/**
 * Find all header rows in a thead-less table and put them in a <thead> tag.
 * This only treats a row as a header row if it contains only <th>s (no <td>s)
 * and if it is preceded entirely by header rows. The algorithm stops when
 * it encounters the first non-header row.
 *
 * After this, it will look at all rows at the bottom for footer rows
 * And place these in a tfoot using similar rules.
 *
 * If the footer is an exact duplicate of the header, it will be hidden.
 *
 * This function was copied from MediaWiki's jquery.tablesorter module
 * @param {jQuery} $table object for a <table>
 */
function emulateTHeadAndFoot( $table ) {
    var $thead, $tfoot, i, len,
        $rows = $table.find( '> tbody > tr' );
    if ( !$table.get( 0 ).tHead ) {
        $thead = $( '<thead>' );
        // T289817
        $thead.addClass('mw-sticky-header-element');
        $rows.each( function () {
            if ( $( this ).children( 'td' ).length ) {
                // This row contains a <td>, so it's not a header row
                // Stop here
                return false;
            }
            $thead.append( this );
        } );
        $table.find( ' > tbody:first' ).before( $thead );
    }
    if ( !$table.get( 0 ).tFoot ) {
        $tfoot = $( '<tfoot>' );
        len = $rows.length;
        for ( i = len - 1; i >= 0; i-- ) {
            if ( $( $rows[ i ] ).children( 'td' ).length ) {
                break;
            }
            $tfoot.prepend( $( $rows[ i ] ) );
        }
        $table.append( $tfoot );

        // Check if footer is duplicate of header and hide if so
        hideDuplicateFooter( $table );
    }
}

/**
 * Hide the table footer if it's an exact duplicate of the header
 * @param {jQuery} $table object for a <table>
 */
function hideDuplicateFooter( $table ) {
    var $thead = $table.find( '> thead' );
    var $tfoot = $table.find( '> tfoot' );

    // Only proceed if both thead and tfoot exist
    if ( !$thead.length || !$tfoot.length ) {
        return;
    }

    var $headerRows = $thead.find( 'tr' );
    var $footerRows = $tfoot.find( 'tr' );

    // Must have same number of rows
    if ( $headerRows.length !== $footerRows.length ) {
        return;
    }

    // Compare each row
    var isDuplicate = true;
    $headerRows.each( function( index ) {
        var $headerRow = $( this );
        var $footerRow = $( $footerRows[ index ] );

        // Compare number of cells
        var $headerCells = $headerRow.find( 'th, td' );
        var $footerCells = $footerRow.find( 'th, td' );

        if ( $headerCells.length !== $footerCells.length ) {
            isDuplicate = false;
            return false; // Break out of each loop
        }

        // Compare each cell's text content and tag name
        $headerCells.each( function( cellIndex ) {
            var $headerCell = $( this );
            var $footerCell = $( $footerCells[ cellIndex ] );

            // Compare tag names (th vs td)
            if ( $headerCell.prop( 'tagName' ) !== $footerCell.prop( 'tagName' ) ) {
                isDuplicate = false;
                return false;
            }

            // Compare text content (trimmed to ignore whitespace differences)
            if ( $.trim( $headerCell.text() ) !== $.trim( $footerCell.text() ) ) {
                isDuplicate = false;
                return false;
            }
        } );

        if ( !isDuplicate ) {
            return false; // Break out of row loop
        }
    } );

    // Hide the footer if it's a duplicate
    if ( isDuplicate ) {
        $tfoot.hide();
        // Optionally add a class or data attribute to indicate it was hidden
        $tfoot.attr( 'data-duplicate-hidden', 'true' );
    }
}

mw.hook('wikipage.content').add( function( $content ) {
    // Do this for wikitable, but sortable does it on it's own already
    $content.find('.wikitable:not(.sortable) ').each( function ( i, table ) {
        if ( table.tBodies && !table.tHead ) {
            // No thead found. Look for rows with <th>s and
            // move them into a <thead> tag or a <tfoot> tag
            emulateTHeadAndFoot( $(table).addClass('mw-sticky-header') );
        }
    } );
} );