#!/usr/bin/env python3

#########################################################################
# Copyright (C) 2011 Tavian Barnes <tavianator@tavianator.com>          #
#                                                                       #
# This file is part of Dimension.                                       #
#                                                                       #
# Dimension is free software; you can redistribute it and/or modify it  #
# under the terms of the GNU General Public License as published by the #
# Free Software Foundation; either version 3 of the License, or (at     #
# your option) any later version.                                       #
#                                                                       #
# Dimension is distributed in the hope that it will be useful, but      #
# WITHOUT ANY WARRANTY; without even the implied warranty of            #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     #
# General Public License for more details.                              #
#                                                                       #
# You should have received a copy of the GNU General Public License     #
# along with this program.  If not, see <http://www.gnu.org/licenses/>. #
#########################################################################

import argparse
import re
import os
import sys
from contextlib import contextmanager

# Specialized parser to print --version output to stdout rather than stderr,
# to pass distcheck
class DimensionArgumentParser(argparse.ArgumentParser):
  def exit(self, status = 0, message = None):
    if message:
      file = sys.stdout if status == 0 else sys.stderr
      file.write(message)
    sys.exit(status)

# Change the working directory within a with statement
@contextmanager
def working_directory(newwd):
  oldwd = os.getcwd()
  try:
    os.chdir(newwd)
    yield
  finally:
    os.chdir(oldwd)

# Parse the command line
parser = DimensionArgumentParser(
  epilog = "@PACKAGE_STRING@\n"
           "@PACKAGE_URL@\n"
           "Copyright (C) 2009-2011 Tavian Barnes <@PACKAGE_BUGREPORT@>\n"
           "Licensed under the GNU General Public License",
  formatter_class = argparse.RawDescriptionHelpFormatter,
  conflict_handler = "resolve", # For -h as height instead of help
)

parser.add_argument("-V", "--version", action = "version",
                    version = "@PACKAGE_STRING@")

parser.add_argument("-w", "--width", action = "store", type = int,
                    default = 768,
                    help = "image width (default: %(default)s)")
parser.add_argument("-h", "--height", action = "store", type = int,
                    default = 480,
                    help = "image height (default: %(default)s)")
parser.add_argument("--region", action = "store", type = str,
                    help = "subregion to render, as \"(x1, y1)->(x2, y2)\"")

parser.add_argument("-v", "--verbose", action = "store_true",
                    help = "print more information")
parser.add_argument("-q", "--quiet", action = "store_true",
                    help = "print less information")

parser.add_argument("--threads", action = "store", type = int,
                    help = "the number of threads to render with")
parser.add_argument("--quality", action = "store", type = str,
                    help = "the scene quality")
parser.add_argument("--adc-bailout", action = "store", type = str,
                    help = "the ADC bailout (default: 1/255)")

parser.add_argument("-o", "--output", action = "store", type = str,
                    help = "the output image file")
parser.add_argument("input", action = "store", type = str,
                    help = "the input scene description file")

# Debugging/testing options
parser.add_argument("--strict", action = "store_true",
                    help = argparse.SUPPRESS)

args = parser.parse_args()

from dimension import *

# Calculate subregion
if args.region is None:
  args.region_x = 0
  args.region_y = 0
  args.region_width = args.width
  args.region_height = args.height
else:
  pattern = r"^\s*\(\s*(\d*)\s*,\s*(\d*)\s*\)\s*->\s*\(\s*(\d*)\s*,\s*(\d*)\s*\)\s*$"
  match = re.match(pattern, args.region)
  if match is None:
    raise RuntimeError("range specified in invalid format.")
  args.region_x = int(match.group(1))
  args.region_y = int(match.group(2))
  region_xmax = int(match.group(3))
  region_ymax = int(match.group(4))
  args.region_width = region_xmax - args.region_x
  args.region_height = region_ymax - args.region_y
  if args.region_width <= 0 or args.region_height <= 0:
    raise RuntimeError("region is degenerate.")
  if region_xmax >= args.width or region_ymax > args.height:
    raise RuntimeError("region exceeds bounds of image.")

# Default output is basename(input).png
if args.output is None:
  noext = os.path.splitext(os.path.basename(args.input))[0]
  args.output = noext + ".png"

# Display a progress bar
def progress_bar(str, future):
  try:
    if not args.quiet:
      print(str, end = " ")
      sys.stdout.flush()

      term_width = terminal_width()
      width = term_width - (len(str) + 1)%term_width
      for i in range(width):
        future.wait((i + 1)/width)
        print(".", end = "")
        sys.stdout.flush()

      print()
      sys.stdout.flush()

    future.join()
  except KeyboardInterrupt:
    print()
    sys.stdout.flush()

    future.cancel()
    try:
      future.join()
    except RuntimeError:
      # Swallow the failure exception
      pass
    raise

# --strict option
die_on_warnings(args.strict)

# Sandbox dictionary for scene
sandbox = __import__("dimension").__dict__
sandbox.update(__import__("math").__dict__)

# Defaults/available variables
sandbox.update({
  "image_width"      : args.width,
  "image_height"     : args.height,
  "objects"          : [],
  "lights"           : [],
  "camera"           : PerspectiveCamera(),
  "default_texture"  : Texture(finish = Ambient(0.1) + Diffuse(0.7)),
  "default_interior" : Interior(),
  "background"       : Black,
  "recursion_limit"  : None,
})

# Execute the input script
if not args.quiet:
  print("Parsing scene ...")

# Run with the script's dirname as the working directory
workdir = os.path.dirname(os.path.abspath(args.input))

parse_timer = Timer()
with open(args.input) as fh, working_directory(workdir):
  exec(compile(fh.read(), args.input, "exec"), sandbox)
parse_timer.stop()

# Make the canvas
canvas = Canvas(width = args.region_width, height = args.region_height)
canvas.optimize_PNG()

# Make the scene object
scene = Scene(canvas   = canvas,
              objects  = sandbox["objects"],
              lights   = sandbox["lights"],
              camera   = sandbox["camera"])
scene.region_x         = args.region_x
scene.region_y         = args.region_y
scene.outer_width      = args.width
scene.outer_height     = args.height
scene.default_texture  = sandbox["default_texture"]
scene.default_interior = sandbox["default_interior"]
scene.background       = sandbox["background"]
if sandbox["recursion_limit"] is not None:
  scene.recursion_limit = sandbox["recursion_limit"]
if args.threads is not None:
  scene.nthreads = args.threads
if args.quality is not None:
  scene.quality = args.quality
if args.adc_bailout is not None:
  pattern = r"^(.*)/(.*)"
  match = re.match(pattern, args.adc_bailout)
  if match is not None:
    args.adc_bailout = float(match.group(1))/float(match.group(2))
  scene.adc_bailout = float(args.adc_bailout)

# Ray-trace the scene
if scene.nthreads == 1:
  render_message = "Rendering scene"
else:
  render_message = "Rendering scene (using %d threads)" % scene.nthreads
progress_bar(render_message, scene.ray_trace_async())

# Write the output file
export_timer = Timer()
progress_bar("Writing %s" % args.output, canvas.write_PNG_async(args.output))
export_timer.stop()

# Print execution times
if args.verbose:
  print()
  print("Parsing time:   ", parse_timer)
  print("Bounding time:  ", scene.bounding_timer)
  print("Rendering time: ", scene.render_timer)
  print("Exporting time: ", export_timer)