#!/usr/bin/python

import os
from pathlib import Path
import subprocess
import sys

# define directories
base_dir = os.getcwd()
content_dir = f"{base_dir}/content"
config_dir = f"{base_dir}/config"
output_dir = f"{base_dir}/output"

def _get_input_files(format):
  # read filenames from file if such a file exists
  list_file = Path(config_dir) / f"source-files.{format}.txt"
  if os.path.isfile(list_file):
    with open(list_file, "r") as file:
      return [line.strip() for line in file]      
  # use all files otherwise
  else:
    input_paths = sorted(Path(content_dir).glob('**/*.md'))
    return [str(p) for p in input_paths]


def _run_command(command):
  # run shell command
  stdout = subprocess.check_output(command)
  print(stdout)

def clean(args):
  pass


def epub(args):
  # define pandoc defaults file
  pandoc_defaults_file = f"{config_dir}/pandoc-defaults.epub.yaml"

  # define executable and options
  executable = "/usr/bin/pandoc"
  executable_opts = ["-d", pandoc_defaults_file]
  executable_opts.append("--verbose")

  # get input files
  input_files = _get_input_files("epub")

  # put together command and run it
  command = [executable] + executable_opts + args + input_files
  print(f"command is {command}")
  _run_command(command)


def cover(args):
  # define executable and options
  executable = "/usr/bin/pdflatex"
  executable_opts = [f"-output-directory={output_dir}"]
  
  # get input files
  cover_dir = f"{base_dir}/cover"
  input_files = [f"{cover_dir}/cover.tex"]

  # put together command and run it
  command = [executable] + executable_opts + args + input_files
  print(f"command is {command}")
  _run_command(command)


def pdf(args):
  # define pandoc defaults file
  pandoc_defaults_file = f"{config_dir}/pandoc-defaults.pdf.yaml"

  # define executable and options
  executable = "/usr/bin/pandoc"
  executable_opts = ["-d", pandoc_defaults_file]
  #executable_opts.append("--verbose")

  # get input files 
  input_files = _get_input_files("pdf")

  # put together command and run it
  command = [executable] + executable_opts + args + input_files
  print(f"command is {command}")
  _run_command(command)


if __name__ == "__main__":
  # get command line parameters
  args = sys.argv[1:]
  if len(args) == 0:
    print("Please specify at least one parameter")
    exit(1)
  
  # call function corresponding to first argument
  if args[0] == "clean":
    clean(args[1:])
  elif args[0] == "pdf":
    pdf(args[1:])
  elif args[0] == "cover":
    cover(args[1:])
  elif args[0] == "epub":
    epub(args[1:])
  elif args[0] == "all":
    pdf(args[1:])
    cover(args[1:])
    epub(args[1:])
  else:
    print("Parameter not recognized")
    exit(2)