#!/usr/bin/env python

import zipfile
import re
import string
import StringIO
import sys

class parsed_file:
	def __init__(self, file, fields):
		self.file = file
		self.fields = fields
		self.rti = fields[fields.keys()[0]]['RTI']

	def __iter__(self):
		return(self)

	def next(self):
		line = self.file.readline()
		if not line:
			raise StopIteration

		rti = line[self.rti[0]:self.rti[1]]
		fields = self.fields[rti]

		record = {'RTI': rti}
		for desc in fields.keys():
			(start, end, type, just) = fields[desc]
			record[desc] = string.strip(line[start:end])
		return(record)

class ATA100zip:
	format_re = re.compile('^([LR]) +([A-Z]+) *([0-9]+) +([0-9]+) {1,3}([^ ]+)? +([^\n\r]+[^ \n\r])')
	rti_descs = ('RECORD TYPE INDICATOR.', 'RECORD TYPE INDICATOR', 'RECORD IDENTIFIER')
	rti_re = re.compile('^ +([A-Z0-9]+)(:| - ) *([A-Z- ]+[^ ]) *\r\n')

	def __init__(self, collection_filename):
		self.collection = zipfile.ZipFile(collection_filename, mode='r')
		self.filenames = self.collection.namelist()
		self.filenames_lc = map(string.lower, self.filenames)
		self.fields_d = None

	def real_filename(self, filename):
		return(self.filenames[self.filenames_lc.index(string.lower(filename))])

	def _open(self, filename):
		return(StringIO.StringIO(self.collection.read(self.real_filename(filename))))
	
	def fields(self, typename):
		format_filename = 'subscriber_file_formats/%s_rf.txt' % (typename)
		#print self.real_filename(format_filename)

		format_file = self._open(self.real_filename(format_filename))

		fields_d = {}
		rti = None
		while 1:
			line = format_file.readline()
			if not line:
				break

			#line = string.strip(line)
			match = self.format_re.match(line)
			if not match:
				continue

			(just, type, length_s, start_s, element, desc) = match.groups()

			if desc in self.rti_descs:
				while 1:
					rti_line = format_file.readline()
					rti_match = self.rti_re.match(rti_line)
					if rti_match:
						(rti, sep, rti_desc) = rti_match.groups()
						fields_d[rti] = {}
						desc = 'RTI' # Standardize this a bit.
						break

		
			start = int(start_s) - 1
			end = start + int(length_s)

			suffix = ''
			while fields_d[rti].has_key(desc + suffix):
				if suffix == '':
					suffix = '-A'
				else:
					suffix = '-' + '%c' % (ord(suffix[-1]) + 1)
			desc += suffix

			fields_d[rti][desc] = (start, end, type, just)

		return(fields_d)

	def parse(self, typename):
		return(parsed_file(
			self._open('%s.txt' % (typename)),
			self.fields(typename),
		))

def seconds_to_degrees(seconds):
	if seconds[-1] in ['S', 'W']:
		return(-float(seconds[:-1])/3600.0)
	else:
		return(float(seconds[:-1])/3600.0)

if __name__ == '__main__':
	args = sys.argv

	if not len(args) == 2:
		print 'usage: %s [ATA-100 zip filename]' % (args[0])
		sys.exit(1)

	data = ATA100zip(args[1])

	parsed_data = data.parse('APT')

	for record_type in parsed_data.fields.keys():
		print record_type
		for field_name in parsed_data.fields[record_type]:
			print '\t' + field_name

	interesting_airports = ['LAF', 'BMG']
	interesting_entry = 0
	for record in parsed_data:
		rti = record['RTI']

		if rti == 'APT':
			ident = record['LOCATION IDENTIFIER']
			if not ident in interesting_airports:
				interesting_entry = 0
				continue
			interesting_entry = 1

			print ident,
			print record['LOCATION IDENTIFIER'], 
			print record['ASSOCIATED CITY NAME'], 
			print record['ASSOCIATED STATE POST OFFICE CODE'], 
			print seconds_to_degrees(record['AIRPORT REFERENCE POINT LONGITUDE (SECONDS)']), 
			print seconds_to_degrees(record['AIRPORT REFERENCE POINT LATITUDE (SECONDS)'])
		elif not interesting_entry:
			continue
		elif rti == 'RWY':
			print '\t', 
			print record['RUNWAY IDENTIFICATION'], 
			print record['PHYSICAL RUNWAY LENGTH (NEAREST FOOT)'],
			print record['PHYSICAL RUNWAY WIDTH (NEAREST FOOT)']