<?php

declare(strict_types = 1);

/**
 * This file is part of the 'Yasumi' package.
 *
 * The easy PHP Library for calculating holidays.
 *
 * Copyright (c) 2015 - 2026 AzuyaLabs
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @author Sacha Telgenhof <me at sachatelgenhof dot com>
 */

namespace Yasumi\Provider;

use Yasumi\Exception\UnknownLocaleException;
use Yasumi\Holiday;
use Yasumi\SubstituteHoliday;

/**
 * Provider for all holidays in the USA.
 */
class USA extends AbstractProvider
{
    use CommonHolidays;
    use ChristianHolidays;

    /**
     * Code to identify this Holiday Provider. Typically, this is the ISO3166 code corresponding to the respective
     * country or sub-region.
     */
    public const ID = 'US';

    /**
     * Initialize holidays for the USA.
     *
     * @throws \InvalidArgumentException
     * @throws UnknownLocaleException
     * @throws \Exception
     */
    public function initialize(): void
    {
        $this->timezone = 'America/New_York';

        // Add common holidays
        $this->addHoliday($this->newYearsDay($this->year, $this->timezone, $this->locale));

        // Add Christian holidays
        $this->addHoliday($this->christmasDay($this->year, $this->timezone, $this->locale));

        // Calculate other holidays
        $this->calculateMartinLutherKingday();
        $this->calculateWashingtonsBirthday();
        $this->calculateMemorialDay();
        $this->calculateJuneteenth();
        $this->calculateIndependenceDay();
        $this->calculateLabourDay();
        $this->calculateColumbusDay();
        $this->calculateVeteransDay();
        $this->calculateThanksgivingDay();

        $this->calculateSubstituteHolidays();
    }

    public function getSources(): array
    {
        return [
            'https://en.wikipedia.org/wiki/Public_holidays_in_the_United_States',
        ];
    }

    /**
     * Dr. Martin Luther King Day.
     *
     * Honors Dr. Martin Luther King, Jr., Civil Rights leader, who was actually born on January 15, 1929; combined
     * with other holidays in several states. It is observed on the third Monday of January since 1986.
     *
     * @see https://en.wikipedia.org/wiki/Martin_Luther_King,_Jr._Day
     *
     * @throws \Exception
     */
    protected function calculateMartinLutherKingday(): void
    {
        if ($this->year >= 1986) {
            $this->addHoliday(new Holiday('martinLutherKingDay', [
                'en' => 'Dr. Martin Luther King Jr’s Birthday',
            ], new \DateTime("third monday of january {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone)), $this->locale));
        }
    }

    /**
     * Washington's Birthday.
     *
     * Washington's Birthday is a United States federal holiday celebrated on the third Monday of February in honor
     * of George Washington, the first President of the United States. Colloquially, it is widely known as
     * Presidents Day and is often an occasion to remember all the presidents.
     *
     * Washington's Birthday was first declared a federal holiday by an 1879 act of Congress. The Uniform Holidays
     * Act, 1968 shifted the date of the commemoration of Washington's Birthday from February 22 to the third Monday
     * in February.
     *
     * @see https://en.wikipedia.org/wiki/Washington%27s_Birthday
     *
     * @throws \Exception
     */
    protected function calculateWashingtonsBirthday(): void
    {
        if ($this->year >= 1879) {
            $date = new \DateTime("{$this->year}-2-22", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            if ($this->year >= 1968) {
                $date = new \DateTime("third monday of february {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            }
            $this->addHoliday(new Holiday('washingtonsBirthday', [
                'en' => 'Washington’s Birthday',
            ], $date, $this->locale));
        }
    }

    /**
     * Memorial Day.
     *
     * Honors the nation's war dead from the Civil War onwards; marks the unofficial beginning of the summer season.
     *
     * Memorial Day was first declared a federal holiday on May 1, 1865. The Uniform Holidays Act, 1968 shifted the
     * date of the commemoration of Memorial Day from May 30 to the last Monday in May.
     *
     * @see https://en.wikipedia.org/wiki/Memorial_Day
     *
     * @throws \Exception
     */
    protected function calculateMemorialDay(): void
    {
        if ($this->year >= 1865) {
            $date = new \DateTime("{$this->year}-5-30", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            if ($this->year >= 1968) {
                $date = new \DateTime("last monday of may {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            }
            $this->addHoliday(new Holiday('memorialDay', [
                'en' => 'Memorial Day',
            ], $date, $this->locale));
        }
    }

    /**
     * Juneteenth National Independence Day.
     *
     * Juneteenth National Independence Day, commonly known simply as Juneteenth, is a federal holiday in the United
     * States commemorating the end of slavery. Established as a federal holiday on June 17, 2021, Juneteenth is
     * celebrated annually on June 19. In case Juneteenth falls on a Sunday, a substituted holiday is observed
     * the following Monday. If it falls on a Saturday, a substituted holiday is observed the previous Friday.
     *
     * @see https://en.wikipedia.org/wiki/Juneteenth
     *
     * @throws \Exception
     */
    protected function calculateJuneteenth(): void
    {
        if ($this->year >= 2021) {
            $date = new \DateTime("{$this->year}-6-19", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            $label = 'Juneteenth';

            $holiday = new Holiday('juneteenth', [
                'en' => $label,
            ], $date, $this->locale);
            $this->addHoliday($holiday);

            $day_of_week = (int) $date->format('w');

            if (0 === $day_of_week || 6 === $day_of_week) {
                $date = clone $holiday;
                $date->modify('previous friday');

                if (0 === $day_of_week) {
                    $date->modify('next monday');
                }

                $this->addHoliday(new SubstituteHoliday(
                    $holiday,
                    [
                        'en' => $label . ' (observed)',
                    ],
                    $date,
                    $this->locale
                ));
            }
        }
    }

    /**
     * Independence Day.
     *
     * Independence Day, commonly known as the Fourth of July or July Fourth, is a federal holiday in the United
     * States commemorating the adoption of the Declaration of Independence on July 4, 1776, declaring independence
     * from Great Britain. In case Independence Day falls on a Sunday, a substituted holiday is observed the
     * following Monday. If it falls on a Saturday, a substituted holiday is observed the previous Friday.
     *
     * @see https://en.wikipedia.org/wiki/Independence_Day_(United_States)
     *
     * @throws \Exception
     */
    protected function calculateIndependenceDay(): void
    {
        if ($this->year >= 1776) {
            $this->addHoliday(new Holiday('independenceDay', [
                'en' => 'Independence Day',
            ], new \DateTime("{$this->year}-7-4", DateTimeZoneFactory::getDateTimeZone($this->timezone)), $this->locale));
        }
    }

    /**
     * Labour Day.
     *
     * Labor Day in the United States is a holiday celebrated on the first Monday in September. It is a celebration
     * of the American labor movement and is dedicated to the social and economic achievements of workers.
     *
     * @see https://en.wikipedia.org/wiki/Labor_Day
     *
     * @throws \Exception
     */
    protected function calculateLabourDay(): void
    {
        if ($this->year >= 1887) {
            $this->addHoliday(new Holiday(
                'labourDay',
                [
                    'en' => 'Labour Day',
                ],
                new \DateTime("first monday of september {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone)),
                $this->locale
            ));
        }
    }

    /**
     * Columbus Day.
     *
     * Honors Christopher Columbus, traditional discoverer of the Americas. In some areas it is also a celebration
     * of Indigenous Peoples, or Italian culture and heritage. (traditionally October 12). Columbus Day first became
     * an official state holiday in Colorado in 1906, and became a federal holiday in the United States in 1937,
     * though people have celebrated Columbus's voyage since the colonial period. Since 1970 (Oct. 12), the holiday
     * has been fixed to the second Monday in October.
     *
     * @see https://en.wikipedia.org/wiki/Columbus_Day
     *
     * @throws \Exception
     */
    protected function calculateColumbusDay(): void
    {
        if ($this->year >= 1937) {
            $date = new \DateTime("{$this->year}-10-12", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            if ($this->year >= 1970) {
                $date = new \DateTime("second monday of october {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone));
            }
            $this->addHoliday(new Holiday('columbusDay', [
                'en' => 'Columbus Day',
            ], $date, $this->locale));
        }
    }

    /**
     * Veterans Day.
     *
     * Veterans Day is an official United States holiday that honors people who have served in the U.S. Armed Forces
     * also known as veterans. It is a federal holiday that is observed on November 11 since 1919. Congress amended
     * a bill on June 1, 1954, replacing "Armistice" with "Veterans," and it has been known as Veterans Day since.
     *
     * @see https://en.wikipedia.org/wiki/Veterans_Day
     *
     * @throws \Exception
     */
    protected function calculateVeteransDay(): void
    {
        if ($this->year >= 1919) {
            $name = $this->year < 1954 ? 'Armistice Day' : 'Veterans Day';

            $this->addHoliday(new Holiday('veteransDay', [
                'en' => $name,
            ], new \DateTime("{$this->year}-11-11", DateTimeZoneFactory::getDateTimeZone($this->timezone)), $this->locale));
        }
    }

    /**
     * Thanksgiving Day.
     *
     * Thanksgiving, or Thanksgiving Day, is a holiday celebrated in the United States on the fourth Thursday in
     * November. It has been celebrated as a federal holiday every year since 1863, when, during the Civil War,
     * President Abraham Lincoln proclaimed a national day of "Thanksgiving and Praise to our beneficent Father who
     * dwelleth in the Heavens", to be celebrated on the last Thursday in November.
     *
     * @see https://en.wikipedia.org/wiki/Thanksgiving_(United_States)
     *
     * @throws \Exception
     */
    protected function calculateThanksgivingDay(): void
    {
        if ($this->year >= 1863) {
            $this->addHoliday(new Holiday(
                'thanksgivingDay',
                [
                    'en' => 'Thanksgiving Day',
                ],
                new \DateTime("fourth thursday of november {$this->year}", DateTimeZoneFactory::getDateTimeZone($this->timezone)),
                $this->locale
            ));
        }
    }

    /**
     * Calculate substitute holidays.
     *
     * When New Year's Day, Independence Day, or Christmas Day falls on a Saturday, the previous day is also a holiday.
     * When one of these holidays fall on a Sunday, the next day is also a holiday.
     *
     * @throws \InvalidArgumentException
     * @throws UnknownLocaleException
     * @throws \Exception
     */
    protected function calculateSubstituteHolidays(): void
    {
        // Loop through all defined holidays
        foreach ($this->getHolidays() as $holiday) {
            if (! $holiday instanceof Holiday) {
                continue;
            }

            $date = null;

            // Substitute holiday is on a Monday in case the holiday falls on a Sunday
            if (0 === (int) $holiday->format('w')) {
                $date = clone $holiday;
                $date->add(new \DateInterval('P1D'));
            }

            // Substitute holiday is on a Friday in case the holiday falls on a Saturday
            if (6 === (int) $holiday->format('w')) {
                $date = clone $holiday;
                $date->sub(new \DateInterval('P1D'));
            }

            // Add substitute holiday
            if ($date instanceof Holiday) {
                $this->addHoliday(new SubstituteHoliday(
                    $holiday,
                    [],
                    $date,
                    $this->locale
                ));
            }
        }
    }
}
