#!/usr/bin/env python
# SPDX-License-Identifier: BSD-3-Clause
#
# Script to generate menu and intermission screen 'text' graphics for
# Freedoom, by compositing individual font character graphics together.
#

from glob import glob
import re
import sys

from config import *
from common import *

# ImageMagick -colorize parameters for colorizing text:
COLOR_BLUE = (100, 100, 0)
COLOR_RED = (0, 100, 100)
COLOR_WHITE = (0, 0, 0)

# Background color for output files.
BACKGROUND_COLOR = '#00ffff'

# Height of font in pixels.
FONT_HEIGHT = 15
FONT_LC_HEIGHT = 15  #12

# If true, the font only has uppercase characters.
UPPERCASE_FONT = False

# Width of a space character in pixels.
SPACE_WIDTH = 7

class Font(object):
	def __init__(self, fontdir, kerning_table={}):
		self.fontdir = fontdir
		self.kerning_table = self.compile_kerning_table(kerning_table)
		self.get_font_widths()

	def compile_kerning_table(self, kerning_table):
		"""Given a dictionary of kerning patterns, compile Regexps."""

		result = {}
		for pattern, adjust in kerning_table.items():
			result[re.compile(pattern)] = adjust
		return result

	def get_font_widths(self):
		charfiles = glob('%s/font*.gif' % self.fontdir)
		self.char_widths = {}
		for c in range(128):
			filename = self.char_filename(chr(c))
			if filename not in charfiles:
				continue
			w, _ = get_image_dimensions(filename)
			self.char_widths[chr(c)] = w

	def __contains__(self, c):
		return c in self.char_widths

	def char_width(self, c):
		return self.char_widths[c]

	def char_filename(self, c):
		return '%s/font%03d.gif' % (self.fontdir, ord(c))

	def kerning_adjust(self, char_1, char_2):
		"""Get kerning adjustment for pair of characters.

		Zero means no adjustment. A negative value adjusts to the
		left and a positive value adjusts to the right.
		"""
		for pattern, adjust in self.kerning_table.items():
			if pattern.match(char_1 + char_2):
				return adjust
		else:
			return 0

	def iterate_char_positions(self, text):
		"""Iterate over characters in string, yielding character with
		   position it should be placed at in the output file.
		"""
		x = 0
		last_c = ' '
		for c in text:
			if c == ' ':
				x += SPACE_WIDTH

			if c in self:
				x += self.kerning_adjust(last_c, c)

				yield c, x

				# Characters overlap by one pixel.
				x += self.char_width(c) - 1

			last_c = c

		# We need to add back the missing pixel from the right side
		# of the last char.
		x += 1
		yield None, x

	def text_width(self, text):
		"""Given a string of text, get text width in pixels."""
		for c, x in self.iterate_char_positions(text):
			if c is None:
				return x

	def _make_command_line(self, text, color):
		"""Command line construction helper, used in render functions"""
		width = self.text_width(text)

		if LOWERCASE_RE.match(text):
			height = FONT_LC_HEIGHT
		else:
			height = FONT_HEIGHT

		command_line = [
			CONVERT_COMMAND,
			'-size', '%ix%i' % (width, height),
			'xc:none',
		]

		for c, x in self.iterate_char_positions(text):
			if c is None:
				break

			filename = self.char_filename(c)
			command_line.extend([
				'-draw',
				'image over %i,%i 0,0 %s' %
				    (x, height - FONT_HEIGHT, filename)
			])

		command_line.extend([
			'-colorize', '%i,%i,%i,0' % color,
		])

		return command_line

	def get_command(self, text, output_filename,
	                color=COLOR_WHITE, bgcolor=BACKGROUND_COLOR):
		"""Get command to render text to a file
		   with the given background color.
		"""

		if UPPERCASE_FONT:
			text = text.upper()
		command_line = self._make_command_line(text, color)

		if bgcolor is not None:
			command_line.extend([
				'-background', bgcolor, '-flatten'])

		command_line.append(output_filename)

		return command_line

def generate_graphics(graphics, color=COLOR_WHITE, bgcolor=BACKGROUND_COLOR):
	for name, text in sorted(graphics.items()):
		print("# %s.gif: '%s'" % (name, text))
		# write a makefile fragment
		target = '%s.gif' % name
		cmd = font.get_command(text, target,
		                       color=color, bgcolor=bgcolor)
		print("%s: %s" % (target, " ".join(sys.argv[1:])))
		print("\t" + " ".join("'%s'" % i for i in cmd))

def generate_kerning_test():
	pairs = []
	for c1 in sorted(font.char_widths):
		char1 = "%c" % c1
		for c2 in sorted(font.char_widths):
			char2 = "%c" % c2
			if font.kerning_adjust(char1, char2) != 0:
				pairs.append(char1 + char2)

	cmd = font.get_command(" ".join(pairs), "kerning.gif")
	invoke_command(cmd)

font = Font('fontchars', kerning_table=FONT_KERNING_RULES)

# Enable to generate test image file for tweaking kerning values:
#generate_kerning_test()

generate_graphics(red_graphics, color=COLOR_RED)
generate_graphics(blue_graphics, color=COLOR_BLUE)
generate_graphics(white_graphics, color=COLOR_WHITE)