#!/usr/bin/env python
"""
Build a 4-up PDF of specific pages of a source PDF.

PAGE RANGES are like Python slices.
		{page_range_help}
EXAMPLES
	conv-sheet.py -o output.pdf convocation-prime-sheets.pdf 5 13 23 32
		Build output.pdf containing a single 4-up page of
		pages 5, 13, 23, and 32 of convocation-prime-sheets.pdf
DEPENDENCIES
	The script requires PyPDF2 (http://mstamy2.github.io/PyPDF2/) and the 
	libraries it uses, all of which can be installed something like this
	(may need admin privileges):

	Linux:
		pip install PyPDF2
	macOS:
		pip3 install PyPDF2
		(note: on macos, launch this script with python3 instead of python)
	Windows:
		cd {your downloads}\pyPDF2
		C:\python33\python.exe setup.py install
"""
# By Lester Ward. Alter or redistribute at will.
# Current version: https://rpg.divnull.com/pub/convocation/conv-sheet.py
# Built to support the role-playing game Convocation Prime
#	https://divnull.com/blog/products/convocation/

from __future__ import print_function
from sys import stderr, stdout, exit
import os
import traceback
import argparse
from papersize import parse_papersize
from collections import defaultdict
from PyPDF2.pagerange import PAGE_RANGE_HELP
from PyPDF2 import PdfFileReader, PdfFileWriter, parse_filename_page_ranges


MARGINX=5
SPACING=3

pagenames = [
	{
		"setname": "eidola",
		"startpage" : 5,
		"pages" : (
			"individual","squad","swarm","acid",
			"air","earth","electricity","fire","ice","metal","water","wood",
			"beast","bug","construct","dragon","elemental","fae","fungus","light","magic","ooze","psychic","shadow","undead",
			"achiever","lesser","companion","corrupter","defender","flyer","healer","striker","uniter"
		)
	},
	{
		"setname": "wild",
		"startpage" : 40,
		"pages" : (
			"behemoth","chimera","nullifier","ravager","scourge","trickster"
		)
	},
	{
		"setname": "pc",
		"startpage" : 47,
		"pages" : (
			"larkspur","nihilund","pax",
			"anger","belonging","bloodlust","compassion","command","connoisseur","conviction","cunning","doubt","fear",
			"harmony","glory","love","optimism","self-loathing","succor","style","temperance","valor","vengeance","passion",
			"ambassador","bridge","chameleon","climber","cryophile","darksighted","debunker","filter","insomniac",
			"liedetector","medium","occultist","orienteer","pyrophile","seer","sneak","sniffer","trembler","tongue",
			"ultravore","waterbreather","woodworker","gift",
			"aggressive","artistic","attuned","empowering","generalist","inspiring","occult","privileged","reassuring",
			"specialized","thrifty","style"
		)
	},
	{
		"setname": "adversity",
		"startpage" : 107,
		"pages" : (
			"peon","mook","average","tough","fast","sturdy","alpha","boss","assault","dreadnought","stats",
			"blighter","bolsterer","blaster","champion","entropic","mender","queen"
		)
	},
]

class Builder(object):
	def __init__(self, writer, width, height, strict=True):
		self.writer = writer
		self.width = width
		self.height = height
		self.pos_on_page = 0
		self.readers = dict()
		self.currentReader = None
		self.currentPage = None
		self.coords = None
		
	def handle_file(self, filename, page_range):
		if filename not in self.readers:
			self.readers[filename] = PdfFileReader(open(filename, "rb"))
		self.currentReader = self.readers[filename]
		pages = page_range.indices(self.currentReader.getNumPages())
		for page in range(*pages):
			if (self.pos_on_page == 0):
				self.currentPage = self.writer.addBlankPage(width, height)
			src = self.currentReader.getPage(page - 1) # pages are zero indexed
			(tx,ty) = self.offset(src)
			self.currentPage.mergeScaledTranslatedPage(src, self.scale, tx, ty)
			self.advancePosition()
				
	def offset(self,src):
		if (self.coords == None):
			destHalfH = self.height/2
			destHalfW = self.width/2
			quarterPageW = destHalfW - MARGINX - SPACING
			srcBox = src.mediaBox
			srcH = srcBox.getHeight()
			srcW = srcBox.getWidth()
			self.scale = quarterPageW / srcW
			quarterPageH = srcH * self.scale
			bottomY = destHalfH - quarterPageH + SPACING
			topY = destHalfH - SPACING
			leftX = MARGINX
			rightX = SPACING + destHalfW
			self.coords = [(leftX,topY), (rightX,topY), (leftX,bottomY), (rightX,bottomY)]
			
		pos = self.pos_on_page
		return self.coords[pos]
		
	def advancePosition(self):
		pos = self.pos_on_page + 1
		if (pos > 3):
			pos = 0
		self.pos_on_page = pos

def parse_args():
	parser = argparse.ArgumentParser(
		description=__doc__.format(page_range_help=PAGE_RANGE_HELP),
		formatter_class=argparse.RawDescriptionHelpFormatter)
	parser.add_argument("-o", "--output",
						metavar="output_file")
	parser.add_argument("-p", "--paper",
						metavar="paper", default="letter",
						help="paper size")
	parser.add_argument("-v", "--verbose", action="store_true",
						help="show page ranges as they are being read")
	parser.add_argument("input", nargs=1,
						metavar="input [page range...]")
	# argparse chokes on page ranges like "-2:" unless caught like this:
	parser.add_argument("fn_pgrgs", nargs=argparse.REMAINDER,
						metavar="filenames and/or page ranges")
	args = parser.parse_args()
	
	# Build an mapping of page name to page number
	page_map = dict()
	for pageset in pagenames:
		pagenum = pageset["startpage"];
		for name in pageset["pages"]:
			page_map[name] = pagenum;
			pagenum += 1
	
	# add the name of the first input file to the front of the list 
	# to be returned
	translated = list()
	translated.append(args.input[0])
	
	# Translate any page names used in the arguments to numbers
	for arg in args.fn_pgrgs:
		try:
			pagenum = page_map[arg]
			translated.append(str(pagenum))
		except:
			# arg not in the map, so just use it untranslated
			translated.append(arg)
	args.fn_pgrgs[0:] = translated
	#print(args, file=stderr)
	return args

if __name__ == "__main__":
	args = parse_args()
	filename_page_ranges = parse_filename_page_ranges(args.fn_pgrgs)
	if args.output:
		output = open(args.output, "wb")
	else:
		stdout.flush()
		output = os.fdopen(stdout.fileno(), "wb")
	
	(width, height) = parse_papersize(args.paper) 
	writer = PdfFileWriter()
	filename = None
	try:
		builder = Builder(writer, width, height)
		for (filename, page_range) in filename_page_ranges:
			if args.verbose:
				print(filename, page_range, file=stderr)
			builder.handle_file(filename, page_range)
	except:
		print(traceback.format_exc(), file=stderr)
		print("Error while reading " + filename, file=stderr)
		exit(1)
	if args.verbose:
		print("Writing to " + args.output, file=stderr)
	writer.write(output)
	# In 3.0, input files must stay open until output is written.
	# Not closing the in_fs because this script exits now.