(PureBasic) IMAP Read PEC Email of Aruba and Extract the Invoice XML Files

IMAP Read PEC Email of Aruba and Extract the Invoice XML Files.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkImap.pb"
IncludeFile "CkBinData.pb"
IncludeFile "CkMessageSet.pb"
IncludeFile "CkMime.pb"
IncludeFile "CkEmail.pb"
IncludeFile "CkXml.pb"
IncludeFile "CkCrypt2.pb"
IncludeFile "CkStringBuilder.pb"

Procedure ChilkatExample()

    ; This example requires the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    imap.i = CkImap::ckCreate()
    If imap.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Connect using TLS.
    CkImap::setCkSsl(imap, 1)
    CkImap::setCkPort(imap, 993)
    success.i = CkImap::ckConnect(imap,"imap.example.com")
    If success = 0
        Debug CkImap::ckLastErrorText(imap)
        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    ; Authenticate
    success = CkImap::ckLogin(imap,"email_account_login","email_account_password")
    If success = 0
        Debug CkImap::ckLastErrorText(imap)
        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    ; Select an IMAP mailbox
    success = CkImap::ckSelectMailbox(imap,"Inbox/postacert")
    If success = 0
        Debug CkImap::ckLastErrorText(imap)
        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    ; Search for messages having "POSTA CERTIFICATA: Invio File" in the subject.
    fetchUids.i = 1
    messageSet.i = CkImap::ckSearch(imap,"SUBJECT " + Chr(34) + "POSTA CERTIFICATA: Invio File" + Chr(34),fetchUids)
    If CkImap::ckLastMethodSuccess(imap) = 0
        Debug CkImap::ckLastErrorText(imap)
        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    If CkMessageSet::ckCount(messageSet) < 1
        Debug "No messages found."
        CkMessageSet::ckDispose(messageSet)

        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    ; For our example, we'll process only the 1st email in the messageSet.
    ; Download the MIME source of the email into a StringBuilder object.
    email.i = CkImap::ckFetchSingle(imap,CkMessageSet::ckGetId(messageSet,0),CkMessageSet::ckHasUids(messageSet))
    If CkImap::ckLastMethodSuccess(imap) = 0
        Debug CkImap::ckLastErrorText(imap)
        CkMessageSet::ckDispose(messageSet)

        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    CkMessageSet::ckDispose(messageSet)

    ; The email should contain an attached email.
    ; The Invoice XML is contained within the attached email.
    attachedEmail.i = CkEmail::ckGetAttachedMessage(email,0)
    If CkEmail::ckLastMethodSuccess(email) = 0
        Debug CkEmail::ckLastErrorText(email)
        CkEmail::ckDispose(email)

        CkImap::ckDispose(imap)
        ProcedureReturn
    EndIf

    CkEmail::ckDispose(email)

    ; Get the MIME of the attached email..
    sbMime.i = CkStringBuilder::ckCreate()
    If sbMime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkEmail::ckGetMimeSb(attachedEmail,sbMime)
    CkEmail::ckDispose(attachedEmail)

    ; Load it into a Chilkat MIME object.
    mime.i = CkMime::ckCreate()
    If mime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkMime::ckLoadMimeSb(mime,sbMime)

    ; Examine the structure of the MIME.
    Debug CkMime::ckGetStructure(mime,"text")

    ; The MIME has this structure:
    ; multipart/mixed
    ;     application/octet-stream
    ;     application/octet-stream     <-- This is where the XML is contained.   It is within an opaque signature.
    ;     text/plain

    ; The 2nd application/octet-stream MIME header looks like this:

    ; ------=_Part_329673_-1348225228.1579889273592
    ; Content-Type: application/octet-stream; name="SM99999_99aaa.xml.p7m"
    ; Content-Transfer-Encoding: base64
    ; Content-Disposition: attachment; filename="SM99999_99aaa.xml.p7m"

    ; Let's get the binary content of the .p7m
    bdP7m.i = CkBinData::ckCreate()
    If bdP7m.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Get the 2nd sub-part, at index 1 because index 0 is the 1st sub-part.
    mimeP7m.i = CkMime::ckGetPart(mime,1)
    If CkMime::ckLastMethodSuccess(mime) <> 1
        Debug "Failed to get 2nd sub-part. Perhaps the MIME does not have a 2nd sub-part?"
        CkImap::ckDispose(imap)
        CkStringBuilder::ckDispose(sbMime)
        CkMime::ckDispose(mime)
        CkBinData::ckDispose(bdP7m)
        ProcedureReturn
    EndIf

    success = CkMime::ckGetBodyBd(mimeP7m,bdP7m)
    CkMime::ckDispose(mimeP7m)

    ; Verify the signature, which also extracts the content contained within the opaque signature.
    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCrypt2::ckOpaqueVerifyBd(crypt,bdP7m)
    If success = 0
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkImap::ckDispose(imap)
        CkStringBuilder::ckDispose(sbMime)
        CkMime::ckDispose(mime)
        CkBinData::ckDispose(bdP7m)
        CkCrypt2::ckDispose(crypt)
        ProcedureReturn
    EndIf

    ; The bdP7m now contains the Invoice XML.
    ; Load it into an XML object.
    xml.i = CkXml::ckCreate()
    If xml.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkXml::ckLoadBd(xml,bdP7m,1)

    Debug CkXml::ckGetXml(xml)

    ; We have XML such as the following:
    ; 
    ; <?xml version="1.0" encoding="windows-1252"?>
    ; <?xml-stylesheet type="text/xsl" href="fatturapa_v1.2.xsl"?>
    ; <p:FatturaElettronica versione="FPR12" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" 
    ;     xmlns:p="http://ivaservizi.agenziaentrate.gov.it/docs/xsd/fatture/v1.2" 
    ;     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    ;     <FatturaElettronicaHeader>
    ; 	...
    ;     </FatturaElettronicaHeader>
    ;     <FatturaElettronicaBody>
    ; 	...
    ;     </FatturaElettronicaBody>
    ; </p:FatturaElettronica>

    ; Use this online tool to generate parsing code from sample XML: 
    ; Generate Parsing Code from XML

    Debug "success."


    CkImap::ckDispose(imap)
    CkStringBuilder::ckDispose(sbMime)
    CkMime::ckDispose(mime)
    CkBinData::ckDispose(bdP7m)
    CkCrypt2::ckDispose(crypt)
    CkXml::ckDispose(xml)


    ProcedureReturn
EndProcedure