# This graph provides the base infrastructure for retrieving
# semantic information from Excel spreadsheets.
#
# You'll need to provide at least the following information to
# the ports of this network:
#
# * READ.SOURCE: Filename of the spreadsheet document
# * SLICEROWS.BEGIN: How many rows to skip from the start of a sheet
# * SLICEROWS.END: How many rows to skip from the end of a sheet (optional)
# * GROUPBYROWLABEL.KEY: Which column provides the label of the row
# * SLICECOLUMNS.BEGIN: How many columns to skip from the start of a sheet
# * SLICECOLUMNS.END: How many columns to skip from the end of a sheet (optional)
#
# In the end the output will be provided through the ENTITIZE.OUT port.
#
# This network uses Apache Tika for parsing the spreadsheet into 
# XHTML. Ensure that Tika can be found in the location set below:
'tika-app-0.9.jar' -> TIKA Read(ReadDocument)

# If reading fails, just display the error
Read() ERROR -> IN Display(Output)

# Parse the file to JSON, get all spreadsheets from it
Read() OUT -> IN Parse(ParseXml) 

# We're only interested in DIVs inside the BODY
'body' -> KEY GetBody(GetObjectKey)
'div' -> KEY GetDiv(GetObjectKey)
# Read DIVs and pass them forward
Parse() OUT -> IN GetBody() OUT -> IN GetDiv()

# Spreadsheet title is in a H1
'h1' -> KEY GroupByTableId(GroupByObjectKey)

# Group the data by spreadsheet titles
GetDiv() OUT -> IN GetSheet(GetObjectKey) OUT -> IN GroupByTableId()

# Get spreadsheet table and the rows from it
'table' -> KEY GetTable(GetObjectKey)
'tbody' -> KEY GetTBody(GetObjectKey)
'tr' -> KEY GetTR(GetObjectKey)
GroupByTableId() OUT -> IN GetTable() OUT -> IN GetTBody() OUT -> IN GetTR() 

# Process each row individually and get the cells
'td' -> KEY GetTD(GetObjectKey)
GetTR() OUT -> IN SliceRows(SliceArray) OUT -> IN SplitRows(SplitArray) OUT -> IN GetTD()

# Group by the row label, and collect into objects
GetTD() OUT -> IN GroupByRowLabel(GroupByObjectKey) OUT -> IN SliceColumns(SliceArray) OUT -> IN Collect(CollectGroups)

# If no columns are found, display that as an error message
SliceColumns() ERROR -> IN Display()

# Turn the columns into objects
Collect() OUT -> IN SplitEntities(SplitArray) OUT -> IN Entitize(PropertiesToObjects)