tko/query_lib.py

#!/usr/bin/python
"""
This library provides a bunch of miscellaneous parameter parsing,
sql generating and list cleanup library functions that are used
by both the reporting cli and web interface.
"""

import sys, os, re

tko = os.path.dirname(__file__)
sys.path.insert(0, tko)

import display, frontend, db

db = db.db()

def dprint(str):
	pass
	#print "! %s<br>" % str

def parse_scrub_and_gen_condition(condition, valid_field_dict):
	me = parse_scrub_and_gen_condition   # shorten the name
	compare_ops = {'=':'=', '<>':'<>', '==':'=', '!=':'<>', '>':'>',
	               '<':'<', '>=':'>=', '<=':'<=', '~':'LIKE', '#':'REGEXP'}

	# strip white space
	condition = condition.strip()

	# ()'s
	#match = re.match(r'^[(](.+)[)]$', condition)
	#if match:
	#	dprint("Matched () on %s" % condition)
	#	depth = 0
	#	for c in match.group(1):
	#		if c == '(':	depth += 1
	#		if c == ')':	depth -= 1
	#		if depth < 0:	break
	#	dprint("Depth is %d" % depth)
	#	if depth == 0:
	#		dprint("Match...stripping ()'s")
	#		return me(match.group(1), valid_field_dict)

	# OR
	match = re.match(r'^(.+)[|](.+)$', condition)
	if match:
		dprint("Matched | on %s" % condition)
		(a_sql, a_values) = me(match.group(1), valid_field_dict)
		(b_sql, b_values) = me(match.group(2), valid_field_dict)
		return (" (%s) OR (%s) " % (a_sql, b_sql),
		        a_values + b_values)

	# AND
	match = re.match(r'^(.+)[&](.+)$', condition)
	if match:
		dprint("Matched & on %s" % condition)
		(a_sql, a_values) = me(match.group(1), valid_field_dict)
		(b_sql, b_values) = me(match.group(2), valid_field_dict)
		return (" (%s) AND (%s) " % (a_sql, b_sql),
		        a_values + b_values)

	# NOT
	#match = re.match(r'^[!](.+)$', condition)
	#if match:
	#	dprint("Matched ! on %s" % condition)
	#	(sql, values) = me(match.group(1), valid_field_dict)
	#	return (" NOT (%s) " % (sql,), values)

	# '<field> <op> <value>' where value can be quoted
	# double quotes are escaped....i.e.  '''' is the same as "'"
	regex = r'^(%s)[ \t]*(%s)[ \t]*' + \
	        r'(\'((\'\'|[^\'])*)\'|"((""|[^"])*)"|([^\'"].*))$'
	regex = regex % ('|'.join(valid_field_dict.keys()),
	                 '|'.join(compare_ops.keys()))
	match = re.match(regex, condition)
	if match:
		field = valid_field_dict[match.group(1)]
		op = compare_ops[match.group(2)]
		if match.group(5):
			val = match.group(4).replace("''", "'")
		elif match.group(7):
			val = match.group(6).replace('""', '"')
		elif match.group(8):
			val = match.group(8)
		else:
			raise "Internal error"
		return ("%s %s %%s" % (field, op), [val])
		

	raise "Could not parse '%s' (%s)" % (condition, regex)