<?php

namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\Statistical;

use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Database\DAverage;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Database\DCount;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Database\DMax;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Database\DMin;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Database\DSum;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception as CalcException;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Functions;

class Conditional
{
	private const CONDITION_COLUMN_NAME = 'CONDITION';
	private const VALUE_COLUMN_NAME = 'VALUE';
	private const CONDITIONAL_COLUMN_NAME = 'CONDITIONAL %d';

	/**
	 * AVERAGEIF.
	 *
	 * Returns the average value from a range of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        AVERAGEIF(range,condition[, average_range])
	 *
	 * @param mixed $range Data values
	 * @param string $condition the criteria that defines which cells will be checked
	 * @param mixed $averageRange Data values
	 *
	 * @return null|float|string
	 */
	public static function AVERAGEIF($range, $condition, $averageRange = [])
	{
		if (!is_array($range) || !is_array($averageRange) || array_key_exists(0, $range) || array_key_exists(0, $averageRange)) {
			throw new CalcException('Must specify range of cells, not any kind of literal');
		}
		$database = self::databaseFromRangeAndValue($range, $averageRange);
		$condition = [[self::CONDITION_COLUMN_NAME, self::VALUE_COLUMN_NAME], [$condition, null]];

		return DAverage::evaluate($database, self::VALUE_COLUMN_NAME, $condition);
	}

	/**
	 * AVERAGEIFS.
	 *
	 * Counts the number of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        AVERAGEIFS(average_range, criteria_range1, criteria1, [criteria_range2, criteria2]…)
	 *
	 * @param mixed $args Pairs of Ranges and Criteria
	 *
	 * @return null|float|string
	 */
	public static function AVERAGEIFS(...$args)
	{
		if (empty($args)) {
			return 0.0;
		} elseif (count($args) === 3) {
			return self::AVERAGEIF($args[1], $args[2], $args[0]);
		}
		foreach ($args as $arg) {
			if (is_array($arg) && array_key_exists(0, $arg)) {
				throw new CalcException('Must specify range of cells, not any kind of literal');
			}
		}

		$conditions = self::buildConditionSetForValueRange(...$args);
		$database = self::buildDatabaseWithValueRange(...$args);

		return DAverage::evaluate($database, self::VALUE_COLUMN_NAME, $conditions);
	}

	/**
	 * COUNTIF.
	 *
	 * Counts the number of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        COUNTIF(range,condition)
	 *
	 * @param mixed[] $range Data values
	 * @param string $condition the criteria that defines which cells will be counted
	 *
	 * @return int|string
	 */
	public static function COUNTIF($range, $condition)
	{
		// Filter out any empty values that shouldn't be included in a COUNT
		$range = array_filter(
			Functions::flattenArray($range),
			function ($value) {
				return $value !== null && $value !== '';
			}
		);

		$range = array_merge([[self::CONDITION_COLUMN_NAME]], array_chunk($range, 1));
		$condition = array_merge([[self::CONDITION_COLUMN_NAME]], [[$condition]]);

		return DCount::evaluate($range, null, $condition, false);
	}

	/**
	 * COUNTIFS.
	 *
	 * Counts the number of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        COUNTIFS(criteria_range1, criteria1, [criteria_range2, criteria2]…)
	 *
	 * @param mixed $args Pairs of Ranges and Criteria
	 *
	 * @return int|string
	 */
	public static function COUNTIFS(...$args)
	{
		if (empty($args)) {
			return 0;
		} elseif (count($args) === 2) {
			return self::COUNTIF(...$args);
		}

		$database = self::buildDatabase(...$args);
		$conditions = self::buildConditionSet(...$args);

		return DCount::evaluate($database, null, $conditions, false);
	}

	/**
	 * MAXIFS.
	 *
	 * Returns the maximum value within a range of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        MAXIFS(max_range, criteria_range1, criteria1, [criteria_range2, criteria2]…)
	 *
	 * @param mixed $args Pairs of Ranges and Criteria
	 *
	 * @return null|float|string
	 */
	public static function MAXIFS(...$args)
	{
		if (empty($args)) {
			return 0.0;
		}

		$conditions = self::buildConditionSetForValueRange(...$args);
		$database = self::buildDatabaseWithValueRange(...$args);

		return DMax::evaluate($database, self::VALUE_COLUMN_NAME, $conditions, false);
	}

	/**
	 * MINIFS.
	 *
	 * Returns the minimum value within a range of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        MINIFS(min_range, criteria_range1, criteria1, [criteria_range2, criteria2]…)
	 *
	 * @param mixed $args Pairs of Ranges and Criteria
	 *
	 * @return null|float|string
	 */
	public static function MINIFS(...$args)
	{
		if (empty($args)) {
			return 0.0;
		}

		$conditions = self::buildConditionSetForValueRange(...$args);
		$database = self::buildDatabaseWithValueRange(...$args);

		return DMin::evaluate($database, self::VALUE_COLUMN_NAME, $conditions, false);
	}

	/**
	 * SUMIF.
	 *
	 * Totals the values of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        SUMIF(range, criteria, [sum_range])
	 *
	 * @param mixed $range Data values
	 * @param mixed $sumRange
	 * @param mixed $condition
	 *
	 * @return null|float|string
	 */
	public static function SUMIF($range, $condition, $sumRange = [])
	{
		$database = self::databaseFromRangeAndValue($range, $sumRange);
		$condition = [[self::CONDITION_COLUMN_NAME, self::VALUE_COLUMN_NAME], [$condition, null]];

		return DSum::evaluate($database, self::VALUE_COLUMN_NAME, $condition);
	}

	/**
	 * SUMIFS.
	 *
	 * Counts the number of cells that contain numbers within the list of arguments
	 *
	 * Excel Function:
	 *        SUMIFS(average_range, criteria_range1, criteria1, [criteria_range2, criteria2]…)
	 *
	 * @param mixed $args Pairs of Ranges and Criteria
	 *
	 * @return null|float|string
	 */
	public static function SUMIFS(...$args)
	{
		if (empty($args)) {
			return 0.0;
		} elseif (count($args) === 3) {
			return self::SUMIF($args[1], $args[2], $args[0]);
		}

		$conditions = self::buildConditionSetForValueRange(...$args);
		$database = self::buildDatabaseWithValueRange(...$args);

		return DSum::evaluate($database, self::VALUE_COLUMN_NAME, $conditions);
	}

	/** @param array $args */
	private static function buildConditionSet(...$args): array
	{
		$conditions = self::buildConditions(1, ...$args);

		// Scrutinizer thinks first parameter of array_map can't be null. It is wrong.
		return array_map(/** @scrutinizer ignore-type */ null, ...$conditions);
	}

	/** @param array $args */
	private static function buildConditionSetForValueRange(...$args): array
	{
		$conditions = self::buildConditions(2, ...$args);

		if (count($conditions) === 1) {
			return array_map(
				function ($value) {
					return [$value];
				},
				$conditions[0]
			);
		}

		return array_map(/** @scrutinizer ignore-type */ null, ...$conditions);
	}

	/** @param array $args */
	private static function buildConditions(int $startOffset, ...$args): array
	{
		$conditions = [];

		$pairCount = 1;
		$argumentCount = count($args);
		for ($argument = $startOffset; $argument < $argumentCount; $argument += 2) {
			$conditions[] = array_merge([sprintf(self::CONDITIONAL_COLUMN_NAME, $pairCount)], [$args[$argument]]);
			++$pairCount;
		}

		return $conditions;
	}

	/** @param array $args */
	private static function buildDatabase(...$args): array
	{
		$database = [];

		return self::buildDataSet(0, $database, ...$args);
	}

	/** @param array $args */
	private static function buildDatabaseWithValueRange(...$args): array
	{
		$database = [];
		$database[] = array_merge(
			[self::VALUE_COLUMN_NAME],
			Functions::flattenArray($args[0])
		);

		return self::buildDataSet(1, $database, ...$args);
	}

	/** @param array $args */
	private static function buildDataSet(int $startOffset, array $database, ...$args): array
	{
		$pairCount = 1;
		$argumentCount = count($args);
		for ($argument = $startOffset; $argument < $argumentCount; $argument += 2) {
			$database[] = array_merge(
				[sprintf(self::CONDITIONAL_COLUMN_NAME, $pairCount)],
				Functions::flattenArray($args[$argument])
			);
			++$pairCount;
		}

		return array_map(/** @scrutinizer ignore-type */ null, ...$database);
	}

	private static function databaseFromRangeAndValue(array $range, array $valueRange = []): array
	{
		$range = Functions::flattenArray($range);

		$valueRange = Functions::flattenArray($valueRange);
		if (empty($valueRange)) {
			$valueRange = $range;
		}

		$database = array_map(/** @scrutinizer ignore-type */ null, array_merge([self::CONDITION_COLUMN_NAME], $range), array_merge([self::VALUE_COLUMN_NAME], $valueRange));

		return $database;
	}
}
