XSLT: move grouped nodes to parent node - xslt-1.0

Question

I have the following XML:
<data>
<request method="PUT">
<context>
<record_count>5</record_count>
<record_type>Customer</record_type>
</context>
<value>
<company>ABC</company>
<customer>Contoso</customer>
</value>
<value>
<company>ABC</company>
<customer>Forest</customer>
</value>
<value>
<company>XYZ</company>
<customer>Forest</customer>
</value>
<value>
<company>XYZ</company>
<customer>Cave</customer>
</value>
<value>
<company>ABC</company>
<customer>Cave</customer>
</value>
</request>
</data>
and the following transformation:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:key name="company-key" match="value" use="company"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*" />
<xsl:apply-templates />
</xsl:copy>
</xsl:template>
<xsl:template match="/data/request/value" />
<xsl:template match="/data/request/value[count(. | key('company-key', company)[1]) = 1]">
<xsl:element name="group">
<xsl:attribute name="company">
<xsl:value-of select="company"/>
</xsl:attribute>
<xsl:attribute name="method">
<xsl:value-of select="/data/request/#method"/>
</xsl:attribute>
<xsl:attribute name="record-type">
<xsl:value-of select="/data/request/context/record_type"/>
</xsl:attribute>
<xsl:for-each select="key('company-key', company)">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:for-each>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
The transformation groups the data in the value nodes into new nodes.
The name of these nodes is group and they have their own attributes.
This works correctly and the ouput looks like this:
<data>
<request method="PUT">
<context>
<record_count>5</record_count>
<record_type>Customer</record_type>
</context>
<group company="ABC" method="PUT" record-type="Customer">
<value>
<company>ABC</company>
<customer>Contoso</customer>
</value>
<value>
<company>ABC</company>
<customer>Forest</customer>
</value>
<value>
<company>ABC</company>
<customer>Cave</customer>
</value>
</group>
<group company="XYZ" method="PUT" record-type="Customer">
<value>
<company>XYZ</company>
<customer>Forest</customer>
</value>
<value>
<company>XYZ</company>
<customer>Cave</customer>
</value>
</group>
</request>
</data>
The problem I have is that I cannot create a transformation that prepares the data as described and then moves all the "group" nodes to parent "data" node and removes the old "request" node.
All this in one transformation.
The output should look like this:
<data>
<group company="ABC" method="PUT" record-type="Customer">
<value>
<company>ABC</company>
<customer>Contoso</customer>
</value>
<value>
<company>ABC</company>
<customer>Forest</customer>
</value>
<value>
<company>ABC</company>
<customer>Cave</customer>
</value>
</group>
<group company="XYZ" method="PUT" record-type="Customer">
<value>
<company>XYZ</company>
<customer>Forest</customer>
</value>
<value>
<company>XYZ</company>
<customer>Cave</customer>
</value>
</group>
</data>

Answer 1

How about simply:
XSLT 1.0
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:key name="company-key" match="value" use="company"/>
<xsl:template match="/data">
<xsl:variable name="method" select="request/#method" />
<xsl:variable name="record_type" select="request/context/record_type" />
<data>
<xsl:for-each select="request/value[count(. | key('company-key', company)[1]) = 1]">
<group company="{company}" method="{$method}" record-type="{$record_type}">
<xsl:copy-of select="key('company-key', company)"/>
</group>
</xsl:for-each>
</data>
</xsl:template>
</xsl:stylesheet>
Note that this assumes that data contains only one request.