Add EDI to ETI converter in edidebug

1 files changed, 149 insertions, 5 deletions

diff --git a/edi/edidebug.py b/edi/edidebug.py
index e70cb2b..a5528af 100755
--- a/edi/edidebug.py
+++ b/edi/edidebug.py
@@ -26,7 +26,8 @@
 #    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 #    THE SOFTWARE.
 
-
+from pprint import pprint
+import io
 import sys
 import struct
 
@@ -84,9 +85,116 @@ class BufferedFile:
         self.buf.extend(dat)
         return dat
 
+def tobyte(xs):
+    return bytes(bytearray([xs]))
+
+class EtiData:
+    def __init__(self):
+        self.clear()
+
+    def new_subchannel(self):
+        new_stc = {}
+        self.stc.append(new_stc)
+        return new_stc
+
+    def clear(self):
+        self.fc = {}
+        self.stc = []
+        self.mnsc = 0
+        self.complete = False
+        self.fic = []
+
+    def generate_eti(self):
+        # generate ETI(NI)
+        # SYNC
+        buf = io.BytesIO()
+        buf.write("\xff") # ERR
+        # FSYNC
+        if self.fc['FCT'] % 2 == 1:
+            buf.write("\xf8\xc5\x49")
+        else:
+            buf.write("\x07\x3a\xb6")
+
+        # LIDATA
+        # FC
+        buf.write(tobyte(self.fc['FCT'] & 0xff))
+
+        NST = len(self.stc)
+        buf.write(tobyte((self.fc['FICF'] << 7) | NST))
+
+        if self.fc['FICF'] == 0:
+            FICL = 0
+        elif self.fc['MID'] == 3:
+            FICL = 32
+        else:
+            FICL = 24
+
+        # EN 300 799 5.3.6
+        FL = NST + 1 + FICL + sum(subch['STL'] * 2 for subch in self.stc)
+
+        print("********** NST {}, FICL {}, stl {}, sum, {}".format(
+            NST, FICL, [subch['STL']  for subch in self.stc],
+                sum(subch['STL'] * 2 for subch in self.stc)))
+
+        buf.write(tobyte( (self.fc['FP'] << 5) |
+                          (self.fc['MID'] << 3) |
+                          ((FL & 0x700) >> 8)))
+
+        buf.write(tobyte(FL & 0xff))
+
+        # STC
+        for subch in self.stc:
+            buf.write(tobyte( (subch['SCID'] << 2) | ((subch['SAD'] & 0x300) >> 8) ))
+            buf.write(tobyte( subch['SAD'] & 0xff ))
+            buf.write(tobyte( (subch['TPL'] << 2) | ((subch['STL'] & 0x300) >> 8)))
+            buf.write(tobyte( subch['STL'] & 0xff ))
+
+        # EOH
+        # MNSC
+        buf.write(tobyte( (self.mnsc & 0xff00) >> 8 ))
+        buf.write(tobyte( self.mnsc & 0xff ))
+        # CRC
+        buf.seek(4)
+        headerdata = buf.read()
+        crc_calc = crc16(headerdata)
+        crc_calc ^= 0xFFFF
+        buf.write(tobyte( (crc_calc & 0xff00) >> 8))
+        buf.write(tobyte( crc_calc & 0xff ))
+
+        mst_start = buf.tell()
+        # MST
+        # FIC data
+        buf.write(bytes(bytearray(self.fic)))
+
+        # Data stream
+        for subch in self.stc:
+            buf.write(bytes(bytearray(subch['data'])))
+
+        # EOF
+        # CRC
+        buf.seek(mst_start)
+        mst_data = buf.read()
+        crc_calc = crc16(mst_data)
+        crc_calc ^= 0xFFFF
+        buf.write(tobyte( (crc_calc & 0xff00) >> 8))
+        buf.write(tobyte( crc_calc & 0xff ))
 
+        buf.write("\xff\xff") # RFU
 
+        # TIST
+        buf.write("\xff\xff\xff\xff") # TODO TIST in EDI is awful
 
+        length = buf.tell()
+
+        padding = 6144 - length
+
+        buf.write(bytes(bytearray("\x55" * padding)))
+
+        buf.seek(0)
+        return buf.read()
+
+
+eti_data = EtiData()
 p = Printer()
 
 # keys=findex
@@ -379,6 +487,7 @@ def tagitems(tagpacket):
 
         i += 8 + length
     p.pr("Completed decoding all TAG items after {} bytes".format(i))
+    eti_data.complete = True
 
 def decode_tag(tagpacket):
     p.pr("Tag packet len={}".format(len(tagpacket)))
@@ -424,20 +533,29 @@ def decode_deti(item):
 
     unpacked = struct.unpack(item_deti_header_struct, tag_value[:6])
     flag_fcth, fctl, stat, mid_fp, mnsc = unpacked
-
+    eti_data.mnsc = mnsc
 
     atstf = flag_fcth & 0x80 != 0
+    eti_data.fc['ATSTF'] = int(atstf)
     if atstf:
         utco, seconds, tsta1, tsta2, tsta3 = struct.unpack("!BL3B", tag_value[6:6+8])
         tsta = (tsta1 << 16) | (tsta2 << 8) | tsta3
+        eti_data.fc['TSTA'] = tsta
 
     ficf  = flag_fcth & 0x40 != 0
+    eti_data.fc['FICF'] = int(ficf)
+
     rfudf = flag_fcth & 0x20 != 0
+
     fcth  = flag_fcth & 0x1F
     fct = (fcth * 250) + fctl
+    eti_data.fc['FCT'] = fct
 
     mid = (mid_fp >> 6) & 0x03
+    eti_data.fc['MID'] = mid
+
     fp  = (mid_fp >> 3) & 0x07
+    eti_data.fc['FP'] = fp
 
 
     p.pr("FICF        = {}".format(ficf))
@@ -462,6 +580,10 @@ def decode_deti(item):
     if rfudf:
         len_fic -= 3
 
+    fic_offset = len(tag_value) - len_fic
+
+    eti_data.fic = tag_value[fic_offset:]
+
     p.pr("FIC data len  {}".format(len_fic))
 
     p.dec()
@@ -478,24 +600,46 @@ def decode_estn(item):
     sad  = scid_sad & 0x3F
     tpl  = tpl_rfa >> 2
 
+    stc = eti_data.new_subchannel()
+    stc['SCID'] = scid
+    stc['SAD']  = sad
+    stc['TPL']  = tpl
+    stl = len(tag_value) - 3
+    stc['STL']  = stl / 8
+
     p.pr("SCID = {}".format(scid))
     p.pr("SAD  = {}".format(sad))
     p.pr("TPL  = {}".format(tpl))
 
     assert(item['length'] == len(tag_value))
 
-    p.pr("MST len = {}".format(len(tag_value) - 3))
+    p.pr("MST len = {}".format(stl))
     p.hexpr("MST {} data".format(scid), tag_value[3:])
+    stc['data'] = tag_value[3:]
 
     p.dec()
 
-if len(sys.argv) > 1:
+if len(sys.argv) > 2:
+    filename = sys.argv[1]
+    edi_fd = BufferedFile(filename)
+
+    eti_fd = open(sys.argv[2], "wb")
+
+
+elif len(sys.argv) == 2:
     filename = sys.argv[1]
 
     edi_fd = BufferedFile(filename)
+    eti_fd = None
 else:
     edi_fd = BufferedFile("-")
+    eti_fd = None
 
+c = 0
 while decode(edi_fd):
-    pass
+    if eti_data.complete and eti_fd:
+        eti_fd.write(eti_data.generate_eti())
+        c += 1
+        if c > 2:
+            break