<?php

use MediaWiki\MediaWikiServices;

/**
 * AJAX Poll class
 * Created by Dariusz Siedlecki, based on the work by Eric David.
 * Licensed under the GFDL.
 *
 * @file
 * @ingroup Extensions
 * @author Dariusz Siedlecki <datrio@gmail.com>
 * @author Jack Phoenix
 * @author Thomas Gries
 * @maintainer Thomas Gries
 * @link https://www.mediawiki.org/wiki/Extension:AJAX_Poll Documentation
 */
class AJAXPoll {

	/**
	 * Register <poll> tag with the parser
	 *
	 * @param Parser $parser A parser instance, not necessarily $wgParser
	 */
	public static function onParserFirstCallInit( $parser ) {
		$parser->setHook( 'poll', [ __CLASS__, 'render' ] );
	}

	/**
	 * The callback function for converting the input text to HTML output
	 *
	 * @param string $input
	 * @param array $args
	 * @param Parser $parser
	 * @param PPFrame $frame
	 * @return string
	 */
	public static function render( $input, $args, Parser $parser, $frame ) {
		$parser->getOutput()->updateCacheExpiry( 0 );
		$parser->addTrackingCategory( 'ajaxpoll-tracking-category' );
		$parser->getOutput()->addModules( [ 'ext.ajaxpoll' ] );

		// ID of the poll
		if ( isset( $args['id'] ) ) {
			$id = $args['id'];
		} else {
			$id = strtoupper( md5( $input ) );
		}

		// get the input
		$input = $parser->recursiveTagParse( $input, $frame );
		$input = trim( strip_tags( $input ) );
		$lines = explode( "\n", trim( $input ) );

		$dbw = wfGetDB( DB_PRIMARY );

		/**
		 * Register poll in the database
		 */

		$row = $dbw->selectRow(
			[ 'ajaxpoll_info' ],
			[ 'poll_show_results_before_voting' ],
			[ 'poll_id' => $id ],
			__METHOD__
		);

		$showResultsBeforeVoting = null;
		if ( array_key_exists( 'show-results-before-voting', $args ) ) {
			if ( strval( $args['show-results-before-voting'] ) !== '0' ) {
				$showResultsBeforeVoting = '1';
			} else {
				$showResultsBeforeVoting = '0';
			}
		}

		$readonly = MediaWikiServices::getInstance()->getReadOnlyMode()->getReason();
		if ( !$readonly ) {
			if ( $row === false ) {
				$dbw->insert(
					'ajaxpoll_info',
					[
						'poll_id' => $id,
						'poll_show_results_before_voting' => $showResultsBeforeVoting,
						'poll_txt' => $input,
						'poll_date' => $dbw->timestamp( wfTimestampNow() ),
					],
					__METHOD__,
					// @todo FIXME: This is a crappy hack to fix obviously incorrect and nonsensical
					// "Error: 1062 Duplicate entry '<whatever>' for key 'PRIMARY' (localhost)"
					// error messages, one of which I saw when literally making the very first poll
					// on a wiki, so it goes w/o saying that there can't (or at least shouldn't) be
					// any other entries in AJAXPoll's DB tables at that time.
					// All the DB queries in this method should be refactored and ideally instead
					// of insert()/update() this'd use upsert().
					// @see https://phabricator.wikimedia.org/T163625
					[ 'IGNORE' ]
				);
			} elseif ( $row->poll_show_results_before_voting !== $showResultsBeforeVoting ) {
				$dbw->update(
					'ajaxpoll_info',
					[
						'poll_show_results_before_voting' => $showResultsBeforeVoting,
					],
					[
						'poll_id' => $id,
					],
					__METHOD__
				);
			}
		}

		switch ( $lines[0] ) {
			case 'STATS':
				$ret = self::buildStats();
				break;
			default:
				if ( method_exists( $parser, 'getUserIdentity' ) ) {
					// MW 1.36+
					$user = MediaWikiServices::getInstance()
						->getUserFactory()->newFromUserIdentity( $parser->getUserIdentity() );
				} else {
					$user = $parser->getUser();
				}
				$ret = Html::rawElement( 'div',
					[
						'id' => 'ajaxpoll-container-' . $id
					],
					self::buildHTML( $id, $user, $readonly, $lines )
				);
				break;
		}

		return $ret;
	}

	private static function buildStats() {
		$dbr = wfGetDB( DB_REPLICA );

		$tab = $dbr->selectRow(
			'ajaxpoll_vote',
			[
				'votes' => 'COUNT(*)',
				'polls' => 'COUNT(DISTINCT poll_id)',
				'actors' => 'COUNT(DISTINCT poll_actor)',
				'timediff' => 'TIMEDIFF(NOW(), MAX(poll_date))'
			],
			[],
			__METHOD__
		);

		$clock = explode( ':', $tab->timediff );

		if ( $clock[0] == '00' && $clock[1] == '00' ) {
			$x = $clock[2];
			$y = 'second';
		} elseif ( $clock[0] == '00' ) {
			$x = $clock[1];
			$y = 'minute';
		} else {
			if ( $clock[0] < 24 ) {
				$x = $clock[0];
				$y = 'hour';
			} else {
				$x = floor( $hr / 24 );
				$y = 'day';
			}
		}

		$clockago = $x . ' ' . $y . ( $x > 1 ? 's' : '' );

		$tab2 = $dbr->selectRow(
			'ajaxpoll_vote',
			[ 'votes' => 'COUNT(*)' ],
			[ 'DATE_SUB(CURDATE(), INTERVAL 2 DAY) <= poll_date' ],
			__METHOD__
		);

		return "There are {$tab->polls} polls and {$tab->votes} votes given by {$tab->actors} different people.<br />
The last vote has been given $clockago ago.<br/>
During the last 48 hours, {$tab2->votes} votes have been given.";
	}

	/**
	 * @param int $id
	 * @param string $answer
	 * @param User $user
	 * @return bool
	 */
	public static function submitVote( $id, $answer, User $user ) {
		$readonly = MediaWikiServices::getInstance()->getReadOnlyMode()->getReason();

		if ( !$user->isAllowed( 'ajaxpoll-vote' ) || $user->isBot() ) {
			return self::buildHTML( $id, $user, $readonly );
		}

		if ( $readonly ) {
			return self::buildHTML( $id, $user, $readonly, '' );
		}

		$dbw = wfGetDB( DB_PRIMARY );

		if ( $answer != 0 ) {
			$answer = ++$answer;

			$row = $dbw->selectRow(
				'ajaxpoll_vote',
				'COUNT(*) AS count',
				[
					'poll_id' => $id,
					'poll_actor' => $user->getActorId()
				],
				__METHOD__
			);

			if ( $row->count > 0 ) {
				$pollContainerText = self::updateVote( $dbw, $id, $user, $answer );
			} else {
				$pollContainerText = self::addVote( $dbw, $id, $user, $answer );
			}
		} else { // revoking a vote
			$pollContainerText = self::revokeVote( $dbw, $id, $user );
		}

		return self::buildHTML( $id, $user, false, '', $pollContainerText );
	}

	/**
	 * @todo FIXME: these three *vote() methods are kinda sucky.
	 * Ideally they'd return a Status or somesuch and wouldn't take a $dbw param
	 * but the param is right now needed since all methods of this class are static...
	 *
	 * I am not amused by having to do all sorts of weird magic to get around jenkins
	 * being stupid.
	 *
	 * @param IDatabase $dbw Write connection to a database
	 * @param string $id Poll ID
	 * @param User $user User (object) who is voting
	 * @param int $answer Answer option #
	 * @return string Name of an i18n msg to show to the user
	 */
	public static function addVote( $dbw, $id, $user, $answer ) {
		global $wgRequest;
		$insertQuery = $dbw->insert(
			'ajaxpoll_vote',
			[
				'poll_id' => $id,
				'poll_actor' => $user->getActorId(),
				'poll_ip' => $wgRequest->getIP(),
				'poll_answer' => $answer,
				'poll_date' => $dbw->timestamp( wfTimestampNow() )
			],
			__METHOD__
		);
		return ( $insertQuery ) ? 'ajaxpoll-vote-add' : 'ajaxpoll-vote-error';
	}

	/**
	 * @param IDatabase $dbw Write connection to a database
	 * @param string $id Poll ID
	 * @param User $user User (object) who is voting
	 * @return string Name of an i18n msg to show to the user
	 */
	public static function revokeVote( $dbw, $id, $user ) {
		$deleteQuery = $dbw->delete(
			'ajaxpoll_vote',
			[
				'poll_id' => $id,
				'poll_actor' => $user->getActorId()
			],
			__METHOD__
		);
		return ( $deleteQuery ) ? 'ajaxpoll-vote-revoked' : 'ajaxpoll-vote-error';
	}

	/**
	 * @param IDatabase $dbw Write connection to a database
	 * @param string $id Poll ID
	 * @param User $user User (object) who is voting
	 * @param int $answer Answer option #
	 * @return string Name of an i18n msg to show to the user
	 */
	public static function updateVote( $dbw, $id, $user, $answer ) {
		$updateQuery = $dbw->update(
			'ajaxpoll_vote',
			[
				'poll_answer' => $answer,
				'poll_date' => $dbw->timestamp( wfTimestampNow() )
			],
			[
				'poll_id' => $id,
				'poll_actor' => $user->getActorId()
			],
			__METHOD__
		);
		return ( $updateQuery ) ? 'ajaxpoll-vote-update' : 'ajaxpoll-vote-error';
	}

	private static function escapeContent( $string ) {
		return htmlspecialchars( Sanitizer::decodeCharReferences( $string ), ENT_QUOTES );
	}

	private static function buildHTML( $id, $user, $readonly, $lines = '', $extra_from_ajax = '' ) {
		global $wgTitle, $wgLang;

		$dbr = wfGetDB( DB_REPLICA );

		$row = $dbr->selectRow(
			'ajaxpoll_info',
			[ 'poll_txt', 'poll_date', 'poll_show_results_before_voting' ],
			[ 'poll_id' => $id ],
			__METHOD__
		);

		if ( empty( $lines ) ) {
			$lines = explode( "\n", trim( $row->poll_txt ) );
		}

		if ( $row->poll_show_results_before_voting !== null ) {
			$showResultsBeforeVoting = ( $row->poll_show_results_before_voting === '1' );
		} else {
			$showResultsBeforeVoting = $user->isAllowed( 'ajaxpoll-view-results-before-vote' );
		}

		$start_date = $row->poll_date;

		$q = $dbr->select(
			'ajaxpoll_vote',
			[ 'poll_answer', 'count' => 'COUNT(*)' ],
			[ 'poll_id' => $id ],
			__METHOD__,
			[ 'GROUP BY' => 'poll_answer' ]
		);

		$poll_result = [];

		foreach ( $q as $row ) {
			$poll_result[$row->poll_answer] = $row->count;
		}

		$amountOfVotes = array_sum( $poll_result );

		// Did we vote?
		$userVoted = false;

		$row = $dbr->selectRow(
			'ajaxpoll_vote',
			[ 'poll_answer', 'poll_date' ],
			[
				'poll_id' => $id,
				'poll_actor' => $user->getActorId()
			],
			__METHOD__
		);

		if ( $row ) {
			$ts = wfTimestamp( TS_MW, $row->poll_date );
			$ourLastVoteDate = wfMessage(
				'ajaxpoll-your-vote',
				$lines[$row->poll_answer - 1],
				$wgLang->timeanddate( $ts, true /* adjust? */ ),
				$wgLang->date( $ts, true /* adjust? */ ),
				$wgLang->time( $ts, true /* adjust? */ )
			)->escaped();
			$userVoted = true;
		}

		$ret = '';
		if ( is_object( $wgTitle ) ) {
			if ( !empty( $extra_from_ajax ) ) {
				$style = 'display:inline-block';
				$ajaxMessage = wfMessage( $extra_from_ajax )->escaped();
			} else {
				$style = 'display:none';
				$ajaxMessage = '';
			}

			$ret = Html::openElement( 'div',
				[
					'id' => 'ajaxpoll-id-' . $id,
					'class' => 'ajaxpoll'
				]
			);

			$ret .= Html::element( 'div',
				[
					'id' => 'ajaxpoll-ajax-' . $id,
					'class' => 'ajaxpoll-ajax',
					'style' => $style
				],
				$ajaxMessage
			);

			$ret .= Html::rawElement( 'div',
				[ 'class' => 'ajaxpoll-question' ],
				self::escapeContent( $lines[0] )
			);

			// Different messages depending whether the user has already voted
			// or has not voted, or is entitled to vote

			$canRevoke = false;

			if ( $user->isAllowed( 'ajaxpoll-vote' ) ) {
				if ( isset( $row->poll_answer ) ) {
					$message = $ourLastVoteDate;
					$canRevoke = true;
					$lines[] = wfMessage( 'ajaxpoll-revoke-vote' )->text();
				} else {
					if ( $showResultsBeforeVoting ) {
						$message = wfMessage( 'ajaxpoll-no-vote' )->text();
					} else {
						$message = wfMessage( 'ajaxpoll-no-vote-results-after-voting' )->text();
					}
				}
			} else {
				$message = wfMessage( 'ajaxpoll-vote-permission' )->text();
			}

			if ( !$user->isAllowed( 'ajaxpoll-view-results' ) ) {
				$message .= '<br/>' . wfMessage( 'ajaxpoll-view-results-permission' )->text();
			} elseif ( !$userVoted
				&& !$user->isAllowed( 'ajaxpoll-view-results-before-vote' )
				&& !$showResultsBeforeVoting
			) {
				if ( $user->isAllowed( 'ajaxpoll-vote' ) ) {
					$message .= '<br/>' . wfMessage( 'ajaxpoll-view-results-before-vote-permission' )->text();
				} else {
					$message .= '<br/>' . wfMessage( 'ajaxpoll-view-results-permission' )->text();
				}
			}

			$ret .= Html::rawElement( 'div',
				[ 'class' => 'ajaxpoll-misc' ],
				$message
			);

			$ret .= Html::rawElement( 'form',
				[
					'method' => 'post',
					'action' => $wgTitle->getLocalURL(),
					'id' => 'ajaxpoll-answer-id-' . $id
				],
				Html::element( 'input',
					[
						'type' => 'hidden',
						'name' => 'ajaxpoll-post-id',
						'value' => $id
					]
				)
			);

			$linesCount = count( $lines );
			for ( $i = 1; $i < $linesCount; $i++ ) {
				$vote = !( $canRevoke && ( $i == $linesCount - 1 ) );

				// answers are counted from 1 ... n
				// last answer is pseudo-answer for "I want to revoke vote"
				// and becomes answer number 0

				$answer = ( $vote ) ? $i : 0;
				$xid = $id . '-' . $answer;

				if ( ( $amountOfVotes !== 0 ) && ( isset( $poll_result[$i + 1] ) ) ) {
					$pollResult = $poll_result[$i + 1];
					$percent = round( $pollResult * 100 / $amountOfVotes, 2 );
				} else {
					$pollResult = 0;
					$percent = 0;
				}

				$border = ( $percent == 0 ) ? ' border:0;' : '';
				$isOurVote = ( isset( $row->poll_answer ) && ( $row->poll_answer - 1 == $i ) );

				$resultBar = '';

				if (
					$user->isAllowed( 'ajaxpoll-view-results' ) &&
					( $showResultsBeforeVoting || ( !$showResultsBeforeVoting && $userVoted ) ) &&
					$vote
				) {
					$resultBar = Html::rawElement( 'div',
						[
							'class' => 'ajaxpoll-answer-vote' . ( $isOurVote ? ' ajaxpoll-our-vote' : '' )
						],
						Html::rawElement( 'span',
							[
								'title' => wfMessage( 'ajaxpoll-percent-votes' )->numParams( $percent )->escaped()
							],
							self::escapeContent( $pollResult )
						) .
						Html::element( 'div',
							[
								'style' => 'width:' . $percent . '%;' . $border
							]
						)
					);
				}

				if ( !$readonly && $user->isAllowed( 'ajaxpoll-vote' ) ) {
					$ret .= Html::rawElement( 'div',
						[
							'id' => 'ajaxpoll-answer-' . $xid,
							'class' => 'ajaxpoll-answer',
							'poll' => $id,
							'answer' => $answer,
						],
						Html::rawElement( 'div',
							[
								'class' => 'ajaxpoll-answer-name' . ( $vote ? ' ajaxpoll-answer-name-revoke' : '' )
							],
							Html::rawElement( 'label',
								[ 'for' => 'ajaxpoll-post-answer-' . $xid ],
								Html::element( 'input',
									[
										'type' => 'radio',
										'id' => 'ajaxpoll-post-answer-' . $xid,
										'name' => 'ajaxpoll-post-answer-' . $id,
										'value' => $answer,
										'checked' => $isOurVote ? 'true' : false,
									]
								) .
								self::escapeContent( $lines[$i] )
							)
						) .
						$resultBar
					);
				} else {
					if ( !$user->isAllowed( 'ajaxpoll-vote' ) ) {
						$disabledReason = wfMessage( 'ajaxpoll-vote-permission' )->escaped();
					} else {
						$disabledReason = wfMessage( 'ajaxpoll-readonly', $readonly )->escaped();
					}

					$ret .= Html::rawElement( 'div',
						[
							'id' => 'ajaxpoll-answer-' . $xid,
							'class' => 'ajaxpoll-answer',
							'poll' => $id,
							'answer' => $answer
						],
						Html::rawElement( 'div',
							[
								'class' => 'ajaxpoll-answer-name'
							],
							Html::rawElement( 'label',
								[
									'for' => 'ajaxpoll-post-answer-' . $xid,
									'id' => 'ajaxpoll-label-disabled',
									'title' => $disabledReason
								],
								Html::element( 'input',
									[
										'disabled' => 'disabled',
										'type' => 'radio',
										'id' => 'ajaxpoll-post-answer-' . $xid,
										'name' => 'ajaxpoll-post-answer-' . $id,
										'value' => $answer
									]
								) .
								self::escapeContent( $lines[$i] )
							)
						) .
						$resultBar
					);
				}
			}

			$ret .= Xml::closeElement( 'form' );

			// Display information about the poll (creation date, amount of votes)
			$pollSummary = wfMessage(
				'ajaxpoll-info',
				$amountOfVotes, // amount of votes
				$wgLang->timeanddate( wfTimestamp( TS_MW, $start_date ), true /* adjust? */ )
			)->text();

			$ret .= Html::rawElement( 'div',
				[
					'id' => 'ajaxpoll-info-' . $id,
					'class' => 'ajaxpoll-info'
				],
				self::escapeContent( $pollSummary ) .
				// @todo Just why are we exposing this in the UI, again?
				// It's ugly and unnecessary even though technically hidden by CSS.
				Html::element( 'div',
					[ 'class' => 'ajaxpoll-id-info' ],
					'poll-id ' . $id
				)
			);

			$ret .= Html::closeElement( 'div' ) .
				Html::element( 'br' );
		}

		return $ret;
	}

	/**
	 * Adds the two new required database tables into the database when the
	 * end-user (sysadmin) runs /maintenance/update.php
	 * (the core database updater script) and performs other DB updates, such as
	 * the renaming of tables, if upgrading from an older version of this extension.
	 *
	 * @param DatabaseUpdater $updater
	 */
	public static function onLoadExtensionSchemaUpdates( $updater ) {
		$db = $updater->getDB();

		$patchPath = __DIR__ . '/../sql/';
		if ( $db->getType() == 'postgres' ) {
			$patchPath .= 'postgres/';
		}

		if ( $db->tableExists( 'poll_info' ) ) {
			# poll_info.poll_title field was dropped in AJAXPoll version 1.72
			$updater->dropExtensionField(
				'poll_info',
				'poll_title',
				$patchPath . 'drop-field--poll_info-poll_title.sql'
			);
			$updater->addExtensionTable(
				'ajaxpoll_info',
				$patchPath . 'rename-table--poll_info.sql'
			);
		} else {
			$updater->addExtensionTable(
				'ajaxpoll_info',
				$patchPath . 'create-table--ajaxpoll_info.sql'
			);
		}

		if ( $db->tableExists( 'ajaxpoll_info' ) ) {
			$updater->addExtensionField(
				'ajaxpoll_info',
				'poll_show_results_before_voting',
				$patchPath . 'add-field--ajaxpoll_info-poll_show_results_before_voting.sql'
			);
		}

		if ( $db->tableExists( 'poll_vote' ) ) {
			$updater->addExtensionTable(
				'poll_vote',
				$patchPath . 'rename-table--poll_vote.sql'
			);
		} else {
			$updater->addExtensionTable(
				'ajaxpoll_vote',
				$patchPath . 'create-table--ajaxpoll_vote.sql'
			);
		}

		// Actor support

		// 1) add new actor column
		$updater->addExtensionField(
			'ajaxpoll_vote',
			'poll_actor',
			$patchPath . 'add-field-ajaxpoll_vote-poll_actor.sql'
		);

		// 2) do magic
		// This includes, but is not limited to, changing the PRIMARY KEY,
		// adding a new, UNIQUE INDEX on a new AUTO_INCREMENT field (which the
		// script also creates) and, of course, finally the new column is populated
		// with data.
		// PITFALL WARNING! Do NOT change this to $updater->runMaintenance,
		// THEY ARE NOT THE SAME THING and this MUST be using addExtensionUpdate
		// instead for the code to work as desired!
		// HT Skizzerz
		$updater->addExtensionUpdate( [
			'runMaintenance',
			'MigrateOldAJAXPollUserColumnsToActor',
			'../maintenance/migrateOldAJAXPollUserColumnsToActor.php'
		] );

		// 3) drop the now unused column
		$updater->dropExtensionField(
			'ajaxpoll_vote',
			'poll_user',
			$patchPath . 'drop-field-poll_user-ajaxpoll_vote.sql'
		);
	}
}