#!/usr/bin/env python
# Export gerber from a board
import sys, os, ConfigParser, subprocess, eagle
OUTPUT_DIR = "./gerbers"

FORMAT_RS274X = 1
FORMAT_EXCELLON = 2

class EagleBoard():
    def __init__(self, fname):
        self.fname = fname

    def export_gerber(self, out_fname, layers, format = FORMAT_RS274X ):
        "Export the given list of layers into a gerber file"

        if format == FORMAT_RS274X:
            fstr = "GERBER_RS274X"
        elif format == FORMAT_EXCELLON:
            fstr = "excellon"
        else:
            raise Exception("Invalid file format requested")

        if eagle.file_version( self.fname )[0] == 4:
            ecmd = "eagle"
        else:
            ecmd = "eagle5"

        cmd = "%s -X -d%s -o%s %s %s" % ( ecmd,
                                          fstr,
                                          out_fname,
                                          self.fname,
                                          " ".join(layers) )
        p = subprocess.Popen( cmd,
                              shell = True,
                              stdout = open("/dev/null", "w") )
        p.communicate()
        p.wait()

        # Remove useless 'gpi' file
        if format == FORMAT_RS274X:
            os.remove( "%s.gpi" % out_fname )
        elif format == FORMAT_EXCELLON:
            os.remove( "%s.dri" % out_fname )

if len(sys.argv) < 2:
    print "Usage: %s CONFIG_FILE BOARD"
    print "Will output gerbers to directory %s" % OUTPUT_DIR
    sys.exit(1)

CONFIG_FILE = sys.argv[1]
BOARD = sys.argv[2]

if os.path.exists( OUTPUT_DIR ) and not os.path.isdir( OUTPUT_DIR ):
    print "%s exists and is not a directory" % OUTPUT_DIR
    print "Cowardly refusing to remove it!"
    sys.exit(1)

if not os.path.exists( OUTPUT_DIR ):
    os.mkdir( OUTPUT_DIR )

board = EagleBoard( BOARD )

conf = ConfigParser.SafeConfigParser()
conf.read( CONFIG_FILE )

for fname in conf.sections():
    if conf.has_option( fname, "layers" ):
        print "Generating gerber: %s" % fname
        layers = conf.get( fname, "layers" ).split()
        board.export_gerber( os.path.join( OUTPUT_DIR, fname ), layers )

    elif conf.has_option( fname, "drill_layers" ):
        print "Generating drill file: %s" % fname
        layers = conf.get( fname, "drill_layers" ).split()
        board.export_gerber( os.path.join( OUTPUT_DIR, fname ), layers, format = FORMAT_EXCELLON )

    else:
        print "Fatal Error: Section '%s' in config file lacks 'layers' or 'drill_layers' option."
        sys.exit(1)