutFirstPercentSign)
            || !is_string($value)
            || is_numeric($valueWithoutFirstPercentSign)
        ) {
            return $value;
        }

        $firstCharCellValue = $valueWithoutFirstPercentSign[0];
        $isFormula = in_array($firstCharCellValue, $formulaStartsWith);
        if ($isFormula) {
            return "'" . $value;
        }

        return $value;
    }

    /**
     * Sends the http headers for csv file
     */
    protected function renderHeader(): void
    {
        $fileName = Piwik::translate('General_Export');

        $period = Common::getRequestVar('period', false);
        $date = Common::getRequestVar('date', false);
        if ($period || $date) {
            // in test cases, there are no request params set

            if ($period === 'range') {
                $period = new Range($period, $date);
            } elseif (strpos($date, ',') !== false) {
                $period = new Range('range', $date);
            } else {
                $period = Period\Factory::build($period, $date);
            }

            $prettyDate = $period->getLocalizedLongString();

            $meta = $this->getApiMetaData();
            $name = !empty($meta['name']) ? $meta['name'] : '';

            $fileName .= ' _ ' . $name
                . ' _ ' . $prettyDate . '.csv';
        }

        $fileName = Filesystem::sanitizeFilename($fileName);

        // silent fail otherwise unit tests fail
        Common::sendHeader("Content-Disposition: attachment; filename*=UTF-8''" . rawurlencode($fileName), true);
        ProxyHttp::overrideCacheControlHeaders();
    }

    /**
     * Flattens an array of column values so they can be outputted as CSV (which does not support
     * nested structures).
     */
    private function flattenColumnArray(array $columns, array &$csvRow = [], string $csvColumnNameTemplate = '%s'): array
    {
        foreach ($columns as $name => $value) {
            $csvName = sprintf($csvColumnNameTemplate, $this->getCsvColumnName($name));

            if (is_array($value)) {
                // if we're translating column names and this is an array of arrays, the column name
                // format becomes a bit more complicated. also in this case, we assume $value is not
                // nested beyond 2 levels (ie, array(0 => array(0 => 1, 1 => 2)), but not array(
                // 0 => array(0 => array(), 1 => array())) )
                if (
                    $this->translateColumnNames
                    && is_array(reset($value))
                ) {
                    foreach ($value as $level1Key => $level1Value) {
                        $inner = $name === 'goals' ? Piwik::translate('Goals_GoalX', $level1Key) : $name . ' ' . $level1Key;
                        $columnNameTemplate = '%s (' . $inner . ')';

                        $this->flattenColumnArray($level1Value, $csvRow, $columnNameTemplate);
                    }
                } else {
                    $this->flattenColumnArray($value, $csvRow, $csvName . '_%s');
                }
            } else {
                $csvRow[$csvName] = $value;
            }
        }

        return $csvRow;
    }

    private function getCsvColumnName(string $name): string
    {
        if ($this->translateColumnNames) {
            return $this->translateColumnName($name);
        } else {
            return $name;
        }
    }

    /**
     * @param array $allColumns
     * @param array $csv
     * @return string
     */
    private function buildCsvString(array $allColumns, array $csv): string
    {
        $str = '';

        // specific case, we have only one column and this column wasn't named properly (indexed by a number)
        // we don't print anything in the CSV file => an empty line
        if (
            sizeof($allColumns) === 1
            && reset($allColumns)
            && !is_string(key($allColumns))
        ) {
            $str .= '';
        } else {
            // render row names
            $str .= $this->getHeaderLine(array_keys($allColumns)) . $this->lineEnd;
        }

        // we render the CSV
        foreach ($csv as $theRow) {
            $rowStr = '';
            foreach ($allColumns as $columnName => $true) {
                $rowStr .= $this->formatValue($theRow[$columnName] ?? '') . $this->separator;
            }
            // remove the last separator
            $rowStr = substr_replace($rowStr, "", -strlen($this->separator));
            $str .= $rowStr . $this->lineEnd;
        }

        return substr($str, 0, -strlen($this->lineEnd));
    }

    /**
     * @param $table
     * @param array $allColumns
     * @return array of csv data
     */
    private function makeArrayFromDataTable($table, array &$allColumns): array
    {
        $csv = [];
        foreach ($table->getRows() as $row) {
            $csvRow = $this->flattenColumnArray($row->getColumns());

            if (!$this->hideMetadata) {
                $metadata = $row->getMetadata();
                foreach ($metadata as $name => $value) {
                    if ($name === 'idsubdatatable_in_db') {
                        continue;
                    }
                    //if a metadata and a column have the same name make sure they don't overwrite
                    if ($this->translateColumnNames) {
                        $name = Piwik::translate('General_Metadata') . ': ' . $name;
                    } else {
                        $name = 'metadata_' . $name;
                    }

                    if (
                        is_array($value)
                        || is_object($value)
                    ) {
                        if (!in_array($name, $this->unsupportedColumns)) {
                            $this->unsupportedColumns[] = $name;
                        }
                    } else {
                        $csvRow[$name] = $value;
                    }
                }
            }

            foreach ($csvRow as $name => $value) {
                if (in_array($name, $this->unsupportedColumns)) {
                    unset($allColumns[$name]);
                } else {
                    $allColumns[$name] = true;
                }
            }

            if (!$this->hideIdSubDatatable && !$this->hideMetadata) {
                $idsubdatatable = $row->getIdSubDataTable();
                if ($idsubdatatable !== false) {
                    $csvRow['idsubdatatable'] = $idsubdatatable;
                }
            }

            $csv[] = $csvRow;
        }

        if (!empty($this->unsupportedColumns)) {
            foreach ($this->unsupportedColumns as $unsupportedColumn) {
                foreach ($csv as $index => $row) {
                    unset($row[$index][$unsupportedColumn]);
                }
            }
        }

        return $csv;
    }

    /**
     * @param $str
     * @return string
     */
    private function convertToUnicode($str)
    {
        if (
            $this->convertToUnicode
            && function_exists('mb_convert_encoding')
        ) {
            $str = chr(255) . chr(254) . mb_convert_encoding($str, 'UTF-16LE', 'UTF-8');
        }
        return $str;
    }

    protected function removeFirstPercentSign(string $value): string
    {
        // remove all null byte chars from the beginning
        $value = ltrim($value, "\0");

        while (0 === strpos($value, '%00')) {
            $value = ltrim(substr($value, 3), "\0");
        }

        $posPercent = strpos($value, '%');
        if ($posPercent !== false) {
            return substr_replace($value, '', $posPercent, 1);
        }
        return $value;
    }
}
