#!/usr/bin/env python2

#---------------------- faust2atomsnippets -----------------------
# Usage: `faust2atomsnippets *.lib > faust-library.cson`
#
# Creates an atom snippets for each function in a library
# Assumes the same format than faust2md.
#
# The generated snippets file as the following structure:
#
#'.source.faust':
#	'noise':
#		'prefix': 'noise'
#		'body': 'no.noise'
#	...
#
# The format of a title is :
#	//############# Title Name #################
#	//  markdown text....
#	//  markdown text....
#	//##########################################
#
# The format of a section is :
#	//============== Section Name ==============
#	//  markdown text....
#	//  markdown text....
#	//==========================================
#
# The format of a comment is :
#	//-------------- foo(x,y) ------------------
#	//  markdown text....
#	//  markdown text....
#	//------------------------------------------
# everything else is considered faust code.
# The translation is the following:
#   ## foo(x,y)
#	markdown text....
#	markdown text....
#--------------------------------------------------------


import sys, re, datetime, string, getopt


# Outdent a comment line by n characters in
# order to remove the prefix "//   "
def outdent(line, n):
	if len(line) <= n:
		return "\n"
	else:
		return line[n:]

# Match the 2-characters prefix of a library.
# We want to extract "no" from "...prefix is `no`..."
def matchPrefixName(line):
	return re.search(r'^.*prefix is .(..).*', line)


# Match the first line of a title
# of type "//#### Title ####
# at least 3 * are needed
def matchBeginTitle(line):
	return re.search(r'^\s*//#{3,}\s*([^#]+)#{3,}', line)

# Match the last line of a title
# of type "//#######"
# or a blank line
def matchEndTitle(line):
	return re.search(r'^\s*((//#{3,})|(\s*))$', line)

# Match the first line of a section
# of type "//==== Section ===="
# at least 3 = are needed
def matchBeginSection(line):
	return re.search(r'^\s*//={3,}\s*([^=]+)={3,}', line)

# Match the last line of a section
# of type "//======="
# or a blank line
def matchEndSection(line):
	return re.search(r'^\s*((//={3,})|(\s*))$', line)

# Match the first line of a comment
# of type "//--- foo(x,y) ----"
# at least 3 - are needed
def matchBeginComment(line):
	return re.search(r'^\s*//-{3,}\s*`([^-`]+)`-{3,}', line)

# Match the last line of a comment
# of type "//-----------------"
# or a blank line
def matchEndComment(line):
	return re.search(r'^\s*((//-{3,})|(\s*))$', line)

# Compute the indentation of a line,
# that is the position of the first word character
# after "//   "
def indentation(line):
	matchComment = re.search(r'(^\s*//\s*\w)', line)
	if matchComment:
		return len(matchComment.group(1))-1
	else:
		return 0

# Indicates if a line is a comment
def isComment(line):
	matchComment = re.search(r'^\s*//', line)
	if matchComment:
		return 1
	else:
		return 0

# Measure the indentation of a md-comment line
# that is the len of the prefix '//   '
def indentation(line):
	matchComment = re.search(r'(^\s*//\s*\w)', line)
	if matchComment:
		return len(matchComment.group(1))-1
	else:
		return 0

#
# THE PROGRAM STARTS HERE
#

tabsize 	= 4		# tabsize used for expanding tabs
mode 		= 0		# 0: in code; 1: in md-comment
idt 		= 0		# indentation retained to outdent comment lines
simplified  = 0		# 0: full mode; 1: body only
libprefix	= "xx"	#

# Analyze command line arguments
try:
	opts, args = getopt.getopt(sys.argv[1:], "st:cf")
	if not args:
		raise getopt.error, "At least one file argument required"
except getopt.error, msg:
	print(msg)
	print("usage: %s [-s][-t tabsize] file ..." % (sys.argv[0],))
	sys.exit(1)

for optname, optvalue in opts:
	if optname == '-t':
		tabsize = int(optvalue)
	if optname == '-s':
		simplified = 1

# Process all the files and print the documentation on the standard output
if simplified:
	sys.stdout.write("let gFaustLibSnippets = ")
	sep = '['
else:
	print("'.source.faust':")

for file in args:
	with open(file) as f:
		for text in f:
			line = string.expandtabs(text, tabsize)
			matchPrefix = matchPrefixName(line)
			if matchPrefix:
				libprefix = matchPrefix.group(1)
			if isComment(line)==0:
				if mode==1:
					# we are closing a md-comment
					mode = 0
			else:
				if mode==0:	# we are in code
					matchComment = matchBeginComment(line)
					matchSection = matchBeginSection(line)
					matchTitle = matchBeginTitle(line)
					if matchComment:
						foo = matchComment.group(1)
						if simplified:
							sys.stdout.write("%s '%s.%s'" % (sep, libprefix, foo))
							sep = ','
						else:
							print("\t'%s':" % (foo,))
							print("\t\t'prefix': '%s'" % (foo,))
							print("\t\t'body': '%s.%s'" % (libprefix, foo))
					if matchComment or matchSection or matchTitle:
						mode=1	# we just started a md-comment
						idt = 0	# we have to measure the indentation
				else:
					# we are in a md-comment
					if idt==0:
						# we have to measure the indentation
						idt = indentation(line)
					# check end of md-comment
					matchComment = matchEndComment(line)
					matchSection = matchEndSection(line)
					matchTitle = matchEndTitle(line)
					if matchComment or matchSection or matchTitle:
						# end of md-comment switch back to mode O
						mode = 0

if simplified:
	print(" ];")

